Jian Xu

The extensive use of antibiotics has caused the contamination of both antibiotics and antibiotic resistance genes (ARGs) in the environment. In this study, the abundance and distribution of antibiotics and ARGs from a sewage treatment plant (STP) and its effluent-receiving river in Beijing China were characterized. Three classes of antibiotics including tetracycline, sulfonamide and quinolone were quantified by LC-MS/MS. In the secondary effluent they were detected at 195, 2001 and 3866 ng L(-1), respectively, which were higher than in the receiving river water. A total of 13 ARGs (6 tet genes: tetA, tetB, tetE, tetW, tetM and tetZ, 3 sulfonamide genes: sul1, sul2 and sul3, and 4 quinolone genes: gryA, parC, qnrC and qnrD) were determined by quantitative PCR. For all ARGs, sulfonamide resistance genes were present at relatively high concentrations in all samples, with the highest ARG concentration above 10(-1). ARGs remained relatively stable along each sewage treatment process. The abundances of detected ARGs from the STP were also higher than its receiving river. Bivariate correlation analysis showed that relative tet gene copies (tetB/16S-rRNA and tetW/16S-rRNA) were strongly correlated with the concentrations of tetracycline residues (r(2)>0.8, p<0.05), while no significant correlations occurred between sulfonamides and sul genes. A negative correlation between the relative abundance of quinolone resistance gene (qnrC/16S-rRNA) and the concentrations of enrofloxacin (ENR) was also determined. The difference of ARGs levels in the raw influent and secondary effluent suggested that the STP treatment process may induce to increase the abundance of resistance genes. The results showed that the sewage was an important repository of the resistance genes, which need to be effectively treated before discharge into the natural water body.

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the environment, which have drawn popular concerns recently. Most studies on the environmental fate of PPCPs have focused on their behaviors during wastewater treatment processes, in aquatic environments, and in the sludge, however, little is known about their behavior in agricultural soils. In this study, adsorption and degradation of six selected PPCPs, including clofibric acid, ibuprofen, naproxen, triclosan, diclofenac and bisphenol A have been investigated in the laboratory using four US agricultural soils associated with reclaimed wastewater reuse. Adsorption test using a batch equilibrium method demonstrated that adsorption of all tested chemicals in soils could be well described with Freundlich equation, and their adsorption affinity on soil followed the order of triclosan>bisphenol A>clofibric acid>naproxen>diclofenac>ibuprofen. Retardation factor (R(F)) suggested that ibuprofen had potential to move downward with percolating water, while triclosan and bisphenol A were readily retarded in soils. Degradation of selected PPCPs in soils generally followed first-order exponential decay kinetics, with half-lives ranging from 0.81 to 20.44 d. Degradation of PPCPs in soils appeared to be influenced by the soil organic matter and clay contents. Sterilization generally decreased the degradation rates, indicating microbial activity played a significant role in the degradation in soils. The degradation rate constant decreased with increasing initial chemical concentrations in soil, implying that the microbial activity was inhibited with high chemical loading levels.

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant around the world. In the present study, for the first time we explored the photocatalytic oxidation of TBBPA by nanoarchitectural BiOBr microspheres. BiOBr photocatalysts were synthesized via solvothermal method with various preparation conditions, and the optimal synthesis condition was determined according to their characterization results and rhodamine B (RhB) removal efficiencies. The prepared optimal BiOBr was mesoporous material of pure tetragonal phase, which removed nearly 100% of RhB from solution after 60 min simulated solar light irradiation. The BiOBr was adopted to decompose TBBPA, which was almost totally eliminated after 15 min in the UV–vis/BiOBr system. The kinetic analysis indicated that the reaction rate constants were 0.388 and 0.101 min−1 for BiOBr and P25 TiO2, respectively, suggesting that BiOBr effectively and kinetically enhanced the decomposition of TBBPA. Eight major reaction products or intermediates were identified by HPLC–MS and HPLC–SIR–MS, and a tentative degradation pathway of TBBPA was proposed. The mechanism originally illustrated that both hydroxylation and debromination played important roles in TBBPA transformation. The exceptional efficiency of mesoporous BiOBr in removing TBBPA represents a promising technique for treatment of TBBPA-containing wastewater or remediation of TBBPA-contaminated environmental matrices.

In this work, three receptor models (Principal Component Analysis-Multiple Linear Regression (PCA-MLR) model, Unmix model and Positive Matrix Factorization (PMF) model) were employed to investigate potential source apportionment of PAHs in sediments from Taihu Lake, China. A total of 15 priority PAHs in 29 sediments from Taihu Lake were measured, with ∑PAHs (sum of 15 PAHs) concentrations ranging from 209 to 1003 ng g(-1) dw. Source apportionment results derived from three different models were similar, indicating that the highest contribution to ∑PAHs was from vehicular emission (53.6-54.3%), followed by coal combustion (23.8-28.8%) and wood combustion (11.9-16.0%). The contribution of mixed wood and coal combustion source identified by PCA-MLR was 41.3%. For the first time the risk assessment for each identified source category was quantitatively calculated by combining the BaP equivalents (BaPE) values with estimated source contributions. The results showed that vehicular emission posed the highest toxic risk, with BaPE values of 26.9-31.5 ng g(-1) dw, and the BaPE values for coal combustion and wood combustion were 6.56-15.6 ng g(-1) dw and 2.94-6.11 ng g(-1) dw, respectively. The distributions of contribution and BaPE for each identified source category were studied as well, and showed similar trends among the sampling sites, for each source category.

The occurrence and distribution of sulfonamide and tetracycline, corresponding bacterial resistant rate and resistance genes (ARGs) and two integrase genes were investigated in seven urban rivers in Beijing, China. The total concentration of sulfonamide and tetracycline ranged from 1.3 × 101–1.5 × 103 ng/L and 3.9 × 101–5.4 × 104 ng/L for water, and 1.0 × 100–2.7 × 102 and 3.1 × 101–1.6 × 102 ng/g for sediment, respectively. The sul resistant rate was 2–3 times higher than tet resistant rate in both surface water and sediment. The average rate of sul resistance and tet resistance were up to 81.3% and 38.6% in surface water, 89.1% and 69.4% in the sediment, respectively. The sul1, tetA and tetE genes were predominant in term of the absolute abundance. The absolute abundance of ARGs in Wenyu River and Qinghe River, which were close to the direct discharging sites, were 5–50 times higher than those in the other investigated urban rivers, suggesting that the source release played an important role in the distribution of ARGs. The sul1 and sul2 genes had positive correlation (p < 0.05) with sulfonamides, and the tet resistance genes was significantly correlated with tetracyclines (p < 0.05), indicating that some ARGs and antibiotics in the urban rivers had identical sources of pollution. Considering principal component analysis, sampling sites (QH5, QH6, B1, B2, B3 and BX2) intimated that a complex interplay of processes govern fate and transport of ARGs in the junction of rivers. These results are significant to understand the fate, and the contribution of ARGs from the source release. In view of the large-scale investigation of urban rivers system in Beijing, it reflected the bacterial resistance in sewage drainage system. Such investigation highlights the management on controlling the pollutant release which was seemed as a major driving force for the maintenance and propagation of many ARGs during the development of urbanization in the future.

The occurrence of 15 antibiotics classified as sulphonamides, fluoroquinolones, macrolides, tetracyclines and trimethoprim in sediment, overlying water, and pore water matrices in Taihu Lake, China was studied. The total concentrations were from 4.1 μg/kg to 731 μg/kg, from 127 ng/L to 1210 ng/L, and from 1.5 ng/L to 216 ng/L in sediment, overlying water and pore water, respectively. Antibiotics in different locations originated from various sources, depending on human, agricultural and aquacultural activities. Composition analysis indicated that human-derived and animal-derived drugs significantly contributed to the total contamination of antibiotics in the lake, indicating the high complexity of contamination sources in Taihu Lake Basin. The in situ sediment–pore water partitioning coefficients were generally greater than sediment–overlying water partitioning coefficients, suggesting continuous inputs into the lake water. This study shows that antibiotics are ubiquitous in all compartments in Taihu Lake, and their potential hazards to the aquatic ecosystem need further investigation.

In this study, the occurrence and distribution of sixteen antibiotics belonging to four groups in surface water, sediment and groundwater samples from the Wangyang River (WYR), a typical river receiving sewage discharges were investigated. Laboratory analyses revealed that antibiotics were widely distributed in the studied area. The aqueous samples were unavoidably contaminated with antibiotics, and the target antibiotics present in high levels were oxytetracycline, tetracycline, chlortetracycline, ofloxacin, sulfamethoxazole, and trimethoprim, with maximum concentrations of the individual contaminant at 3.6 × 105, 9.7 × 103, 6.9 × 104, 1.2 × 104, 4.8 × 103, and 1.1 × 103 ng L−1, respectively. Oxytetracycline, tetracycline, ciprofloxacin and roxithromycin were the most frequently detected compounds in sediment samples, with maximum concentrations of the individual contaminant at 1.6 × 105, 1.7 × 104, 2.1 × 103 and 2.5 × 103 ng g−1, respectively. The results also revealed that the high intensity of aquaculture activities could contribute to the increasing levels of antibiotics in the area. According to the ratios of measured environmental concentration (MEC) to predicted no-effect concentration (PNEC), chlortetracycline, tetracycline, ofloxacin, ciprofloxacin, erythromycin-H2O and sulfamethoxazole may present possible environmental risk to Pseudokirchneriella subcapitata, Synechococcus leopoliensis and M. aeruginosa. Attention should be given to the long-term ecological effects caused by the continuous discharge of antibiotics in the WYR area.

A series of AgBr/P-g-C3N4 (AB/CN) were fabricated via in-situ growth of AgBr particles on the surface of calcined P-g-C3N4 layered mesoporous materials, and the catalysts were used for the photocatalytic degradation of ephedrine (EHP) under simulated solar irradiation. All photocatalysts demonstrated high photocatalytic performances for EPH degradation, and the AB/CN (5:1) showed the best photocatalytic activity. The holes, superoxide radicals and singlet oxygen were the dominant reactive oxygen species involved in EPH degradation. The enhanced photocatalytic performance of AgBr/P-g-C3N4 was ascribed to the formation of Ag nanoparticles and the Z-scheme mechanism. EPH degradation was accelerated by dissolved organic matter or HCO3− at low concentrations, but inhibited at high levels. The addition of CO32- enhanced EPH degradation, and NO3− suppressed the degradation. AB/CN was also able to degrade EPH in surface water and secondary effluent, implying the potential of the prepared materials in illicit drugs removal in practical applications.

Norfloxacin (NOR) is a widely used fluoroquinolone antibacterial that has drawn much concern due to its adverse effect on aquatic ecology and human health. In this study, a novel magnetically recoverable BiOBr/iron oxides (BiOBr/Fe3O4) heterojunction photocatalyst with high photocatalytic activity on NOR was successfully synthesized using a facile in-situ coprecipitation method. The samples were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectra, N2 adsorption-desorption analysis, and vibrating sample magnetometer. Several factors affecting the catalytic performance of BiOBr/Fe3O4 were investigated. Results showed that the catalytic degradation efficiency of NOR increased with the increasing bicarbonate doses, but decreased with the increasing natural organic matter concentrations. The presence of nitrate stimulated NOR degradation by BiOBr/Fe3O4 at low concentrations but inhibited the degradation at high concentrations. The photogenerated reactive species were determined based on free radicals trapping experiments, revealing that the photodegradation of NOR over BiOBr/Fe3O4 under visible light was dominated by superoxide radicals and hydroxyl radicals rather than oxidation by direct holes. On the basis of the degradation products identified by HPLC–MS, the NOR degradation pathway was proposed. NOR possibly underwent the piperazine ring transformation, decarboxylation and defluorination to generate eleven intermediates. Toxicity assays by Vibrio fischeri proved that the NOR photocatalytic transformation products retained negligible antibacterial activity relative to the parent compound. The catalytic degradation of NOR by BiOBr/Fe3O4 was also effective in the actual natural waters.

A novel flower-like three-dimensional BiOBr/BiOI/Fe3O4 heterojunction photocatalyst was synthesized using a simple in situ co-precipitation method at room temperature. The hybrid composites were characterized by a couple of techniques including X-ray powder diffraction, scanning electron microscope, transmission electron microscopy, ultraviolet-visible diffuse reflection spectroscopy, Brunauer-Emmett-Teller, X-ray photo-electron spectroscopy, photoluminescence technique, and vibrating sample magnetometer. Fe3O4 nanoparticles were perfectly loaded on the surface of BiOBr/BiOI microspheres. The recyclable magnetic BiOBr/BiOI/Fe3O4 was employed to degrade TBBPA under visible light irradiation. The optimal removal efficiency of the ternary BiOBr/BiOI/Fe3O4 (2:2:0.5) nanocomposite reached up to 98.5% for TBBPA in aqueous solution. The superior photocatalytic activity of BiOBr/BiOI/Fe3O4 was mainly ascribed to large surface area and appropriate energy gaps, resulting in the effective adsorption and separation of electrons-hole pairs. The photogenerated reactive species determined by free radicals trapping experiments revealed that the excellent catalytic activity was primarily driven by O2− radical. The photocatalytic degradation kinetics and a detailed mechanism were also proposed. Result demonstrated that the BiOBr/BiOI/Fe3O4 can be magnetically recycled, and maintain high photocatalytic activity after reuse over five cycles. It suggested that the synthesized material had a potentially promising application for TBBPA removal by photocatalytic degradation from wastewater.

Our previous study demonstrated that high levels of antibiotic resistance genes (ARGs) in the Haihe River were directly attributed to the excessive use of antibiotics in animal agriculture. The antibiotic residues of the Xiangjiang River determined in this study were much lower than those of the Haihe River, but the relative abundance of 16 detected ARGs (sul1, sul2 and sul3, qepA, qnrA, qnrB, qnrD and qnrS, tetA, tetB, tetW, tetM, tetQ and tetO, ermB and ermC), were as high as the Haihe River particularly in the downstream of the Xiangjiang River which is close to the extensive metal mining. The ARGs discharged from the pharmaceutical wastewater treatment plant (PWWTP) are a major source of ARGs in the upstream of the Xiangjiang River. In the downstream, selective stress of heavy metals rather than source release had a significant influence on the distinct distribution pattern of ARGs. Some heavy metals showed a positive correlation with certain ARG subtypes. Additionally, there is a positive correlation between individual ARG subtypes and heavy metal resistance genes, suggesting that heavy metals may co select the ARGs on the same plasmid of antibiotic resistant bacteria. The co-selection mechanism between specific metal and antibiotic resistance was further confirmed by these isolations encoding the resistance genotypes to antibiotics and metals. To our knowledge, this is the first study on the fate and distribution of ARGs under the selective pressure exerted by heavy metals in the catchment scale. These results are beneficial to understand the fate, and to discern the contributors of ARGs from either the source release or the selective pressure by sub-lethal levels of environmental stressors during their transport on a river catchment scale.

Inactivating antibiotic resistant bacteria (ARB) and removing antibiotic resistance genes (ARGs) are very important to prevent their spread into the environment. Previous efforts have been taken to eliminate ARB and ARGs from aqueous solution and sludges, however, few satisfying results have been obtained. This study investigated whether photocatalysis by TiO2 was able to reduce the two ARGs, mecA and ampC, within the host ARB, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively. The addition of H2O2 and matrix effect on the removal of ARB and ARGs were also studied. TiO2 thin films showed great effect on both ARB inactivation and ARGs removal. Approximately 4.5-5.0 and 5.5-5.8 log ARB reductions were achieved by TiO2 under 6 and 12mJ/cm2 UV254 fluence dose, respectively. For ARGs, 5.8 log mecA reduction and 4.7 log ampC reduction were achieved under 120mJ/cm2 UV254 fluence dose in the presence of TiO2. Increasing dosage of H2O2 enhanced the removal efficiencies of ARB and ARGs. The results also demonstrated that photocatalysis by TiO2 was capable of removing both intracellular and extracellular forms of ARGs. This study provided a potential alternative method for the removal of ARB and ARGs from aqueous solution.

Effective removal of pollutants that affect human health and ecosystem stability is a crucial challenge. Here, the structural confinement engineering strategy realizes the effective anchoring of atomically dispersed Co in the B-doped-CN network (BCN) (BCN/CoN[2 +2]). The advanced oxidation process (AOP) involved BCN/CoN[2 + 2] has realized the rapid and complete degradation to tetracycline (TCL), the removal of approximately 80% and 100% of tetracycline was achieved in 5 min and 30 min, respectively. The AOP with BCN/CoN[2 + 2] can degrade TCL over a wide pH; in addition, BCN/CoN[2 + 2] has the ability to efficiently degrade common pollutants, and its catalytic activity did not decay even if it was used repeated five times. Electron paramagnetic resonance (EPR) spectroscopy shows that BCN/CoN[2 + 2] drives the complete conversion of peroxymonosulfate (PMS) to 1O2, and density functional theory calculations demonstrate that the base for the conversion of PMS to 1O2 is from the isolated state of the active site Co.

Environmentally friendly electrochemical reduction pathways from NO3- to NH3 or N2 have provided feasible strategy into the green production of ammonia or the treatment of nitrate wastewater. Here, we anchored single-atom Cu with boron carbon nitride on carbon nanotube (BCN@Cu/CNT), and achieved the efficient operation of electrochemical nitrate reduction reaction (NIRR). BCN@Cu/CNT can efficiently catalyze the selective conversion of high-concentration nitrate into high-value-added ammonia, where the ammonia yield rate and Faradaic efficiency are as high as 172,226.5 μg h-1 mgcat.-1 and 95.32% (at -0.6 V), respectively. BCN@Cu/CNT also shows the ability to efficiently remove low-concentration nitrates in sewage. Specifically, here only takes 5 h to nearly 100% (99.32%) eliminate NO3- (50 mg L-1) in sewage without any residual NO2-. The excellent catalytic activity and physicochemical stability of BCN@Cu/CNT for NIRR suggest the promising industrial application prospects, including the green production of ammonia and the purification of nitrate wastewater.

The effect of reclaimed wastewater irrigation on the alteration of soil properties and accumulation of trace metals in soil profiles was investigated by monitoring different plots from Palmdale, California that had been irrigated with effluents for various lengths of time (3, 8, and 20 years, respectively). The non-effluent-irrigated plot served as the control and provided reference "background" values. Total metals at different soil depths were analyzed by acid digestion, and EDTA-extractable metals were analyzed as available fraction. Results show that soil pH values were significantly (p<0.05) lowered in plots with 20-year irrigation to a depth of 140 cm, while EC was elevated for all three plots compared with control. OM, TC and TN contents increased in the top 10-cm soil layers in plots with 8- and 20-year effluent irrigation. Irrigation with effluents also increased both the total and EDTA-extractable metals in the fields. It showed that long-term effluent irrigation could be of agricultural interest due mainly to its organic matter concentrations and nutrients input, however, trace contaminants such as heavy metals in the upper horizons may be accumulated, which may eventually lead to deterioration of soil and groundwater quality and affect the sustainability of land-based disposal of effluent.

Fourteen surface sediment samples were collected from Lanzhou Reach of Yellow River, China in July 2005. The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography equipped with a mass spectrometry detector (GC–MS). Total concentrations of the PAHs ranged from 464 to 2621 ng/g dry weight. Sediment samples with the highest PAH concentrations appeared at the downstream of Lanzhou City, where there was the biggest wastewater discharge pipeline from Lanzhou Oil Refinery Factory and Lanzhou Chemical Industry Company. Municipal sewage also contributed to the PAH contamination in the sediments. A correlation existed between the sediment organic carbon content (foc) and the total PAH concentrations (r2 = 0.57), suggesting that sediment organic carbon content played an important role in controlling the PAHs levels in the sediments. According to the observed molecular indices, PAHs contamination in Lanzhou Reach of Yellow River originated both from the high-temperature pyrolytic processes and from the petrogenic source, showing a mixed PAH input pattern, which was also confirmed by the results of a principal component analysis (PCA). According to the numerical effect-based sediment quality guidelines (SQGs) of the United States, the levels of PAHs at most studied sites in Lanzhou Reach of Yellow River should not exert adverse biological effects. Although at some sites (such as S10, S12, etc.) one PAH may exceed the effects range low (ERL), individual PAH did not exceed the effects range median (ERM). The results indicated that sediments in all sites should have potential biological impact, but should have no impairment.

Analytical methods have been developed for simultaneous determination of six different pharmaceuticals and personal care products (PPCPs) (clofibric acid, ibuprofen, naproxen, ketoprofen, diclofenac, and triclosan), three endocrine disrupting compounds (EDCs) (4-tert-octylphenol, 4-n-nonylphenol, and bisphenol A (BPA)) and one estrogenic compound (estrone) in soil matrix. The soils were extracted by different solvents with the help of an ultrasonic treatment at 42 kHz, followed by a solid phase extraction (SPE) as a cleanup procedure. The purified extracts were derivatized with N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) and then analyzed by GC–MSD (SIM mode). The method was evaluated by testing the following variables: initial spiking levels, extraction solvents, solvent volumes, and soil types (sandy and clay soils). For 5 g of soil, four successive extraction steps with the mixture of acetone–ethyl acetate provided satisfactory recoveries. In the sandy soil, the recoveries of all the compounds were from 63.8 to 110.7% for the spiking level of 100 ng/g dry soil, and from 52.2 to 108.2% for 5 ng/g dry soil, respectively. Result was similar for the clay soil. The precision across all recoveries was high, suggesting that this method has a good reproducibility. The method was successfully employed to soil samples collected from a golf course irrigated with reclaimed wastewater in southern California, and resulted in the detection of clofibric acid, ibuprofen, naproxen, triclosan, bisphenol A, and estrone at ng per gram dry weight concentration levels. The method is robust and simple, and provides straightforward analyses of these current-emerging trace organic pollutants in solid matrices.

This study firstly explored the photodegradation of carbamazepine, one of the most frequently detected pharmaceuticals, with tailored BiPO4 nanomaterials. BiPO4 was synthesized with a hydrothermal method. The physicochemical properties of the obtained samples were characterized and the results indicated that both the hydrothermal temperature and reaction time influenced the phase, morphology and optical properties of the BiPO4 catalysts, which may further determine their specific photocatalytic performances. The intrinsic microstructure and optical properties reflected the crystal properties of the catalysts to some extent. The BiPO4 prepared at 180 °C for 72 h (BPO-180-72) displayed the best photocatalytic activity under UV irradiation, during which carbamazepine was nearly completely eliminated from ultrapure water after 60 min irradiation. The good photocatalytic activity was ascribed to the synergistic effect of monoclinic phase and relatively ordered morphology of the resulting BiPO4. Particularly, the monoclinic phase was firstly proved to be more active than the hexagonal phase for BiPO4 samples. BPO-180-72 removed approximately 72.4% of carbamazepine from lab-prepared simulated wastewater after 60 min irradiation, suggesting the potential application of this material in wastewater treatment. Ten reaction intermediate products were observed and identified by HPLC–MS/MS, and a tentative reaction pathway was proposed. Results indicated that photogenerated holes and hydroxyl radicals were the main reactive species for the photodegradation of carbamazepine in the system.

A novel 3D heterojunction photocatalyst Fe3O4/BiOI microsphere with hollow structure was successfully fabricated for the first time via a facile in-situ coprecipitation method. The materials were characterized by a number of techniques including X-ray powder diffraction, scanning electron microscope, transmission electron microscopy, ultraviolet–visible diffuse reflection spectroscopy, Brunauer-Emmett-Teller, X-ray photo-electron spectroscopy, photoluminescence technique, and vibrating sample magnetometer. The photocatalyst was employed to degrade bisphenol A (BPA) in aqueous solution under visible-light irradiation. Among the prepared samples, the Fe3O4/BiOI with molar ratio of 1:4 (FB-4) heterojunction showed the best photocatalytic activity. The optimal dose of FB-4 was 1.0 g/L. The catalytic degradation also showed a dependence on initial pH, and the maximal degradation efficiency was obtained at pH 9.0. The presence of nitrate and bicarbonate stimulated BPA degradation by Fe3O4/BiOI at low concentrations but inhibited the degradation at high concentrations. HA inhibited the degradation at all concentrations. The photogenerated reactive species determined by free radicals trapping experiments revealed that the photodegradation of BPA over Fe3O4/BiOI under visible light was dominated by direct hole and hydroxyl radicals rather than oxidation by superoxide radicals. The disappearance of BPA as well as the formation of its intermediates/products were determined by high-performance liquid chromatography-mass spectroscopy, and possible photocatalytic degradation pathways were proposed. Cycling test showed that the magnetic Fe3O4/BiOI composite could be easily recycled after five cycles and separated well by an external magnetic field, and could maintain an excellent photocatalytic activity on BPA degradation.

In this study, the bioaccumulation of perfluorinated compounds from a food web in Taihu Lake in China was investigated. The organisms included egret bird species, carnivorous fish, omnivorous fish, herbivorous fish, zooplankton, phytoplankton, zoobenthos and white shrimp. Isotope analysis by δ13C and δ15N indicated that the carnivorous fish and egret were the top predators in the studied web, occupying trophic levels intermediate between 3.66 and 4.61, while plankton was at the lowest trophic level. Perfluorinated carboxylates (PFCAs) with 9–12 carbons were significantly biomagnified, with trophic magnification factors (TMFs) ranging from 2.1 to 3.7. The TMF of perfluorooctane sulfonate (PFOS) (2.9) was generally comparable to or lower than those of the PFCAs in the same food web. All hazard ratio (HR) values reported for PFOS and perfluorooctanoate (PFOA) were less than unity, suggesting that the detected levels would not cause any immediate health effects to the people in Taihu Lake region through the consumption of shrimps and fish.

A series of Ag/P-g-C3N4 composites with different Ag content were synthesized for the first time by thermal polymerization combined with photo-deposition method. The composites were characterized by X-ray powder diffraction, field emission scanning electron microscope coupled with energy-dispersive X-ray spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectra, N2 absorption-desorption and X-ray photoelectron spectroscopy. Ag was successfully dispersed on the surface of P-g-C3N4. The photocatalytic performance of P-g-C3N4 and Ag/P-g-C3N4 was evaluated by degrading sulfamethoxazole (SMX) under visible light irradiation. In the presence of 5% Ag/P-g-C3N4, 100% of SMX was degraded within 20 min. The enhanced photocatalytic activity of Ag/P-g-C3N4 was attributed to the surface plasmon resonance effect of metallic Ag and Schottky barrier formed on the interface between Ag and P-g-C3N4, which could speed up the generation rate of electrons and holes and inhibit the recombination of photogenerated electron-hole pairs. The radical quenching tests indicated that holes and superoxide radicals were the dominant active species involved in SMX degradation. The synthesized materials maintained high catalytic activity after five cycle runs. The concentration and the intermediates during the degradation process were determined by LC–MS/MS, and the tentative degradation pathways of SMX in photocatalytic system were proposed.

In this paper, two one-dimensional (1D) TiO2 nanostructures, nanotube and nanowire were synthesized by a hydrothermal method using Degussa P25 TiO2 as a precursor. The synthesized anatase TiO2 nanotubes with the diameters of 10–20 nm and length of several hundred nanometers were formed from P25 and NaOH with the hydrothermal treatment temperature at 150 °C, and anatase TiO2 nanowires with the diameters of 10–40 nm and length up to several micrometers were prepared at 180 °C. The photocatalytic activity of the two nanostructures was evaluated by degrading rhodamine B (RhB) and methyl orange (MO) in aqueous solutions under simulated solar light irradiation. The results suggested that the TiO2 nanocatalysts displayed higher degradation activity compared to P25. For RhB, 98.9% and 91.9% of RhB were removed by nanotubes and nanowires, respectively after 60 min irradiation in comparison to the 81.8% removal by P25. Similar trend was observed for MO, with the removal percentage of 95.6%, 88.3% and 74.9%, respectively by TiO2 nanotubes, nanowires and P25. Meanwhile, RhB and MO showed different photodegradation rates in nanotubes and nanowires suspensions, probably due to the morphology and crystal structure of the TiO2 nanocatalysts which play important roles in the degradation activity of the catalysts.

In this study, mesoporous aurivillius bismuth molybdenum oxide (Bi2MoO6) (A-BMO) microspheres were fabricated via a template-free solvothermal process in the presence of ethylene glycol. The as-prepared Bi2MoO6 products were characterized by X-ray diffraction, scanning electron microscopy, UV–vis diffuse reflectance spectroscopy and nitrogen adsorption–desorption techniques, respectively. Results showed that the synthesized Bi2MoO6 microspheres were composed of nanosheets, with diameters of 0.5–1.0 μm, specific surface areas of about 50.86 m2 g−1, and a band gap energy of about 2.59 eV. The photocatalytic activity of the Bi2MoO6 microspheres was evaluated in the decomposition of rhodamine B (RhB) under xenon lamp irradiation. The A-BMO showed superior performance for the photodegradation of RhB, in comparison to the commercial P25 in the H2O2-containing system. The sedimentation, stability and recycling performance of the prepared A-BMO catalysts were also investigated. This study provided new insights into the design and preparation of functional nanomaterials with sphere structures in high yields, and the as-grown architectures exhibited potential ability to remove organic pollutants in wastewater.

In this paper, two-dimensional bismuth oxybromide (BiOBr) nanoplates and three-dimensional BiOBr microspheres were prepared via facile co-precipitation methods with Bi(NO3)3·5H2O as the Bi source. The resulting BiOBr catalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), N2 adsorption–desorption and ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS) techniques, and were used to degrade benzotriazole under simulated solar light irradiation. The BiOBr catalysts were of pure tetragonal phase, and their band gaps were about 2.7 eV. Nearly 90% of benzotriazole was stepwisely eliminated in the presence of the synthesized BiOBr catalysts after 3 h of irradiation compared to the removal efficiency of about 50% by P25 under identical conditions. The superior photocatalytic performance of BiOBr can be attributed to its special nanostructure and optical abilities. With the help of various radical scavengers, the degradation mechanism of benzotriazole by BiOBr was found to be mainly driven by the direct hole and HO radicals oxidation. Four major reaction intermediates identified by gas chromatography–mass spectrometry (GC–MS) analysis confirmed the role of direct hole and HO radicals during the oxidation process, and a tentative photodegradation pathway was proposed. The research showed promising results for the application of the obtained BiOBr materials to benzotriazole removal from wastewater.

The occurrence and distribution of 19 antibiotics including ten sulfonamides, four quinolones, three tetracyclines and two macrolides in water, sediment, and biota samples from the Liao River Basin, China were investigated in the present study. The samples were collected in May 2012, and laboratory analyses revealed that antibiotics were widely distributed in the Liao River Basin. Macrolides made up the majority of antibiotics in the water ranging from not detected (ND) to 3162.22 ng L(-1), while tetracyclines and macrolides were the predominant antibiotics in the sediments, ranging from ND to 404.82 μg kg(-1) (mean 32.11 μg kg(-1) dw) and ND to 375.13 (mean 32.77 μg kg(-1) dw), with detection frequencies of 37.3% and 38.1%, respectively. In biological samples, quinolones were the most frequently detected antibiotics (57.1-100%), with concentrations ranging from 286.6-1655.3 μg kg(-1). The highest bioaccumulation factor (BAF) of 45407 L kg(-1) was found for enrofloxacin. The phase distribution calculation showed that tetracyclines were the most strongly adsorbed antibiotics in the sediment, with the highest pseudo-partitioning coefficient values, ranging from 1299 to 1499 L kg(-1). The geographical differences of antibiotic concentrations were largely due to anthropogenic activities and the sewage discharges from the local cities along the rivers.

Fates and transport of 9 commonly found PPCPs of the reclaimed water were simulated based on the HYDRUS-1D software that was validated with data generated from field experiments. Under the default scenario in which the model parameters and input data represented the typical conditions of turf grass irrigation in southern California, the adsorption, degradation, and volatilization of clofibric acid, ibuprofen, 4-tert-octylphenol, 4-n-nonylphenol, naproxen, triclosan, diclofenac sodium, bisphenol A and estrone in the receiving soils were tracked for 10 years. At the end, their accumulations in the 90 cm soil profile varied from less than 1 ng g(-1) to about 140 ng g(-1) and their concentrations in the drainage water in the 90 cm soil depth varied from nil to μg L(-1) levels. The adsorption and microbial degradation processes interacted to contain the PPCPs entirely within surface 40 cm of the soil profiles. Leaching and volatilization were not significant processes governing the PPCPs in the soils. The extent of accumulations in the soils did not appear to produce undue ecological risks to the soil biota. PPCPs did not represent any potential environmental harm in reclaimed water irrigation.

The objective of this study was to synthesize bismuth molybdate (Bi2MoO6) nanostructures with different morphologies for potential application in the removal of sulfamethazine (SMZ) from wastewater. Bismuth molybdate nanostructures were synthesized via a simple hydrothermal route followed by calcination. The nanosheet and microsphere morphologies of the Bi2MoO6 obtained were controlled by adjusting the pH value of the reactants. The solids were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), Raman spectroscopy, N2-Brunauer–Emmett–Teller and UV–vis DRS methods. The optimal catalyst with the best photocatalytic performance was determined by batch experiments. The Langmuir–Hinshelwood kinetic model was employed to examine the heterogeneous photocatalysis reaction. The results indicated that the photocatalyst was very effective for SMZ photodegradation under solar light irradiation and that the photolysis followed pseudo-first order kinetics. The catalyst with the optimal photocatalytic performance could be obtained by controlling the precursor pH value, and the nanocrystalline morphology of the Bi2MoO6 played an important role in determining its catalytic activity. The main reactive species involved in the photocatalytic degradation of SMZ were identified, showing that superoxide radicals and holes were mainly responsible for the SMZ photodegradation by Bi2MoO6. Five reaction intermediates/products were observed and identified by gas chromatography–mass spectrometry (GC–MS) analysis, and a tentative reaction pathway was proposed. Toxicity tests further confirmed that the toxicity of the initial SMZ solution was efficiently eliminated during this photocatalytic process.

Lanthanum-based adsorbents are promising phosphate (P) adsorbents and their selectivity determines their potential for application in P recovery. However, there have been few systematic studies for quantifying the selectivity of lanthanum-based adsorbents for P. In this study, lanthanum carbonate/biochar (LCB300) and lanthanum hydroxide/biochar (LHB800) composites were synthesized to quantify their selectivity for P adsorption. Batch adsorption experiments were conducted to investigate the influence of environmental factors on their selectivity. The results showed that both LCB300 and LHB800 exhibit similar maximum adsorption capacities for P (64.3 and 65.0 mg g−1, respectively). However, the selectivity of LHB800 (90–100%) for P was higher than that of LCB300 (73–99%), and the former was less susceptible to environmental conditions than the latter. In addition, competing ions accelerated the intermediate process of P adsorption by LHB800, but slightly inhibited the adsorption rate of LCB300 for P. These results show that the form of lanthanum on the adsorbent affects its adsorption mechanism and corresponding selectivity for P. Moreover, LHB800 demonstrates significant potential for application in the recovery of phosphate from wastewater.

Persulfate-based advanced oxidation processes (persulfate-AOPs) offer great promise for environmental remediation, with heterogeneous catalysts providing the backbone of many wastewater purification technologies. Unlike conventional nanocatalyst heterogeneous systems, the immobilized-catalyst system can bypass the separation problem to reduce scour and prevent aggregation by anchoring nanoparticles onto porous or large-particle carriers. This review presents the state-of-the-art of knowledge concerning immobilization methodologies and reactors, reaction mechanisms, and activation performance. Immobilization techniques onto supports are summarized and discussed, including membrane-based reaction systems (immersion mode, and filtration mode), electrocatalytic auxiliary systems, and alternative supports (metallic glasses, aerogels, hydrogels, and specific materials). Key scientific problems and important prospects for the further development of immobilized catalysts are outlined.

MnFe Prussian blue analogues (MnFe PBAs) were fabricated for acetamiprid degradation with peroxymonosulfate (PMS) as an oxidant. MnFe PBAs (200) are the most active facets for PMS activation due to the superior chemisorption affinity and electron-transfer ability. Density functional theory calculation verified that Mn(III) served as an electron donor and acceptor to adjust the electron density between Fe and Mn, which played a crucial role in the high activation performance of MnFe PBAs (200). PBA lattice (−C═N) did not exhibit direct PMS activation capability in this system, which differed from previously reported Fenton counterparts. Based on the electronic localization function calculation and probe experiments, the O–O of HSO5– was broken, and the bonds of PBA could be restored during the activation reaction, leading to the continuous generation of reactive oxygen species in the MnFe PBAs/PMS system. Transformation product studies indicated that the oxidized products were primarily the result of aromatic hydroxylation, N–C bond cleavage, azo reaction, and so forth, achieving the mineralization and ecotoxicity mitigation of acetamiprid efficiently. Findings in this study provided new insights into developing advanced facet-dependent catalysts to activate PMS for the efficient degradation of emerging contaminants in the aqueous environment.

Perfluorinated compounds (PFCs) have received much attention on their distribution in various matrices including water bodies, precipitations, sediment and biota in different areas globally, however, little attention has been paid to their occurrence and distribution in urban lakes. In this study, water and sediment samples collected from 26 sites in Dianchi Lake, a plateau urban lake in the southwestern part of China were analyzed via high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) for ten analytes involving nine perfluoroalkyl carboxylic acids (PFOAs) and perfluorooctanesulfonate (PFOS). Total levels of PFCs were 30.98 ± 32.19 ng L−1 in water and 0.95 ± 0.63 ng g−1 in sediment. In water samples PFOA was the dominant PFC contaminant, with concentrations ranging from 3.41 to 35.44 ng L−1, while in sediments PFOS was the main PFC contaminant at levels from 0.07–0.83 ng g−1 dry weight. Field-based sediment water distribution coefficients (KD) were calculated and corrected for organic carbon content (Koc), which reduced variability among samples. The logKoc ranged from 2.54 to 3.57 for C8–C12 perfluorinated carboxylic acids, increasing by 0.1–0.4 log units with each additional CF2 moiety. The logKoc of PFOS was 3.35 ± 0.32. Magnitudes and trends in logKD or logKoc appeared to agree well with previously published laboratory data. Results showed that different PFC composition profiles were observed for samples from the lake water and sediments, indicating the presence of dissimilar characteristics of the PFCs compounds, which is important for PFC fate modeling and risk assessment.

In this work, sixteen U.S. EPA priority PAH compounds in the dated sediment cores were detected from five lakes in western China. In most lakes, the concentrations of the total PAHs (ΣPAHs) increased from the deep layers to the surface sediments. Two source categories, i.e. vehicular emission and biomass & domestic coal combustion were identified by Unmix, a factor analysis receptor model to explore the source contributions of PAHs in the dated sediments. The source apportionment results showed that biomass & domestic coal combustion contributed larger proportion of PAHs in the five lakes. The toxicities of PAHs in the dated sediments, assessed by BaP equivalent (BaPE) values showed that the BaPE increased gradually from the deep layers to the surface sediments in most lakes. For the first effort, the contribution of each source to BaPE was apportioned by Unmix-BaPE method, and the result indicated that the vehicular emission posed the highest toxic risk. The percentage contribution of vehicular emission for PAHs and BaPE also increased from the deep layers to the surface sediments, while biomass & domestic coal combustion exhibited the opposite tendency.

Illicit drugs constitute a class of emerging contaminants that has been drawing significant concern due to its potent pharmacological and biological activities. In this study, an in situ passive sampling approach that uses diffusive gradients in thin films (DGT) was successfully tested for measuring ketamine (KET), methamphetamine (METH), and amphetamine (AMP) in water. The diffusion coefficients of KET, METH, and AMP in diffusive gel were (8.13 ± 0.12) × 10-6, (8.55 ± 0.14) × 10-6, and (7.72 ± 0.18) × 10-6 cm2 s-1 at 22 °C, respectively. The capacities of an XAD binding gel for KET, METH, and AMP were 92, 57, and 45 μg per binding gel disc, which were suitable for long-term environmental monitoring. The DGT measurement of these drugs was not influenced by the pH (4 to 9) and the ionic strength (0.001 M - 0.1 M) and unaffected by the water flow, demonstrating the effectiveness of the XAD-based DGT for the in situ monitoring of illicit drugs. DGT samplers were deployed in a WWTP influent and natural rivers in Beijing, China. The ng L-1 levels of the drugs were high in the wastewater influent and low in river waters, with an insignificant fluctuation during the seven-day monitoring. The DGT-measured concentrations were comparable to the average concentrations determined by SPE method, which suggested that the average data measured by DGT could be substituted for high-frequency grab sampling. This study has demonstrated systematically for the first time that DGT is effective and accurate for monitoring illicit drugs in wastewater and surface waters, and provides a powerful tool to investigating the presence, transport, and environmental behaviors of these drugs in the aquatic ecosystem.

In this study, the photoinduced degradation of sulfapyridine (SPY) was investigated under simulated light irradiation (λ > 200 nm). The effect of pH and main water constituents including nitrate ion, bicarbonate, dissolved organic matter (DOM) and iron(III) on the photodegradation was explored. SPY was effectively removed in aqueous solution at pH 8 under UV–vis irradiation, with removal efficiency of 100% within 120 min. DOM and iron(III) had retarding influence on the SPY removal, whereas nitrate ion and bicarbonate did not show any obvious effect. Under UV–vis irradiation, the formation of singlet oxygen (1O2) accelerated the SPY photodegradation and the contribution of indirect photolysis due to reaction with 1O2 was up to 42%. The transformation products of SPY were identified by HPLC–MS and the possible photoreaction pathways were proposed. It showed that photoinduced hydrolysis, photo-oxidation via 1O2 and desulfonation were the main degradation ways for SPY decomposition. Toxicity assays by Vibrio fischeri proved that the transformation products were more toxic than the parent compound.

The occurrence and distribution of five drugs of abuse and their metabolites, namely, methamphetamine (METH), amphetamine (AMP), ketamine (KET), ephedrine (EPH), and hydroxylimine (HY), were investigated in the surface water in urban rivers in Beijing, China. A total of 117 surface water samples were collected from the seven rivers in the Beijing urban areas during four different seasons. Laboratory analyses revealed that EPH and METH were the most predominant drugs, with detection frequency ranging from 94% to 100% and from 65% to 100%, respectively. High levels of METH and KET were observed in the center part of the urban areas, which was likely associated with the drug abuse and the entertainment activities. Seasonal variation of the drug occurrence showed that the highest concentration of drugs of abuse was found during winter, which was likely due to the high consumption, low temperature, and low water flows during the cold weather. By contrast, the concentration and detection frequency of AMP and HY were relatively low. Risk assessment by the risk quotient method indicated that the five drugs of abuse and their metabolites were not likely to exert biological effects on the aquatic ecosystems at current levels in the surface water. However, the potential adverse effect of drugs of abuse and their metabolites on ecosystem functioning and human health should not be neglected.

The levels, distribution, possible sources, and inventory of perfluoroalkyl acids (PFAAs) in the eutrophic freshwater Taihu Lake, East China were investigated in this study. Among the target 11 PFAAs, perfluorooctanoic acid (PFOA) (2.15-73.9 ng L(-1)) and perfluorohexanoic acid (PFHxA) (<LOQ-22.2 ng L(-1)) were the dominant components in surface water, followed by perfluorooctanesulfonic acid (PFOS) with the maximum concentration of 10.5 ng L(-1). PFOS was also dominant (0.13-6.95 ng g(-1) dw) in the sediments, accounting for 15-85% of ΣPFAAs concentrations in 70% of the sediment samples. Sediment-water partitioning coefficients showed that logKOC increased linearly with the increasing chain length, with the logKOC values increased by 0.1-0.4 log unit with each CF2 moiety from C8 to C12 perfluorinated carboxylic acids. Three specific molecular ratios, PFOS/PFOA, PFOA/PFNA and PFHpA/PFOA were used to characterize the potential sources. It indicated that the majority of pollutants was from direct emissions from manufacturing processes. The PFOA/PFNA ratios between 1.7 and 56.8 in surface water suggested the influence of secondary sources such as the degradation of volatile precursor substances. Given the high ratios of PFHpA/PFOA (0.05-7.93), it also indicated the influence from atmospheric deposition to the epilimnion. The predicted environmental concentrations were calculated from European Union system for the evaluation of substances model (EUSES). As expected, the predicted environmental concentration (PEC) of PFOS in sediment fit well to the monitored level of PFOS in this region, and the inventory of ΣPFCA and PFOS were estimated to be 989 kg and 646 kg in Taihu Lake.

In this study, novel magnetic BiOBr/Fe2O3 and BiOBr/Fe3O4 heterojunction composites were successfully synthesized by a simple solvothermal method. The characterization of the materials, based on their crystallite phase, chemical composition, morphology, and structure, indicated that the heterojunction structures were factually constructed. Under visible light irradiation, both composites exhibited significantly enhanced photocatalytic activity over BiOBr towards degradation of rhodamine B (RhB) and methyl orange (MO). In the case of RhB, 97.8% and 100% of RhB could be removed after 120 min irradiation in the presence of BiOBr/Fe2O3 and BiOBr/Fe3O4, respectively. A similar trend was observed for MO, with the degradation percentages of 91.7% and 100%, respectively, by BiOBr/Fe2O3 and BiOBr/Fe3O4 after 60 min. The extended visible light absorption range, investigated by UV–vis diffuse reflectance spectroscopy, was one of the factors responsible for the improvement of the photocatalytic performance. The formation of p–n junction between p-type BiOBr and n-type Fe2O3 or n-type Fe3O4 semiconductors could promote the effective separation of photogenerated electron–hole pairs. In addition, the superparamagnetic BiOBr/Fe2O3 and BiOBr/Fe3O4 composites can not only be easily isolated by an external magnetic field, but also maintained high activity after four recycles for the degradation of RhB and MO

Ketamine (KET) has been increasingly used for medical purposes and abused by individuals around the world. In this study, decomposition of KET was investigated by UV-activated persulfate (S2O82−, PS). Influence of key parameters, such as pH, PS dosage, HCO3−, Cl−, NO3−, and humic acid (HA) on KET decomposition was evaluated. The results showed that KET degradation followed pseudo-first order reaction kinetics well (R2 > 0.99). The combination of UV-254 nm and persulfate could completely degrade 100 μg/L of KET in 30 min with a PS dosage of 500 μM at pH 7. Both hydroxyl radical (radOH) and sulfate radical (SO4−rad) were demonstrated to participate in the KET degradation through scavenging experiments. The degradation rate constant of KET was proportional to the PS dosage (0–800 μM), while self-scavenging of SO4−rad occurred with an excessive amount of PS dosage (1000 μM). The KET degradation rate was pH-dependent, and was highest at neutral pH condition. The presence of HCO3− had a positive impact on the KET decomposition, however, NO3− induced a negative effect even at a relatively low concentration. Of note, Cl− had a dual impact on the KET decomposition. The bimolecular reaction rates of KET with SO4−rad and radOH at pH 7 were 3.76 × 109 and 4.43 × 109 M−1 s−1, respectively. KET decomposition was significantly inhibited by the presence of HA due to the effect of UV absorption and free radical quenching. The intermediates of KET degradation were identified by HPLC-MS and possible transformation pathways were proposed. Results indicated that the combination of UV/PS is an effective approach for the removal of KET in the aquatic environment.

Abstract Background Phthalates were detected in various environments due to their widespread application. In this study, indoor dust samples from 94 buildings, including 72 residences and 22 dormitories, were collected in seven geographical regions in China and analyzed for eight phthalate esters (PAEs). Investigation of contamination profiles, geographical distribution, sources, and risks of PAEs in indoor dusts was explored. Results The highest Σ 8 PAEs concentration in residential buildings was found in Northeast China (median: 164.71 μg·g −1 ), which was 2.3 and 2.8 times higher than that in South China (median: 71.71 μg·g −1 ) and Southwest China (median: 58.53 μg·g −1 ), respectively. Di (2-ethylhexyl) phthalate (DEHP), di-iso-butyl phthalate (DIBP), and di-n-butyl phthalate (DBP) were the dominant compounds of Σ 8 PAEs in indoor dusts from residences and dormitories. The administrative levels revealed that the highly serious contamination occurred in the provincial capital, followed by nonprovincial cities and countries. Such an occurrence was related to the usage of PAE products and the level of urbanization. Principal component analysis (PCA) and positive matrix factorization (PMF) showed that the emission from cosmetics and personal care products, plasticizers, and household building materials were the possible PAE sources in indoor dusts. Among three routes of ingestion, dermal adsorption, and inhalation, dust ingestion was the main route of human exposure to PAEs. The health risk of PAE exposure for different populations in descending order of children &gt; women &gt; men. The hazard indexes of noncancer were higher than the threshold value of 10 −6 during human exposure to DBP and DEHP. Children also faced potential noncancer risk due to benzyl butyl phthalate (BBzP) and di-n-octyl phthalate (DnOP) exposure. The carcinogenic risks via exposure to BBzP and DEHP were negligible. Conclusion Overall, PAEs were widely presented in indoor dusts. Obvious difference was observed in the distribution of PAEs concentration in indoor dusts due to the differences in economic development and usage of PAEs product. Plasticizers, household building materials, and cosmetics and personal care products were likely PAE sources in indoor dusts. The risk assessment suggested that carcinogenic risks of BBzP and DEHP were negligible, but DBP, DEHP, DnOP, and BBzP may pose noncancer risks to humans.

The occurrence of 187 pharmaceuticals and personal care products (PPCPs) was investigated in bottled water samples (35 and 33 from Chinese and foreign brands, respectively). Forty-four compounds belonging to 14 PPCP categories were detected in 56 of the 68 bottled water samples. Further, more than 35% of water samples contained at least three PPCPs, and in one particular sample, 11 different PPCPs were detected. Macrolides constituted the most prevalent PPCP category, and salbutamol, erythromycin, and azithromycin showed the highest detection frequency (17.6%). The thermal stabilities of the 187 PPCPs were determined, and the results obtained showed that only 35 out of the 187 compounds were degraded by more than 50% after boiling for 5 min. Even though the risk quotients (RQs) of detected PPCPs showed low risk levels, the RQs of 13 compounds with RQs ≥ 0.0001 were 2–4 fold higher in infants than in other life stages. Moreover, further studies are necessary to evaluate the toxicity of PPCP mixtures, the effects of PPCPs on human intestinal microbiota, and their risk of induction of drug-resistant bacteria and drug-resistant genes.

As phosphate is one of the key causes of water eutrophication, its removal from aquatic ecosystems is essential. Adsorption methods have been widely used to remove phosphate from water bodies. However, most of the adsorbents are unstable and difficult to separate from solution. In this paper, we used a simple electrospinning method to prepare a new, well-dispersed, lanthanum (La)-based porous polyacrylonitrile nanofiber (LPS) with more active sites, which improve its phosphate removal efficiency. The maximum phosphate adsorption capacity on LPS was 218.5 mg P/g (La) (50.4 mg P/g). After complete adsorption, the P/La molar ratio on LPS was 0.98. After 48 h of oscillation, the leakage of La from LPS in deionized water was only 74 μg/L, effectively ruling out secondary pollution of the water-body. Moreover, unlike most adsorbents, LPS has the advantage that it can be readily isolated from water. After treatment with LPS, the total phosphorus (TP) of a water sample from Yangzonghai Lake (Yunnan, China) was reduced to 4.2 μg/L, a value lower than the concentration threshold of eutrophication (10 μg/L) set by the United States Environmental Protection Agency (USEPA) and the first category of the surface water environmental quality standard (10 μg/L) set by China for lakes and reservoirs.

Electrochemical nitrate reduction reaction (NIRR) driven by sustainable energy is not only expected to realize the green production of ammonia under ambient conditions, but also a promising way to purify nitrate wastewater. The ammonia yield rate and Faradaic efficiency of NIRR catalyzed by Pd10Cu/BCN constructed with structural constraints and pre-embedded reducing agent strategies were as high as 102,153 μg h-1 mgcat.-1 and 91.47%, respectively. Pd10Cu/BCN can remove nearly 100% of 50 mg L-1 NO3- without NO2- residue within 10 h, and the realization of this effect does not require the participation of any chloride. Control experiments and DFT calculations explain the efficient operation mechanism of NIRR on Pd10Cu/BCN, where the Pd and CuN4 sites play the role of synergistic catalysis. Compared with the reported literature, Pd10Cu/BCN with good biocompatibility has become an outstanding representative of NIRR catalyst, which provides an alternative way for the green production of ammonia and the purification of nitrate wastewater.

Thiamethoxam (THM) is a commercial neonicotinoid insecticide with broad-spectrum insecticidal activity. It has been widely detected in the aquatic environment, but its behavioral toxicity on aquatic organisms received limited attention. In this study, adult zebrafish were exposed to THM at three levels (0.1, 10, and 1000 μg/L) for 45 days to investigate its effect on their ecological behavior, histopathology, bioaccumulation, and stress response. The bioconcentration factor in zebrafish brain was significantly higher (p < 0.05) at low concentration of THM (0.1 μg/L) than in other treatment groups. In terms of individual behavior, the locomotor activity, aggregation, and social activity of fish were enhanced after THM exposure, but the memory of the food zone was disturbed and abnormal swimming behavior was observed. THM exposure caused brain tissue necrosis, erythrocyte infiltration, cloudy swelling, and other pathological changes in brain tissue and affected the concentrations of acetylcholinesterase and cortisol related to neurotoxicity. The condition factor and organ coefficients (brain, heart, and intestine) of zebrafish were markedly impacted by THM treatment at 0.1 and 1000 μg/L, respectively. This finding showed that THM was more harmful to fish behavior than lethality, reproduction, and growth, and a behavioral study can be a useful tool for ecological risk assessment.

As hotspots for the dissemination of antibiotic resistance genes (ARGs), wastewater treatment plants (WWTPs) have attracted global attention. However, there lacks a sufficient metagenomic surveillance of antibiotic resistome in the WWTPs located on the Qinghai-Tibet Plateau. Here, metagenomic approaches were used to comprehensively investigate the occurrence, mobility potential, and bacterial hosts of ARGs in influent and effluent of 18 WWTPs located on the Qinghai-Tibet Plateau. The total ARG relative abundances and diversity were significantly decreased from influent to effluent across the WWTPs. Multidrug, bacitracin, sulfonamide, aminoglycoside, and beta-lactam ARGs generally consisted of the main ARG types in effluent samples, which were distinct from influent samples. A group of 72 core ARGs accounting for 61.8-95.8 % of the total ARG abundances were shared by all samples. Clinically relevant ARGs mainly conferring resistance to beta-lactams were detected in influent (277 ARGs) and effluent (178 ARGs). Metagenomic assembly revealed that the genetic location of an ARG on a plasmid or a chromosome was related to its corresponding ARG type, demonstrating the distinction in the mobility potential of different ARG types. The abundance of plasmid-mediated ARGs accounted for a much higher proportion than that of chromosome-mediated ARGs in both influent and effluent. Moreover, the ARGs co-occurring with diverse mobile genetic elements in the effluent exhibited a comparable mobility potential with the influent. Furthermore, 137 metagenome-assembled genomes (MAGs) assigned to 13 bacterial phyla were identified as the ARG hosts, which could be effectively treated in most WWTPs. Notably, 46 MAGs were found to carry multiple ARG types and the potential pathogens frequently exhibited multi-antibiotic resistance. Some ARG types tended to be carried by certain bacteria, showing a specific host-resistance association pattern. This study highlights the necessity for metagenomic surveillance and will facilitate risk assessment and control of antibiotic resistome in WWTPs located on the vulnerable area.

Pharmaceuticals in freshwater posed ecological risks to aquatic ecosystem, however, most risk assessments of pharmaceuticals were conducted at screening level, which were limited by the availability of the toxicity data. In this study, risks of 80 pharmaceuticals including 35 antibiotics, 13 antiviral drugs, 13 illicit drugs, and 19 antidepressants in surface water of Beijing were assessed with a proposed multilevel environmental risk optimization strategy. Target pharmaceuticals were detected in surface water samples with the detection frequency from 1.7 % to 100 % and the total concentrations from 31.1 ng/L to 2708 ng/L. Antiviral drugs were the dominant pharmaceuticals. Preliminary screening-level risk assessment indicated that 20 pharmaceuticals posed low to high risks with risk quotient from 0.14 (chloroquine diphosphate) to 27.8 (clarithromycin). Thirteen pharmaceuticals were recognized with low to high risks by an optimized risk assessment method. Of them, the refined probabilistic risk assessment of joint probability curves coupling with a quantitative structure activity relationship-interspecies correlation estimation (QSAR-ICE) model was applied. Clarithromycin, erythromycin and ofloxacin were identified to pose low risks with maximum risk products (RP) of 1.23 %, 0.41 % and 0.35 %, respectively, while 10 pharmaceuticals posed de minimis risks. Structural equation modeling disclosed that human land use and climate conditions influenced the risks of pharmaceuticals by indirectly influencing the concentrations of pharmaceuticals. The results indicated that the multilevel strategy coupling with QSAR–ICE model was appropriate and effective for screening priority pollutants, and the strategy can be used to prioritize pharmaceuticals and other emerging contaminants in the aquatic environment.

Nonylphenol (NP) is known as an endocrine disruptor and consequently has drawn much environmental concern. This study focused on seasonal variation and spatial distribution of NP in various matrices including water, suspended particles, and sediment taken from Lanzhou Reach of Yellow River in China. NP was measured in July and November in 2004. Concentrations of NP in water ranged from 34.2 to 599.0 ng/l, in suspended particles from 49.6 to 2835.2 ng/g dry wt, and in sediment from 38.4 to 863.0 ng/g dry wt. In terms of most water and suspended particles samples, concentrations were higher in warmer seasons than in colder seasons. Good linear correlations (R2 = 0.90 in July, R2 = 0.97 in November) were obtained for NP concentrations between water and suspended particles. In terms of sediment samples, concentrations were higher in November than in July, probably due to greater deposition of suspended particles. Reasonable linear correlations (R2 = 0.60 in July, R2 = 0.79 in November) were obtained for NP concentrations between water and sediment.

Emerging pollutants inherent in reclaimed municipal wastewater, including endocrine-disrupting compounds (EDCs) and pharmaceutical and personal care products (PPCPs), often have cast uncertainties on the safety of water reuse. We examined the fate and transport behavior of several PPCP and EDC compounds through observations made at experimental turf fields irrigated with naproxen, clofibric acid, diclofenac sodium, ibuprofen, estrone, 4-tert-octylphenol, bisphenol A, 4-n-nonylphenol, and triclosan latent irrigation water. The potential of the compounds to contaminate underlying groundwater was assessed using three screening protocols that employed the attributes of soils, chemicals, and water fluxes as the estimators. No compound was detected in the leachate draining through the 89-cm profile of a loamy sand soil and a sandy loam soil turf grass field during four months of irrigation according to operations typical of golf courses in southern California (USA). Ibuprofen, naproxen, triclosan, bisphenol A, clofibric acid, and estrone were detected in the surface to 30-cm soil profiles. Higher irrigation rate and coarser textural soil enhanced the downward movement of chemicals in both soils. The pollution risk screenings identified the same six compounds as having the potential to contaminate groundwater, and under conditions of turf grass irrigation, clofibric acid and ibuprofen would be most prone to cause the pollution.

Pollution of polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment has drawn much attention around the world. The occurrence of 16 priority PAHs in the sediments and corresponding porewaters in Lanzhou Reach of Yellow River, China, and their partitioning behavior between the two phases were investigated. The results demonstrated that the total PAH levels in the sediments were positively correlated with the sediment clay contents (R(2)=0.756). Concentrations of total PAHs in porewaters ranged from 48.2 to 206 microg/L, and indeno[1,2,3-cd]pyrene (InP) was the most abundant compound measured in the porewater samples with a mean value of 42.9 microg/L. The compositions of PAHs in porewaters were dominated by their compositions in the sediment samples. The in situ organic carbon normalized partition coefficients logK(oc)(') of the PAHs between sediments and porewaters were significantly correlated with their octanol-water partition coefficients (logK(ow)) when logK(ow) values were less than 5.5 (naphthalene (Nap) excluded). logK(oc)(') values of 14 PAHs were lower than those predicted by the Karickhoff relationship. This discrepancy was largest for InP, dibenzo[a,h]anthracene (DBA), and benzo[ghi]perylene (BgP). The results in present study showed the tendency of PAHs release from sediment to porewater, indicating that PAHs sequestered in the sediments may be a pollution source to aquatic ecosystem.

The occurrence and distribution characteristics of tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) in water and sediments from Taihu Lake, China, were investigated. The analytes were quantified by reversed-phase liquid chromatography coupled to electrospray ionization mass spectrometry. The TBBPA levels in water ranged from below the limit of detection (LOD) to 1.12 ng/L, whereas levels in sediments were between 0.056 ng/g dry weight and 2.15 ng/g dry weight. Regarding HBCD, concentrations were from below the LOD to 0.37 ng/L for water samples and from 0.046 ng/g dry weight to 2.56 ng/g dry weight for sediments. No correlation was found between sediment total organic carbon content and TBBPA/HBCDs, while significant positive correlations (r2 = 0.63, p < 0.005) were observed between TBBPA concentrations and HBCD concentrations in sediments. The highest TBBPA (2.15 ng/g dry wt) and total HBCD concentration (2.56 ng/g dry wt) was found at sampling site 1 (S1), while total HBCD levels fell dramatically with increasing distance from S1, suggesting that the estuary inputs around Taihu Lake were important sources of TBBPA and HBCDs. Compared with the pollution levels in the other regions of the world, the concentrations of TBBPA and HBCDs in Taihu Lake were at a moderate or low level. Further study on the sources of TBBPA and HBCDs is required for both assessment of their potential risks and better pollution management in Taihu Lake.

Abstract BACKGROUND; In this study, simultaneous photocatalytic degradation of four fluoroquinolone (FQ) compounds (i.e. ofloxacin, norfloxacin, ciprofloxacin and enrofloxacin) was investigated in TiO 2 suspensions under simulated solar light irradiation. Effects of experimental variables including pH, TiO 2 dosage, initial substrate concentration and hydrogen peroxide (H 2 O 2 ) on the degradation processes were also investigated. RESULTS: The antibiotics degradation was pH‐influenced. The photocatalytic reaction followed the pseudo‐first‐order model, with reaction rate constants ( k ) 0.026, 0.027, 0.022 and 0.026 min −1 for ofloxacin, norfloxacin, ciprofloxacin and enrofloxacin, respectively. Complete elimination of four FQs was achieved in a reaction system composed of 0.5 g L −1 of TiO 2 and 82.5 mg L −1 of H 2 O 2 at pH 6 after 90 min irradiation. Mineralization of FQs during TiO 2 photocatalysis was slower than the FQs conversion, and the antibacterial activity of the four FQs was completely removed by TiO 2 under simulated solar light irradiation. CONCLUSION: The four FQs can be simultaneously degraded and mineralized with commercially available TiO 2 under simulated solar light irradiation. Microbiological analysis showed that the antibacterial activity of the four FQs was completely removed. These results are helpful for antibiotics removal in the environment, and for exploring new technology for wastewater treatment. Copyright © 2012 Society of Chemical Industry

In this study, a passive sampling technique, diffusive gradients in thin films (DGT) was developed to simultaneously measure two drugs, methcathinone (MC) and ephedrine (EPH) in surface water. Four types of binding gels and four types of filter membranes were tested for the optimal configuration. XAD18 agarose binding gel and agarose diffusive gel, together with polyethersulfone filter membrane were used for measuring MC and EPH in the DGT device. 5% NH3 in acetonitrile was used as the elution solvent, with the elution efficiency for MC and EPH higher than 71%. At 25°C, the diffusion coefficients of MC and EPH in the diffusive gel were 7.60×10-6cm2s-1 and 6.62×10-6cm2s-1, respectively. The DGT was effective in a wide range of pH (4-11) and ionic strength (NaCl: 0.001-0.5M). The DGT device was deployed in Beijing urban surface water for successive 7days to measure the time-weighted concentrations of MC and EPH. Results showed that EPH was detected in all samples, while MC was below its detection limit. DGT concentrations were comparable to the concentrations determined by SPE. This study demonstrated that the developed DGT method was effective to monitor the two drugs in surface water in situ.

Environmental contaminant source apportionment is essential for pollution management and control. This study analysed surface sediment samples for 16 priority polycyclic aromatic hydrocarbons (PAHs). PAH sources were identified by two receptor models, which included positive matrix factorization (PMF) and multilinear engine 2 (ME2). Three PAH sources in the Liaohe River sediments were identified by PMF, including traffic, coke oven and coal combustion. The ME2 model apportioned one additional source. The two models yielded excellent correlation coefficients between the measured and predicted PAH concentrations. Traffic emission was the primary PAH source associated with the Liaohe River sediments, with estimated PMF contributions of 58% in May and 63% in September. Coke oven (19%-25%) and coal combustion (13%-18%) were the other two major PAH sources. For ME2, gasoline and diesel were separated: accounted for 14% in May and 16% in September; and 53% in May and 48% in September. This study marks the first application of the ME2 model to study sediment contaminant source apportionment. The methodology can potentially be applied to other aquatic environment contaminants.

Abstract Background As a class of contaminants of emerging concern (CECs), illicit drugs should be taken into account in the water management because of their social and public health risks. Wastewater treatment plants (WWTPs) are usually considered as the source and sink of contaminants, and drug residues are observed in their effluents due to the inefficient removal of CECs. In this study, wastewater samples were collected from eight WWTPs in Changzhou City for assessment of the abuse of 12 illicit drugs in the city by wastewater-based epidemiology (WBE) method. Results Drug concentrations ranged from &lt; LOD-51.62 ng/L to &lt; LOD-22.44 ng/L in influent and effluent samples, respectively. The highest removal rate of drugs was 79.0% in the WWTP which used sequencing batch reactor activated sludge (SBR) process method, while the lowest was found in the WWTP using anoxic oxic (A/O) process (47.0%), indicating that the drug removal rates were closely related to the treatment techniques. WBE method was applied to estimate the population normalized illicit drugs consumption. It demonstrated that methamphetamine (METH) was the most abused drug in Changzhou City, ranging from 0.16 to 20.65 mg/d/1000 inh, while other target drugs ranged from &lt; LOD-1.52 mg/d/1000 inh. Consumption of cocaine (COC) and ecstasy was very low among the samples. Conclusion Overall, this research suggests that drug removal rates varied in different WWTPs and the SBR process is the best for removing illicit drugs. All target drugs were incompletely removed in wastewater treatment plants. WBE can be readily used to monitor the abuse of drugs in those regions, compared with traditional monitoring models.

Abstract Background The prevalence of antibiotic resistance genes (ARGs) in animal manure poses a threat to environmental safety. Organic fertilizers fermented by livestock and poultry manure are directly applied to farmland and have the potential to cause outbreaks of bacterial resistance in agricultural environments. This study investigated the composition of ARGs in different animal manures and their derived organic fertilizers. Results The results showed that the abundance of several ARGs, such as sul 2, Tet B-01, Tet G-01 and Tet M-01, in organic fertilizer samples was 12–96% lower than that in animal manure. However, the abundance of Tet K and erm C was higher in animal manure than in organic fertilizers. No correlation between ARGs and environmental factors such as pH, TN, and antibiotics was observed by redundancy analysis (RDA). Procrustes analysis revealed a significant correlation between bacterial community structures and ARG abundance ( r = 0.799, p &lt; 0.01). Nonmetric multidimensional scaling (NMDS) analysis suggested that microorganisms in organic fertilizer may be derived from animal manure. Additionally, the abundance of pathogenic bacteria (especially Actinomadura ) would increase rather than decrease in manure compared to organic fertilizer. Conclusion The diversity and abundance of most ARGs significantly decreased from animal manure to organic fertilizer. Microorganisms in the prepared organic fertilizer may mainly be inherited from the animal manure. The results also showed that the pathogens in the prepared organic fertilizer would significantly reduce, but would still cause partial pathogen proliferation.

Drugs of abuse are a group of emerging contaminants . As the prevalence of manufacture and consumption, there is a growing global environmental burden and ecological risk from the continuous release of these contaminants into environment. The widespread occurrence of drugs of abuse in waste wasters and surface waters is due to the incomplete removal through traditional wastewater treatment plants in different regions around the world. Although their environmental concentrations are not very high, they can potentially influence the aquatic organisms and ecosystem function. This paper reviews the occurrence of drugs of abuse and their metabolites in waste waters and surface waters, their bioaccumulation in aquatic plants, fishes and benthic organisms and even top predators, and the toxicological effects such as genotoxic effect, cytotoxic effect and even behavioral effect on aquatic organisms. In summary, drugs of abuse occur widely in aquatic environment , and may exert adverse impact on aquatic organisms at molecular, cellular or individual level, and even on aquatic ecosystem . It necessitates the monitoring and risk assessment of these compounds on diverse aquatic organisms in the further study. • Drugs of abuse are widespread in aquatic environment due to low removal efficiencies. • Drugs of abuse may cause toxic effects at molecular, cellular or individual level. • Drugs of abuse may bioaccumulate in aquatic organisms via aquatic food chain. • Research focusing on fate and combined effects of drugs of abuse is warranted

The urbanization of Tibetan Plateau (TP) probably results in a significant contamination of organic pollutants in the area, such as phthalate esters (PAEs). However, there is a lack of monitoring and evaluation of their occurrence and risks in the outdoor dust on TP. This study for the first time investigated the concentrations, distributions and health risk of PAEs in outdoor dust samples on TP, China. A total of 132 outdoor dust samples were collected from five different functional areas, and results showed the ubiquitous detection of all PAEs in the samples. The Σ6PAEs concentrations ranged from 0.08 to 31.49 μg·g-1 with a mean of 3.57 μg·g-1. High concentrations of Σ6PAEs in the outdoor dust were found in commercial districts, which were attributed to the heavy use of PAEs in the public commerce such as consumer products, commodities, and building materials. Di-n-butyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were the dominant components accounting for 30.65% and 53.19% of the Σ6PAEs. Principal component analysis, positive matrix factorization, and correlation analysis were used to apportion the potential sources of PAEs in outdoor dust samples. The PAEs in the outdoor dust originated mainly from wide application of plasticizers as well as cosmetics and personal care products. The main pathways of human exposure to PAEs in the outdoor dust were ingestion and dermal absorption of dust particles. The total intakes of PAEs from outdoor dusts for children and adults were 1.50 × 10-5 and 2.47 × 10-6 mg·kg-1·d-1, respectively. Children were more susceptible to the PAEs intake than the adults. Although the estimated health risks of the six PAEs are currently acceptable, caution is needed given the likely future increase in use of these PAEs and the currently unknown contribution to human exposure by other medium.

Freshwater biodiversity and ecosystem services may decline because of toxicant input, and other environmental variables often co-occur with contaminants to jeopardize the freshwater ecosystem. In this study, Danjiangkou Reservoir (DJKR) in central China was selected as the target research area to investigate the impact of multiple categories of micropollutants coupled with other stressors on the reservoir ecosystem. A total of 140 samples were collected from 28 sites in DJKR, and 124 micropollutants, including pesticides, organophosphate esters (OPEs), psychoactive substances, antiviral drugs, and pharmaceutical and personal care products, were quantified. A total of 108 micropollutants were detected in the water samples, with sum concentrations ranging from 82.35 ng·L-1 to 1436.57 ng·L-1, and 71 of them had a detection frequency above 50 %, indicating the prevailing micropollutant contamination in the reservoir. The most severe pollution and risks were observed in the tributaries of DJKR. Pesticides (neonicotinoid and triazine) and OPEs were the major contributors to the ecological risk in the reservoir. Insecticides, herbicides, and OPEs accounted for the majority of the risks to fish, algae, and invertebrates, respectively. The determined priority pollutants should be paid increased attention. Environmental variables and human activities, such as human land use, induced the potential aquatic threats of micropollutants in DJKR. Results demonstrated that micropollutant pollution was one of the dominant pressures faced by aquatic organisms and human beings, and human activities played important roles as well.

Industry wastewater is considered one of the worst polluters of our precious water ecologies. However, the types of pollutants present in wastewater from industrial wastewater treatment plants (IWTPs) are still unclear. In this study, a simple and effective chemical fingerprinting method for checking the source-sink relationships among different industrial wastewaters and their effluent-receiving river was established. 107, 228, 155, and 337 chemicals were screened out in wastewater from electronics, steel, textile, and printing and dyeing plants, respectively. Chemical fingerprinting of the detected chemicals was performed, and results showed that aromatic compounds were the most prevalent among the pollutant categories (i.e., 56, 189, and 168 in electronics, iron and steel, and printing and dyeing plants, respectively). The traceability analysis of the chemicals selected in the effluent determined the characteristic pollutants of different industrial enterprises. Sixty-eight compounds were identified as the characteristic pollutants in the different process stages of wastewater of the four IWTPs. Of the 84 effluent-receiving river water signature pollutants, 47.6% (n = 40) were also detected in the effluent from the four IWTPs. Effective screening of organic pollutants in industrial wastewater and determining their sources will help accelerate the improvement of industrial wastewater treatment technology.

Mounting evidence indicated the associations between air pollution and outpatient visits for allergic rhinitis (AR), while few studies assessed the effect modification of these associations by ambient temperature and relative humidity (RH). In this study, dataset of AR outpatients was obtained from Chinese People's Liberation Army Strategic Support Force Characteristic Medical Center in Beijing during 2014 to 2019, and the average concentrations of air pollutants including particulate matter ≤2.5 μm in diameter (PM2.5) and ≤10 μm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and meteorological factors (temperature and RH) at the same period were collected from one nearby air monitoring station. We performed a time-series study with Poisson regression model to examine the effects of air pollutants on AR outpatients after adjustment for potential confounders. And the effects modification analysis was further conducted by stratifying temperature and RH by tertiles into three groups of low, middle and high. In total of 33,599 outpatient visits for AR were recorded during the study period. Results found that a 10 μg/m3 increase in PM2.5, PM10, NO2 and SO2 was associated with significant increases in AR outpatients of 1.24% (95% confidence interval (CI): 0.69%, 1.78%), 0.79% (95% CI: 0.43%, 1.15%), 3.05% (95% CI: 1.72%, 4.40%) and 5.01% (95% CI: 1.18%, 8.96%), respectively. Stronger associations were observed in males than those in females, as well as in young adults (18-44 years) than those in other age groups. Air pollution effects on AR outpatients increased markedly at low temperature (<33.3th percentile) and high RH (>66.7th percentile). Findings in this study indicate that air pollution is associated with increased risk of AR outpatients, and the effects of air pollution on AR could be enhanced at low temperature and high RH.

Wastewater-based epidemiology (WBE) is considered a cost-effective alternative approach capable of determining the consumption and prevalence of drug use in communities, however, the application of WBE for estimating the prevalence of depression has seldom been reported. In this study, the prevalence of antidepressants was estimated in five cities in Qinghai Province, west China to examine the feasibility of using WBE to estimate the depression prevalence. Residual concentrations of the drugs varied from different wastewater treatment plants (WWTPs) in five cities. Venlafaxine (0.06-720 ng/L), O-desmethylvenlafaxine (1.31-1659 ng/L), paroxetine (<LOD-69.9 ng/L), sertraline (0.20-3.36 ng/L), and nortriptyline (<LOD-50.8 ng/L) were in the top concentrations quartile in the influent samples of 17 WWTPs. Back-calculation estimated venlafaxine (538 mg/1000 inh/d) as the most consumed antidepressant in Qinghai Province, followed by paroxetine (159 mg/1000 inh/d), sertraline (150 mg/1000 inh/d) and amitriptyline (97.2 mg/1000 inh/d). The prevalence of depression was 17.8 % based on antidepressant usage (2.50 %), which was consistent with the data conducted by traditional survey (16.7 %). Risk assessment showed that fluoxetine, citalopram and venlafaxine in effluents might cause ecological risks to aquatic environment. This study provided a promising way for monitoring antidepressant usage and depression prevalence through WBE, which would improve the understanding of depression disease and provide guidance for public health care.

Lack of knowledge on the destiny of organic micropollutants (OMPs) in the Tibetan Plateau region of China prevents the public from being aware of the need for protecting these unique aquatic ecosystems that are precious water resources and source areas of the Yellow River. To address this knowledge gap, this study systematically investigated the multi-residue analysis, distribution, and potential risks of six types of OMPs, namely, neonicotinoid pesticides (NEOs), fungicides, organophosphate esters (OPEs), organophosphorus pesticides (OPPs), psychoactive substances (PSs), and antidepressants (ADs), in surface waters of major cities in Qinghai. A total of 31 compounds, consisting of 8 NEOs, 1 fungicide, 12 OPEs, 2 OPPs, 5 PSs, and 3 ADs, were detected in >50% of the sites, showing their ubiquitous nature in the study area. Results showed that the total OMP concentration in surface water was 28.3–908 ng/L, and OPEs were the dominant composition (48.6%–97.4%). The risk quotient values of the detected diazinon and dursban regularly exceeded 1 for aquatic organisms at all sampling sites, indicating moderate–high chronic ecological risk. The joint probability curves showed that dursban and NEOs have higher risk levels than other OMPs. Although the results of the non-carcinogenic total hazard quotient of the OMPs in the surface water was less than 1 in all age groups and the carcinogenic risk was lower than the negligible risk level, the potential risks to children and infants were considerably greater and should not be underestimated. In addition to pollutant concentration and exposure duration, ingestion rate and body weight (BW) are also important factors affecting health risk, with BW having a negative effect. To the best of the authors’ knowledge, this report is the first to describe OMP pollution in Qinghai, and the results provide new insight into the ecological security of the water resources of the Tibetan Plateau.

Contaminants of emerging concerns (CECs) include numerous chemicals that may pose known and unknown risks to the ecosystem, and identification and risk ranking of these compounds is essential for the environmental management. In this study, liquid and gas chromatography time-of-flight mass spectrometry (LC-QTOF-MS and GC-QTOF-MS) were used to characterize the occurrence of CECs in the surface water of the Yellow River Estuary (YRE). A total of 295 and 315 chemicals were identified by LC-QTOF-MS and GC-QTOF-MS, respectively. The occurrence of two compounds, erucamide and 2-phenylquinoline, was for the first time reported in the aquatic environment in YRE. The concentrations of 121 CECs, including 35 antibiotics, 49 pesticides and veterinary, 16 polycyclic aromatic hydrocarbons and 21 phthalic acid esters were further quantified by target analysis, which showed the detection of 99 compounds in the surface water in the range of 7.07-4611.26 ng/L. Ecological risks of pollutants based on the risk quotient (RQ) method revealed that 13 pollutants posed ecological risks to the aquatic ecosystem (RQ > 1), and pesticides (n = 12) were the main risk contributors. Here, all CECs data sets were finally transformed and ranked in the framework of the toxicological priority index (ToxPi), and a total of 81 priority control pollutants were identified in the surface water of YRE. This study highlighted the necessity of suspect and nontarget screening for CECs in estuaries, and revealed the importance of localized contamination sources in urban and agricultural environment.

The function of heterogeneous catalyst in singlet oxygen (1O2) generation under acidic and neutral conditions and the effect of sulfate radical on the generation of 1O2 is still unclear. This study provided a novel generation pathway of 1O2 in the heterogeneous Mn single − atom catalyst (Mn SAC)/peroxymonosulfate (PMS) system. The MnN4 site with the ideal binding strength promoted the activation of PMS to generate sulfate radical (SO4•–), which would be adsorbed on the carbon/nitrogen sites forming SO4•–(s), reacting spontaneously to produce 1O2. The presence of MnN4 and carbon/nitrogen structure sites could shift the oxidation process from a bulk–phase oxidation to a surface oxidation. This shift has important implications in terms of reaction rate and product distribution, as the dual reaction sites decrease the required migration distance for the active species to form 1O2, avoiding the pointless consumption of active substances.

Peroxymonosulfate (PMS) based advanced oxidation processes have shown great potential to remove refractory organic pollutants. Developing catalysts that can effectively activate PMS and rapidly degrade pollutant in complex water environment remains a challenge. This study focused on the development of heterogeneous catalyst with high activity comparable to its homogeneous counterpart. The cobalt nanocrystals and single cobalt atom was anchored on porous N–doped graphene fabricating Co–NC and Co SAC, respectively. The PMS activation performance by Co2+, Co–NC, and Co SAC was evaluated by nitenpyram (NPR) degradation. Co SAC/PMS was determined as the radical and nonradical hybrid system, exhibiting great interference capability (100 % degradation of nitenpyram within 15 min in tap water, groundwater, river water, and seawater), high stability (maintaining ∼100 % NPR removal efficiency over a 10–hour operation period), and broad pH suitability (effective from pH 3.0 to 11.0). The identification of catalytic site and the oxidation mechanism of NPR were further elucidated through theoretical calculation, revealing the synergistic oxidation of 1O2, •OH, and SO4•− for NPR degradation. The content of Co2+ in the used Co SAC increased while the content of Co3+ decreased, implying that the role of HSO5− acted as electron donors to transfer electrons to Co site, forming 1O2. Results in this study provided practical application of PMS activation based on single–atom catalyst, which outperforms its homogeneous counterpart.

Ketoprofen, a nonsteroidal anti‐inflammatory drug (NSAID), was commonly found in treated wastewater due to its incomplete removal during sewage treatment plant processes. As treated wastewater is increasingly used for landscape irrigation, it is imperative to understand the leaching potential for ketoprofen in receiving soils. In this study, adsorption and degradation experiments were conducted in four U.S. soils with different physicochemical characteristics. Ketoprofen was not strongly adsorbed to the four soils with K d values ranging from 1.26 to 8.24 L kg −1 , suggesting its potential to move downward with percolating water. The adsorption was positively related to the soil organic matter (OM) content ( R 2 = 0.890). Degradation experiment showed that half‐lives (t 1/2 ) of ketoprofen were 4.58 d in Arlington sandy loam (ASL, coarse‐loamy, mixed, active, thermic Haplic Durixeralfs), 8.04 d in Hanford loamy sand (HLS, coarse‐loamy, mixed, superactive, nonacid, thermic Typic Xerorthents), 15.37 d in Imperial silty clay (ISC, fine, semectitc, calcareous, hyperthermic Vertic Torrifluvents), and 27.61 d in Palouse silt loam (PSL) soil (fine‐silty, mixed, superactive, mesic Pachic Ultic Haploxerolls), respectively. Degradation of ketoprofen in soils appeared to be influenced by the soil OM content. The prolonged t 1/2 by sterilization indicated that microbial degradation was the dominant pathway for ketoprofen degradation in soils, while photodegradation only contributed a small portion to the ketoprofen degradation. The t 1/2 and K oc values were fitted to screening models to predict the leaching potential of ketoprofen in soils. It appeared that relatively high leaching potential of ketoprofen existed in ISC and PSL soils.

Abstract An unprecedented olefination reaction of secondary amines with carbon nucleophiles has been developed through C–N/C–H functionalization under metal‐free oxidative conditions. In the presence of a stoichiometric amount of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ), a range of secondary N ‐alkylanilines smoothly underwent oxidative olefination with 2‐alkylazaarenes, acetophenone, and malononitrile to give structurally diverse polysubstituted alkenes in moderate to excellent yields with excellent ( E ) selectivity. Preliminary mechanistic studies revealed that the oxidative olefination reaction proceeds through amine oxidation followed by imine olefination.

A novel approach for the synthesis of Ag-loaded Fe3O4@C nanospheres (Ag-Fe3O4@C) was successfully developed. The catalysts possessed a carbon-coated magnetic core and grew active silver nanoparticles on the outer shell using hydrazine monohydrate as the AgNO3 reductant in ethanol. The morphology, inner structure, and magnetic properties of the as-prepared composites were studied with transmission electron microscopy (TEM), X-ray powder diffraction (XRD), fourier translation infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. Catalytic activity was investigated by degrading rhodamine B (RhB) in the designed experiment. The obtained products were monodispersed and bifunctional with high magnetization, as well as exhibited excellent catalytic activity toward organic dye with 98% of RhB conversion within 20 min in the presence of NaBH4. The product also exhibited convenient magnetic separability and maintained high catalytic activity after six cycle runs.

The formal insertion of double and triple bonds into the C–Cl bond of carbon tetrachloride has enabled the full utilization of carbon tetrachloride in chemical synthesis. A range of unactivated imines and electron-deficient nitrogen heteroarenes served as effective sources of C=N bonds to react with arynes and carbon tetrachloride to afford functionalized anilines whose core structures are present in some valuable arthropodicides. Control experiments and DFT calculations suggest the involvement of a trichloromethyl anion intermediate.

With 2-(trimethylsilyl)aryl triflates as aryne precursors, the title reaction proceeds smoothly to afford functionalized tertiary amines under transition metal-free conditions.

A novel photocatalytic material that is phosphorus-doped and graphite-like (carbon nitride (g-C3N4)) was successfully prepared through direct thermal co-poly-condensation using ammonium dihydrogen orthophosphate as the phosphorus source and melamine as the g-C3N4 precursor. The catalyst was characterized by analyses from multiple tools: X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, BET surface area, ultraviolet–visible diffuse reflection spectroscopy, and X-ray photoelectron spectroscopy. The unique bubble-like structure provided the phosphorus-doped g-C3N4 (P-C3N4) with a unique property for spatial electron transfer and a large specific surface area (40.89 m2g-1). The photocatalytic performance of P-C3N4 was determined by assessing rhodamine B (RhB) degradation under visible-light irradiation. The results showed that P-C3N4 exhibited superior photocatalytic performance that is 18 and 4 times higher than pristine bulk g-C3N4 (B-C3N4) and modified multi-aperture g-C3N4 (M-C3N4), respectively. The enhancement of photocatalytic activity was attributed to the improved light harvesting capacity and the narrowing energy band structure of the copolymer that result from the substitution of phosphorus atoms by carbon atoms in the g-C3N4 framework. The photoelectron emission measurements confirmed that P-C3N4 promoted the separation efficiency of the charge carriers. The bubble-like structured P-C3N4 also possessed superior durability and stability. The radical quenching tests indicated that superoxide radicals (O2−) and holes (h+) were the dominant active species for RhB degradation.

As one of the most abused illicit drugs, ketamine (KET) has been widely detected in different water environments around the globe, which necessitates the development of effective approaches for KET removal from water. In the present study, several novel Ag3PO4/P-g-C3N4 heterojunction composites were successfully constructed using an in situ growth method, and the samples were characterized by a series of instruments. The synthesized samples were deployed for KET degradation. Results showed that Ag3PO4/P-g-C3N4 (1:1) exhibited the most excellent photocatalytic degradation performance on KET with a pseudo-first-order rate constant of 0.0326 min–1 at a neutral pH value, which was 3- and 6-fold faster than those of Ag3PO4 and P-g-C3N4, respectively. The elevated photocatalytic performance of Ag3PO4/P-g-C3N4 was attributed to the synergistic effects of the high charge separation capacity and Z-scheme heterojunction structure. Low concentrations of dissolved organic matter, nitrate, or bicarbonate accelerated KET degradation by Ag3PO4/P-g-C3N4, but high levels of these constituents would inhibit KET degradation. The scavenging experiments revealed that photogenerated superoxide radicals and holes were the main reactive species in the KET removal. A total of 12 degradation intermediates of KET over Ag3PO4/P-g-C3N4 were identified, and a possible degradation pathway was proposed. Demethylation, dehydrogenation, hydroxylation, deamination, ring opening, and sodium modification were the major pathways for KET degradation. Ag3PO4/P-g-C3N4 also exhibited a relatively good photocatalytic performance on KET degradation in surface water and a secondary effluent.

An enantioselective method for quantifying amphetamine-type chiral illicit drugs (CIDs) in wastewater and surface water was developed, validated, and applied to samples from a wastewater treatment plant (WWTP) and its effluent-receiving river in Beijing, China. Water samples were subjected to solid-phase extraction (SPE) and then quantified via liquid chromatography-tandem mass spectrometry. The enantioseparation of CIDs was performed with a CHIRALPAK CBH column. Chromatographic parameters, including mobile phase composition and flow rates, were tested to identify the satisfactory enantiomeric resolution. The SPE method was optimized by evaluating variables, including SPE cartridge types, extraction solvents, and solvent volumes. The Oasis HLB sorbent showed good performance with recoveries exceeding 60% and matrix effects ranging from -19.6% to 26.6% for most target enantiomers, except for norephedrine (NE), in three different aquatic matrixes. The established method was superior to previously reported methods and had a low limit of detection, low limit of quantification, and short runtime (<45 min). The repeatability and reproducibility of the method reached 19.1% and 17.8%, respectively. The method was successfully utilized to monitor the daily variations in CIDs in the influent, effluent, and effluent-receiving river of a WWTP in Beijing over 1 week. The common occurrence of 1 R,2 S-(-)-ephedrine (1 R,2 S-(-)-EPH), 1 S,2 S-(+)-pseudoephedrine (1 S,2 S-(+)-PEPH), R-(-)-methamphetamine (METH), and S-(+)-METH in wastewater samples was observed. Ephedrines (1 R,2 S-(-)-EPH and 1 S,2 S-(+)-PEPH) were the most abundant CIDs in the influent, effluent, upstream, and downstream samples with concentrations of 725.8 ± 181.2 ng/L, 22.9 ± 4.9 ng/L, 12.96 ± 0.79 ng/L, and 11.6 ± 6.7 ng/L, respectively. METH was detectable in most water samples and was present in excess in S-enantiomer form in the influent and in R-enantiomer form in the effluent and surface water. R-(-)-MDMA was detected at a concentration of up to 2.4 ng/L in the influent. The metabolites norketamine (NK), amphetamine(AMP), MDA, and NE were not detected in water samples given the low concentration of their parent drugs.

The increasing prevalence of antibiotic resistance genes (ARGs) in the soil environment poses a serious threat to crop safety and even public health. In this study, the fate of ARGs in the soil was investigated during the growth period of pakchoi and after harvesting with the application of different kinds of fertilizers. The result showed that increasing rate of soil ARGs during the growth period of pakchoi followed the order of composted manure > commercial fertilizer > mineral fertilizer. After harvesting, soil ARGs abundance treated with mineral fertilizer, commercial fertilizer or composted manure significantly increased by 0.63, 3.19 and 8.65 times (p < 0.05), respectively, compared with the non-fertilized soil. The ARGs abundance in the pakchoi treated with composted manure was significantly higher than that of treatments with mineral fertilizer and commercial organic fertilizer. These findings indicated the application of composted pig manure would significantly increase the pollution load of ARGs in farmland soil and plant, and also promote the proliferation of farmland ARGs. Principal component analysis suggested that bacterial communities might have a significant influence on ARGs changes during the growth period of pakchoi. Network analysis further indicated ARGs changes may be mainly related to their host bacteria (including Gammaproteobacteria, Flavobacteriia and Bacilli). The results provided a proper method and useful information on reducing transmission risk of ARGs and control the propagation of ARGs in agricultural activities.

The heterogeneous activation of persulfate-based advanced oxidation processes (persulfate AOPs) has been defined as potential wastewater treatment methods due to their excellent chemical reactivity. However, the reaction mechanisms of these processes are extremely intricate because of the simultaneous participation of many substances from the solid, liquid, and even gas phases. The development of novel active catalysts is hindered due to divergent mechanisms and deficient research techniques. In this review, the up-to-date development of heterogeneous catalyst category, catalytic characteristics, and reaction mechanism are comprehensively discussed. Essentially, the detection of persulfate, the identification of reactive oxygen species, and the evolution and analysis of organic oxidation pathways are reviewed, highlighting the innovation integration experimental/theoretical protocol to reveal the reaction mechanism in a future study. Finally, the limitations and possible breakthrough directions of persulfate AOPs were discussed, including the further study of the internal reaction mechanism in persulfate AOPs, the requirement of reasonable evaluation of the treatment effect, and the feasibility of full-scale application.

Abstract Background As a triazole fungicide, triadimefon is widely used around the world. The ubiquitous occurrence of triadimefon in aquatic environments and potential adverse effects on aquatic organisms have resulted in global concerns. In this review, the current state of knowledge on occurrence, environmental behavior, and toxic effects are presented and used to conduct an assessment of risks posed by current concentrations of triadimefon in aquatic environments. Results The key findings from this review are that: (1) triadimefon occurred widely in surface waters, with high rates of detection; (2) abiotic degradation of triadimefon was affected by many factors. Stereoselectivity was found during biotic degradation and metabolism of triadimefon. Different enantiomers can cause various adverse effects, which complicates the assessment and requires enantiomers-specific considerations; (3) triadimefon exposure can affect organisms by causing multiple toxic effects on the thyroid, reproductive system, liver, nervous system as well as carcinogenicity and teratogenicity, and it can also act synergistically with other pesticides. Long-term, low-dose effects were considered to be the main characteristics of toxic effects of triadimefon; (4) results of the risk assessment based on probabilistic relationships represented by joint probability curves (JPCs) indicated that risk of triadimefon was classified as low risk. Conclusion Triadimefon occurred widely in surface waters, with high rates of detection, while the concentration data of triadimefon in surface water is insufficient. Researches about toxic effects and mechanisms of triadimefon on invertebrate are needed. Meanwhile, researches about toxic effects and environmental exposure of chiral monomers are also required. Due to its reproductive toxicity, triadimefon might result in adverse effects on the population level or even on the ecosystem level. Risk assessments for pesticides that cause long-term and low-dose effects on aquatic organisms such as triadimefon need to consider higher-level ecological risk.

Experiments were conducted to investigate the degradation of aldicarb, an oxime carbamate insecticide, in sterile, non-sterile and plant-grown soils, and the capability of different plant species to accumulate the pesticide. The degradation of aldicarb in soil followed first-order kinetics. Half lives (t1/2) of aldicarb in sterile and non-sterile soil were 12.0 and 2.7 days, respectively, which indicated that microorganisms played an important part in the degradation of aldicarb in soil. Aldicarb disappeared more quickly (p< or =0.05) in the soil with the presence of plants, and t1/2 of the pesticide were 1.6, 1.4 and 1.7 days in the soil grown with corn, mung bean and cowpea, respectively. Comparison of plant-promoted degradation and plant uptake showed that the enhanced removal of aldicarb in plant-grown soil was mainly due to plant-promoted degradation in the rhizosphere.

In recent years, nitrogen pollution has been increasingly serious in natural waters including drinking source water. A simulated river biofilm reactor fed with contaminated drinking source water was established to evaluate the effects of dissolved oxygen (DO) partitioning and step feeding on the nitrogen removal performance and biofilm microbial community. Results showed that after the hydraulic retention time of anoxic zone extending and step feeding, the effluent concentration of ammonia was below 0.2 mg L−1, and the removal efficiency of total nitrogen increased from 12.02% ± 4.59% to 34.98% ± 2.65%, which indicated the occurrence of simultaneous nitrification and denitrification. The results of denaturing gradient gel electrophoresis showed that the microbial community of biofilm obviously shifted via DO controlling and step feeding. Low DO concentration favored the enrichment of denitrifying bacteria and coexistence of algae and bacteria, and the pattern of step feeding could increase the community abundance. The dominant heterotrophic bacteria species of biofilm in oligotrophic niche belonged to Hyphomicrobium sp., Pseudomonas sp., Chloroflexi sp., Enterobacter sp., Pantoea sp., and Synechococcus sp., which were mostly associated with denitrification and refractory organics utilization. It was worth noting that the ammonia-oxidizing bacteria (AOB) community of biofilm was stable throughout the whole experiment, and Nitrosomonas sp. was the predominant AOB in the oligotrophic niche.

An emerging pollutant, diatrizoate (DTZ) has been frequently detected in aqueous solution. Unique reticular peanut shell biochar (BC)-supported nano zero-valent iron (nZVI) composite (nZVI/BC) was successfully synthesized and used as a catalyst for activating persulfate (PS) to promote the removal of DTZ. The structure and morphology of the nanocomposite materials were characterized by scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller measurements, and Fourier transform infrared spectroscopy. The degradation of DTZ (20 mg L-1) was achieved by activating PS with the nanocomposite material. The removal of DTZ reached nearly 100% using 25 mM PS and 0.45 g L-1 nZVI/2BC (mass ratio of nZVI and BC at 1:2) nanocomposite material at pH 3.0 and 25 °C. Influencing factors, such as dosages of nZVI/2BC and PS, temperature, and pH were also investigated. The mechanisms of PS activation with nZVI/2BC were discussed, including BC property, electron transfer, and the identification of free radicals in the reaction. The findings demonstrated that nZVI/BC-PS (peanut shell BC-supported nZVI activating PS) is a promising material for the treatment of refractory organic pollutants.

Tetracyclines and sulfonamides are the two classes of antibiotics commonly used in the medical, industrial and agricultural activities. Their extensive usage has caused the proliferation and propagation of resistant bacteria (ARB) and resistance genes (ARGs) in the environment. In this study, the occurrence and distribution of tetracyclines (TC, OTC and CTC) and sulfonamides (SMX, SCX and TMP), their associated ARB and ARGs were quantified in water and sediments collected from the mainstream of Liaohe River, northeast China. The average concentration of tetracyclines was higher in May, while the concentration of sulfonamides was slightly higher in October. The highest concentrations of the total tetracyclines and sulfonamides in sediments were 2.7×103 ng/g and 2.1×102 ng/g respectively detected in May. All detected ARGs were found generally with high abundance. The tetA, tetB and tetE genes were dominant (4.4×10-2 to 9.8×10-1 copies of tet genes/copies of 16S rRNA genes) in total communities, and the average abundance of sul genes was expressed above 10-1 in the water samples in May and October. Redundance analysis (RDA) and principle component analysis (PCA) indicated that the antibiotic residue was the most important contributor to the level of tetracycline and sulfonamide resistance genes, and some hydrogeological conditions (e.g. flow rate, intersection settlement) influenced the distribution of resistance genes. Results from this study could help understand the proliferation and propagation of antibiotic resistance on a river catchment scale and mitigate the potential risks to public health.

In this study, removal of methamphetamine (METH) was investigated by UV activated persulfate (PS), and the influence of key factors was evaluated. Results suggested that METH degradation followed pseudo-first order reaction kinetics. The combination of UV and persulfate (UV/PS) could completely degrade 100 μg/L of METH in 30 min with a PS dosage of 200 μM at pH 7. Both hydroxyl radical (OH) and sulfate radical (SO4−) were confirmed to contribute to the degradation of METH. The bimolecular reaction rate constants of METH with OH and SO4− were 7.91 × 109 and 3.29 × 109 M−1 s−1, respectively. The degradation rate constant of METH was proportional to the PS dosage (0–800 μM) and was high at neutral pH condition. The presence of inorganic anions significantly reduced METH degradation to different degrees, with the inhibitory effect order of Cl− > NO3− > HCO3−. The degradation efficiency of METH was suppressed by the presence of humic acid due to the effect of UV absorption and free radical quenching. The degradation intermediates and products were identified by UPLC-MS/MS and possible transformation pathways were proposed. Results suggested that the combination of UV/PS is a promising treatment technique for the removal of METH in the water environment.

Pharmaceuticals and personal care products (PPCPs) in reclaimed water can enter into soil, groundwater, and air during the irrigation of urban green spaces, leading to potential risks due to their negative effects of feminization, on root elongation, and as carcinogens. In this study, a validated HYDRUS-1D model by field experiments and an exposure model were used to simulate the distributions of 67 PPCPs detected in the effluent from municipal wastewater treatment plants of Beijing under two scenarios (1, uniform irrigation concentrations; 2, detected irrigation concentrations) in soil, groundwater, and air. To determine the priority ranks of the 67 PPCPs, the effect values of the PPCPs in soil, groundwater, and air were calculated on the basis of distributions and toxicity data, and then weighted and scored. Under scenario 1, roxithromycin, medroxyprogesterone acetate, and megestrol acetate, characterized by high adsorption and low volatilization and degradation, had the highest accumulations in soil, and ofloxacin, characterized by the lowest degradation and adsorption, had the highest leaching to groundwater. The highest volatilization was observed for galaxolide abbalide, tonalid, and dioctyl phthalate. Under scenario 2, based on their overall scores and priority ranks, the 67 PPCPs were divided into three groups: I, high priority; II, moderate priority; III, low priority. Of the 67 PPCPs, 17 were classified in group I, with the highest priority rankings for ofloxacin, 17α-ethynylestradiol, dibutyl phthalate, dioctyl phthalate, and sulfamethoxazole. In group III (total 33 PPCPs), 28 of the PPCPs were not of urgent concern under reclaimed water irrigation in Beijing.

The abuse of illicit drugs has led to their extensive detection worldwide and subsequently exerted adverse effects upon aquatic organisms and ecosystem. However, less attention has been paid to the uptake, biotransformation, internal distribution, and toxicokinetic processes in the exposed organisms. In this study, zebrafish (Danio rerio) was exposed to methamphetamine (METH) and ketamine (KET) at three different concentrations in a semi-static exposure system. METH and KET, together with their metabolites, amphetamine (AMP) and norketamine (NK), were consistently detected in zebrafish. Over 14-day exposure, the relative magnitude of mean concentrations of illicit drugs in zebrafish generally followed the order of brain > liver > intestine > ovary > muscle. The uptake rate constants (Ku) of METH and KET were in the range of 0.590–1.38 × 103 L/(kg·d), the elimination rate constants (Ke) were in the range of 0.18–6.98 1/d, and the half-lives were in the range of 0.18–6.98 d, respectively. METH and KET demonstrated relatively rapid uptake and elimination kinetics and short half-lives, and concentrations in organs were driven by external concentrations. Illicit drugs were not persistent within zebrafish organs when there were no substantial external contaminant sources. The observed values of bioconcentration factor (BCFo, L/kg) and kinetically-derived bioconcentration factor (BCFk, L/kg) were at the similar level. The ability of different zebrafish organs accumulating target chemicals from the aquatic environment was different, and brain was the target organ of the test illicit drugs.

Photoconversion of CO2 into fuel is critical for realizing a net-zero emission future, but it remains an open challenge due to the unsatisfactory light absorption and photogenerated carriers’ separation efficiency of catalysts. In this work, upon in situ thermal polymerization method, the nanodiamond (ND) are homogeneously and solidly modified on the defective graphitic carbon nitride (g-C3N4) surface. Under visible light irradiation, the ND/g-C3N4(NH) exhibits excellent CO2 photocatalytic performance with a CO yield of 10.98 μmol/h (18.6 times higher than bulk g-C3N4), predominant performance in the selectivity of CO and cyclic stability. The improved CO2 photoreduction ability was sourced from the synergetic effect of nitrogen vacancies engineering and ND decoration, which also significantly improved visible light absorption capacity and facilitated electron transport pathways, and promoted the separation and transfer of charge carriers efficiently.

A series of FeS 2 /Bi 2 WO 6 S-scheme photo-Fenton catalysts with efficient catalytic performances were successfully prepared by coupling FeS 2 into the surface oxygen vacancy enriched Bi 2 WO 6 using calcination and solvothermal methods.

We studied the status of selenium, iodine and fungal contamination in 353 school children (age 5–14 years) from four rural villages in the District of Yulin. In three villages Kashin-Beck disease (KBD) was endemic, whereas there were no cases of KBD in the fourth village. Clinical, biological and radiological examinations (right hand) were performed and KBD was established by X-ray diagnosis. The prevalence rate of KBD was 30.2%, 44.2% and 45.3% in the three endemic villages. Mean hair selenium and urine iodine concentrations were lower in affected than in unaffected children and fungal contamination in cereal grains stored in families with KBD was more elevated than in families without KBD. Low hair selenium concentration and presence of fungal cereal contamination were significantly associated with an increased risk of KBD, but low urine iodine was not.

Understanding the levels, distribution and sources of perfluorinated compounds (PFCs) in sediments is of great significance for the management of aquatic environments. In this work, 26 sediment samples were collected from Dianchi Lake in China and ten PFCs compounds were measured. The concentrations of the total PFCs (∑PFCs) in the sediments ranged from 0.21 to 2.45 ng g−1 dw (dry weight), with an average value of 0.95 ng g−1 dw. PFOS was the most abundant compound among the ten PFCs with the average concentration of 0.33 ng g−1 dw, followed by PFOA at 0.21 ng g−1 dw. A two-dimensional HCA (hierarchical cluster analysis) heat map was depicted to analyze the spatial variation of individual PFCs compound and the possible origins in the sediments. Two groups were clustered by HCA, showing the possible source categories (PFOS-cluster and PFOA-cluster). Additionally, PCA-MLR, PMF and Unmix models were employed to quantitatively calculate the contribution of extracted sources. Three models concluded consistent results that PFOS-factor and PFOA-factor were the two main source categories for PFCs in the sediments. The contribution percentages were 43% (PCA-MLR), 48% (PMF) and 46% (Unmix) from the former source, and were 54% (PCA-MLR), 43% (PMF) and 44% (Unmix) from the latter source, respectively. The findings and the approaches used in this work can provide useful information for further study of source apportionment for PFCs in sediments and other environmental compartments.

Sulfonamides, a group of antibacterial agents, are not readily biodegradable and as a result have often been detected in wastewater effluents, rivers and lakes. This work investigated the photocatalytic degradation of sulfadimethoxine (SDM) and related sulfonamides in H2O2 containing aqueous suspensions of mesoporous TiO2 microspheres exposed to simulated solar light irradiation. The three-dimensional mesoporous TiO2 microsphere catalyst was fabricated by a facile method via a one-step solvothermal process without templates. The performance of mesoporous TiO2 microspheres exceeded the commercially available P25 TiO2 catalyst in the photocatalytic degradation of sulfonamides. Sulfadimethoxine degradation increased and reached the optimal H2O2 concentration of 5.9 mM. Particularly, the disappearance of SDM as well as the formation and decomposition of some degradation intermediates were determined by high-performance liquid chromatography-mass spectroscopy (HPLC-MS) and high-performance liquid chromatography-selective ion recording (HPLC-SIR) data modules, and possible photocatalytic degradation mechanisms were proposed. The hydroxylation and cleavage of the S–N or C–N bonds through •OH attacks on the aromatic rings and aminopyrimidine rings under simulated solar light irradiation with the assistance of H2O2 played important roles during SDM photocatalytic degradation.

In this study, granular activated carbon (GAC) coated with cetyltrimethyl ammonium chloride (GAC-CTAC) was synthesized to remove perchlorate from water. Bench scale kinetics and adsorption isotherm tests were performed to evaluate the effects of factors affecting the adsorption efficiency, including the CTAC content, solution pH and ionic strength (I). When the content of CTAC on GAC increased from 0.031 to 0.16 mmol/g, the rate constant in the pseudo-second order reaction was decreased from 46.35 to 23.24 h·g/mmol, and the K value in the Freundlich equation was increased from 0.087 to 0.20 mmol/g correspondingly. Typically, GAC-CTAC exhibited a higher adsorption capacity than GAC, which highlighted the key role of CTAC. The optimum perchlorate removal by GAC or GAC-CTAC was observed at pH 2–3, equivalent to pHpzc determined by zeta potential measurement. The adsorption capacity of perchlorate onto GAC-CTAC at pH 2.5 (0.36 mmol/g) was 3.8 times as high as that onto GAC-CTAC at pH 5.6 (0.094 mmol/g). Ionic strength appeared to significantly inhibit the perchlorate adsorption on GAC-CTAC. Finally, our results demonstrated that the primary mechanisms for the adsorption of perchlorate on GAC-CTAC were associated with electrostatic interaction, surface complexation and ion exchange.

An unprecedented allylation reaction of protected hydrazines with enantioenriched allylic amines has been developed in a stereospecific manner with net stereoretention. A wide variety of protected hydrazines underwent palladium/acid-catalyzed allylation with highly enantioenriched primary allylic amines to give structurally diverse N-allylhydrazines in moderate to excellent yields with extremely high regioselectivity and complete retention of the configuration. Importantly, the reaction exhibits high atom-economy by yielding ammonia as the sole byproduct.