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Eighteen selected pharmaceuticals and personal care products (PPCPs), consisting of five non-antibiotic pharmaceuticals (N-APs), four sulfonamides (SAs), four tetracyclines (TCs), four macrolides (MCs), and one quinolone (QN) were detected in water, pore water, and sediment samples from Baiyangdian Lake, China. A total of 31 water samples and 29 sediment samples were collected in March 2017. Caffeine was detected with 100% frequency in surface water, pore water, and sediment samples. Carbamazepine was detected with 100% frequency in surface water and sediment samples. Five N-APs were prominent, with mean concentrations of 4.90-266.24 ng/l in surface water and 5.07-14.73 μg/kg in sediment samples. Four MCs were prominent, with mean concentrations of 0.97-29.92 ng/l in pore water samples. The total concentrations of the different classes of PPCPs followed the order: N-APs (53.26%) > MCs (25.39) > SAs (10.06%) > TCs (7.64%) > QNs (3.64%) in surface water; N-APs (42.70%) > MCs (25.43%) > TCs (14.69%) > SAs (13.90%) > QNs (3.24%) in sediment samples, and MCs (42.12%) > N-APs (34.80%) > SAs (11.71%) > TCs (7.48%) > QNs (3.88%) in pore water samples. The geographical differences of PPCP concentrations were largely due to anthropogenic activities. Sewage discharged from Baoding City and human activities around Baiyangdian Lake were the main sources of PPCPs in the lake. An environmental risk assessment for the upper quartile concentration was undertaken using calculated risk quotients and indicated a low or medium-high risk from 18 PPCPs in Baiyangdian Lake and its five upstream rivers.

The Three Gorges Reservoir (TGR) is the largest reservoir in China. Cadmium (Cd) is a primary pollutant in the TGR, and its speciation and bioavailability have attracted extensive attention since TGR submergence. In this study, Chelex-100 DGT (diffusive gradient in thin films) and the sequential extraction method were used to investigate the bioavailable Cd in sediments obtained from a typical tributary (Meixi) and mainstream (Yangtze) in the TGR. The total Cd concentrations in sediments of the four stations were also determined. In comparison to the concentrations of labile Cd measured by DGT (C DGT -Cd) in four profiles, CJ and MX-upstream/downstream were at potential risk for Cd release from surface sediments using the apparent diffusion flux across the interface numerical model. The order of C DGT -Cd in surface sediments was as follows: CJ > MX-downstream > MX-upstream > MX-midstream. Additionally, a positive correlation was demonstrated between C DGT -Cd and Cd in the exchangeable fraction (F1) in the surface sediments, indicating that Cd in the exchangeable fraction was readily captured by DGT. A negative correlation was observed between C DGT -Cd and C DGT -Fe, C DGT -Mn in the sediment-water-interface (SWI), suggesting that Fe/Mn oxides did not control the release of labile-Cd from sediments. Furthermore, a positive correlation existed between the C DGT -Cd in the surface sediments and Cd in the oxidizable fraction (F3), illustrating that Cd sorbed or bound with organic matter or sulfide was labile and released into the water phase from the surface sediments. A dark area was found in the AgI gel, which further demonstrated that Cd simultaneously was released with sulfide in this area., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The Three Gorges Reservoir (TGR) is one of the world's largest man-made hydropower projects, which has posed great challenges to the aquatic environment of the Yangtze River since the impoundment of water. As a non-essential toxic metalloid, information on the bioavailability of Antimony (Sb) in TGR sediments is lacking. Four sediment cores were collected from a tributary and the mainstream in the TGR to investigate the distribution and remobilization of Sb using the diffusive gradients in thin films (DGT) technique. The results showed that the concentrations of Sb obtained by DGT (CDGT-Sb) at all of the sampling stations were low (below 0.30 μg/L), compared to the relatively high Sb concentrations in the sediments. The lateral and vertical distributions of CDGT-Sb revealed different tendencies in overlying water and sediments at all of the sampling sites in the TGR, which may be attributed to anthropogenic impacts, the heterogeneity of sediments and the unevenness of the sediment-water interface (SWI) during the deployment of DGT probes. In addition, CDGT-Sb in the surface sediments were lower than those in the overlying water, and concentration gradients were found near the SWI, demonstrating that Sb has the potential to diffuse from the overlying water into the sediment. In the sediment cores, different peaks were discovered in the DGT probes and the remobilization of Sb simultaneously appeared in the vicinity of -10 cm. Correlation analysis showed that CDGT-Sb had no or negative correlation with CDGT-Fe and CDGT-Mn in all of the DGT probes, suggesting that the release of Sb was unassociated with Fe and Mn in the sediments in the study area., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The impoundment of the Three Gorges Reservoir (TGR) in China influences the quality of the water supply. Surface sediment samples from the TGR mainstream and three tributaries were collected. Acid volatile sulfide (AVS), simultaneously extractable metals (SEMs), and the fraction of organic carbon (f(oc)) were used to assess the toxicity of heavy metals. Sediment quality guidelines (SQGs) were established using the equilibrium partitioning approach. The results showed that the surface sediments were found to be oxic or suboxic. AVS concentrations in sediments were relatively low, below SEM concentrations. The [SEM] - [AVS] model indicated that all sediments possibly have adverse effects on aquatic life. However, ([SEM] - [AVS])/f(oc) predicted no adverse biological effects in some areas of the Meixi and Caotang Rivers, while adverse effects to aquatic life were uncertain for the other sediments. The partitioning coefficients, water quality criteria, and residual metals in the sediments were the main factors influencing the SQGs for the TGR, while the metals bound to AVS had a negligible effect. The normalized TGR SQGs were all much higher than the existing standards except for cadmium and copper. The differences might be attributed to the approaches used for derivation of SQGs and the physical and chemical characteristics of the sediments.

Owing to the growing public awareness on the safety and aesthetics in water sources, more attention has been given to the adverse effects of volatile organic compounds (VOCs) on aquatic organisms and human beings. In this study, 77 target VOCs (including 54 common VOCs, 13 carbonyl compounds, and 10 taste and odor compounds) were detected in typical drinking water sources from 5 major river basins (the Yangtze, the Huaihe, the Yellow, the Haihe and the Liaohe River basins) and their occurrences were characterized. The ecological, human health, and olfactory assessments were performed to assess the major hazards in source water. The investigation showed that there existed potential ecological risks (1.30 × 10 ≤ RQtotals ≤ 8.99 × 10) but little human health risks (6.84 × 10(-7) ≤ RQtotals ≤ 4.24 × 10(-4)) by VOCs, while that odor problems occurred extensively. The priority contaminants in drinking water sources of China were also listed based on the present assessment criteria., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Impoundment of the Three Gorges Reservoir has created an artificial riparian zone with a vertical height of 30 m and a total area of 349 km(2), which has been subjected to seasonal inundation and exposure due to regular reservoir impoundment and the occurrence of natural floods. The significant alteration of hydrologic regime has caused numerous environmental changes. The present study investigated the magnitude and spatial pattern of sedimentation and metal enrichment in a typical section of the riparian zone, composed of bench terraces with previous agricultural land uses, and explored their links to the changed hydrologic regime. In particular, we measured the total sediment depths and collected surface riparian sediments and down-profile sectioned riparian soils (at 5 cm intervals) for trace metal determination. Our analysis showed that the annual average sedimentation rates varied from 0.5 to 10 cm·yr(-1) and they decreased significantly with increasing elevation. This lateral distribution was principally attributed to seasonal variations in water levels and suspended sediment concentrations. Enriched concentrations of trace metals were found both in the riparian sediments and soils, but they were generally higher in the riparian sediments than in riparian soils and followed a similar lateral decreasing trend. Metal contamination assessment showed that the riparian sediments were slightly contaminated by Ni, Zn, and Pb, moderately contaminated by Cu, and moderately to strongly contaminated by Cd; while riparian soils were slightly contaminated by As, and moderately contaminated by Cd. Trace metal enrichment in the riparian sediments may be attributed to external input of contaminated sediments produced from upstream anthropogenic sources and chemical adsorption from dissolved fractions during pure sediment mobilization and after sink for a prolonged flooding period due to reservoir impoundment., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Sorption of phthalic acid esters (PAEs: diethyl phthalate, DEP: dibutyl phthalate, DBP as model compounds) in landfill leachates by activated carbon (AC), carbon nanotubes (CNTs), and biochars, were examined. The young leachate (YL) and old leachate (OL) were synthesized to imitate acetogenic and methanogenic phases, respectively, and glucose (GLU) and fulvic acid (FA) were selected to represent dissolved organic matter (DOM). GLU in leachates generally facilitated the sorption of PAEs while FA restrained sorption of PAEs, suggesting the type of DOM associated with leachates possibly regulated the removal efficiency of PAEs from leachates. The pores and organic carbon of carbonaceous sorbents should be major factors in influencing the sorption of PAEs in leachates. The data showed PAEs in acetogenic leachates was removed more easily than those in methanogenic leachates and CNTs have the less advantage to remove PAEs from methanogenic leachates compared to AC., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

This study was conducted to investigate the current contamination status of polyhalogenated aromatic hydrocarbons (PHAHs) in sediments from the mainstream and 22 primary tributaries of the Yangtze River in the Three Gorges Reservoir region. To accomplish this, the concentrations of 22 polybrominated biphenyl (PBB) congeners, 27 polybrominated diphenyl ether (PBDE) congeners, and 27 polychlorinated biphenyl (PCB) congeners in sediment samples were measured by GC-MS/MS. The result showed that the observed values of PBBs and PBDEs were 22.41 and 35.24 pg g(-1) dw, respectively. PBB1, 31 and 103 were the predominant PBB congeners, while PBDE28, 47, 77 and 99 were the predominant PBDE congeners. PBB209 and BDE209 were detected in >39% of the samples, with geometric means 2.43 and 11.92 pg g(-1) dw, respectively. PCBs were found to be the predominant compounds in sediment samples among the three PHAH subfamilies, with a geometric mean of 1,231.11 pg g(-1) dw, and PCB8, 18, 28, 52 and 66 were the primary PCB congeners. The measured levels of PHAHs were compared with results recently reported in the literature and their respective sediment quality guidelines recommended by the USEPA. The levels of PHAHs in the present study were generally lower than their respective threshold-effect levels, or were comparable to those reported in relatively uncontaminated freshwater samples from other regions. Taken together, these results suggest that, in the reservoir, toxic biological effects on aquatic biota in response to PHAHs contamination of sediments can be expected to be negligible.

This study was undertaken to investigate the current contamination status of polyhalogenated aromatic hydrocarbons (PHAHs) in sediments from 14 principal rivers of the Hai River basin. The concentrations of 22 polybrominated biphenyl (PBB) congeners, 27 polybrominated diphenyl ether (PBDE) congeners, and 27 polychlorinated biphenyl (PCB) congeners in sediments were measured using GC-MS/MS technique. The highest PBB levels were detected in sediments from River Daqing: PBB3, 10, 4, 15, 26, 31, and 49 were observed in the sediments. The highest concentrations of PBDEs were in River Tuhe (G.M.=2.10 ng g(-1) dw), and PBDE15 was the most predominant congener in the sediments from all of the rivers of this study, except for River Tuhe, which accounted for >13.5% of the total PBDEs in sediments. PBDE209 was detected in sediments from the Beijingpaiwu, Nanyun, Majia and Tuhe rivers, with observed values ranging from 0.06 to 0.13 ng g(-1) dw. PCBs had the highest concentrations in sediment samples collected from River Luan and River Daqing, with levels of 18.13 and 25.62 ng g(-1) dw, respectively. The most predominant PCB congener in these samples was PCB138, which accounted for about 24% of the sum of the seven indicator PCB congeners (PCB28, 52, 101, 118, 138, 153, and 180) measured in the two rivers. The measured levels of PHAHs were compared with recent results, reported in the literature, and the respective sediment quality guidelines recommended by USEPA. The levels of PHAHs in the present study were generally lower than respective threshold-effect levels, or were comparable to those reported in relatively uncontaminated freshwaters from other regions. This suggests that, in these rivers, toxic biological effects on aquatic biota-due to PHAH contamination of sediments-can be expected to be negligible. Thus, in terms of PHAHs, the sediments can be regarded as relatively uncontaminated., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Concentrations and enrichment of heavy metals were determined in sediments collected from Beijiang River, South China. The Pb isotopic compositions in these sediment samples were also employed to effectively identify metal pollution sources. According to the measured Pb concentrations, the total Pb concentrations in sediments varied from 62.1 to 1,152.5 μg/g, with an average concentration of 249.6 μg/g. The assessment by Geoaccumulation Index indicates that Pb is at the 'strongly contaminated' level, indicating that the Pb pollution was mainly due to anthropogenic inputs. The observed isotopic ratios varied from 1.174 to 1.204 for ²⁰⁶Pb/²⁰⁷Pb, 2.452 to 2.478 for ²⁰⁸Pb/²⁰⁷Pb, 18.404 to 18.937 for ²⁰⁶Pb/²⁰⁴Pb, 15.631 to 15.790 for ²⁰⁷Pb/²⁰⁴Pb, 38.455 to 39.121 for ²⁰⁸Pb/²⁰⁴Pb. The majority of these ratios are lower than those reported for natural geological sources, especially for sediments collected from a smelter. Significant correlation between Pb concentration and isotopic ratios suggested possible binary mixing of Pb. Combined with Pb concentration and enrichment levels, our results show that Pb pollution in the sediments of Beijiang River was mainly derived from anthropogenic sources. The mining activities and metal smelting processing was the main source of Pb pollution in this region.

Although contamination by organic pollutants has previously been reported to occur in the Haihe River basin, few studies have been carried out on the levels of source water reservoir contamination and the health risk in the Haihe River basin. To understand the organic pollution status of the reservoirs in the Haihe River basin, samples were collected from 16 source water reservoirs. The samples were analyzed for the representative organic pollutants, which included benzene homologues, chlorobenzene compounds, organophosphorus pesticides, and nitrobenzene compounds, a total in all of 17 compounds. It was observed that the concentrations of the 17 compounds in the 16 reservoirs were all less than the limit laid down by Chinese surface water quality standards. In addition, benzene, toluene, nitrobenzene, p-nitrochlorobenzene, 2,4-dinitrotoluene and 2,4-dinitrochlorobenzene, dichlorvos, demeton, dimethoate methyl parathion, malathion and parathion were frequently detected in the 16 source water reservoirs, especially the organophosphorus pesticides; the detection rates of dichlorvos, dimethoate, methyl parathion, malathion and parathion were all 100% in the 16 source water reservoirs. The detection rate of target compounds suggested that organic pollution had been common in the source water of the Haihe River basin. The health risk assessment results suggested that the noncarcinogenic risk hazard quotient values of the target compounds were less than one, and the cancer risk values were all below 1 × 10(-6), which indicated that the heath risk produced by the target compounds in the 16 reservoirs was at an acceptable level.

This study was undertaken to investigate the current contamination status of polyhalogenated aromatic hydrocarbons (PHAHs) in sediments from large reservoirs located in Hebei and Hubei provinces in China. The concentrations of 21 polybrominated biphenyl (PBB) congeners, seven polybrominated diphenyl ether (PBDE) congeners, and 27 polychlorinated biphenyl (PCB) congeners in sediments were measured using the GC-MS/MS technique. Low-brominated PBBs (including 1, 3, 4, 10, 30, 31 and 53) were the most abundant PBB congeners and PBDEs 28, 47 and 99 were the most prevalent PBDE congeners in these samples. Among the three subfamilies of PHAHs, PCBs were the most predominant pollutants detected. The measured levels of PHAHs were compared with recent results reported in the literature and their respective sediment quality guidelines recommended by USEPA. The levels of PHAHs in the present study were generally lower than their respective threshold-effect levels, or were comparable to those reported in relatively uncontaminated freshwaters from other regions. This suggests that, in these reservoirs, toxic biological effects on aquatic biota--due to PHAH contamination of sediments--can be expected to be negligible. Thus, in terms of PHAHs, the sediments in the selected reservoirs are relatively uncontaminated.

The organophosphorous pesticides (OPPs) contaminations have been reported to occur in some Chinese waters. To describe the contamination status and the spatial distribution of OPPs in the surface water throughout China, samples were collected from over 600 sites located in the surface water of seven major river basins and three main internal rivers drainage areas during 2003 and 2004. The surface water samples were analyzed for the representative OPPs including dichlorvos, demeton, dimethoate, methyl parathion, malathion and parathion. In general, the most frequently detected compound was dichlorvos and demeton, being detected in 89.1% of samples (mean = 17.8 ng/L; range <1.4-1,552.0 ng/L) for dichlorvos, and 78.2% of samples (mean = 35.4 ng/L; range <1.5-2,560.0 ng/L) for demeton. While the detection frequencies of the dimethoate, methyl parathion, malathion, and parathion were all less than 50% in all the surface water samples. Measured concentrations for the six compounds were low and rarely exceed the environment quality standard for surface water of China. The six OPPs compounds were more frequently detected at much higher concentrations in the rivers of north China compared with those of south China. The results of this investigation indicate that OPPs contamination in the Yellow River, Huaihe River, Liaohe River, and Haihe River basins of north China should be of particular concern. When compared with other regions of the world, it appears that the Chinese surface water is some moderately polluted by dimethoate, methyl parathion, malathion, parathion and contaminated by dichlorvos and demeton in certain degree.

Persistent organochlorine pesticides pollutants (OCPs) have been reported to occur at relatively high concentrations in some Chinese waters. In order to map the distribution of organochlorine pesticides in the surface water throughout China, samples were collected from over 600 sites in seven major river basins and three main internal rivers drainage areas during 2003 and 2004. The surface water samples were analyzed for the representative organochlorine pesticides contaminants including lindane (gamma-HCH), p,p'-DDT and heptachlor epoxide. In general, the most frequently detected compound was lindane, being detected in 83.9% of samples (mean=31.3 ng/l; range <0.17-860 ng/l), and the highest concentration was present in the Yellow River basin. p,p'-DDT was detected in 63.1% of the samples collected (mean=14.6 ng/l; range <0.14-368 ng/l) with the highest concentration present in the Huaihe River basin. Heptachlor epoxide was detected in only 9.3% of water samples (range <0.11-10 ng/l). Measured concentrations for the three compounds were low and rarely exceed the environment quality standard for surface water of China. Lindane was more frequently detected at much higher concentrations in the rivers of northern China compared with those of southern China. The sites with higher concentration of lindane and p,p'-DDT mainly occurred in the Yellow River and Huaihe River basins, so the results of this investigation indicate that the organochlorine pesticide contamination of Yellow River and Huaihe River basins should be of particular concern relative to the other basins. When compared with other regions of the world, it appears that the Chinese surface water is moderately polluted by lindane and p,p'-DDT.

Nitrobenzene was reported to occur at relatively high concentrations in some Chinese surface water and to cause an environmental pollution event in 2005. To map the distribution of nitrobenzene in the Chinese surface water throughout China, surface water samples were collected from over 600 sites in the 7 major watersheds and three drainage areas. The samples were analyzed for concentration of nitrobenzene. Overall, nitrobenzene was more frequently detected at higher concentrations in the rivers of North China, including Songhua River, Liaohe River, Haihe River, Yellow River, Huaihe River, and Northwest drainage area rivers, compared with those in the rivers of South China, including Yangtze River, Pearl River, Southeast drainage area rivers and Southwest drainage rivers. The detection rate of nitrobenzene was 83.2% for all the samples, with a mean value of 18.1 ng/L and a range of < 0.3-8450.0 ng/L. The highest mean concentration of nitrobenzene was observed in the Yellow River, followed by Huaihe River. The results of this investigation indicated that nitrobenzene should be of particular concern in China and its ecological and health risk should be assessed.