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Fanping Meng

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DOI: 10.1016/j.ecoenv.2018.03.089
2018
Cited 173 times
Ecotoxicity of phenol and cresols to aquatic organisms: A review
With the development of industrial production and continuous demand for chemicals, a large volume of wastewater containing phenols was discharged into the aquatic environment. Moreover, chemical leakage further increased the emission of phenols into aquatic systems. Phenol and its methylated derivative (cresols) were selected due to their extensive use in industry and ecotoxicity to freshwater and marine organisms. This review focused on the ecotoxicity of phenol and m-, o-, and p-cresol on aquatic systems. The mechanism of action of phenols was also discussed. The aim of this literature review was to summarise the knowledge of the behaviour, and toxicity on marine and freshwater organisms, of phenols as well as to try to select a series of sensitive biomarkers suitable for ecotoxicological assessment and environmental monitoring in aquatic environments.
DOI: 10.1016/j.envpol.2021.118541
2022
Cited 56 times
Antibiotics in mariculture systems: A review of occurrence, environmental behavior, and ecological effects
Antibiotics are widely applied to prevent and treat diseases occurred in mariculture. The often-open nature of mariculture production systems has led to antibiotic residue accumulation in the culturing and adjacent environments, which can adversely affect aquatic ecosystems, and even human. This review summarizes the occurrence, environmental behavior, and ecological effects of antibiotics in mariculture systems based on peer-reviewed papers. Forty-five different antibiotics (categorized into ten groups) have been detected in mariculture systems around the world, which is far greater than the number officially allowed. Indiscriminate use of antibiotics is relatively high among major producing countries in Asia, which highlights the need for stricter enforcement of regulations and policies and effective antibiotic removal methods. Compared with other environmental systems, some environmental characteristics of mariculture systems, such as high salinity and dissolved organic matter (DOM) content, can affect the migration and transformation processes of antibiotics. Residues of antibiotics favor the proliferation of antibiotic resistance genes (ARGs). Antibiotics and ARGs alter microbial communities and biogeochemical cycles, as well as posing threats to marine organisms and human health. This review may provide a valuable summary of the effects of antibiotics on mariculture systems.
DOI: 10.1016/j.ecoenv.2019.109658
2019
Cited 90 times
Biodegradation of phenol in saline or hypersaline environments by bacteria: A review
With the continuous demand from industry for chemical raw materials, a large amount of high-salinity wastewater containing phenol is discharged into the aquatic environment, and the leakage of dangerous chemicals into the sea may lead to phenol pollution of the ocean. Phenol is a common chemical posing serious environmental hazard. Biodegradation is an effective, low-cost, environment-friendly method of removing phenol from water, but in hypersaline environments, traditional freshwater organisms are less efficacious. Here, at least 17 genera of bacteria from three phyla are found that can degrade phenol in different saline environments. The sources and taxonomy of halotolerant and halophilic bacteria are reviewed. Moreover, the pathway of phenol removal, kinetics of biodegradation, influencing factors, and recent treatment processes of wastewater are discussed.
DOI: 10.1016/j.marpolbul.2017.11.017
2018
Cited 86 times
Assessment of metal contamination in estuarine surface sediments from Dongying City, China: Use of a modified ecological risk index
Surface sediments and clam Meretrix meretrix were collected from a northern estuarine region in Dongying City, China. Sediments were analysed for heavy metals (Hg, As, Cd, Cr, Cu, Pb, and Zn) and the clams were tested for metallothioneins (MTs) and lysosomal membrane stability (LMS). The heavy metal total concentrations decreased in the order of Cr>Zn>Cu>Pb>As>Cd>Hg. The results of Bureau Communautaire de Référence (BCR) sequential extraction of heavy metals showed that the geochemical speciation of all heavy metals was dominated by residual fraction. According to the responses of biomarkers in M. meretrix, the modified potential ecological risk index (PERI-B) can more accurately reflect heavy metals pollution. PERI-B showed all sediment samples have low or moderate risk, except at site S10 (considerable risk), and the main contribution of ecological risk heavy metals were Cd and Hg.
DOI: 10.1016/j.etap.2017.04.006
2017
Cited 82 times
Toxicological effects of phenol on four marine microalgae
The toxic effects of phenol on four marine microalgae (Dunaliella salina, Platymonas subcordiformis, Phaeodactylum tricornutum Bohlin, and Skeletonema costatum) were evaluated. The 96 h EC50 values were 72.29, 92.97, 27.32, and 27.32 mg L−1, respectively, which were lower than those values of freshwater microalgae reported in the literature. During a 96-h exposure to a sub-lethal concentration of phenol (1/2 96 h EC50) with green alga (D. salina) and diatom (S. costatum), reactive oxygen species (ROS) accumulation, and chlorophyll a (Chl a) content decrease were simultaneously observed in diatom cells after 48 h treatment. On the contrary, other chlorophylls in both algae were unaffected. Under transmission electron microscopy (TEM), the phenol-induced ultrastructure alterations included disappearance, or shrinkage, of nucleolus and enlargement of vacuoles, which may result in programmed cell death (PCD). The increase in number of lipid droplets may be related to phenol detoxification. These results indicate that the sensitivity of marine microalgae to phenol was dependent on some biotic factors such as cell size, ROS production, and phenol degradation ability in algal cells.
DOI: 10.1016/j.chemosphere.2023.138916
2023
Cited 10 times
Elimination of tetracyclines in seawater by laccase-mediator system
Long-term exposure of antibiotics at low level leads to the accumulation of antibiotics in environmental media and organisms, inducing the formation of antibiotic resistance genes. Seawater is an important sink for many contaminants. Here, laccase from Aspergillus sp. and mediators that follow different oxidation mechanisms were combined to degrade tetracyclines (TCs) at environmentally relevant levels (ng·L-1-μg·L-1) in coastal seawater. The high salinity and alkaline of seawater changed the enzymatic structure of laccase, resulting in a reduced affinity of laccase to the substrate in seawater (Km of 0.0556 mmol·L-1) than that in buffer (Km of 0.0181 mmol·L-1). Although the stability and activity of the laccase decreased in seawater, laccase at a concentration of 200 U·L-1 with a laccase/syringaldehyde (SA) ratio of 1 U: 1 μmol could completely degrade TCs in seawater at initial concentrations of less than 2 μg·L-1 in 2 h. Molecular docking simulation showed that the interaction between TCs and laccase mainly includes hydrogen bond interaction and hydrophobic interaction. TCs were degraded into small molecular products through a series of reactions: demethylation, deamination, deamidation, dehydration, hydroxylation, oxidation, and ring-opening. Prediction of the toxicity of intermediates showed that the majority of TCs can be degraded into low-toxic or non-toxic, small-molecule products within 1 h, indicating that the degradation process of TCs by a laccase-SA system has good ecological safety. The successful removal of TCs by the laccase-SA system demonstrates its potential for the elimination of pollutants in marine environment.
DOI: 10.1016/j.jhazmat.2008.10.052
2009
Cited 86 times
Defluoridation of water using neodymium-modified chitosan
The water containing high fluoride ions could do harm to human and environment. In this work, the applicability of neodymium-modified chitosan as adsorbents for the removal of excess fluoride ions from water was studied. The effect of various physico-chemical parameters such as temperature (283-323 K), pH (5-9), adsorbent dose (0.2-2.0 g L(-1)), particle size (0.10-0.50mm) and the presence of co-anions (NO(3)(-), Cl(-) and SO(4)(2-)) on removal of fluoride ions were studied. The equilibrium sorption data were fitted reasonably well for Langmuir isotherm model, the maximum equilibrium sorption had found to be 11.411-22.380 mg g(-1). Sorption dynamics study revealed that the pseudo-second-order was suitable to describe the kinetics process of fluoride ions sorption onto the adsorbent with the initial sorption rate 1.70, 2.10 and 2.67 mg g(-1)min(-1) at 283, 303 and 323 K, and the sorption process was complex, both the boundary of liquid film and intra-particle diffusion contributed to the rate-determining step. The used adsorbents could be regenerated in 24h by 4 g L(-1) of sodium hydroxide.
DOI: 10.1016/j.foodcont.2021.108356
2021
Cited 29 times
Immunochromatographic assay for the detection of antibiotics in animal-derived foods: A review
Nowadays, adverse human reactions such as allergies and organ damage caused by antibiotics, as well as the drug resistance of bacteria have raised popular concern. Due to abuse in livestock production and aquaculture, many countries have established standards limiting the residual amounts of antibiotics in food. Therefore, it is necessary to develop analytical methods for the wholesale screening of antibiotics in animal-derived foods. Immunochromatographic assay (ICA) is suitable for simultaneously analyzing considerable numbers of samples at low cost, with high portability, and faster detection. This review introduces the current research status of ICA for eight categories of antibiotics including chloramphenicols (CAPs), tetracyclines (TCs), quinolones (QNs), sulfonamides (SAs), macrolides (MAs), aminoglycosides (AGs), lincosamides (LMs), and β-lactams in animal-derived foods. We summarize pre-treatment (extraction and clean-up) of ICA for the detection of antibiotics in animal-derived foods. Furthermore, the improved optimization strategies for weaknesses (low sensitivity and efficiency) are summarized. Trends in the development of ICA for detection of antibiotics are also reviewed.
DOI: 10.1016/j.envpol.2023.122248
2023
Cited 7 times
Efficiency, mechanism, influencing factors, and integrated technology of biodegradation for aromatic compounds by microalgae: A review
Aromatic compounds have received widespread attention because of their threat to ecosystem and human health. However, traditional physical and chemical methods are criticized due to secondary pollution and high cost. As a result of ecological security and the ability of carbon sequestration, biodegradation approach based on microalgae has emerged as a promising alternative treatment for aromatic pollutants. In light of the current researches, the degradation efficiency of BTEX (benzene, toluene, ethylbenzene, and xylene), polycyclic aromatic hydrocarbons (PAHs), and phenolic compounds by microalgae was reviewed in this study. We summarized the degradation pathways and metabolites of p-xylene, benzo [a]pyrene, fluorene, phenol, bisphenol A, and nonylphenol by microalgae. The influence factors on the degradation of aromatic compounds by microalgae were also discussed. The integrated technologies based on microalgae for degradation of aromatic compounds were reviewed. Finally, this study discussed the limitations and future research needs of the degradation of these compounds by microalgae.
DOI: 10.1016/j.jenvman.2023.119482
2024
Deriving seawater quality criteria of tris(2-chloroethyl) phosphate for ecological risk assessment in China seas through species sensitivity distributions
Tris(2-chloroethyl) phosphate (TCEP), one of the widely used organophosphorus flame retardants (OPFRs), has been frequently detected in the marine environment in the seas off China. The existing freshwater biotoxicity data are not suited to derivation of the seawater quality criteria of TCEP and evaluating the associated ecological risks. This study aimed at deriving water quality criteria (WQC) of TCEP for marine organisms based on species sensitivity distribution (SSD) approach using the acute toxicity data generated from multispecies bioassays and chronic toxicity data by converting acute data with the acute-to-chronic ratios (ACRs); the derived WQC were then used to evaluate the ecological risk for TCEP in China Seas. According to median effective concentration (EC50) and median lethal concentration (LC50), TCEP had a moderate or low toxicity to eight marine species selected, among which mysid Neomysis awatschensis (96h-LC50 of 39.65 mg/L) and green alga Platymonas subcordiformis (96-h EC50 of 395.42 mg/L) were the most sensitive and the most tolerant, respectively. The acute and chronic hazardous concentrations of TCEP for 5% of marine species (HC5) were estimated to be 29.55 and 2.68 mg/L, respectively. The short-term and long-term WQC were derived to be 9.85 and 0.89 mg/L, respectively. The risk quotient (RQ) values indicated that TECP at current levels poses a negligible risk to marine ecosystems in China. These results will provide valuable reference for the government to establish a seawater quality standard for TCEP.
DOI: 10.3389/fmicb.2021.737248
2021
Cited 23 times
Adaptive Laboratory Evolution of Microalgae: A Review of the Regulation of Growth, Stress Resistance, Metabolic Processes, and Biodegradation of Pollutants
Adaptive laboratory evolution (ALE) experiments are a serviceable method for the industrial utilization of the microalgae, which can improve the phenotype, performance, and stability of microalgae to obtain strains containing beneficial mutations. In this article, we reviewed the research into the microalgae ALE test and assessed the improvement of microalgae growth, tolerance, metabolism, and substrate utilization by ALE. In addition, the principles of ALE and the key factors of experimental design, as well as the issues and drawbacks of the microalgae ALE method were discussed. In general, improving the efficiency of ALE and verifying the stability of ALE resulting strains are the primary problems that need to be solved in future research, making it a promising method for the application of microalgae biotechnology.
DOI: 10.1016/j.marpolbul.2024.116073
2024
Emergency response to ecological protection in maritime phenol spills: Emergency monitor, ecological risk assessment, and reduction
Recently, hundreds of maritime accidental spills of hazardous chemicals have raised public concerns, especially for phenol due to its potential of spills and highly toxicity. Therefore, for marine ecological protection, this article prepared specific strategies of emergency response to phenol spills. Through the identification for phenol behavior at sea, migration prediction, emergency monitor, as well as their new methods were reviewed. Further, ecological risk assessment and seawater quality criteria were conducted by using a species sensitivity distribution (SSD) approach, wherein, risk quotient (RQ) indicated phenol of simulated marine spills posed a high risk (RQ > 1) in 30 days. The method with eco-friendliness and high-efficiency for phenol reduction was constructed by combination of dredging equipment such as pneumatic dredgers (Airlift) and bioremediation, where marine microorganisms that degraded phenol were summarized, as well as future research needs. This study provided a guidance for emergency response and policy development of phenol spills.
DOI: 10.1016/j.ecoenv.2017.07.050
2017
Cited 38 times
Environmental behavior and eco-toxicity of xylene in aquatic environments: A review
With the demand for chemicals and fuels increasing continuously, the occurrence of accidental leakage poses great risks to the aquatic environment. Xylene, a hazardous and noxious substance, has been major concerns with regard to heterogeneity and eco-toxicity towards aquatic organisms. This review focused on the ecotoxicological hazards of m-, o-, and p-xylene, as well as mixed xylene, on aquatic organisms. The mechanism of action of xylenes was also demonstrated in details. The purpose of this review was to further understand transfer and diffusion of toxicity on marine and freshwater organisms of xylene in the aquatic environment. Another aim was to screen sensitive biomarkers which were suitable for ecotoxicological assessment and monitoring in an aquatic system.
DOI: 10.1016/j.aquatox.2018.05.003
2018
Cited 34 times
Dynamics of paralytic shellfish toxins and their metabolites during timecourse exposure of scallops Chlamys farreri and mussels Mytilus galloprovincialis to Alexandrium pacificum
New C-11 hydroxyl metabolites of paralytic shellfish toxins (PSTs) have been reported in shellfish. To gain further information on these metabolites, as well as the potential for formation of phase-II metabolites and acyl esters of PSTs, bivalves were fed with the PSTs-producing dinoflagellate Alexandrium pacificum (strain ATHK). Through independent experiments, scallops (Chlamys farreri) were fed for 9 days and mussels (Mytilus galloprovincialis) for 5 days plus an additional 5 days of depuration, with representative samples taken throughout. Several common PSTs (C1-4, GTX1-6 and NEO) and metabolites including M1, M3, M5, M7, M9, M2 and M8 were detected in the hepatopancreas of scallops during toxin accumulation and in the hepatopancreas of mussels during both toxin accumulation and elimination periods. The relative molar ratio of metabolites to precursor molecules was used to estimate relative metabolic conversion rates. Conversion rates of C1/2 and GTX2/3 were higher than those of C3/4 and GTX1/4, in scallops and mussels. The first metabolites observed in both bivalve species investigated were M1/3, which are formed from C1/2. However, the conversion of GTX2/3 to M2 was more complete than other biotransformation reactions in both mussels and scallops. In general, metabolic conversion of PSTs was observed after a shorter time and to a greater extent in mussels than in scallops in the exposure period. No acyl esters or conjugation products of PSTs with glucuronic acid, glutathione, cysteine and taurine were detected by liquid chromatography with high resolution tandem mass spectrometry in the samples investigated. Additionally, only GTX1/4 and GTX2/3 were detected in the kidney of scallops, which demonstrates that PSTs are mainly metabolized through the hepatic metabolism pathway in bivalves. This work improves the understanding of PST metabolism during toxin accumulation and depuration in commercially harvested shellfish.
DOI: 10.1007/s10811-018-1517-z
2018
Cited 33 times
Biodegradation of phenol by Isochrysis galbana screened from eight species of marine microalgae: growth kinetic models, enzyme analysis and biodegradation pathway
DOI: 10.1007/s11802-020-4302-y
2020
Cited 27 times
Effect of pH, Temperature, and CO2 Concentration on Growth and Lipid Accumulation of Nannochloropsis sp. MASCC 11
DOI: 10.1016/j.envres.2021.110873
2021
Cited 20 times
Attenuation pathways of erythromycin and biochemical responses related to algal growth and lipid synthesis in a microalga-effluent system
Microalgal cultivation in municipal wastewater treatment plants (WWTPs) can realize the coupling of wastewater treatment and microalgae energy utilization, however, the residual antibiotics in effluents from WWTPs affect the growth of microalgae. In this study, green alga (Scenedesmus obliquus) cells were inoculated into the effluents to ascertain the attenuation pathways of erythromycin (ERY) and the biochemical responses of microalga in a microalga-effluent system. Results showed that hydrolysis, photolysis, and biodegradation (including bioadsorption) cause the attenuation of ERY in a microalga-effluent system, and the biodegradation (including bioadsorption) has the greatest removal rate (reaching a maximum of 57.87%), followed by hydrolysis (reaching a maximum of 34.13%), and photolysis (less than 5%) after five days. The photosynthetic pigment contents in cells of microalga decreased the most (by 35.66% for chlorophyll a), and the production of ROS was stimulated (by 33.75%) after five-day exposure to ERY at an initial concentration of 100 μg/L. Meanwhile, the activity of ribulose-1,5-biphosphate carboxylase (RuBPCase) decreased by 55.65%, and the activity of acetyl-CoA carboxylase (ACCase) increased by 55.65%. The ROS level, photosynthetic pigment content, and RuBPCase activity were extremely significantly correlated with each other (P < 0.01), indicating that exposure to ERY changed those biochemical responses related to the rate of photosynthesis of microalga, inhibiting the growth thereof. On the other hand, exposure to ERY increased lipid production by microalga through the induced ACCase activity.
DOI: 10.3390/toxins13040293
2021
Cited 20 times
Effects of Polystyrene Microplastics on Growth and Toxin Production of Alexandrium pacificum
Microplastics (MP) widely distributed in aquatic environments have adverse effects on aquatic organisms. Currently, the impact of MP on toxigenic red tide microalgae is poorly understood. In this study, the strain of Alexandrium pacificum ATHK, typically producing paralytic shellfish toxins (PST), was selected as the target. Effects of 1 and 0.1 μm polystyrene MP with three concentration gradients (5 mg L−1, 25 mg L−1 and 100 mg L−1) on the growth, chlorophyll a (Chl a), photosynthetic activity (Fv/Fm) and PST production of ATHK were explored. Results showed that the high concentration (100 mg L−1) of 1 μm and 0.1 μm MP significantly inhibited the growth of ATHK, and the inhibition depended on the size and concentration of MP. Contents of Chl a showed an increase with various degrees after MP exposure in all cases. The photosynthesis indicator Fv/Fm of ATHK was significantly inhibited in the first 11 days, then gradually returned to the level of control group at day 13, and finally was gradually inhibited in the 1 μm MP treatments, and promotion or inhibition to some degree also occurred at different periods after exposure to 0.1 μm MP. Overall, both particle sizes of MP at 5 and 25 mg L−1 had no significant effect on cell toxin quota, and the high concentration 100 mg L−1 significantly promoted the PST biosynthesis on the day 7, 11 and 15. No significant difference occurred in the cell toxin quota and the total toxin content in all treatments at the end of the experiment (day 21). All MP treatments did not change the toxin profiles of ATHK, nor did the relative molar percentage of main PST components. The growth of ATHK, Chl a content, Fv/Fm and toxin production were not affected by MP shading. This is the first report on the effects of MP on the PST-producing microalgae, which will improve the understanding of the adverse impact of MP on the growth and toxin production of A. pacificum.
DOI: 10.1016/j.ecoenv.2023.115106
2023
Cited 4 times
Ecological risk assessment for xylenes and propylbenzenes in aquatic environment using a species sensitivity distribution approach
Xylenes and propylbenzenes (PBZs) are volatile aromatic hydrocarbons with high aquatic toxicity. Xylenes can be present in three isomers: o-xylene (OX), m-xylene (MX), and p-xylene (PX), while PBZs include two isomers: n-propylbenzene (n-PBZ) and isopropylbenzene (i-PBZ). Their accidental spills and improper discharges from petrochemical industries can cause severe contamination in water bodies posing potential ecological risks. In this study, the published acute toxicity data of these chemicals for aquatic species were collected to calculate hazardous concentrations protecting 95% species (HC5) using a species sensitivity distribution (SSD) approach. The acute HC5 values for OX, MX, PX, n-PBZ, and i-PBZ were estimated to be 1.73, 3.05, 1.23, 1.22, and 1.46 mg/L, respectively. The risk quotient (RQ) values calculated based on HC5 indicated their high risk (RQ: 1.23 ∼ 21.89) in groundwater, but low risk (RQ < 0.1) in natural seawater, river water, and lake water. When xylenes or PBZs leaked into the sea, they were expected to pose a high risk (RQ > 1) at the start and then a low risk (RQ < 0.1) after 10 days due to natural attenuation. These results may help to derive more reliable protection thresholds for xylenes and PBZs in aquatic environment and provide a basis for evaluating their ecological risks.
DOI: 10.1016/j.ecoenv.2020.111571
2021
Cited 16 times
Acclimation of Isochrysis galbana Parke (Isochrysidaceae) for enhancing its tolerance and biodegradation to high-level phenol in seawater
Marine microalgae with high removal efficiency of phenol are needed for the remediation of polluted seawater in cases involving phenol spills. To achieve this purpose, adaptive laboratory evolution (ALE) was performed by a microalga Isochrysis galbana Parke MACC/H59, which is capable of degrading phenol at concentrations of less than 100 mg L−1 in 4 d. Two acclimation conditions were used: (i) 90 d at 100 mg L−1 phenol, and (ii) 90 d at 100 mg L−1 phenol followed by another 90 d at 200 mg L−1 phenol. By doing so, two strains (PAS-1 and PAS-2) could be obtained respectively. They grew rapidly at phenol concentrations up to 200 mg L−1 and 300 mg L−1, respectively, with a specific growth rate 2.52–3.40 times and 1.93–3.23 times that of the control (without phenol). Also, both strains had a higher removal capacity of phenol than the unacclimated alga. Phenol at an initial concentration of 200 mg L−1 was completely removed in 5 d thereby. For 300 mg L−1 phenol, a removal efficiency of 92% was achieved in 10 days by using PAS-2, with a removal rate constant of 30.01 d−1 (about twice that of PAS-1) and a half-life of 4.90 d (about half that of PAS-1), showing that a better strain may be obtained by extending the acclimation time. The enhancement of phenol biodegradation can be explained by the elevated activity of phenol hydroxylase (PH) in both strains. These results indicated that ALE could be an efficient tool used to enhance the tolerance and biodegradation of marine microalgae to phenol in seawater.
DOI: 10.1016/j.marenvres.2013.01.003
2013
Cited 29 times
The assessment of environmental pollution along the coast of Beibu Gulf, northern South China Sea: An integrated biomarker approach in the clam Meretrix meretrix
The clam Meretrix meretrix was used as a biomonitor to implement an environmental monitoring program along the coast of Beibu Gulf in October 2011. This program not only analyzed biomarkers including acetylcholinesterase, glutathione peroxidase, glutathione S-transferase, catalase and superoxide dismutase activities, total glutathione content and lipid peroxidation level in M. meretrix but also adopted a multi-biomarker approach – integrated biomarker response (IBR) to assess the environmental quality in this ecosystem. In addition, the metal (Hg, As, Cu, Pb, Zn, Cd and Cr) and polychlorinated biphenyls (PCBs) content in the surface sediment at the study area were also measured. The results showed that IBR index was able to distinguish a space trend between sampling sites with different degrees of anthropogenic environmental stress. Integrated contamination degree were displayed in the form of star plots and compared to IBR plots. There was a visual consistency between the pollution level and IBR variation. Based on the results, it was proved that the IBR method coupled with chemical analysis was quite useful for the assessment of environmental pollution in the coastal system.
DOI: 10.1016/j.ecoenv.2014.09.038
2015
Cited 24 times
Biochemical responses in the gills of Meretrix meretrix after exposure to treated municipal effluent
The biochemical effects in marine bivalves exposed to increasing concentrations of treated municipal effluent (TME), as discharged into receiving marine waters, are investigated. The effluent was collected from a municipal sewage treatment plant (STP) in Qingdao (China). Meretrix meretrix were exposed to effluent volume ratio (EVR, ratio of effluent volume accounted for tailwater seawater mixture) 0%, 1%, 5%, 10%, and 20% (v/v) TME for 15 days and the following biochemical responses in gills were measured: (1) the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione (GSH) content, and lipid peroxidation levels of malondialdehyde (MDA), as oxidative stress biomarkers; (2) the activity of 7-ethoxyresorufin O-deethylase (EROD) and gluthathione S-transferase (GST), as phase I and phase II conjugation enzymes, respectively; (3) acetylcholinesterase (AChE), as a biomarker of neurotoxicity, and (4) metallothioneins (MTs), as proteins strongly induced by heavy metals. Most of the biochemical indices present high and significant variation frequency (above 50%). There is enhancement in the antioxidant enzymes, EROD, GST, AChE, and MTs, as well as consumption of GSH. The current experimental results suggest that effluent with concentrations less than 20% (v/v) do not cause lipid peroxidation damage. This implies that the activated defense is sufficient to protect the bivalves' gill tissues from cytotoxicity produced by the effluent. Furthermore, GSH, GPx, MTs, and GR are suitable, and sufficiently sensitive, biomarkers to indicate the pollution levels in marine environments receiving such effluent.
DOI: 10.1016/j.hal.2018.05.005
2018
Cited 21 times
Screening of cyclic imine and paralytic shellfish toxins in isolates of the genus Alexandrium (Dinophyceae) from Atlantic Canada
The dinoflagellate genus Alexandrium Halim has frequently been associated with harmful algal blooms. Although a number of species from this genus are known to produce paralytic shellfish toxins (PST) and/or cyclic imines (CI), studies on comprehensive toxin profiling using techniques capable of detecting the full range of PST and CI analogues are limited. Isolates of Alexandrium spp. from Atlantic Canada were analyzed by targeted and untargeted liquid chromatography-tandem mass spectrometry (LC–MS). Results showed a number of distinct profiles and wide ranging cell quotas of PST and spirolides (SPX) in both A. catenella (Whedon & Kofoid) Balech and A. ostenfedii (Paulsen) Balech & Tangen. The concentration of PST in A. catenella ranged from 0.0029 to 54 fmol cell−1 with the major components being C2 and GTX4. In addition, putative PST metabolites were confirmed for the first time in A. catenella by high resolution MS/MS. By comparison, A. ostenfeldii isolates showed much lower concentrations of PST (<LOD to 2 fmol cell−1) and high total levels of SPX (14 to 43 fmol cell−1). The SPX profile of the A. ostenfeldii strains mainly included 13-desmethyl SPX-C, SPX-C and 20-methyl SPX-G, with low levels of other SPX and gymnodimine-like analogues detected by untargeted –high-resolution LC-MS. This work demonstrates the importance of using screening methods capable of detecting the full suite of PST and CI compounds when analyzing Alexandrium isolates for toxin production and adds further complexity to the known toxin profiles of this genus.
DOI: 10.1186/s13568-017-0488-9
2017
Cited 20 times
Two-stage mixotrophic cultivation for enhancing the biomass and lipid productivity of Chlorella vulgaris
This study proposes a two-stage mixotrophic process for cultivating Chlorella vulgaris. Heterotrophic growth is the dominant step in Phase I (to increase microalgal biomass) and photoautotrophic growth occurs in Phase II (to improve biomass concentration and lipid production). The results show that the addition of the low-cost antioxidant sodium erythorbate (8 g L-1) significantly accelerates the growth of microalgae in the first stage with air aeration. Furthermore, a higher CO2 fixation rate was obtained in the second stage (at least 344.32 mg CO2 L-1 day-1) with 10% CO2 aeration. This approximately corresponds to an increase of 177% over simple photoautotrophic cultivation with 10% CO2 aeration during the whole period. The two-stage cultivation strategy achieved a maximum C. vulgaris biomass concentration of 3.45 g L-1 and lipid productivity of 43.70 mg L-1 day-1, which are 1.85 and 1.64 times those arising due to simple photoautotrophy, respectively. Moreover, an analysis of the product's fatty acid profile indicates that C. vulgaris might be an ideal candidate for two-stage mixotrophic cultivation of a renewable biomass for use in biodiesel applications. Another interesting point to note from the study is that it is an insufficiency of N and CO2 that probably limits the further growth of C. vulgaris.
DOI: 10.1080/10807039.2016.1159503
2016
Cited 19 times
Distribution, speciation, and ecological risk assessment of heavy metals in surface sediments of Jiaozhou Bay, China
This paper analyzed the distribution and speciation of seven heavy metals in sediments in Jiaozhou Bay. The ecological risk was assessed using three index approaches (i.e., risk assessment code (RAC), contamination factor (CF), and potential ecological risk index (PERI)) and by a comparison with sediment quality guidelines (Chinese Marine Sediment Quality Standards (CMSQS), and threshold effect level (TEL) and probable effect level (PEL) from the USEPA). Pb, Cr, As, Cu, Zn, and Hg contents at most sites were above the corresponding TEL and Class I criteria (CMSQS) value. Particularly, high contents of Cu, detected at sites S7 (124.5 mg kg−1) and S8 (118.3 mg kg−1), exceeded the respective PEL value, indicating that harmful biological effects might occur. Speciation analysis, individual CF, and RAC calculations suggested that Cd had the highest bioavailable fraction and thus posed a very high risk to aquatic ecosystem; Cu and Zn showed a medium–high risk. Both global CF and PERI analysis indicated a high pollution risk at sites S7, S1, S3, and S2, but the assessments of specific sites were different. The incomplete consistency suggested that it is necessary to consider both total contents and chemical speciation for providing a more realistic appraisal for the risk of heavy metals in sediments.
DOI: 10.1016/j.ecoenv.2020.110687
2020
Cited 17 times
The pathways by which the marine diatom Thalassiosira sp. OUC2 biodegrades p-xylene, combined with a mechanistic analysis at the proteomic level
A marine diatom, Thalassiosira sp. OUC2, was isolated from natural seawater collected from Daya Bay, China. This diatom degraded 1.25–40 mg L−1 p-xylene within five days, at a removal efficiency exceeding 98%. Gas chromatography-mass spectrometer (GC-MS) analysis indicated that p-xylene was converted into 4-methylbenzyl alcohol, p-toluic acid, and p-cresol in the presence of strain OUC2. Meanwhile, proteomic analysis showed that, after exposure to p-xylene, several algal enzymes were significantly upregulated: including monooxygenase, alcohol dehydrogenase, benzaldehyde dehydrogenase, benzoate 1,2-dioxygenase, and catechol 2,3-dioxygenase. Moreover, ecotoxicological tests suggested that the intermediate metabolites were less toxic than the parent compound (p-xylene). Thalassiosira sp. OUC2 may thus be suitable for the remediation of p-xylene-contaminated marine environments.
DOI: 10.1016/j.jece.2024.111939
2024
Construction of a continuous packed bed laccase reactor for the elimination of tetracyclines in seawater
Tetracycline antibiotics (TCs) are extensively present in the marine environment and have adverse effects on human health and aquatic ecosystems. Laccases are a type of green biocatalyst for TCs degradation. In this study, a continuous packed bed reactor based on the immobilized modified laccase was constructed to degrade TCs at environmentally relevant levels in seawater. Results showed that the chemical modification and immobilization of laccase had a synergistic effect on its activity and stability in seawater: after incubation in seawater for 12 h, the residual activity of free laccase was only 22.3%, while that of the immobilized modified laccase (A/PhA-Lac) was 79.3%. A laccase reactor was constructed based on A/PhA-Lac, and the response surface regression model was established to optimize the laccase reactor operating conditions. The laccase reactor under optimal conditions could continuously degrade TCs (5 μg/L each) in seawater within 10 h and reach the highest removal rate at 4 to 5 h (removal rates of tetracycline, oxytetracycline, and chlorotetracycline were 94.7%, 86.6% and 98.0%, respectively). The luminescent bacteria microtoxicity and seawater microbial community analysis revealed that the laccase reactor significantly mitigated the toxicity of TCs in seawater. This study provided an environmentally friendly and effective method for the elimination of antibiotics in seawater.
DOI: 10.1016/j.ecoenv.2022.113686
2022
Cited 7 times
Oxidative stress responses in two marine diatoms during acute n-butyl acrylate exposure and the toxicological evaluation with the IBRv2 index
n-Butyl acrylate (nBA), a typical hazardous and noxious substance (HNS), is the largest-volume acrylate ester used to produce various types of polymers. With the increasing volume of nBA subject to maritime transportation, its accidental leakage poses a great risk to the marine organisms. Therefore, it is necessary to evaluate the ecological risk of nBA in marine environments. In this study, two species of marine microalgae, Skeletonema costatum and Phaeodactylum tricornutum, were used to explore the toxic effects of nBA based on their growth, pigment content, and oxidative stress. The growth of each species was significantly inhibited by nBA, showing a 96 h-EC50 value of 2.23 mg/L for P. tricornutum and 8.19 mg/L for S. costatum, respectively. Although chlorophylls a and c exerted a hormesis effect in P. tricornutum, contents of pigments generally decreased at high concentrations. In P. tricornutum, all detected antioxidants (reduced glutathione, GSH; superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) were stimulated at concentrations ranging from 1.50 to 3.82 mg/L. However, these elevations were not enough to reduce the oxidative damage caused by nBA, because the content of malondialdehyde (MDA) increased continuously during 96-h exposure. For S. costatum, the activities of only two antioxidants (GSH and CAT) were enhanced, which is enough to prevent the MDA content from rising, even at higher concentrations of nBA (5-10 mg/L). The Integrated Biomarker Response Version 2 (IBRv2) index that combines responses of the above five oxidative stress biomarkers, was not only correlated positively with nBA concentration but could also indicate the occurrence of oxidative stress caused by acute concentration of nBA. These findings showed that P. tricornutum was sensitive to nBA compared to S. costatum, and the IBRv2 index was an effective tool for evaluating ecotoxicological effects on marine microalgae due to nBA spills.
DOI: 10.1016/j.chemosphere.2024.141424
2024
Detection and dietary risk of per- and polyfluoroalkyl substances in shellfish products from the coasts of Bohai Sea and South China Sea
Artificial per- and polyfluoroalkyl substances (PFASs) are widely distributed in the environment and are potentially harmful to human health. This study assessed the matrix effect of different shellfish on LC-MS analysis and the recoveries of PFASs in purified extracts purified by adding ENVI-Carb graphitized carbon black. Total 76 samples were collected from coastal cities of the Bohai Sea and South China Sea in China. Results showed that the signal response of perfluorocarboxylic acid increased with the length of fluorocarbon chains. ENVI-Carb can mitigate the shellfish matrix effects for analysis of PFASs. Ten PFASs components were detected in shellfish samples at concentrations ranging from 1.3 to 8.5 ng/g wet weight. The PFOA and PFHxS were the dominant components, and PFOA, PFTrDA and PFNA were detected at high rates of 58-93%. The highest levels of ∑PFASs were accumulated in clams, while the lowest levels were found in mussels. The dietary risk assessment indicated that PFASs potentially threaten human health via consumption of clam products in the Bohai Sea region. This study will improve the understanding of the contamination status and the dietary risk of PFASs in shellfish products along the coasts of Bohai Sea and South China Sea in China.
DOI: 10.1016/j.envpol.2024.123738
2024
Adsorption, natural attenuation, and microbial community response of ofloxacin and oxolinic acid in marine sediments
The pollution of quinolone antibiotics in the marine environment has attracted widespread attention, especially for ofloxacin (OFL) and oxolinic acid (OXO) due to their frequent detection. However, few studies have been conducted to assess the behaviors and microbial community response to these antibiotics in marine sediments, particularly for potential antibiotic-resistant bacteria. In this work, the adsorption characteristics, natural attenuation characteristics, and variation of microbial communities of OFL and OXO in marine sediments were investigated. The adsorption process of antibiotics in sediments occurred on the surface and internal pores of organic matter, where OFL was more likely to be transferred from seawater to sediment compared with OXO. Besides, the adsorption of two antibiotics on sediment surfaces was attributed to physisorption (pore filling, electrostatic interaction) and chemisorption (hydrogen bonding). The natural attenuation of OFL and OXO in marine sediment followed second-order reaction kinetics with half-lives of 6.02 and 26.71 days, respectively, wherein biodegradation contributed the most to attenuation, followed by photolysis. Microbial community structure in marine sediments exposure to antibiotics varied by reducing abundance and diversity of microbial communities, as a whole displaying as an increase in the relative abundance of Firmicutes whereas a decrease of Proteobacteria. In detail, Escherichia-Shigella sp., Blautia sp., Bifidobacterium sp., and Bacillus sp. were those antibiotic-resistant bacteria with potential ability to degrade OFL, while Bacillus sp. may be resistant to OXO. Furthermore, functional predictions indicated that the microbial communities in sediment may resist the stress caused by OFL and OXO through cyano-amino acid metabolism, and ascorbate and aldarate metabolism, respectively. The research is key to understanding fate and bacterial resistance of antibiotics in marine sediments.
DOI: 10.1007/s00343-023-3203-5
2024
Effects of inorganic nutrients and environmental factors on the removal of n-propylbenzene and isopropylbenzene in seawater by cryptophytes Rhinomonas reticulata S6A
DOI: 10.5603/pjnns.97759
2024
Predicting haemorrhagic transformation through serum biochemical indices for patients after endovascular treatment: a retrospective study
Introduction. The aim of this study was to determine the serum biochemical markers that can predict the risk of haemorrhagic transformation (HT) before and after endovascular treatment (EVT). Material and methods. This study included patients with anterior circulation large vessel occlusion (ACLVO) who underwent EVT within six hours of symptom onset between September 2017 and September 2022. These patients were retrospectively categorised into two groups: an HT group and a No-HT group. Results. A total of 180 patients were included in the study, of whom 55 (30.6%) had HT. The monocyte count before EVT (p = = 0.005, OR = 0.694, 95% CI 0.536–0.898), the activated partial thromboplastin time before EVT (p = 0.009, OR = 0.186, 95% CI 0.699–0.952), and the eosinophil count after EVT (p = 0.038, OR = 0.001, 95% CI 0.000–0.018) were all found to be independent predictors of HT, with warning values of 6.65%, 22.95 seconds, and 0.035*10^9/L, respectively. When compared to prediction using only demographic data [AUC = 0.662,95% CI (0.545, 0.780)], adding biochemical indices before EVT [AUC = 0.719,95% CI (0.617, 0.821)], adding biochemical indices after EVT [AUC = 0.670,95% CI (0.566, 0.773)], and adding both [AUC = 0.778,95% CI (0.686, 0.870)], the prediction efficiency of HT was improved among all three combinations, with no statistical significance. Conclusions. The levels of serum biochemical markers were found to show significant changes before and after EVT in ACLVO patients. A combination of demographic data and serum biochemical markers proved to be effective in predicting the occurrence of HT in patients with ACLVO who underwent EVT.
DOI: 10.1016/j.ecolind.2018.05.062
2018
Cited 16 times
Development of a classification scheme for evaluating water quality in marine environment receiving treated municipal effluent by an integrated biomarker approach in Meretrix meretrix
To evaluate the pollution level of marine environment received treated municipal effluent (TME), the water quality classification index (WQCI) capable of integrating biomarker results into a four-level pollution for effluent assessment was proposed and applied. The WQCI calculation was that of the integrated biomarker responses vesion 2 (IBRv2) index based on the expert system classification scale. In this research, mussels of Meretrix meretrix were treated with different effluent volume ratios (EVRs, 0–40%, v/v) for 12 days, six biomarkers of oxidative stress, metal exposure and neurotoxicity in both gills and digestive glands as well as the other two biomarkers of general health and genotoxicity in hemocytes were measured. Then based on the correlation analysis between the response of biomarkers and EVRs, the lysosomal membrane stability (LMS) and micronucleus frequency (MF) in hemocytes, glutathione (GSH) and acetylcholinesterase (AChE) in gills were chosen to calculate the IBRv2 and WQCI. The results showed that the control (EVR = 0%) was defined as Level I, EVR of 1–5% as Level II, EVR of 10–30% as Level III, and EVR of 40% as Level IV. In addition, two other sets of data of biomarkers in previous studies were used to test the applicability of the classification scheme established. The WQCI values and the evaluation results based on them were almost identical to those obtained by using the first set of data. This study is the first attempt to develop an index on water quality assessment of marine environment received discharged effluent from a biological perspective. The findings confirm that WQCI offers a potential measurement of water quality evaluation of marine environment and possible to be a water quality standard.
DOI: 10.1007/s10811-018-1411-8
2018
Cited 15 times
Responses of a new isolated Cyanobacterium aponinum strain to temperature, pH, CO2 and light quality
DOI: 10.1016/j.jwpe.2020.101311
2020
Cited 12 times
The biodegradation of Para-xylene in seawater by a newly isolated oceanic microalga Rhodomonas sp. JZB-2
Para-xylene (PX), as an important industrial chemical, has largely been transported by sea, which is followed by frequent PX leakage accidents at sea. Seawater contaminated by PX can be treated by bioremediation using microalgae, but there are a limited number of microalgal species that can be used to biodegrade PX. In this study, a novel Rhodomonas sp. JZB-2 (Cryptophyta) was isolated from Jiaozhou Bay (China), which could efficiently remove high concentrations of PX from seawater. The experimental result indicated that Rhodomonas sp. JZB-2 could completely biodegrade 30 mg/L of PX in 6 d. The growth inhibitory kinetics of this strain matched those of the Yano model, and it was calculated that 9.682 mg/L was the best concentration for degradation of PX by Rhodomonas sp. JZB-2. Besides, the biodegradation was the main PX removal mechanism. Therefore, Rhodomonas sp. JZB-2 is expected to be used in the bioremediation of marine environments polluted by PX.
DOI: 10.1016/j.jenvman.2022.114980
2022
Cited 6 times
Natural attenuation of sulfometuron-methyl in seawater: Kinetics, intermediates, toxicity change and ecological risk assessment
This research aims to evaluate the environmental feasibility of sulfometuron-methyl (SM) as a growth inhibitor for restricting the growth of Spartina alterniflora. To achieve this purpose, the natural attenuation characteristics, ecological risk, degradation pathway, and comprehensive toxicity changes of SM in seawater were investigated under the simulated marine environmental conditions of Jiaozhou Bay, China. The natural attenuation of SM in seawater followed first-order reaction kinetics with a rate constant (K) of 0.0694 d-1 and a half-life of 9.99 days. When photolysis, hydrolysis, and biodegradation pathways act alone, the rate constants K of SM were 0.0167, 0.0143, and 0.0099 d-1 respectively, indicating that their contributions to the total removal of SM decreased in turn. The calculation results of risk quotient (RQ) showed that the seawater containing 10 mg/L of SM demonstrated a very high risk to marine diatom Skeletonema costatum before and after 21 days of attenuation with RQ values of 24.46 and 6.32, respectively, however, the risk to other marine organisms (fish, crustaceans, and bivalves) decreased from moderate (RQ < 1) to low (RQ < 0.01). Four attenuation products of SM were identified and two degradation pathways of SM in seawater were proposed. Based on the rate of inhibition of bioluminescence, SM in seawater was not harmful to Photobacterium phosphoreum T3, whereas the toxicity of seawater containing SM increased with the extension of attenuation time, suggesting the formation of intermediate products with high aquatic toxicity. According to the toxicity values predicted by ECOSAR, the toxicity of one identified attenuation product was higher than that of SM. To the best of our knowledge, this is the first report on the attenuation characteristics and toxicity changes of SM in seawater. The results indicated that the toxicity of both SM and its degradation products to non-target marine organisms should be considered in evaluating the feasibility of SM in controlling coastal Spartina alterniflora.
DOI: 10.1016/j.ecoenv.2017.10.005
2018
Cited 14 times
Application of activated carbon to accelerate detoxification of paralytic shellfish toxins from mussels Mytilus galloprovincialis and scallops Chlamys farreri
Contamination of economic bivalves with paralytic shellfish toxins (PST) occurs frequently in many parts of the world, which potentially threatens consumer health and the marine aquaculture economy. It is the objective of this study to develop a suitable technology for accelerating detoxification of PST from shellfish using activated carbon (AC). The adsorption efficiency of PST by eight different AC materials and by different particle sizes of wood-based AC (WAC) were tested and compared. Then WAC particles (37–48 µm) were fed to mussels Mytilus galloprovincialis and scallops Chlamys farreri previously contaminated with PST through feeding with dinoflagellate Alexandrium tamarense ATHK. Results showed that the maximum adsorption ratio (65%) of PST was obtained by WAC. No significant differences in adsorption ratios were found between different particle sizes of WAC. The toxicity of mussels decreased by 41% and 68% after detoxification with WAC for 1 d and 3 d, respectively. Meanwhile, the detoxification ratio of mussels was approximately 3 times higher than that of scallops. This study suggests that the WAC could be used to accelerate the detoxification of PST by shellfish.
DOI: 10.1016/j.marpolbul.2018.04.024
2018
Cited 14 times
Integrated toxicity evaluation of metals in sediments of Jiaozhou Bay (China): Based on biomarkers responses in clam Ruditapes philippinarum exposed to sediment extracts
To evaluate the integrated toxicity of metals in sediments of Jiaozhou Bay, we exposed clam (Ruditapes philippinarum) to sediments extracts obtained using of sediment extraction with deionised water adjusted to pH 4 which simulated the weak acidity in the digestive juice of clams and tested the selected biomarkers responses in clams for exposure over 15 days. At the same time, the contents of metals in sediments were assessed with method of the mean sediment quality guideline quotient (SQG-Q). The integrated biomarker response version 2 (IBRv2) was used to assess the integrated toxicity induced by metals in sediment extracts based on biomarkers response in clams: the results demonstrated that site S7 located in the mouth of Nanxin'an River show higher IBRv2 values compared to the other sites. The IBRv2 values exhibited the good consistency with SQG-Q values.
DOI: 10.1016/j.jes.2021.02.029
2021
Cited 9 times
Natural attenuation characteristics and comprehensive toxicity changes of C9 aromatics under simulated marine conditions
Microcosmic experiments were performed under a simulated marine environment to investigate the natural attenuation of C9 aromatics using nine components (propylbenzene, isopropylbenzene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and indene). This research aims to assess the contribution of biodegradation and abiotic activity to total attenuation of C9 aromatics and ascertain the changes in the comprehensive toxicity of seawater in the natural environment. The process of natural attenuation indicates the agreement with pseudo-first-order kinetics for all nine components in microcosmic experiments. The half-lives of the nine main compounds in C9 aromatics ranged between 0.34 day and 0.44 day under optimal conditions. The experiments showed that the natural attenuation of nine aromatic hydrocarbons mainly occurred via abiotic processes. Seawater samples significantly inhibited the luminescence of P. phosphoreum (the luminescence inhibition ratio reached 100%) at the beginning of the experiment. In addition, the toxicity declined slowly and continued for 25 days. The attenuation kinetics and changes in toxicity could be applied to explore the natural attenuation of C9 aromatics in the marine environment.
DOI: 10.1007/s00216-021-03724-7
2021
Cited 8 times
Performance of different extraction methods for paralytic shellfish toxins and toxin stability in shellfish during storage
DOI: 10.1016/j.seppur.2010.10.011
2010
Cited 13 times
Coagulation enhancement of exopolysaccharide secreted by an Antarctic sea-ice bacterium on dye wastewater
The purpose of this paper is to study the enhancement of Bsi20310 exopolysaccharide (Bsi20310 EPS, secreted by an Antarctic sea-ice bacterium Pseudoalteromonas sp. Bsi20310), on coagulation of reactive brilliant red X-3B (RX-3B) by ferric chloride. The effect of solution pH, EPS addition timing and NaCl concentration for coagulation of RX-3B was investigated. The results showed that at pH 10, Fe(III) dosage of 55 mg/L, adding 150 mg/L Bsi20310 EPS enhanced the decolorization effectively. NaCl had little effect on the enhancement of Bsi20310 EPS. The EPS had negative surface charge and could combine with positive Fe(III)–dye flocs to form neutralized settleable Fe(III)–dye–EPS flocs. Results of residual Fe(III) concentration and ferric–ferron reaction kinetics indicated that EPS addition led not only more Fe(III) to participate in coagulation but also to form more Feb (the most effective ferric hydrolysis species) in coagulation. Bsi20310 EPS enhanced Fe(III) coagulation performance by neutralization, bridging and sweeping to improve the floc aggregation.
DOI: 10.1016/j.ecoenv.2018.10.103
2019
Cited 10 times
Kinetic analysis and degradation mechanism for natural attenuation of xylenes under simulated marine conditions
Microcosm experiments were conducted to examine the attenuation of selected chemicals, i.e. m-xylene (MX), o-xylene (OX) and p-xylene (PX), under simulated marine conditions. Natural attenuation and the contribution of oxidation, photodegradation, biodegradation and volatilization to total attenuation were evaluated. The development of attenuation was in agreement with pseudo-first-order kinetics for all xylenes. The half-lives of MX, OX, and PX under optimal conditions were 0.76, 0.74 and 0.88 days, respectively. Attenuation kinetics were proposed to analyze the natural attenuation of xylenes. The leading attenuation type of MX, OX, and PX was volatilization, and the attenuation rate constants (KV) were 0.5587, 0.6733, and 0.4821 d-1, respectively. Biodegradation of OX (Kb: 0.0003 d-1) was extremely inhibited. The attenuation kinetics presented the attenuation of xylenes in microcosm. The reaction kinetics could be applied to analyze the natural attenuation of chemicals. MX and OX can be converted to one another under certain conditions. Toluene and ethylbenzene were detected for OX in the OP (oxidation and photodegradation) experiment under simulated marine conditions. 4-Methylbenzyl alcohol, p-methyl benzaldehyde and p-toluic acid, as the major intermediates, were identified during the natural attenuation of PX using GC/MS.
DOI: 10.1007/s00343-019-9125-6
2019
Cited 10 times
Removal of phenol by Isochrysis galbana in seawater under varying temperature and light intensity
Phenol is a common industrial chemical produced and transported worldwide largely. Therefore, accidental spillage of phenol in the ocean causes an increasing concern. Microalgae are promising to remove phenol from marine waters. However, temperature and light intensity are two main factors that markedly influence biodegradation in marine environments. In this study, a marine golden alga Isochrysis galbana is selected to research the removal of phenol under different temperatures (10–30°C) and light intensities (0–240 µmol/(m2·s)). The results show that the most suitable temperature and light intensity for phenol removal are 20°C and 180 µmol/(m2·s), respectively, and 100 mg/L of phenol can be completely removed by microalga in 24 h at these conditions. I. galbana can also remove phenol under dark and low-temperature conditions. The removal of phenol by I. galbana at diverse temperatures and light intensities conform to first-order kinetics, and the process under dark conditions conform to zero-order kinetics. Thus, I. galbana can be used in the in-situ bioremediation of polluted seawater by phenol.
DOI: 10.1080/15320383.2016.1166175
2016
Cited 9 times
Distribution, Speciation and Bioaccumulation of Hg and As in Mariculture Sediments from Dongshan Bay, China
Hg and As are the major hazardous pollutants in marine sediments due to their high toxicity to benthonic organisms. Understanding the spatial distribution, speciation and bioaccumulation of these toxic elements in sediments is therefore of high environmental importance for identifying their potential risks. Sediments and bivalves Paphia undulata were collected from the mariculture area of Dongshan Bay, China, for characterizing geochemistry (by using the European Community Bureau of Reference (BCR) sequential extraction procedure) and bioaccumulation of Hg and As [by calculating the biota sediment accumulation factor (BSAF)]. Both elements in sediments were mostly associated with the residual fraction (69.52–95.06% and 88.22–91.12% of the total concentration, respectively), followed by the oxidizable (bound to sulfides and organic matter) fraction (1.25–25.32% and 3.62–6.00%, respectively). However, Hg presented a higher bioaccumulation than As. Correlation analysis indicated that As in residual fraction and Hg in oxidizable fraction exert positive contributions (R = 0.927, P < 0.01 and R = 0.869, P < 0.05, respectively) on their own bioaccumulation factor. This indicated that P. undulata could adsorb both Hg in organic fraction and As in residual fraction from the sediments. Therefore, we should pay more attention to the potential dissolution and release of metals bound to sediments in the digestive tracts of marine organisms.
DOI: 10.3389/fmars.2023.1171944
2023
Bioremediation of propylbenzenes by a novel marine microalga Rhinomonas reticulata S6A isolated from Daya Bay: acute toxicity, growth kinetics and biodegradation performance
This study investigated the degradation characteristics of propylbenzenes (PBZs, including isopropylbenzene and n-propylbenzene), with high leakage risks and ecological hazards, by a newly isolated marine microalga named Rhinomonas reticulata S6A which is a promising candidate for eco-friendly bioremediation from marine. About 72% and 56% of n-PBZ and i-PBZ can be degraded after 7 days in culture. The acute toxicity of n-PBZ (96h - EC 50 = 2.38 mg/L) was higher than that of i-PBZ (96h - EC 50 = 3.65 mg/L). The growth inhibition kinetics of this strain were consistent with the Edwards model ( R 2 = 0.998) and Aiba model ( R 2 = 0.999). The optimal concentrations for the degradation of n-PBZ and i-PBZ were calculated to be 2.42 mg/L and 2.78 mg/L, respectively. The degradation trends of PBZs conformed to the zero-order kinetic model, and k increased with initial concentrations. The moderate increase in inoculation density could accelerate the degradation of PBZs, with the maximum specific growth rates ( r ) of 1.116/d (n-PBZ) and 1.230/d (i-PBZ) at the initial inoculation density of 10 4 cells/mL, while over-inoculation (initial microalgae density more than 10 5 cells/mL) was not conducive to the degradation of the pollutants. There is not much data on the biodegradation of PBZs in the aquatic environment, so it would be worthwhile to try to apply the new microalgae to explore the fate of PBZs.
DOI: 10.1007/s00343-022-2074-5
2023
Marine ecological risk assessment for the herbicide sulfometuron-methyl based on species sensitivity distribution approach
DOI: 10.1007/s11802-023-5428-5
2023
Colloidal Gold Immunochromatographic Assay for Rapid On-Site Detection of Tetracycline in Seawater
DOI: 10.1007/s00128-019-02646-6
2019
Cited 8 times
Toxicological Assessment of Intermediates in Natural Attenuation of p-Xylene to Marine Microalgae
DOI: 10.1016/j.chemosphere.2017.07.045
2017
Cited 7 times
Four types of attenuation of phenol and cresols in microcosms under simulated marine conditions: A kinetic study
Phenol, o-cresol, m-cresol, and p-cresol were selected to conduct microcosm experiments to examine their attenuation under simulated marine conditions, aiming at estimating natural attenuation and the contribution of oxidation, photolysis, biodegradation, and volatilisation to total attenuation of phenol and three cresols in the marine environment. The development of attenuation in microcosms showed the relevance of the pseudo-first-order kinetic for all phenols. The half-lives of phenol, o-cresol, m-cresol, and p-cresol attenuation under optimal conditions were 7.9, 4.3, 5.3, and 4.4 d, respectively. Attenuation kinetics was proposed to analyse the natural attenuation of phenol and cresols. The leading attenuation type of phenol, o-cresol, and p-cresol was volatilisation, and the attenuation rate constants (Kv) were 0.0356, 0.0687, and 0.0710 d-1. Photolysis (Kp: 0.0584 d-1) was the major attenuation type for m-cresol. Biodegradation of phenol (Kb: 0.0021 d-1) and m-cresol (Kb: 0.0049 d-1) were extremely inhibited. The rank between the contributions of the four types of attenuation to total attenuation differed between phenol and the three cresols. The attenuation kinetics proposed in this study possibly demonstrated the attenuation of the phenol and cresols in microcosm. This new reaction kinetics can be used in the analysis of natural attenuation of chemical substances.
DOI: 10.1109/icassp.2008.4518696
2008
Cited 9 times
Voice conversion by combining frequency warping with unit selection
In this paper, we propose a novel voice conversion method by combining frequency warping and unit selection to improve the similarity to target speaker. We use frequency warping to get the warped source spectrum, which will be used as estimated target for later unit selection of the target speaker's spectrum. Such estimated target can preserve the natural transition of human's speech. Then, part of the warped source spectrum is replaced by the selected target speaker's real spectrum before reconstructing the converted speech to reduce the difference in detailed spectrum. TC- STAR 2007 voice conversion evaluation results show that the proposed method can achieve about 20% improvement in similarity score compared to only frequency warping.
DOI: 10.1016/j.chemosphere.2020.128533
2021
Cited 5 times
Environmental fate and aquatic effects of propylbenzenes and trimethylbenzenes: A review
Propylbenzenes (PBZs) and trimethylbenzenes (TMBs) are aromatic hydrocarbon compounds widely used in many industries with potential release to different environments. The fate and aquatic effects of these compounds in the environment were evaluated. Evidence suggests that PBZs and TMBs will rapidly volatilise from water and bioaccumulate in aquatic organisms. Under both aerobic and anaerobic conditions, these compounds are readily biodegradable, whereby 1,2,3-TMB is more stable than the others. In air, all five compounds have atmospheric photo-oxidation half-lives ranging from 0.31 to 1.55 d. The toxicity data collectively show that PBZs, 1,2,4- and 1,3,5-TMB pose high acute toxicity effects on aquatic organisms. Furthermore, freshwater species are more sensitive to these compounds than marine species. There is not much data on the occurrence of PZBs and TMBs in the aquatic environment. This review presents the current state of knowledge on the fate of PBZs and TMBs. Moreover, the acute and joint toxicity of these compounds to different aquatic organisms, especially in marine organisms, warrants further investigation.
DOI: 10.1007/s10811-022-02775-2
2022
Cited 3 times
Enhanced biodegradation of para-xylene by the marine cryptophyte Rhodomonas sp. JZB-2 by changing the concentrations of nutrients, iron, and vitamins
DOI: 10.1007/s11802-020-4480-7
2020
Cited 5 times
Microalgal Cultivation in Secondary Effluents: Enhancement of Algal Biomass, Nutrient Removal, and Lipid Productivity
DOI: 10.1007/s00343-019-8205-y
2019
Cited 5 times
Growth inhibition and oxidative stress in two species of marine diatoms exposed to 1-phenylethanol
DOI: 10.1007/s10811-016-1021-2
2016
Cited 4 times
Application of sodium erythorbate to promote the growth of Chlorella vulgaris
DOI: 10.1007/s10811-019-01945-z
2019
Cited 4 times
Effects of two common antibiotics on the growth and lipid production of Tetradesmus obliquus cultivated in the effluent of municipal wastewater treatment plant
2014
Cited 3 times
Adsorption Behavior of Acid Bordeaux B from Aqueous Solution onto Waste Biomass of Enteromorpha prolifera
Enteromorpha prolifera green algae is the main species that causes green tide in China’s Yellow Sea. To effectively realize the resourceful utilization of this biomass, batch experiments were carried out to investigate factors that impact the Acid Bordeaux B (ABB) absorption of E. prolifera powder, such as exposure time, pH, adsorbent dose, and oscillation frequency. The dye adsorption onto adsorbent was confirmed by Fourier transform infrared spectroscopy (FTIR). Results showed that amide, hydroxy, carboxylate, and C-O groups were involved in the adsorption process. The treatment conditions for dye concentration of 100 mg·L -1 were opti
2012
Cited 3 times
[Marine environmental assessment approaches based on biomarker index: a review].
Biomarkers are applied worldwide in marine environmental assessment due to their "early warning" function to chemical pollutants. Several integrative index approaches such as multi-marker pollution index (MPI), integrated biomarker response (IBR), bioeffect assessment index (BAI), biomarker response index (BRI), and health assessment index (HIS), have been developed based on biomarkers. By transforming the complex alterations of biomarkers into a single class or value, these approaches have been so far the useful tools for assessing the environmental quality. This review summarized the establishment of evaluation indicator system, the calculation of integrative index, the grading of pollution status, and the practical applications of each approach, and discussed the existing problems in marine environmental assessment based on biomarker index. Some improving suggestions were also proposed.
DOI: 10.1109/cesce.2010.161
2010
Cited 3 times
Metallothionein Levels in Gills and Visceral Mass of Ruditapes Philippinarum Exposed to Sublethal Doses of Cadmium and Copper
Metallothioneins (MTs) are widespread in various organisms, being suggested as specific biomarkers of heavy metal pollution, because their induction is obviously elevated by heavy metal exposure. Marine bivalves are suitable organisms for evaluating the impact of marine metal pollution. In this study we compare short-term, sub-lethal responses of one marine clam, Ruditapes philippinarum, exposed to Cu and Cd under laboratory conditions. MT concentrations are analyzed by mercury-saturation assay in gills and visceral mass of Ruditapes philippinarum collected from one control group and five experimental groups which differ by metal concentrations. Furthermore, MT concentrations are also studied in a time-series experiment after exposure to both metals. The visceral mass shows higher background values of MT than the gills. MT concentrations increase significantly in gills and visceral mass after Cu or Cd treatment for 5 days and the two metals show similar induced regulations in different organs after short-term exposure. But MT induced trend differs by Cu and Cd during the whole exposure time. In addition, it is also revealed that the ratio of MT inducement differs in gills and visceral mass. The inducible capacity of MT in visceral mass is greater than gills, therefore, MT in the visceral mass may combine great majority of the ingested heavy metals and prevent them from transferring to other organisms. We suggest that the MT in visceral mass of Ruditapes philippinarum be considered as a potential biomarker to indicate heavy metal pollution in marine system.
2013
Organic contamination assessment of Beibu Gulf intertidal zone with IBR index based on biomarkers of oxidative stress
DOI: 10.2139/ssrn.4594303
2023
Adsorption, Natural Attenuation, and Microbial Community Response of Ofloxacin and Oxolinic Acid in Marine Sediments
The pollution of quinolone antibiotics in marine environment has attracted widespread attention, especially for ofloxacin (OFL) and oxolinic acid (OXO) due to their frequent detection. However, few studies have been conducted for the behaviors and microbial community response to these antibiotics in marine sediments, particularly for potential antibiotic-resistant bacteria. In this work, the adsorption characteristics, natural attenuation characteristics, and variation of microbial community of OFL and OXO were investigated in sediments of Jiaozhou Bay, China. The adsorption process of antibiotics in sediments occurred on the surface and internal pores of organic matter, where OFL was more likely to be transferred from seawater to sediment compared with OXO. Besides, the adsorption of two antibiotics on sediment surfaces was attributed to physisorption (pore filling, electrostatic interaction) and chemisorption (hydrogen bonding). The natural attenuation of OFL and OXO in marine sediment followed second-order reaction kinetics with half-lives of 6.02 and 26.71 days, respectively. Wherein biodegradation contributed the most to attenuation, followed by photolysis. Microbial community structure in marine sediments exposure to antibiotics varied by reducing abundance and diversity of microbial communities, as a whole displaying as an increase in the relative abundance of Firmicutes while a decrease of Proteobacteria. In detail, Bacillus sp. was the antibiotic-resistant bacteria with potential degradation ability for two antibiotics. Our research is crucial to understanding fate and bacterial resistance of antibiotics in marine sediments.
DOI: 10.13227/j.hjkx.201701048
2017
[Spatial Distribution, Source and Ecological Risk Assessment of Heavy Metals in the Coastal Sediments of Northern Dongying City].
Concentrations of seven heavy metals in the coastal sediments of the northern Dongying City were measured. The spatial distribution and sources of heavy metals were discussed and the ecological risk was assessed using sediment quality guidelines (SQGs) and the potential ecological risk index (PERI). The concentration ranges of Hg, As, Pb, Cd, Cr, Cu, and Zn were calculated as 0.005-0.092, 3.44-10.41, 6.59-19.00, 0.50-1.10, 32.42-60.25, 1.72-23.78, and 31.13-69.96 mg·kg-1, respectively. Higher metal concentrations were observed at site S10, which was close to the mouth of Tiaohe River and contained plenty of organic matter, silt, and clay. Principal component analysis (PCA) indicated that As and Pb in the sediments were derived from natural weathering processes, while other metals were mainly attributed to anthropogenic sources, i.e., land-sourced pollutants transported by runoff. Concentrations of As, Cd, Cr, and Cu at some sampling sites exceeded the threshold effect level (TEL) stated in the SQGs implying occasional harmful effects on biological life. PERI showed that the sediments in this area generally had a medium risk, except sites S10, S3, and S9 posing a considerable risk, and that Cd and Hg were the major contributors to the ecological risk. It is necessary to take effective measures to control heavy metal fluxes from rivers around this area and to reduce the risk.
2009
[Recent progress in treatment of aquaculture wastewater based on microalgae--a review].
Microalgae enables aquaculture wastewater recycling through a biological conversion. Recently, many studies have been reported on microalgae cultivation and wastewater treatment, including developing various wastewater treatment technologies such as algae pond, activated algae, immobilized algae and algae photo-bioreactor. In this review, we address the mechanisms, progress and application in the purification of aquaculture wastewater, as well as some research perspectives.
DOI: 10.21437/interspeech.2007-217
2007
Combining length distribution model with decision tree in prosodic phrase prediction
2016
中国,Dongshan湾内養殖場海底堆積物におけるHgとAsの分布,化学種,生体内蓄積
DOI: 10.1360/032012-500
2013
北部湾文蛤体内氧化逆境标志物对重金属积累的响应研究
2011
Preliminary Exploration of User Education in Public Library
Based on the analysis of the significance of carrying on user education in library,this paper expounds the main contents of user education in public library,and puts forward the measures for strengthening the user education of public library.
2011
Application of Parametric Design Technology for Hydraulic Support Parts Based on Rapid Design Technology of Pro/E
As the starting point of rapid design,Pro/E which comes with Pro/Toolkit secondary development of model is a powerful tool to develop design capabilities and model deformation-aided design functionality.Process is achieved by using dynamic-link library with Microsoft Foundation Class(MFC) development of Pro / E dialog interface communication mechanism to VC + +6.0 as development platform,take Wildfire Pro / E 3.0 as second development test platform.
2012
Effects of benzo[a]pyrene and vitamin E on antioxidant defense system in redfin puffer Takifugu rubripes.
2012
On Challenges and Opportunities of Volunteerism Nurturing in China
With the development of volunteerism in China a series of achievements in recent years,focus on volunteerism in the community as well as pioneering the construction of spiritual civilization in China,all provide a good opportunity for cultivation of volunteerism.At the same time,cultivation of volunteerism is also facing a number of challenges,such as the lack of strong public awareness,congenital lack of volunteerism nurture,backward legal system,lack of protection mechanisms in volunteer spirit cultivation,undeveloped civil organizations,vector missing,insufficient government support and lack of power.Therefore,volunteerism nurturing needs to seize the opportunity and meet the challenge.
2012
Research of Automation System of Coal Mine Drainage
At requirements high yield and high efficiency coal mine drainage pump station automation requirements,a integration system with PLC and iFIX software is researched,which is named coal mine automatic drainage system.Introduced goal that system to reach,the composition of system and application of iFIX.The design of automatic drainage system can realize automatic drainage and ground monitor.
2012
The Development of Voluntary Organizations in China
The voluntary organizations in China have developed rapidly since 1980s.With the growth of voluntary teams,the role of voluntary organizations is highlighted.The most active voluntary organizations are voluntary organizations of community,voluntary organizations of the youth,the Red Cross Society of China and women voluntary organizations of China.These voluntary organizations are compensating for the lack of government functions,promoting socialist spiritual civilization and the building of a harmonious society.With the development of the voluntary organizations,the voluntary spirit is promoted,and the voluntary organizations provide a carrier for the cultivation of voluntary spirit.
2013
Effect of Illumination on Microalgae Cultured at High Cell Density in Photo-bioreactor
Photo-bioreactors(PBR) are important device for realizing high-density culture of microalgae.One of the key technologies for designing PBR is to choose the appropriate illumination mode.According to related research achievements domestic and international in recent years,the present research conditions of illumination technique in PBR were reviewed.An introduction is emphatically given of the effect of two factors as incident light properties(including light source,light intensity,light quality and light dark cycle etc.) and light energy distribution,on the microalgae growth.The future research directions are also put forward.It could provide reference for the efficient PBR system design and optimize.
2012
[Pollution assessment in the intertidal zone of Beibu Gulf using multi-biomarker pollution index].
This paper assessed the coastal environmental quality along the Beibu Gulf using a statistical approach, multi-biomarker pollution index (MPI). Samples of clam (Paphia undulata) and sediment were collected at nine sites from the intertidal zone of Beibu Gulf in April 2011. Nine biomarkers of response were measured both in gill and digestive gland in Paphia undulata, and twelve kinds of contaminants were measured in different sediment samples. According to the Pearson' s correlation coefficients between biomarker responses in Paphia undulata and contaminant levels in sediments, five biomarkers either in gill for oxidized glutathione (GSSG), reduced glutathione (GSH), glutathione S-transferase (GST) or in digestive gland for thiobarbituric acid reactive substances (TBARS) and glutathione peroxidase (GPx) were selected for MPI calculation. For each biomarker at each site, a response index was allocated, and the MPI value of this site was calculated as the sum of the response index of the five biomarkers. The results of the calculation (MPI values from 18 to 39) showed significant differences among sampling sites. The environmental quality of all sites ranged from class 1 (clean) to class 3 (lightly contaminated), and no site fell into class 4 (contaminated) or class 5 (heavily contaminated), indicating a good environmental quality in the intertidal zone of Beibu Gulf. However, the environmental quality at some sites (S1, S3, 54 and S7) fell into class 3 (lightly contaminated), indicating mild interference from human activities has occurred.
2010
Effects of BDE-47 on the chlorophyll fluorescence parameters of two species of marine microalgae.
Effects of 2,2',4,4'-tetrabrominated biphenyl ether(BDE-47) on photosynthetic characteristics of two marine microalgae were comprehensively investigated.The results showed that no significant inhibition of maximal photochemical efficiency of PSII(Fv/Fm),photochemical quenching(qP) of Chlorella sp.and Heterosigam akshiwo were determined at the concentration of 0.1~2.5μg/L,which meant that BDE-47 didn't cause damage to PSII reaction center of the two algae.At the dose of 2.5 μg/L PSII potential fluorescence efficiency(Fv/Fo),actual photochemical efficiency of PSII(φPSII) and electron transport rate(ETR) of Chlorella sp..were inhibited distinctly after exposed to BDE-47 for 96h.And φPSII,Fv/Fo and ETR of Heterosigam akashiwo,weren't observed inhibition at the BDE-47 concentration of 2.5 μg/L,which revealed that this microalgae was more tolerant than Chlorella sp..Among all of chlorophyll fluorescence parameters,Fv/Fo,φPSII and ETR are more suitable to be used as biomarkers for evaluation of pollution level of BDE-47 in marine environment.
2010
STUDY THE IMPACT AND COUNTERMEASURES OF THE GAS PIPELINE CONSTRUCTION ON THE ECOLOGICAL ENVIRONMENT
To study the impacts of gas pipeline construction on the ecological environment,the quantitative prediction of the eight houses to Changchun pipeline during the construction of the region of the soil environment,agricultural production,wildlife and ecological environmental by Bawu to Changchun pipeline.The results showed that: the construction of gas pipeline in the region have an impact on soil environment and thus on local agricultural production to a certain influence,but these effects are primarily concentrated in the construction period,and the impact of the construction period is temporary,recoverable of pipeline have no obvious effect on the regional ecological environment,ecological systems still remains its stable.
2010
Distribution Characteristics of Total Organic Carbon,Oil,Sulfide and Microorganisms in the Estuary Tidal Beach of Sanba River
In order to investigate the distribution of primary contaminants and the environmental bioremediation potential of indigenous microorganisms in the tidal beach of Sanba River estuary at Muping,Yantai, Shandong,the horizontal and vertical distribution characteristics of total organic carbon(TOC),oil,sulfide and microorganisms in the sediment samples collected from this area were determined.The environmental quality in this area was also evaluated using the single factor pollution index method.The results showed that the pollution index was in the order TOC sulfide oil.Moreover,the pollution degrees of TOC,oil and sulfide in the contaminated estuary area were significantly higher than those in the control site;and,more serious pollution was found in surface sediment(0-≤20 cm) closer to the estuary.These results indicate that tidal beach pollution could be mainly attributed to pollution discharge from the river.The investigation of the vertical profile of pollutants revealed that the pollutant contents were highest in the subsurface layer(5-≤20 cm),and with increasing depth(0-≤50 cm),the pollutants increased first but then decreased in the deep layer.With regards to the distribution profile of microorganisms,it suggested that the organic matter input could elevate the number and respiratory intensity of heterotrophic microorganisms in the sediment.This indicated that indigenous microorganisms could improve the mineralization and output of organic matter by respiration process,showing some bioremediation potential.
2010
Development of parameterized module about gear based on UG customization
As the development of industry,application of gear in mechanical equipment is more diffusively.Based on the method of dummy design in product,involute equation is used during the build process of gear.For avoiding repeated build in design and enhancing the efficiency,four tools of the software UG are used to develop a parameterized module about straight toothed cylindrical gear in the machine based on the feature of the working equipment in the mining excavator.User can realize the build of gear quickly only to input the parameter such as the number of tooth、modulus and so on.
DOI: 10.2991/emim-17.2017.123
2017
The Research of Oil Pipeline Patrol by UAV in the First Sub-Factory of PCOC
The main body of PCOC (Petrochina Changqing Oilfield Company) is in the Ordos Basin, exploration with a total area of about 37 square kilometers, and whose exploration area is highly fragmented.The situation of the pipeline rupture emerge in endlessly as the result of natural conditions and human factors each year.The first sub-factory of PCOC is located in the Yishan Slope of the Ordos Basin in Yan'an, all of the region is hilly gully region, most of the oil pipeline is laying along the topography, which is difficult for labor patrol, UAV patrol is still in stage of testing.The STX-100 four rotor industrial-grade UAV has good performance, suitable for complex area of oil pipeline patrol work, can effectively relieve the staff.
2009
The Chinese and Foreign School Moral Education Comparison on Moral Control Mode
School moral education is one of the fundamental ways to achieve moral control.The overseas school moral education's merits mainly include: The moral education venerates the rationalism tradition;the goal and the content of moral education are clear and concrete;the moral education ways are in line with their own national conditions and so on.Refer to the merit of the overseas school moral education,our school moral education pattern mainly pay great attention the following several aspects: the moral education idea should adapt to the requirements of the times;the moral education content should manifest the level request;the moral ability raising should become the education base;the moral education way should respect the needs of students.
2008
Study on Optimum Process Conditions of Extracting Sludge Protein by Acid Hydrolysis
In order to fully extract the cell protein in the sewage sludge and to realize the incremental use of the sludge,the residual sludge from Licunhe Wastewater Treatment Plant of Qingdao City was hydrolyzed by acid to extract protein.By a series of orthogonal test,the impacts of hydrolysis temperature,reaction time,pH of the reaction system,and ratio of solid(g) to liquid(mL),etc.on the extraction ratio of protein out of the sludge were examined.The result showed that the hydrolysis temperature and pH could obviously influence the protein extraction ratio.The optimal process conditions for extraction of sludge protein were as follows: temperature(121 ℃),reaction time 5 h,(pH 1.25) and ratio of solid to liquid(1∶3.0).Under these conditions,the maximal protein extraction ratio was 62.71% and reductive ratio of sample could reach to 30.49%.It was indicated that after extracting protein from residual sludge,the mass of sludge could also be reduced.
2009
The relations between function and modeling of kitchen cabinet
The article analysed the relationship of function and modeling of the furniture from the design of kitchen cabinet according the markect experience in the harbin district.
2009
[Spectroscopy study of methyl parathion molecularly imprinted polymers].
Three molecularly imprinted polymers were synthesized with different functional monomers respectively, using methyl parathion as the template. These monomers are methacrylic acid, acrylamide and 4-vinylpyridine. According to the UV spectrum study the interaction between methyl parathion and 4-vinylpyridine was stronger than that of the others. Comparably, the infrared spectrum study showed the same results which indicated that 4-vinylpyridine could associate with the template at two different kinds of binding sites, the P-O-C and the -NO2 site, and is most likely to form steady covalent bonds with methyl parathion, while the other two monomers could only associate with the template at the P-O-C site. Furthermore, the infrared spectra of the synthesized polymers confirmed the existence of the functional groups in each kind of polymer, which might interact with the template.
2009
ANALYSIS OF CITY ECO-SYSTEM DESTRUCTION CAUSED BY LIVING GARBAGE AND COUNTERMEASURE OF PREVENTION AND CONTROL
With the growth of economic development and urbanization of China,the living standard of urban residents are raising constantly,but the environmental problems concerned by public,especially for problem of urban living garbage,have become worse.The status quo of city living garbage treatment is summarized,and its destruction on city eco-system and measures of prevention and control are discussed.
2009
Influence of Solvents and Functional Monomers on Preparation of Methyl Parathion Molecularly Imprinted Polymers
In order to separate and concentrate the organophosphorus pesticides in water efficiently, the molecularly imprinted polymers (MIPs) were synthesized by bulk polymerization with methyl parathion as template molecule and ethylene glycol dimethacrylate as crosslinking agent. A number of experiments were conducted to investigate the factors, such as the species and amount of the used solvent and functional monomer, which are likely to be the important factors affecting the recognition properties of MIPs. It was found that both the specific area and swelling ratio of the MIPs prepared vary significantly as the used solvent volume changes, and the MIP prepared with chloroform as the solvent exhibits high selectivity for methyl parathion. The 1H-NMR spectra show that the functional monomer 4-vinylpyridine (4VP) forms stable complex with template molecules via π-π accumulation effect; and the experimental results indicate that the 4VP is more efficient to be used as the functional monomer than other two tested monomers, methacrylic acid (MAA) and acrylamide (MA), especially when the used molar ratio of 4VP to template is 4:1. Moreover, the adsorption isotherm of the MIP prepared with 4VP: template=4:1 was studied, and the Langmuir isotherm analysis shows that the maximum adsorption capacity of this MIP is 625.5μmol·g-1, which is much higher than that of the nonimprinted polymer (NIP) (285.7μmol·g- 1). The above prepared MIP was also used to extract different kinds of organophosphorus pesticides in seawater sample, and it exhibits different affinities toward different pesticides with various molecular structures. It seems that, after improving and enhancing the selectivity of the prepared MIP, it is hopeful to be used to separate and concentrate specially the methyl parathion in water.
2009
[Biofabrication with chitosan and its application progress].
Chitosan is a polymer with good biocompatibility, unique pH-responsive solubility, convenient modification and easier film-formability. Chitosan could serve as an active mediator between biological components and microfabricated devices to prepare biological micro electro mechanical systems (BioMEMS) with high selectivity and sensitivity. Recently, there has been a growing interest in BioMEMS based on biofabrication of chitosan. We reviewed the mechanisms and processes of three biofabrication methods based on chitosan, including directed assembly, enzymatic assembly and self-assembly. Current applications and research progress in biological, medical and environmental fields are also discussed. Finally, future research directions are prospected.
DOI: 10.1016/j.envres.2021.112558
2022
Intermediates formed during natural attenuation of C9 aromatics under simulated marine conditions: Identification, transformation pathway, and toxicity to microalgae
C9 aromatics - benzene hydrocarbon containing nine carbon atoms among - leakage accident has caused serious damage to the marine ecology near Quangang District, Fujian Province, China. The ecological restoration of the accident sea area is basically realized through natural attenuation. To determine whether the natural attenuation of C9 aromatics in the marine environment will generate highly toxic intermediates, and thus cause more serious harm to marine ecology, the intermediates of C9 aromatics (n-propylbenzene, isopropylbenzene, 2-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, and indene) in the process of natural attenuation were studied under the marine conditions simulated by a microcosm. The acute toxic effects of 12 intermediates with longer residual time on Phaeodactylum tricornutum were also ascertained. Twenty natural attenuation intermediates of C9 aromatics were identified. These products primarily include the derivatives of phenols, aromatic alcohols, aromatic aldehydes, aromatic ketones, and aromatic acids, as well as an aromatic lactone compound. No intermediates of 1,3,5-trimethylbenzene and indene during the attenuation process were determined. The indirect photooxidation initiated by hydroxyl radical might play an essential role in the formation of intermediates of C9 aromatic. Based on the 96-h EC50 values for P. tricornutum, the toxicity of the 12 intermediates, in descending order, was: 4-ethylphenol, 2-methylacetophenone, 2,3-dimethylbenzyl alcohol, 4-methylacetophenone, 3-methylacetophenone, 1-phenyl-1-propanol, 1-(2-methylphenyl) ethanol, 2-phenyl-2-propanol, 3,4-dimethylbenzoic acid, 2,4-dimethylbenzoic acid, 2,5-dimethylbenzoic acid, then 4-tolylacetic acid. The 96-h EC50 values of the intermediates of C9 aromatics to P. tricornutum ranged from 8.4 to 199.1 mg/L, which were lower than that of their corresponding parent compound. The findings provided essential fundamental insights for the assessment of marine environmental risk of C9 aromatics leakage accidents, and subsequent emergency disposal countermeasures.
DOI: 10.3389/fmars.2022.996263
2022
Emergency responses to acrylonitrile maritime spills from the perspective of marine ecological protection
The increases in chemical shipping volumes increase the risk of hazardous noxious substances (HNSs) spills at sea. As one of the most frequently transported HNSs, acrylonitrile (ACN) spill incidents occur from time to time. The spilled ACN will have a wide range of short-term and long-term impacts on the marine environment. To reasonably standardise and optimise the emergency response countermeasures for ACN spill and maintain marine ecological health, the marine ecological hazards and physico-chemical behaviours of ACN were summarised. Based on this, the emergency response countermeasures for ACN spill at sea were studied and summarised in five aspects: spill source control, rapid prediction, emergency monitoring, numerical simulation and impact assessment, and elimination of ACN. This review forms a set of systematic emergency response countermeasures for deployment in ACN maritime spill incidents.
2007
[Relationship among hepatocyte apoptosis, P450 2E1 and oxidative stress in alcoholic liver disease of rats].
OBJECTIVE To observe the pathological changes and investigate the correlation of hepatocyte apoptosis with cytochrome P450 2E1(CYP2E1) expression and oxygen free radical in alcoholic liver disease (ALD) in rat. METHODS 40% ethanol in the dose of 8 g/kg body weight was given to rats by gavage twice daily for 8 weeks in model group (n=37), and rats in control group (n=33) received same volume of saline by gavage. At the end of the 8th week, the contents of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. The pathological changes in the liver was observed under light microscope with hematoxylin and eosin (HE) staining, and hepatocyte apoptosis was detected by the terminal deoxynucleotidyl transferase mediated dUTP biotin nick and labeling (TUNEL) method. Expression of serum CYP2E1 was determined by polymerase chain reaction (PCR), the contents of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) in serum were detected by thibabituric acid (TBA) quantifying method. RESULTS The TUNEL positive cells were located around the central vein, and spotty and focal necrosis was found in the ALD group. The apoptotic index (AI) in the ALD group was significantly higher than in the control group (P<0.05). To express in CYP2E1, the allelic frequency of c1 and c2 were 91.65%, and 8.35% respectively, in control group, while the allelic frequency of c1 and c2 were 53.35% and 46.65%, respectively, in ALD group, and there were significantly differences between two groups (all P<0.05). The content of MDA in serum had positive correlation with hepatocyte apoptosis index (MDA vs. AI, r( MDA ) =0.644), and the activity of SOD in serum had negative correlation with AI (SOD vs. AI, r( SOD ) =-0.511, all P<0.05) in the ALD group, and there was negative correlation between MDA and SOD (r=-0.582, P<0.05). CONCLUSION Chronic alcohol administration induced alcoholic liver disease and liver dysfunction, and hepatocyte apoptosis is enhanced. Rsa I and Pst I RFLPs are related with ALD in model rats, and c2 gene might be related with the development of ALD. The content of MDA and activity of SOD play an important role in the process of hepatocyte apoptosis and lipid peroxidation process.
2007
Comparison of Genomic DNA Extraction Methods from Artemisia sphaerocephala Krasch Seed
Comparison test was carried out on three genomic DNA extraction methods from Artemisia sphaerocephala Krasch seed.The results showed that SDS-CTAB method was the best one,then SDS method,and CTAB method was not recommended.
2007
Study on characters of fixed Acetycholinesterase(AChE) in seawater
The characters of fixed enzyme in seawater showed that there is a good reproducibility(RSD=2.33%,n=12),when concentration of subsrate(ATCh) ranged from 5.2 mmol/L to 41.6 mmol/L,there is a good linearity(r=0.997) between response of biosensor and ATCh,and the optimum concentration and injection volume of ATCh were 41.6 mmol/L and 40 μL respectively.The work also showed excessive substrate decreased the activity of immobilized enzyme.The optimum salinity and temperature of immobilized enzyme were 24.9 and 30℃ respectively in different seawater.But when pH of seawater ranged 7 to 9,the activity of immobilized enzyme is increased with ascending of pH value.
2006
Flow injection biosensor based on the immobilized AChE
A biosensor based on the flow injection system was constructed with the immobilized AChE from Scomberomorus niphonius (Curier) as identification element and a pH electrode as transducer. When phosphate buffer was used as carrier liquid, a good reproducibility (RSD = 1.427% , n=10) of the biosensor response was obtained after the substrate was injected repetitively. After an incubation time of 20 min, the calibration graph to methyl-parathion is linear (r = 0.9986) when its concentration ranges from 4.29 x 10(-10) mol x L(-1) to 4.29 x 10(-8) mol x L(-1) , and the detection limit is 1.3 x 10(-10) mol x L(-1). However, the sensitivity of this biosensor to methyl-parathion when using clean seawater as carrier liquid is not as good as that using phosphate buffer. But after preoxidation of methyl-parathion with NaClO as oxidant, the detection limit of the biosensor to methyl-parathion in seawater can be improve to 2.16 x 10(-7) mol x L(-1).
2005
A Study on Dye Adsorption by Sewage Sludge in Dye Wastewater
On the basis of optimizing the operation conditions for dye adsorption by sewage sludge in dye wastewater, the maximum capacity and the adsorption patterns for sewage sludge adsorbing 3 kinds of dye, Neutral Black BL(NB-BL), Neutral Orange(NO) and Acid Black(AB), were studied. It was shown that, the percent removal of dyes in wastewater depended not only on the temperature at which the sewage sludge was baked, but also on the pH of wastewater and the absorbent time. However, the change in wastewater temperature was somewhat less effective. The optimal operation conditions were found to be as follows: the sewage sludge was baked at 400℃ as an absorbent, the pH value and temperature of the wastewater were 1.0 and 30℃, respectively, and the adsorption time was 30min. A maximum adsorption of dyes of about 29mg·g -1 by sewage sludge could be obtained under the optimal conditions mentioned above, with a percentage color removal of 98% in wastewater. This removal was higher than that of other absorbents and close to that of active charcoal. The pattern for sewage sludge adsorbing NB-BL fits well to the Langmuir Equation; whereas, the other two dyes were adsorbed based on the Henry Equation. The excellent decolor ability of sewage sludge made it possible to be applied extensively in dye wastewater treatment.
2005
The Inheritance and Innovation of Deng Xiaoping's Development Theory by the Concept of Scientific Development
Deng Xiaoping's Development Theory initiates focusing on economic construction, seeking a coordinated and sustainable development and taking the interest of people as the final goal. The Concept of Scientific Development not only inherits Deng's theory, but also overcomes its idealistic limitations as it attaches more importance to economic, political and cultural developments, puts emphasis on the promotion of human's all-round development by constantly meeting people's various needs, hence realizes the innovation of Deng Xiaoping's Development Theory.
DOI: 10.15446/esrj.v25n1.93184
2021
Fault diagnosis mechanism of gears and bearings for coal mining equipment in a complex geological environment
The traditional research method of fault diagnosis mechanism has poor stability, which leads to the difference of fault diagnosis and location results. Therefore, under the complex geological environment, a new research method of fault diagnosis mechanism of gear and bearing for coal mining equipment is proposed. This method calculates gears and bearings’ yield strength by analyzing coal mining equipment’s bearing capacity elasticity. According to the fitting degree, the equipment sample’s projection space is confirmed, the fault features of gear and bearing are extracted by segmentation algorithm, the optimal fitness is set by positioning algorithm, the location of fault center is obtained, and the fault mechanism diagnosis is studied. Experimental results show that compared with the traditional method, the proposed method is more stable, and the difference in fault diagnosis results is minimal. It can be seen that this method is more suitable for fault diagnosis of coal mining equipment.