Search

Objective: To study the variation of the residual polycyclic aromatic hydrocarbons (PAHs) from disposable paper cups into different food stimulants with time., Methods: The disposable paper cups were soaked with water, 4% acetic acid, 20% ethanol and hexane respectively, and the 16 PAHs were extracted with CH2Cl2, and then determined by gas chromatography-mass spectrometry (GC-MS)., Results: The residual PAHs from disposable paper cups could be leached from the four stimulants, and the amounts increased with the increase of time. The mainly PAHs extracts were phenathrene, pyrene, naphthalene, anthracene and fluorene with lower molecular weight. Largest leaching ability of hexane was observed., Conclusion: The supervision of disposable paper cups should be strengthened and it should be avoided using for prolonged immersion.

Heavy metal pollution in water has become a global environmental problem, threatening aquatic ecosystems and human health. Physical and chemical methods can effectively remove heavy metal pollutants, while their applications are limited due to the high costs, complex operation, and susceptibility to secondary pollution. Bioremediation is the most promising method for eliminating toxic pollutants. Microorganisms including bacteria, fungi, and algae can convert toxic heavy metals into less toxic forms, which has become an effective and environmentally friendly solution for the remediation of heavy metal pollution in water environments. This paper expounds the toxicity and mechanism of heavy metal pollution, microbial remediation mechanisms, and primary microbial remediation strategies, providing a reference for the removal or reduction of metal pollutants in water environments as well as the development of related technologies.

Concerns over the emergence of steroid hormones as pollutants in water have grown. Steroid hormone compounds present challenges in the simultaneous detection of total residual hormones owing to their analogous structures and diverse types. In this study, we established a rapid and high-throughput continuous online method based on solid phase extraction (SPE) coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of 61 hormone components, including 48 glucocorticoids, 1 mineralocorticoid, 4 androgens, and 8 progesterones, in water. Various SPE columns were investigated to assess their extraction efficiency for enriching and purifying target compounds in a large sample volume (1 L). An HC-C18 SPE column was selected because of its superior performance. Acetonitrile was used as a washing solution during SPE to ensure that the majority of the tested substances achieved recoveries exceeding 70% and effectively avoid interferences from water-soluble components. Various C8 and C18 columns were tested, and the optimal HPLC conditions for hormone retention were established. We systematically evaluated different UPLC columns and mobile phases, including methanol-water and acetonitrile-water systems with 0.1% formic acid added to the aqueous phase. The optimized UPLC conditions were as follows: BEH C 18 column (100 mm×2.1 mm, 1.7 μm); column temperature, 40 ℃; flow rate, 0.3 mL/min; injection volume, 5 μL; mobile phase A: 0.1% formic acid aqueous phase; mobile phase B: acetonitrile. Gradient elution was performed as follows: 0-0.5 min, 30%B; 0.5-15.0 min, 30%B-75%B; 15.0-18.0 min, 75%B-98%B; 18.0-19.0 min, 98%B; 19.0-19.1 min, 98%B-30%B; 19.1-20.0 min, 30%B. Both positive- and negative-ion modes were explored in the UPLC-MS/MS experiment to obtain the full scan of the parent ions, and positive mode was finally selected for electrospray ionization (ESI). Two product ions exhibiting strong signals and minimal interference were selected for quantitative and qualitative ion analyses, using an external standard method for quantification. MS/MS was performed in positive-ion (ESI + ) mode with multiple reaction monitoring (MRM) scanning. The MS/MS parameters were as follows: atomizing gas pressure, 379 kPa; curtain air pressure, 241 kPa; spray voltage, 5500 V; desolvation temperature, 550 ℃; collision exit voltage (CXP), 13 V; intake voltage (EP), 10 V; and residence time of each ion pair, 0.5 ms. Other instrument settings, such as the collision energy and declustering voltage, were also optimized. The 61 hormones exhibited excellent linear relationships within their corresponding concentration ranges, with correlation coefficients greater than 0.99. The method detection limits (MDLs) were in the range of 0.05-1.50 ng/L. The average recoveries of the 61 hormones across three spiked levels ranged from 62.3% to 125.2%, with relative standard deviations (RSDs, n =6) of 1.1%-10.5%. Using this method, we successfully detected 10 hormone components (cortisone, fluticasone propionate, ciclesonide, betamethasone dipropionate, clobetasone butyrate, diflucortolone valerate, halobetasol propionate, isoflupredone, difluprednate, and hydroxyprogesterone caproate) in various surface water and groundwater samples collected from the Taihu Basin region. The SPE-UPLC-MS/MS method presented in this paper is simple, highly sensitivity, and exceptionally accurate. Thus, it exhibits promising potential for tracing targeted hormone residues in water and will be of great value in monitoring and ensuring water safety. Finally, a regional analysis was conducted on the hormone levels in water, and suggestions were made for the targeted treatment of hormone residues in future sewage treatment processes.

The revision of the national standards for drinking water quality is an important, rigorous and delicate endeavor. The paper introduced the revision of this standard, emphasizing the revision principle, overall technical considerations, and revision contents. Recommendations were also proposed for the implementation of this standard.

Through the investigation and detection of the surface water and sediments of Luoma Lake, the structure and occurrence characteristics of PFASs (perlyfluoroalkyl substances) in the two types of media were analyzed, and the principal component analysis method was used to analyze the characteristics of such substances in the surface water. The source was analyzed, and the potential health risks of such substances were evaluated using the risk quotient method. The results showed that a total of 13 PFASs were detected in the surface sediments of Luoma Lake, and one more species was detected in the surface water (PFTeA); ρ (ΣPFASs) in the surface water ranged from 46.09 to 120.34 ng·L -1 , and ω (ΣPFASs) in sediments ranged from 2.22 to 9.55 ng·g -1 . PFPeA was the major component in surface water, and the mass fraction of PFPeA was 38%. PFBA was the major component in sediment, and the mass fraction of PFPeA was 61%. The multi-media PFASs in Luoma Lake were mainly short-chain substances; the high concentration area of PFASs in the surface water of Luoma Lake was concentrated and distributed at the mouth of the northern rivers. Its concentration showed a decreasing trend from north to south, and the content of PFASs in the sediments showed a decreasing trend from southwest to northeast. The distribution of ΣPFASs, PFBA, and PFOS in the sediments of Luoma Lake and the TOC content in the sediment were related; the principal component analysis showed that the PFASs in the surface water of Luoma Lake were mainly from textile flame retardant, rubber product emulsification, food packaging processes and paper surface treatment industries, the metal electroplating industry, and leather and textile manufacturing industries. PFASs in the surface water of Luoma Lake were at a relatively low health risk level.

Due to the limitations of the treatment process of urban sewage treatment plants and the complexity of water sources, the rich inorganic nitrogen and trace persistent organic matter in the reclaimed water cause potential human health risks through lateral leakage or bioaccumulation during the replenishment process of rivers and lakes. Exploring the distribution law of different types of reclaimed water characteristic water quality factors and their formation in reclaimed water replenishment river channels is of great significance to river and lake management. This study takes the Beijing-Tianjin-Hebei section of the North Canal as the research area and explores the spatial variation characteristics of conventional physical parameters, full index, inorganic nitrogen, and salinity hydronium antibiotics in river water quality with the help of clustering, discrimination, principal components, and variance decomposition. The results showed that, although the spatial distribution patterns of different types of water quality factors were consistent, they all showed significant mid-upstream and downstream distribution; however, there were big differences in the degree of variation and the mechanism of variation. The spatial variation of inorganic nitrogen and antibiotics was the most obvious, whereas the variation in conventional physical parameters and the full index was the weakest, and the salinity hydronium showed moderate variation. The spatial variation mechanism of conventional physical parameters was mainly reflected in microbial degradation. The full index was the result of the combined effect of microorganisms, diffusion, the synergy of the two, and a certain degree of source-sink homogeneity. Diffusion was the main mechanism affecting the spatial variation in salinity hydronium. The spatial variation mechanism of inorganic nitrogen was mainly reflected in the source-sink homogenization and microbial degradation; as a secondary mechanism of the spatial variation of inorganic nitrogen, diffusion had a synergistic mode with microbial degradation. Antibiotics, which have great differences in chemical structural stability and biodegradability, showed high spatial variability and had the highest diffusion and microbial synergy mechanism. This research provides a quantitative analysis of the spatial variability mechanism of water quality based on variance decomposition, which has practical guiding significance for the causes of the spatial variability of river pollutants and river management.

Disinfection by-products(DBPs) are secondary pollutants generated by the reaction of disinfectants with organic or inorganic precursors during drinking water disinfection. DBPs have received considerable global attention due to their carcinogenic, teratogenic, and mutagenic characteristics. Focusing on drinking water, this paper introduces the main classification and research history of DBPs, and then summarizes the concentration levels of common DBPs in drinking water, and DBPs regulatory compliance in global drinking water standards. Further, the control strategies for DBPs in drinking water, including source control, process control, DBPs removal and integrated control are introduced together with the advantages and disadvantages. Finally, a summary and review of the current level and future trends of DBPs research in China are presented with the proposed control strategies. On the one hand, when evaluating the control effect of a process or technology, the DBPs concentration and comprehensive toxicity should be considered; on the other hand, in order to realize the efficient control of DBPs in drinking water, the focus should be on the integrated methods coupling different DBPs control methods.

Along with the economic and technological development and growing demand for high-quality drinking water, direct drinking water has gained general popularity in China. However, no authoritative policy has been issued, giving a clear definition of direct drinking water and existing standards and regulations concerning direct drinking water are not definitive in nature. Existing water quality parameters are not well supported and sometimes even contradict each other. We elaborated, in this paper, the history of direct drinking water in China and systematically reviewed the existing regulations and standards related to direct drinking water. We also compared and analyzed the important microbiology, toxicology, sensory perception and general chemistry parameters in the standards. This paper is the first ever attempt at an in-depth analysis of the chaotic state of the direct drinking water industry. We have also highlighted the problems in the current standards and regulations for direct drinking water. Our study provides a basis for market regulation and the supervision and management of direct drinking water. In addition, the paper provides helpful information for laying down a definition of direct drinking water, calling for and approving of project proposals concerning the establishment of national standards for direct drinking water, and actually formulating the standards. We have made a number of suggestions: A. defining direct drinking water clearly and formulating the national standards for direct drinking water as soon as possible; B. conducting research on water quality benchmarks to provide scientific support for the formulation of the national standards for direct drinking water; C. giving more attention to the formulation of standards concerning microbiology parameters and their limits and giving consideration to the inclusion of parameters concerning viruses., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)

Rapid urbanization and industrialization may potentially impact the spatial distribution and transmission of polyfluoroalkyl substances (PFASs). Tianjin, a typical industrialized city with a high urbanization level around Bohai Bay, was selected to evaluate the spatial distribution and ecological risks of PFASs. Water and soil samples were systematically collected and analyzed by using solid-phase extraction and high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS-MS) methods. The results showed that all 12 PFASs were detected in water and soils, and the detection rates of the other congeners were low. The concentrations of ΣPFASs in water ranged from 3.93 to 357.85 ng ·L -1 , and the levels of ΣPFASs in soils ranged from 4.60 to 63.85 ng ·g -1 . PFBA was the major component in water and soils, and the contribution of PFBA was 37% and 67% in water and soils, respectively. The spatial difference in ΣPFASs in the water bodies was significant. ΣPFAS concentrations in the surface water were higher in the north (mean value of 63.83 ng ·L -1 ) than in the south (mean value of 51.71 ng ·L -1 ) and higher in the eastern coastal area (mean value of 71.36 ng ·L -1 ) than in the western area (mean value of 36.08 ng ·L -1 ). ΣPFAS concentrations from upstream to downstream of the rivers showed an increasing trend. The highest PFAS concentration was found in the Chaobai River, and the lowest was detected in the South Canal. The spatial distribution of PFASs in soils was higher in the south (mean value of 13.33 ng ·g -1 ) than in the north (mean value of 6.38 ng ·g -1 ) and higher in the eastern coastal region (mean value of 11.45 ng ·g -1 ) than in the western region (mean value of 6.94 ng ·g -1 ). The soil concentrations of ΣPFASs in the Haihe River Basin were the highest. The source analysis results showed that the emulsification of rubber products, food packaging process, paper surface treatment, fire extinguishing agent use, and electrochemical fluorination process in industrial production were the main sources of PFASs in the soils in the study area. PFOS/PFOA, PFOA/PFNA, and PFHpA/PFOA analyses showed that the main source of PFASs in water bodies was the degradation of precursors. ΣPFASs in a few areas originated from the direct emissions from production, but the atmospheric deposition was small. The results of the ecological risk evaluation indicated that the exposure concentrations of PFASs in water and soils in the study area were at a low ecological risk level. However, the long-term ecological effects of PFASs cannot be ignored because of their long-distance transport capability and high food chain (web) accumulation capability.

Biocides are widely added to personal care products and enter the environment through sewage treatment plant (STP) discharge, which affects ecological health. This paper evaluated the pollution characteristics of triclosan and triclocarban in a river network during the COVID-19 epidemic. Moreover, a continuous dynamic river network model coupling a one-dimensional hydrodynamic model and four-level fugacity model was established to address the temporal and spatial heterogeneity of pollutants in the river network migration process; then, this model was applied to evaluate two biocides in the Shima River Basin. The model passed calibration and in-field concentration verification tests and yielded satisfactory simulation results. The results of the study showed that the concentration of biocides in the river network during the new crown epidemic was twice that of the non-epidemic period. The concentration of triclosan and triclocarban in the river channel first increased and then decreased with the increase of the river migration distance after STP discharge. The time variation characteristics of the concentrations were affected by the river flow. The biocide concentration in the river network of the low flow upstream area first increased and then decreased, gradually stabilizing in about 20 h. The pollution concentration in the high flow downstream area was increased, and the concentration did not stabilize at 24 h. These results indicate the necessity of evaluating the temporal and spatial characteristics of migration of typical biocides in the river network by stages and time on the premise of distinguishing the flow.

Haloacetaldehydes (HALs), as emerging disinfection by-products in drinking water, are the third largest group by weight of identified disinfection by-products (DBPs) in drinking water. The formation of HALs is associated with the level of natural organic matter and halide in the source water, the treatment process of drinking water and the type of disinfectant. Recent studies have shown that HALs are more cytotoxic and genotoxic than regulated trihalomethanes and halo-acetic acids in drinking water. Currently, only a few countries and regions have set limit values for trichloroacetaldehyde with high detection rate in drinking water. However, there is growing evidence that unregulated HALs have a higher potential risk to human health compared to regulated HALs. This paper reviews the current research progress on the formation and transformation, cytotoxicity and genotoxicity of HALs in drinking water, and looks forward to the problems that should be paid attention in the future toxicological research of HALs in order to support the development of scientific drinking water standards.

To promote the application of ANAMMOX process in landfill leachate treatment, a pilot reactor based on the ANAMMOX process was established at a landfill site. In this paper, we aim to further analyze the influence of different coupling modes of denitrification (DN) and partial nitrification and ANAMMOX (PN-ANAMMOX) on the diversity of microbial community. The DN+(PN-ANAMMOX) process could effectively treat the mature leachate. However, with an increase in organic matter in the influent, the oxygen demand of PN zone increased, and the enrichment of Nitrosomonadaceae in the PN zone was limited. The lack of substrate supply for ANAMMOX zone further limited the enrichment of Brocadiaceae as well; thus, the total nitrogen removal rate (TNRR) remained at 0.44 kg ·(m 3 ·d) -1 . In the DN-(PN-ANAMMOX) process, Saprospiraceae with denitrifying ability was enriched in the DN zone, and the organic matter was gradually degraded and removed; thus, a good low-carbon environment was provided for the subsequent PN-ANAMMOX process. Nitrosomonadaceae and Brocadiaceae were enriched in the functional zones, and the TNRR and total nitrogen removal efficiency (TNRE) of the DN-(PN-ANAMMOX) were further elevated to 0.55 kg ·(m 3 ·d) -1 and 94.65%, respectively. Moreover, the direct treatment of mature leachate with 2233 mg ·L -1 NH 4 + -N and 2712 mg ·L -1 COD was finally realized. In addition, Candidatus Kuenenia was better adapted to leachate and high substrate concentration wastewater, and it became the dominant genus in the ANAMMOX zone.

In this paper, the effects and mechanism of ciprofloxacin (CIP) degradation with peroxymonosulfate (PMS) catalyzed by solid waste red mud (RM) was firstly studied. The results indicated that RM has large specific surface area (10.96 m 2 ·g -1 ) and complex pore structure, containing ferric, alumina and calcium oxide, which enhanced ciprofloxacin degradation by PMS effectively. Radical quenching experiments revealed that SO 4 - ·and HO·were contributed to ciprofloxacin oxidation, and the reaction was mainly occurred on RM's surface. An increase in temperature could accelerate CIP degradation, and the corresponding reaction activation energy E a was about 5.74 kJ·mol -1 . Meanwhile, CIP degradation rate increased with PMS concentration and the optimal dosage of RM was 1.0 g·L -1 . Eight degradation intermediates were identified using HPLC/MS/MS, and consequently, CIP was degraded mainly through two pathways; the piperazine groups were preferentially attacked by active free radicals. This study further indicated that RM is a cheap catalyst and can be potentially used in the treatment of antibiotic contaminated wastewater.

As an emerging environmental pollutant, microplastics have attracted more and more attention for its influence on the ecological environment and human health. Due to its wide range of usage and production, difficult degradation and other characteristics, as well as the continuous and substantial increase in the use of plastic products, the number of plastic fragments in the environment continues to increase, which leads to the accumulation of microplastics in the environment and organisms, spread through the food chain, and ultimately poses a threat to human health. At the same time, in the plastic production, synthetic textile, and other industries, the incidence of workers related occupational diseases greatly increased. In this paper, the concept, classification, source, impact on biological and human health of microplastics are summarized, and propose solutions on the current situation of microplastics pollution in China, we hope this review could provide effective reference for further carry out risk assessment of microplastics pollution on human health and formulate legislation to control microplastics pollution.

In this paper, nutrient elements (N and P), heavy metals (Pb, Cu, Zn, Cd, Cr, Co, Ni, and Sn), and grain size in surface sediments of Baiyangdian Lake, northern China, are studied. We also analyze the spatial variation in elemental characteristics and undertaken a pollution risk assessment. By combining data with information on the river sediment characteristics, we use multivariate statistical methods to reveal the sources and variation of elements in sediments. The results showed that the average contents of heavy metals in surface sediments from the lake and associated rivers were higher than background values. Within the area of the lake, nutrient elements are relatively high in the northwest region but low in the southeast region, and heavy metals are relatively high in the middle of the lake but low in the southern and northern areas. The sequence of comprehensive pollution index ( I ) in sediments was Cd > Pb > Cr > Cu=Zn > Ni > Sn > Co, with Cd being assessed as severe pollution and other elements as moderate pollution, although severe pollution of Cr was found in the Zaolinzhuang area. The order of potential ecological risk coefficients ( E r i ) was determined as Cd > Pb > Cu > Cr > Ni > Zn, whereby Cd was associated with a strong potential ecological risk (except in the Caiputai area) and other elements were associated with a slight potential ecological risk. Differences in the lake sediment texture were found to be slight. Non-point source pollution after rivers flow into the lake was determined as the main reason for the spatial variation of elements in the surface sediments of Baiyangdian Lake, although point source pollution in the villages surrounding the lake should not be ignored, especially with respect to N, P, Pb, and Cr.

As an important branch of traditional medicines,medicinal marine organisms have many advantages,including biological diversity,remarkable biological activity,especial for the treatment of anti-cancer,anti-virus,anti-coagulation,analgesia,anti-bacterial,cardiovascular and cerebrovascular diseases. In recent years,with the continuous exploration of marine organisms by human beings,many marine organisms with specific biological activities and medicinal prospects have been found,which have attracted great attention around the world and thus called " new hope" to solve human health problems. However,due to the rapid development of modern industry,heavy metal pollution not only poses a great threat to medicinal marine living resources,but also hinders the development of marine biomedical industry and threatens human health. In view of this,this paper introduced the development trend of medicinal marine organisms and the current situation of heavy metal pollution and focusing on the analysis technology and chemical removal technology of heavy metals in medicinal marine organisms,which is to provide reference for the heavy metals control in marine medicines and the development and utilization of marine medicines.

Steroid hormones have been continuously detected and well studied in freshwater bodies in recent years, although information regarding their contamination characteristics in seawater is rare. In this paper, samples were collected in Liusha Bay, South China Sea, and the contamination characteristics, as well as the spatial distribution of 33 steroid hormones, were studied by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that 7 steroid hormones occurred with concentrations ranging from 0.003 (medroxyprogesterone, MP) to 9.023 ng·L -1 (dehydroprogesterone, DGT), and from 0.017 (androsta-1,4-diene-3,17-dione, ADD) to 9.281 ng·g -1 (4-androstene-3,17-dione, AED) in seawater and sediment samples, respectively. The concentrations of detected steroid hormones were higher during wet weather than during the dry weather, and higher in the aquaculture area compared to that in the non-aquaculture area. There were no significant differences in the spatial and temporal distribution of steroid hormones in sediment. Wastewater discharge and additives in aquaculture feeds were the main routes of steroid hormones entering the marine environment. The results of the ecological risk assessment indicated that the AED posed low risk to the marine environment, whereas other steroid hormones posed no risk. Correlation analysis indicated that the concentration distribution of steroid hormones was related to salinity, water temperature, particulate matter (SS), and chemical oxygen demand (COD) in the marine environment. The results of this study contribute to the understanding of the contamination characteristics of steroid hormones in the Liusha Bay area and provide a scientific basis for ecological risk assessment and control.

In the bioremediation of eutrophic water, a large number of aquatic plants will be produced. How to continue the reasonable disposition is the question that needs to be solved. In this paper, biomass carbon was prepared from aquatic plants, and the adsorption capacity of the biomass carbon on nitrogen and phosphorus in water was improved by magnesium modification. The characterization results of material properties showed that magnesium modification not only formed nanometer MgO sheets on the surface of biomass carbon to increase the specific surface area, but also introduced hydroxyl functional groups to promote the adsorption of ammonium nitrogen. The adsorption processes of modified biomass carbon on nitrates and ammonium nitrogen belonged to multi-layer adsorption, and the adsorption isotherms conformed to the Freundlich model. The adsorption mechanism of modified biomass carbon changed from single layer adsorption to multi-layer diffusion. The maximum adsorption capacity of the modified biomass carbon on nitrate nitrogen, ammonium nitrogen, and phosphorus were 5.66, 62.53, and 90.92 mg·g -1 , respectively. The adsorption capacity of the modified biomass carbon on ammonium nitrogen is 178 times that of unmodified biomass carbon. When phosphorus, nitrate nitrogen, and ammonium nitrogen coexist, the adsorption amounts of modified biomass carbon increase by 79.1%, 67.5%, and 47.1%, respectively. The results of this paper showed that the preparation of biomass carbon can realize the resource recovery of aquatic plants, and can be used for the removal of nitrogen and phosphorus pollution from water, which has good prospects for application.

Antibiotic pollution in the environment is becoming increasingly serious, and the induced antibiotic resistance has become a major threat to human health. A literature review of the antibiotic concentration in the influent and effluent of many sewage treatment plants around the world has shown that current sewage treatment processes do not effectively remove antibiotics. Studies have shown that adsorption and biodegradation are the main ways of removing antibiotics from sewage. The mechanisms of adsorption and the different adsorption extents of diverse antibiotics were analyzed in this paper. Biodegradation of antibiotics in a biological sewage treatment process were analyzed in terms of biodegradability, degrading bacteria, and degradation products. The effects of the operation conditions of biological sewage treatment processes, such as hydraulic retention time, sludge retention time, temperature, and process selection (conventional activated sludge, membrane bioreactor, or biological nitrogen removal processes), on adsorption and biodegradation pathways as well as on the removal efficiency of antibiotics are also discussed. The effects of bacterial composition, growth substrate, and coexisting micro-pollutants on the fate of antibiotics in biological wastewater treatment require more in-depth research.

A method was established to determine the trace amounts of oxytetracycline (OTC) in surface water samples by bubble enrichment-high performance liquid chromatography (HPLC). A novel sample pretreatment method, bubble enrichment, was used to enrich trace amounts of oxytetracycline in aqueous solutions, and the effects of bubble enrichment conditions on the enrichment efficiency was investigated. Enrichment factor of oxytetracycline had a maximum of 37.06, RSD was 4.8% ( n =11), and LOD was 0.038 mg/L under the optimized conditions of bubble enrichment and chromatography. The method was applied to the determination of oxytetracycline in surface water samples, with an average recovery of 101.9%. It is obvious that bubble enrichment has a positive effect on the enrichment of oxytetracycline, and hence, can be combined with chromatography to realize rapid, sensitive, and accurate detection of oxytetracycline in surface water samples. Additionally, the bubble enrichment method used in this paper does not require any organic solvent for the pretreatment of samples, and furthermore, the device is simple, inexpensive, and easy to operate; therefore, it is a very green sample pretreatment method with great research and promotion value. It is expected to be applicable to the analysis of other trace substances in complex samples.

This paper used three plots of paddy field in Wangjiagou small catchment in Fuling District, Chongqing Municipality as a case study. Wangjiagou, located in Three Gorges Reservoir Area, provided a good case in terms of its closeness of surface runoff. The samples of individual rainfall of twelve times and process of two typical individual rainfalls on three plots of sloping paddy field were collected from 2014 to 2015. These samples were used to analyze the influence of spatial pattern of sloping paddy field on the concentration of nitrogen and phosphorus in the surface runoff. The samples of daily runoff in subcatchments in 2010 and 2015 were used to analyze the influence of spatial pattern change of subcatchments' paddy field on the concentration of nitrogen and phosphorus in the surface runoff. The results indicated that the removal rates of TN, NO 3 - -N and TP of paddy field at the valley bottom were higher than those in the mid-slopes. The removal rate of TP would be higher if plot size of paddy field at the bottom got bigger. During individual rainfall event, the losses concentration of TN, NO 3 - -N and TP in the paddy fields was significantly different among three different spatial patterns during the previous period of heavy rain event, but it became different during the next period of moderate rain event. The two subcatchments' spatial pattern change of paddy field had weakened the intercepting purification ability of nitrogen and phosphorus losses of paddy field in 2015, compared with that in 2010. TN's losses concentration increased significantly during the periods of light and moderate rain event and base flow. TP's losses concentration fluctuated during the event from moderate rain to heavy rain. Hence, increasing the area of paddy field of catchment and optimizing its spatial pattern reasonably were found as effective measures to control agricultural non-point source pollution in the Three Gorges Reservoir Region.

The impact analysis of different environments on the fluorescence emission spectrum of pesticides is critical in detecting the concentration of pesticides. In this paper, three kinds of pesticides, carbendazim, carbaryl and fuberidazole, were selected as the research objects. Under different environment, such as different pH values and the presence of different common anion or cation, three-dimensional fluorescence spectral emission (EEM) characteristic of pesticides were analyzed. The experimental results showed that the primary fluorescence peaks for three kinds of pesticides were at λex/λem=280/300, 310/340 and 280/335 nm (respectively); Carbendazim and fuberidazole had a secondary peak at 245/305 nm (PeakB) and 250/340 nm (PeakB). We can come to the conclusion that with the change of pH value, the characteristic of fluorescence emission of carbendazim and fuberidazole is similar. We can find that the fluorescence intensities of carbendazim and fuberidazole were enhanced with the declining of the solution acidity or alkalinity and the fluorescence intensity of carbaryl had not changed with the declining of the solution acidity, but it increased with the declining of the solution alkalinity; the fluorescence emission spectra of the three kinds of pesticides had good fluorescence characteristics with the scope of the pH varying from 6.16 to 7.4. Twelve common ions in water (CO2-3，SO2-4，NO-3，Cl-，HPO2-4，HCO-3，Mg2+，Zn2+，NH+4，Na+，Ca2+，K+) had no significant effect on fluorescence emission characteristics of carbendazim and fuberidazole. The fluorescence intensities were seriously influenced by Fe3+ and Cu2+. The results showed that the pesticides fluorescence intensities were decreased with the ion concentration increasing. It was necessary to consider the quenching effects on pesticides of Fe3+ and Cu2+for the analytic results. The obtained results provided the basic research for improving the accuracy of the heterocyclic pesticides measurement in water.

To reduce the impact of Fluctuating Zone, the Three Gorges Reservoir pre-dam is rare in the world which is specially designed and is the largest artificial lake body in China. The ecological benefits of landscape, farmland and lake and the social benefits of livable city have been significantly enhanced since the successful commissioning of the Hanfeng Lake pre-dam system. The paper proposed the application of layered hydrology and water quality monitoring for analysis of Tributary runoff and lake body section in the pre-dam commissioning in the whole year, and a total of 17 measured indicators inlucding hydrological parameters such as v, H , etc, physical parameters such as T , pH, SD, DO, TSS etc. and chemical parameters such as permanganate index, Chl-a, TN, DN, NO 3 - -N, NH 4 + -N, NO 2 - -N, TP, DP, SRP etc. We found that the water quality was poor during beginning drain and impoundment period and was the worst in tributary inflow section of South River, while the best water quality was located in water section of regulating dam in February and October. The TLI Water Quality Evaluation and factor analyses performed have shown that the water body of Hanfeng Lake was slightly eutrophicated, and the main pollution indicators included DN, TN, NO 3 - -N, TP. By the control of pre-dam in three Gorges to eutrophication in commissioning, we found that the average Chl-a reduction effect reached up to 57.73%, the average reduction rate of permanganate index was 28.12%, SRP, TP, TN, TSS, NO 2 - -N, DN, DP etc. were on average cut down by 20.15%-22.81%, the average reduction rates of NH 4 + -N and NO 3 - -N were 16.92%-18.74%, and the average eutrophic index of water body was reduced by 15.74%. The highest reduction average rate in lake form period appeared from January to March and October to December, and the lowest in river form period was during May to August.The analysis results showed that the commissioning of pre-dam was good and remarkable for controlling eutrophication, and cutting the concentrations of pollutant water storage in the Three Gorges.

Black and odorous (BO) water body reflects very typical serious water pollution related to organic pollution, sediment re-suspension and thermal pollution. Also, the insufficiency of water cycle is one of the most important hydrodynamic factors for formatting BO water body. The blackening substances mainly include suspended particles, Fe- and S-containing substances; the odour causing substances include the small molecule gases such as H 2 S, NH 3 and some compounds such as VOSCs, Geosmin and 2-MBI. Evaluation methods of BO water were summarized from the evaluation index, BO index, multiple linear regression model and comprehensive evaluation method in this paper. Correspondingly, the relative research direction in the future was discussed. All these works not only defined the identifying technology for urban BO water body, but also would further support the water environment improvement and ecological recovery in urban region.

Mercury is harmful to the environment, which has gradually become one of the research hotspots. Sediments, as a main repository of pollutants, have an important impact on water quality and the internal organisms, which deserves our research. In this paper, we focused on Hefei landscape water sediment and tried to investigate the status of inorganic mercury and methylmercury pollutions in the sediment. To study the conversion process from inorganic mercury to methylmercury and their enrichment levels and mechanism, we established the ecological chain of "sediment-water-grass-fish" through analog microcosm examination. The results were as follows: from ten water and sediment samples in Hefei landscape water sediment, we found that the contents of inorganic mercury and methylmercury ranged 11.74-13.12 µg · kg⁻¹ and 0.37-2.23 µg · kg⁻¹, respectively. The microcosm examination showed that: with increasing culture time, inorganic mercury in sediments gradually decreased. There was a phenomenon that the content of methylmercury increased at first and then decreased to reach the balance later. Both the inorganic mercury and methylmercury in water change showed an increasing trend. The enrichment contents of inorganic mercury in Egeria densa Planch, and golden mandarin fish (Siniperca scherzeri Steindachner) were low while their enrichment of methylmercury could he great. In addition, we found that both the bioaccumulation ability and the enrichment coefficient of methylmercury in the body of golden mandarin fish were the maximum during the same period.

Non-point source (NPS) pollution has become a key water pollution problem under the condition of point source pollution was controlled. The complexity and uncertainty research of NPS pollution influential factors has always been important and difficult. This paper simulated NPS pollution of the Fanhe River watershed in 2003-2012 by the soil and water assessment tool (SWAT) and analyzed its spatial distribution. Meanwhile, the boosted regression tree (BRT) method was proposed to quantitatively analyze the corresponding influential factors including land use, soil, elevation and slope. The results showed that NPS pollution in the Fanhe River watershed had high spatial heterogeneity. The spatial distribution of total nitrogen (TN) had greater difference than that of total phosphorus (TP). The three pollutants, TN, TP and sediment, were all positively related to slope gradients (P<0.01). The slope gradients played the strongest role in determining the sediment and TP output with the contribution rate of 46.5% and 38.2%, respectively. Land use had important influence on sediment and TP loads, with the contribution rate of 27.2% and 35.3%, respectively. TN was produced abundantly in low-elevation and steep-slope locations and with cultivated land use. Cinnamon soil was most vulnerable to the TN load while meadow soil took the second place in terms of soil erosion and TP load. The paper overcame the complexity of influential factors for NPS pollution by BRT, and deepened the understanding of NPS pollution mechanism.

The main purpose of this paper is to illustrate the influence of nutrients distribution in sediments on the eutrophication of drinking water reservoir. The sediments of three representative locations were field-sampled and analyzed in laboratory in March 2015. The distribution characteristics of TOC, TN and TP were measured, and the pollution status of sediments was evaluated by the comprehensive pollution index and the manual for sediment quality assessment. The content of TOC in sediments decreased with depth, and there was an increasing trend of the nitrogen content. The TP was enriched in surface sediment, implying the nutrients load in Zhoucun Reservoir was aggravating as the result of human activities. Regression analysis indicated that the content of TOC in sediments was positively correlated with contents of TN and TP in sediments. The TOC/TN values reflected that the vascular land plants, which contain cellulose, were the main source of organic matter in sediments. The comprehensive pollution index analysis result showed that the surface sediments in all three sampling sites were heavily polluted. The contents of TN and TP of surface sediments in three sampling sites were 3273-4870 mg x kg(-1) and 653-2969 mg x kg(-1), and the content of TOC was 45.65-83.00 mg x g(-1). According to the manual for sediment quality assessment, the TN, TP and TOC contents in sediments exceed the standard values for the lowest level of ecotoxicity, so there is a risk of eutrophication in Zhoucun Reservoir.

With increasing consumption and applications of chromium in metallurgy, electroplating, tanning process and stainless steel industry, chromium contamination has become a global environmental problem. In general, Cr(VI) has higher permeability across the cell membrane than Cr(III) and hence is considered more toxic than Cr(III). Oxidative stress could be induced following reactive oxygen species (ROS) normally produced in fish under Cr(VI) exposure due to its variable valences. Furthermore, the intermediates of Cr, e.g. Cr(V) and Cr(IV) , produced by cellular reduction processes can bind with DNA and result in mutagenic effects. These combined effects will threaten the growth, development and population structure of different fish species. In this paper, we reviewed published results on the toxic effects of Cr(VI) in fish at levels of molecules, tissues, organs and individuals. The mechanisms of toxicity and detoxification of Cr(VI) in various aspects were discussed. In addition, we also put forward perspectives on the toxicity of chromium in aquatic organisms.

This paper studied the effects of different concentrations of natural dissolved organic matter (DOM) on the passive sampling technique. The results showed that the presence of DOM affected the organic pollutant adsorption ability of the membrane. For lgK(OW), 3-5, DOM had less impact on the adsorption of organic matter by the membrane; for lgK(OW), > 5.5, DOM significantly increased the adsorption capacity of the membrane. Meanwhile, LDPE passive sampling technique was applied to monitor PAHs and PAEs in pore water of three surface sediments in Taizi River. All of the target pollutants were detected in varying degrees at each sampling point. Finally, the quotient method was used to assess the ecological risks of PAHs and PAEs. The results showed that fluoranthene exceeded the reference value of the aquatic ecosystem, meaning there was a big ecological risk.

This paper focuses on the sources, pollution status and potential ecology risks of heavy metals (Cr, Cu, Hg, As, Cd, Pb, and Zn) in the surface water, top sediment of river bed and soil along banks of Bortala River, which locates in the oasis region of Xinjiang, northwest China. Results showed that: (1) As a whole, contents of 7 tested heavy metals of Bortala River were low, while the maximum values of Hg, Cd, Pb, and Cr in the river water were significantly higher than those of Secondary Category of the Surface Water Quality Standards of People's Republic of China (GB 3838-2002) and Drinking Water Guideline from WHO. Analysis showed that the heavy metals contents of top sediment on river bed and soils along river banks were significantly higher than those of the river water. (Correlation analysis and enrichment factor (EF) calculation showed that in the river water, top sediment on river bed and soils along river banks, Hg, Cd, Pb, and Cr mainly originated from industrial emissions, urban and rural anthropogenic activities, transportation and agricultural production activities; While Cu, Zn, and As mainly originated from natural geological background and soil parent materials. (3) Pollution assessment showed that in three matrices, the single factor pollution index(Pi) and the integrated pollution index (Pz) of 7 heavy metals were all lower than 1, and they all belonged to safe and clean levels. (4) Potential ecology risk evaluation showed that as a whole the single factor potential ecological risk (Eir) and the integrated potential ecology risks (RI) of 7 heavy metals were relatively low, and would not cause threats to the health of water and soil environment of river basin, while the potential ecology risks of Cd, Hg, Pb, and Cr were significantly higher than those of other heavy metals.

The paper used the method of iron copper catalyst reduction to degrade low concentrations of bromochloracetonitrile (BCAN) to lighten the damage to human being, which is a kind of disinfection by-products (DBPs) produced during the chlorination process of drinking water. The removal efficiency of BCAN and its influencing factors were investigated. The mechanism of degradation and kinetics were also explored. The results indicated that iron copper had a greater degradation ability towards BCAN, and the degradation rate of iron copper (mass ratio of 10:1) was 1.5 times that of the zero-valent iron. The removal of BCAN increased obviously with the increase of Fe/Cu dosage. When the initial concentration was set at 20 microg x L(-1), after a reaction time of 150 min, removal of BCAN was improved from 51.1% to 89.5% with the increase of iron copper (mass ratio of 10:1) dosage from 5 g x L(-1) to 10 g x L(-1). The temperature also had great impact on BCAN removal and the removal increased with the increase of temperature. However, BCAN removal did not change a lot with the variation of the initial concentration of BCAN when it was at a low level. The BCAN degradation by iron copper catalytic-reduction followed the first-order kinetics model.

In this paper, the surface sediment samples were harvested from Aibi Lake, and total contents of 8 heavy metals ( Cu, Pb, Zn, As, Hg, Cr, Ni and Cd) were determined. Then the sources, pollution statue, and potential ecological risk were analyzed by using multiple analysis methods. The results show that: (1) The order of the skewness for these 8 heavy metals is: Hg > Cd > Pb > Zn > As > Cu > Cr > Ni. (2) Multivariate statistical analysis shows that 8 heavy metals can be classified to 2 principle components, among which PC1 ( Cd, Pb, Hg and Zn) is man-made source factor and mainly came from all kinds of waste of agriculture; PC2 ( Cu, Ni, Cr and As) is natural source and was mainly controlled by the background of the natural geography of this area. (3) Accumulation of index evaluation results show that the order of pollution degree values of 8 heavy metals in surface sediments of Aibi Lake is: Cd > Hg > Pb > Zn > As > Cu > Ni > Cr. In all samples, heavy metals Hg, Cd and Pb all belong to low and partial moderate pollution statue, while Zn, As, Cr, Ni and Cu belong to no pollution statue in majority samples. (4) Potential ecological risk assessment results show that the potential ecological risk of heavy metals in surface sediments of Aibi Lake mainly caused by Cd, Hg and Pb, and they accounting for 42.6%, 28.6% and 24.0% of the total amount, respectively, among which Cd is the main ecological risk factor, followed by Hg and Pb. In all samples, the potential ecological risk index values (RI) of 8 heavy metals are all lower than 150, and they are all at low ecological risk levels. However, this research also shows that there have high content of Cd and Pb in the sediment. Therefore, we should make long-term monitoring of the lake environment.