[Comparison and Source Apportionment of PAHs Pollution of Runoff from Roads in Suburb and Urban Areas of Shanghai].

Rapid urbanization has driven surface runoff pollution in urban areas to a serious state. In particular, polycyclic aromatic hydrocarbons(PAHs)from road surface runoff has attracted wide attention. Two traffic roads in Shanghai (Caobao Road in an urban central area, and Jiajin Expressway in the suburbs) were identified as research objects. Runoff samples from these two traffic roads were collected for 7 rainfall events between 2007 and 2018. Then, the concentration characteristics and composition ratio of PAHs were analyzed. The differences in pollution sources of runoff PAHs from two types of traffic roads were identified based on characteristic ratio method and positive matrix factorization(PMF). The results showed that the geometric mean value (5539.2 ng·L-1) of 16 PAHs of runoff from Jiajin Expressway in the suburbs was 10 times greater than that from Caobao Road (548.1 ng·L-1), which was related to a higher truck traffic and a lower cleaning frequency on Jiajin Expressway. The benzo(a)pyrene(BaP)concentration on both roads exceeded the national emission standard, and the amount in the Jiajin Expressway was up to 21 times higher than the standard. There was no significant difference in the composition of PAHs of runoff between Caobao Road and Jiading Expressway, and 4-6 ring were dominant and responsible for 80% of total PAHs loads in both sites. Based on the analysis of the characteristic ratio method, the PAHs of runoff from Caobao Road mostly came from coal-fired sources and traffic sources, while that from Jiajin Expressway were mostly from fossil fuels, coal, and other traffic sources. Quantitative source analysis through PMF method showed that the primary sources of PAHs were gas and coal, accounting for 48.6%, followed by traffic emission sources (29.8%), and oil sources (21.7%). The contribution ratios of PAHs sources of runoff from Jiajin Expressway, sorted in descending order, are:traffic emission sources (38.5%), coal-fired sources (34.6%), oil sources (14.6%), and coking sources (12.6%). PAHs sources and contribution rates between urban and suburban roads are completely different. Gas and coal were the main sources of PAHs of runoff from Caobao Road, which was related to the high population density and relatively large gas consumption in the Xuhui District. Traffic emission was the main source of PAHs from surface runoff on Jiajin Expressway, which was related to the massive flow of coaches and trucks, and their higher PAHs emission compared to small cars. In addition, there are still coking sources of PAHs of runoff from Jiajin Expressway, which can be related to the massive industrial coal consumption in the Qingpu District.

[Distribution Characteristics of Sulfonamide Antibiotic Resistance Genes in a Drinking Water Source in East China].

Antibiotic resistance genes (ARGs) in drinking water sources have attracted widespread attention due to the threat they pose to water security and human health. This study mainly focused on the distribution of sulfonamide ARGs (sul 1, sul 2) and one integrase gene (intI 1) in water and sediment using qualitative and fluorescent quantitative PCR, based on previous work on the characteristics of 13 kinds of sulfonamides in a drinking water source in East China. Results showed that the three target genes were all detected in water and sediment. The sul 1 gene was the sulfonamide ARG with highest concentration, with 1.5×104-6.4×105 copies·mL-1 in source water and maximum concentration of 1.6×108 copies·g-1 in sediment. Concentration of sul 1 was 0.6-2.2, 0.5-1.9 order of magnitudes higher than sul 2 and intI 1 genes, respectively. There was no significant difference between the absolute concentrations of sul 1, sul 2, and intI 1 in inflow and outflow. However, in the case of sediment, absolute abundances of sul 1, sul 2, and intI 1 in outflow were higher than those in inflow. The maximum concentration of sul 1 was detected in outflow in summer (6.4×105 copies·mL-1). The concentration of intI 1 was higher in winter compared to other seasons. There was a positive correlation between sul 1 and 13 sulfonamides (r=0.69, P<0.05), and the relative concentration of sul 1 and amount of sulfamethoxazole were significantly positively related (r=0.79, P<0.01). There were also positive correlations between the relative concentrations of intI 1 and sul 1, sul 2 (r:0.80 and 0.73, P<0.05), respectively, suggesting that intI 1 played an important role in horizontal gene transfer of sulfonamide ARGs in this drinking water source. This study provides basic data for monitoring pollution of ARGs, as well as a basis for controlling ARG pollution in the drinking water environment and making management decisions.

Ecotoxicological evaluation of low-concentration bisphenol A exposure on the soil nematode Caenorhabditis elegans and intrinsic mechanisms of stress response in vivo.

As a representative species of nematodes, Caenorhabditis elegans is an attractive animal model for evaluating ecotoxicological effects and intrinsic mechanisms of the stress response in vivo. To acquire a better knowledge of environmental effects of bisphenol A (BPA), ecotoxicological evaluations were conducted using C. elegans on the physiological (growth, locomotion behaviors, and reproduction), biochemical (lipofuscin accumulation, reactive oxygen species production, and cell apoptosis), and molecular (stress-related gene expression) responses. Nematodes were exposed to BPA (0.001-10 µM) in 2 assay systems (L4 larvae for 24 h and L1 larvae for 72 h). Exposure to BPA could significantly (p < 0.05) alter body length, locomotion behaviors, brood size, cell apoptosis, and selected stress-related gene expression. At the physiological level, BPA exerted adverse effects on nematodes at the microgram per liter level in both assay systems, with head thrashes as the most sensitive endpoint. At the biochemical level, apoptosis degree showed increases at concentrations above 0.1 µM in both assay systems. At the molecular level, BPA induced increases in selected stress-related gene expression, even at the lowest tested concentration. In addition, BPA-induced cell apoptosis was suggested as a potential mode of action, resulting in adverse physiological effects. Therefore, BPA exposure was speculated to impose developmental, reproductive, and neurobehavioral toxicities on C. elegans and caused variations of stress-related gene expression. Environ Toxicol Chem 2016;35:2041-2047. © 2016 SETAC.

Ecotoxicity of bisphenol A to Caenorhabditis elegans by multigenerational exposure and variations of stress response in vivo across generations.

In order to understand how bisphenol A (BPA) exposure acts on the evolutionary dynamics of populations and changes of stress response across generations, the model animal Caenorhabditis elegans was used to conduct the multigenerational testing. Multiple endpoints at the physiological (growth, reproduction, and locomotion behaviors) and molecular (stress-related gene expressions) levels were examined by multigenerational exposure to low-concentration BPA (0.001-10 µM) across four generations. The results showed that changes of physiological-level effects across four generations varied in magnitude and direction, depending on the exposure concentrations. C. elegans individuals in the first generation grew smaller, moved slower, and produced less offsprings than the controls by BPA exposure. As for each trait tested, the first generation response could be commonly mirrored in the subsequent generations at the highest concentration of 10 µM. However, at lower concentrations, response of parental generation was a relatively poor predictor of the effects on progeny, as acclimation or cumulative damage could occur in the subsequent generations. The integrated gene expression profiles visually illustrated that the tested gene expressions at low concentrations (0.001-0.01 µM) were more obviously changed in both G1 and G4 generations, and the G1 generation showed a much greater degree of increase in stress-related gene expressions than the G4 generation. The multigenerational toxicity data emphasize the need of considering biological effects over multiple generations to conduct accurate assessment of environmental risks of toxicants on population dynamics.

[Distribution Characteristics and Health Risk Assessment of Thirteen Sulfonamides Antibiotics in a Drinking Water Source in East China].

Trace levels of residual antibiotics in drinking water sources may threaten public health and becomes a serious issue in modern society. Occurrence and distribution of 13 sulfonamides antibiotics in a drinking water source in East China were investigated using solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. The results revealed that all 13 sulfonamides were detected with the total concentrations ranging from 10.5 ng·L-1 to 238.5 ng·L-1. Sulfamethoxazole (SMX) and sulfonamide (SAM) presented the 100% detected frequency, and the maximum concentrations reached 107.0 ng·L-1 and 43.1 ng·L-1, respectively. Sulfonamides contamination levels in the inlet were relatively higher than those in the outlet. The concentration of SMX was substantially unchanged in different positions of drinking water source. Seasonal variation of sulfonamide concentration showed that the concentrations were higher in winter and spring compared with those in summer and autumn. The range of total sulfonamides concentration detected in winter and spring was from 110.8 ng·L-1 to 117.9 ng·L-1, which was 3.6-3.8 times higher than those in summer and autumn. Human health risk characterization of residual sulfonamides in drinking water source was based on the assessment of risk quotients (RQs) for which different life stages were taken into account. The results showed that no sulfonamides had a RQs higher than 1. Trimethoprim (TMP) was the most risky antibiotic to the 0-3 months old infants with RQs reaching 0.001. Although the sulfonamides detected in the drinking water source do not pose any risk to the peoples' health, the implication of long-time exposure and comprehensive risk still deserve attention.

Characterization of Chlorinated Aliphatic Hydrocarbons and Environmental Variables in a Shallow Groundwater in Shanghai Using Kriging Interpolation and Multifactorial Analysis.

CAHs, as a cleaning solvent, widely contaminated shallow groundwater with the development of manufacturing in China's Yangtze River Delta. This study focused on the distribution of CAHs, and correlations between CAHs and environmental variables in a shallow groundwater in Shanghai, using kriging interpolation and multifactorial analysis. The results showed that the overall CAHs plume area (above DIV) was approximately 9,000 m(2) and located in the 2-4 m underground, DNAPL was accumulated at an area of approximately 1,400 m(2) and located in the 6-8m sandy silt layer on the top of the muddy silty clay. Heatmap of PPC for CAHs and environmental variables showed that the correlation between "Fe(2+)" and most CAHs such as "1,1,1-TCA", "1,1-DCA", "1,1-DCE" and "%TCA" were significantly positive (p<0.001), but "%CA" and/or "%VC" was not, and "Cl-" was significantly positive correlated with "1,1-DCA" and "1,1-DCE" (p<0.001). The PCA demonstrated that the relative proportions of CAHs in groundwater were mostly controlled by the sources and the natural attenuation. In conclusion, the combination of geographical and chemometrics was helpful to establishing an aerial perspective of CAHs and identifying reasons for the accumulation of toxic dechlorination intermediates, and could become a useful tool for characterizing contaminated sites in general.

Natural attenuation model and biodegradation for 1,1,1-trichloroethane contaminant in shallow groundwater.

Natural attenuation is an effective and feasible technology for controlling groundwater contamination. This study investigated the potential effectiveness and mechanisms of natural attenuation of 1,1,1-trichloroethane (TCA) contaminants in shallow groundwater in Shanghai by using a column simulation experiment, reactive transport model, and 16S rRNA gene clone library. The results indicated that the majority of the contaminant mass was present at 2-6 m in depth, the contaminated area was approximately 1000 m × 1000 m, and natural attenuation processes were occurring at the site. The effluent breakthrough curves from the column experiments demonstrated that the effectiveness of TCA natural attenuation in the groundwater accorded with the advection-dispersion-reaction equation. The kinetic parameter of adsorption and biotic dehydrochlorination of TCA was 0.068 m(3)/kg and 0.0045 d(-1). The contamination plume was predicted to diminish and the maximum concentration of TCA decreased to 280 µg/L. The bacterial community during TCA degradation in groundwater belonged to Trichococcus, Geobacteraceae, Geobacter, Mucilaginibacter, and Arthrobacter.

High-throughput screening for a moderately halophilic phenol-degrading strain and its salt tolerance response.

A high-throughput screening system for moderately halophilic phenol-degrading bacteria from various habitats was developed to replace the conventional strain screening owing to its high efficiency. Bacterial enrichments were cultivated in 48 deep well microplates instead of shake flasks or tubes. Measurement of phenol concentrations was performed in 96-well microplates instead of using the conventional spectrophotometric method or high-performance liquid chromatography (HPLC). The high-throughput screening system was used to cultivate forty-three bacterial enrichments and gained a halophilic bacterial community E3 with the best phenol-degrading capability. Halomonas sp. strain 4-5 was isolated from the E3 community. Strain 4-5 was able to degrade more than 94% of the phenol (500 mg · L(-1) starting concentration) over a range of 3%-10% NaCl. Additionally, the strain accumulated the compatible solute, ectoine, with increasing salt concentrations. PCR detection of the functional genes suggested that the largest subunit of multicomponent phenol hydroxylase (LmPH) and catechol 1,2-dioxygenase (C12O) were active in the phenol degradation process.

Polybrominated diphenyl ethers in resident Eurasian Tree Sparrow from Shanghai: geographical distribution and implication for potential sources.

An investigation of polybrominated diphenyl ethers (PBDEs) in Eurasian Tree Sparrow (Passer montanus) samples (n=37) collected from different land use areas in Shanghai provided information about the levels, compositional patterns, geographical distribution, potential sources of PBDEs and the evaluation of contamination status in Shanghai. The concentrations of BDE 209 and Sum-PBDEs were within the range of 8.20-292.0 ng g(-1) lw (median: 47.0 ng g(-1) lw) and 33.16-375.63 ng g(-1) lw (median: 78.7 ng g(-1) lw), respectively. As the predominant individual congener, BDE 209 was detected in all samples with a mean percentage of 62.8%, followed by BDE 47, 99 and 100 sequentially. The geographical distribution of PBDEs in ETS muscles followed the order below: landfill>urban>industrial parks>suburban>rural>remote, indicating that Shanghai Laogang Municipal Landfill was an important emission source of PBDEs in Shanghai, and also the PBDE levels were in association with urbanization and industrialization. Compared with other regions, contamination status in Shanghai was relatively good with the exception of these high concentration areas. There was significant correlation (r(2)=0.89, P<0.01) between PBDEs concentrations in soil and ETS, indicating ETS could be used as a useful biomonitoring tool for PBDEs in Shanghai.

Aerobic biodegradation of trichloroethylene and phenol co-contaminants in groundwater by a bacterial community using hydrogen peroxide as the sole oxygen source.

Trichloroethylene (TCE) and phenol were often found together as co-contaminants in the groundwater of industrial contaminated sites. An effective method to remove TCE was aerobic biodegradation by co-metabolism using phenol as growth substrates. However, the aerobic biodegradation process was easily limited by low concentration of dissolved oxygen (DO) in groundwater, and DO was improved by air blast technique with difficulty. This study enriched a bacterial community using hydrogen peroxide (H2O2) as the sole oxygen source to aerobically degrade TCE by co-metabolism with phenol in groundwater. The enriched cultures were acclimatized to 2-8 mM H2O2 which induced catalase, superoxide dismutase and peroxidase to decompose H2O2 to release O2 and reduce the toxicity. The bacterial community could degrade 120 mg/L TCE within 12 days by using 8 mM H2O2 as the optimum concentration, and the TCE degradation efficiency reached up to 80.6%. 16S rRNA gene cloning and sequencing showed that Bordetella, Stenotrophomonas sp., Sinorhizobium sp., Variovorax sp. and Sphingobium sp. were the dominant species in the enrichments, which were clustered in three phyla: Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria. Polymerase chain reaction detection proved that phenol hydroxylase (Lph) gene was involved in the co-metabolic degradation of phenol and TCE, which indicated that hydroxylase might catalyse the epoxidation of TCE to form the unstable molecule TCE-epoxide. The findings are significant for understanding the mechanism of biodegradation of TCE and phenol co-contamination and helpful for the potential applications of an aerobic bioremediation in situ the contaminated sites.

[Distribution of polybrominated diphenyl ethers in wild crucian carp and exposure estimation of dietary intake].

The concentration and distribution of PBDEs in liver, heart, brain, egg and muscle tissues of market farmed fish and wild river fish (crucian carp) from Taizhou, which is a large e-waste recycling site in China, were quantitatively measured using gas chromatography -negative chemical ion tandem mass spectrometry (GC-NCI-MS). The dietary intake of PBDEs via the consumption of fish by the population of this region was also estimated. The results showed that the concentrations of PBDEs in the muscle of river fish samples near the e-waste recycling site were significantly higher than those in the market farmed fish without obviously polluted sources of PBDEs. The distribution of PBDEs in various tissues was not even, and the highest and lowest mean concentrations of total PBDEs ( sigma PBDEs) were 18.82 ng x g(-1) and 1.97 ng x g(-1) (wet weight), in heart and egg tissues, respectively. A similar PBDE congener profiles in different tissues of farmed fish were found. Among PBDE congeners, BDE-47 was predominant in various tissues accounting for above 50% of the total PBDEs, and followed by BDE-183 (about 20%), BDE-99 and BDE-153. While different profiles of PBDEs in muscle tissues between wild fish in river and market farmed fish were observed, that BDE-47, -153 and -99 were dominant for the former type. These facts suggested primitive e-waste recycling behavior to be a pollution source of high levels of PBDEs in wild fish. The average estimated daily intake of PBDEs via river fish consumption by local residents near the e-waste recycling site in Taizhou was approximately 29.0 ng, slightly higher than that in other regions.

Bio-beads with immobilized anaerobic bacteria, zero-valent iron, and active carbon for the removal of trichloroethane from groundwater.

Chlorinated hydrocarbons are the most common organic pollutants in groundwater systems worldwide. In this study, we developed bio-beads with immobilized anaerobic bacteria, zero-valent iron (ZVI), and activated carbon (AC) powder and evaluated their efficacy in removing 1,1,1-trichloroethane (TCA) from groundwater. Bio-beads were produced by polyvinyl alcohol, alginate, and AC powder. We found that the concentration of AC powder used significantly affected the mechanical properties of immobilized bio-beads and that 1.0 % (w/v) was the optimal concentration. The bio-beads effectively degraded TCA (160 mg L(-1)) in the anaerobic medium and could be reused up to six times. The TCA degradation rate of bio-beads was 1.5 and 2.3 times greater, respectively, than ZVI + AC treatment or microbes + AC treatment. Measuring FeS produced by microbial reactions indicated that TCA removal occurred via FeS-catalyzed dechlorination. Analysis of clonal libraries derived from bio-beads demonstrated that the dominant species in the community were Betaproteobacteria and Gammaproteobacteria, which may contribute to the long-term stability of ZVI reactivity during TCA dechlorination. This study shows that the combined use of immobilized anaerobic bacteria, ZVI, and AC in bio-beads is effective and practical for TCA dechlorination and suggests they may be applicable towards developing a groundwater treatment system for the removal of TCA.

Acute and chronic toxic effects of bisphenol A on Chlorella pyrenoidosa and Scenedesmus obliquus.

The acute and chronic toxic effects of Bisphenol A (BPA) on Chlorella pyrenoidosa (C. pyrenoidosa) and Scenedesmus obliquus (S. obliquus) were not well understood. The indoor experiments were carried out to observe and analyze the BPA-induced changes. Results of the observations showed that in acute tests BPA could significantly inhibit the growth of both algae, whereas chronic exposure hardly displayed similar trend. Superoxide dismutase (SOD) and Catalase (CAT) activities of both algae were promoted in all the treatments. Chlorophyll a synthesis of the two algae exhibited similar inhibitory trend in short-term treatments, and in chronic tests C. pyrenoidosa hardly resulted in visible influence, whereas in contrast, dose-dependent inhibitory effects of S. obliquus could be clearly observed. The experimental results indicated that the growth and Chlorophyll a syntheses of S.obliquus were more sensitive in response to BPA than that of C. pyrenoidosa, whereas for SOD andCAT activities, C. pyrenoidosa was more susceptible. This research provides a basic understanding of BPA toxicity to aquatic organisms.

Effects of Pb(â ¡) exposure on Chlorella protothecoides and Chlorella vulgaris growth, malondialdehyde, and photosynthesis-related gene transcription.

Greater exposure to Pb(Ⅱ) increases the likelihood of harmful effects in the environment. In this study, the aquatic unicellular alga Chlorella protothecoides (C. protothecoides) and Chlorella vulgaris (C. vulgaris) were chosen to assess the acute and chronic toxicity of Pb(Ⅱ) exposure. Results of the observations show dose-response relationships could be clearly observed between Pb(Ⅱ) concentration and percentage inhibition (PI). Exposure to Pb(Ⅱ) increased malondialdehyde (MDA) content by up to 4.22 times compared with the control, suggesting that there was some oxidative damage. ANOVA analysis shows that Pb(Ⅱ) decreased chlorophyll (chl) content, indicating marked concentration-dependent relationships, and the lowest levels of chl a, chl b, and total-chl were 14.53, 18.80, and 17.95% of the controls, respectively. A real-time PCR assay suggests the changes in transcript abundances of three photosynthetic-related genes. After 120 h exposure Pb(Ⅱ) reduced the transcript abundance of rbcL, psaB, and psbC, and the relative abundances of the three genes of C. protothecoides and C. vulgaris in response to Pb(Ⅱ) were 54.66-98.59, 51.68-95.59, 37.89-95.48, 36.04-94.94, 41.19-91.20, and 58.75-96.80% of those of the controls, respectively. As for 28 d treatments, the three genes displayed similar inhibitory trend. This research provides a basic understanding of Pb(Ⅱ) toxicity to aquatic organisms.

Biodegradation of perchloroethylene and chlorophenol co-contamination and toxic effect on activated sludge performance.

This study investigated the effects of PCE and 2-CP co-contamination on growth of microbial community in terms of enzymatic activity and microbial diversity in activated sludge. Results showed that the activities of three key enzymes (dehydrogenase, phosphatase and urease) decreased significantly when PCE (in the range of 5-150 mg/L) was mixed with 2-CP (in the range of 25-150 mg/L). Especially, activity of dehydrogenase decreased by more than 93% as the concentration of PCE and 2-CP both reached 150 mg/L. PCR-DGGE revealed that short-term exposure with PCE and 2-CP did not lead to shift in the microbial community structure, while clone library demonstrated a significant change in the microbial diversity after long-term exposure. As the population of Alphaproteobacteria and Gamaproteobacteria decreased, with Actinobacteria eventually disappeared, species including Firmicutes, Bacteroidetes and Synergistetes became dominating groups. This study demonstrated that co-contamination with PCE and 2-CP affected the performance of activated sludge in a significant way.

Distribution and temporal trend of polybrominated diphenyl ethers in one Shanghai municipal landfill, China.

The scarcity of information on polybrominated diphenyl ethers' (PBDEs) flow in landfill restricts the life cycle analysis of PBDEs. In this study, eight PBDE congeners (BDEs 28, 47, 99, 100, 153, 154, 183, and 209) in topsoil, vegetation leaves, leachate, and municipal aged refuse collected from Shanghai Laogang Municipal Landfill (SLML) were investigated. The present study revealed elevated PBDE concentrations in topsoil and proved PBDE leakage from SLML and vegetation uptake. BDE-209 was the predominant congener, and this could be due to massive usage of deca-BDE mixture in Shanghai. ΣPBDE concentrations in leachates treated by reed wetland and A(2)/O process fell in the low end of the worldwide range. ΣPBDE concentrations in aged refuse samples rose from under 50 ng/g dw in 1989 to the range of 5,150-5,718 ng/g dw in 2002. PBDE concentrations increase in aged refuse samples throughout the 1990s into the 2000s paralleled municipal solid waste output from 1991 to 2002 in Shanghai. Exponential increase in BDE-209 concentration in aged refuse suggested the increasing market demands for deca-BDE mixture after 1990 in China. Notably, the inventory of PBDEs in SLML was 28.7 MT, and the doubling time of BDE-209 in aged refuse was calculated to be 1.6 year. SLML can be considered as a source of PBDE and one main recipient of PBDE as well, receiving inputs predominantly from the PBDE-containing waste. Priority should be given to formulate regulation on PBDEs and sorting work before landfill disposal.

[Effects of soil compositions on sorption and desorption behavior of tetrachloroethylene in soil].

Sorption and desorption play an important role in the transport and the fate of tetrachloroethylene (PCE) in soil. In order to examine influences of different soil compositions on PCE sorption-desorption, equilibrium batch experiments were carried out using four sorbents (natural soil with 2.23% total organic carbon (TOC), H2O2-treated soil, 375 degrees C-treated soil and 600 degrees C-treated soil) with different initial PCE liquid concentrations (c0). The effects of main parameters (TOC, soft carbon, hard carbon, minerals, c0) on PCE sorption-desorption were investigated. At 16 degrees C, when c0 was increased from 5 to 80 mg x L(-1), the results showed that sorption and desorption isotherms of PCE on four sorbents can be best described by the Freundlich model (r2 > 0.96). The sorption contribution rate of SOM was higher than 60% in natural soil, and hard carbon was the main influencing factor,while the desorption contribution rate of SOM was close to that of minerals in natural soil, and soft carbon accounted for more than 80% in the total desorption contribution rate of SOM. In addition, the higher the c0, the higher the sorption contribution rate of PCE in hard carbon and desorption contribution rate of PCE in soft carbon and minerals were. Moreover, desorption of PCE from four sorbents exhibited hysteresis, and hard carbon played a remarkable role in the hysteresis of natural soil.

[Control effect of different covering patterns on indigenous nutrient release from sediment].

A laboratory simulation experiment was conducted to study the release of sediment phosphorous and nitrogen under the effects of coating the sediment with plastic, clinoptilolite, calcite, quartz sand, and calcium nitrate, aimed to provide scientific basis and technical support to control the sediment nutrient release under the background of water environment pollution by different concentrations of nitrogen and phosphorus. The control efficacy of test coating materials for sediment total phosphorous release was in the order of plastic > calcium nitrate > clinoptilolite > calcite > quartz sand, and that for sediment total nitrogen release was in the order of clinoptilolite > plastic > calcite > quartz sand > calcium nitrate. As for the release of sediment NO(3-)-N, the control efficacy of test coating materials was calcium nitrate > quartz sand > clinoptilolite > calcite > plastic coating; whereas for the release of sediment NH(4+)-N, the sequence was calcium nitrate > plastic coating > clinoptilolite > calcite > quartz sand. Water temperature had definite relativity to the sediment nutrient release. With the increase of water temperature, the concentrations of water total phosphorous and nitrogen and NO(3-)-N increased, while the concentration of water NH(4+)-N presented a declining trend.

Biodegradation of benzene homologues in contaminated sediment of the East China Sea.

This study focused on acclimating a microbial enrichment to biodegrade benzene, toluene, ethylbenzene and xylenes (BTEX) in a wide range of salinity. The enrichment degraded 120 mg/L toluene within 5d in the presence of 2M NaCl or 150 mg/L toluene within 7d in the presence of 1-1.5M NaCl. PCR-DGGE (polymerase chain reaction-denatured gradient gel electrophoresis) profiles demonstrated the dominant species in the enrichments distributed between five main phyla: Gammaproteobacteria, Sphingobacteriia, Prolixibacter, Flavobacteriia and Firmicutes. The Marinobacter, Prolixibacter, Balneola, Zunongwangia, Halobacillus were the dominant genus. PCR detection of genotypes involved in bacterial BETX degradation revealed that the degradation pathways contained all the known initial oxidative attack of BTEX by monooxygenase and dioxygenase. And the subsequent ring fission was catalysed by catechol 1,2-dioxygenase and catechol 2,3-dioxygenase. Nuclear magnetic resonance (NMR) spectroscopy profiles showed that the bacterial consortium adjusted the osmotic pressure by ectoine and hydroxyectoine as compatible solutes to acclimate the different salinity conditions.

Toxicological effect of joint cadmium selenium quantum dots and copper ion exposure on zebrafish.

Quantum dots (QDs) have strong adsorption capacity; therefore, their potential toxicity to aquatic organisms from the facilitated transport of other trace toxic pollutants when they coexist has received increasing interest. However, the impact of cadmium selenium (CdSe) QDs and copper ion (Cu(2+)) joint exposure on zebrafish (Danio rerio) embryo and larvae remains almost unknown. Therefore, the present study was performed to determine the developmental toxicities to zebrafish exposed to combined pollution with CdSe QDs (500 µg/L) and Cu(2+) (0, 0.1, 1, 10, and 100 µg/L CuC1(2)) compared with single exposure. Our findings for the first time revealed that: (1) QDs facilitated the accumulation of Cu(2+) in zebrafish; (2) QDs caused higher mortality, lower hatch rate, and more malformations of the exposed zebrafish; (3) junction, bifurcation, crossing, particles, and aggregation of the exposed FLI-1 transgenic zebrafish larvae can be observed; (4) embryo cell apoptosis appeared in the head and tail region; and (5) synergistic effects played an important role during joint exposure. These observations provide a basic understanding of CdSe QDs and Cu(2+) joint toxicity to aquatic organisms and suggest the need for additional research to identify the toxicological mechanism.