鄱阳湖流域南昌市城市湖泊水体抗生素污染特征及生态风险分析

采用固相萃取-超高效液相色谱-质谱法对南昌市5个城市湖泊——艾溪湖、瑶湖、青山湖、象湖和东西湖水体的抗生素进行监测,并分析其污染来源和生态风险.结果表明,南昌市5个城市湖泊水体中四环素类、磺胺类、喹诺酮类、林可霉素及大环内酯类5类抗生素的检出浓度范围分别为ND~6.3、ND~32.0、ND~97.2、ND~54.7和ND~98.4 ng/L;红霉素和林可霉素是5个城市湖泊水体中的主要抗生素类型;相比于其他湖泊,南昌市城市湖泊水体中主要检出抗生素浓度总体处于中等水平,其中恩诺沙星的检出浓度高于其他对比湖泊.南昌市城市湖泊中6种主要抗生素的风险商均小于0.1,表明均为最低生态风险;5个城市湖泊的主要生态风险因子分别是艾溪湖为红霉素,瑶湖为磺胺二甲嘧啶,青山湖为罗红霉素,象湖为红霉素,东西湖为磺胺嘧啶.本研究可为南昌市城市湖泊水环境管理,特别是新型污染物的环境管理提供基础依据.     

宁波月湖水体中抗生素的分布与生态风险评价

为探讨城市湖泊中抗生素的污染分布特征和生态风险,以宁波月湖为研究对象,利用固相萃取、超高效液相色谱串联质谱法（HPLC-MS/MS）对月湖水体抗生素进行分析,并采用生态风险熵值法（RQ）和混合抗生素的风险法（MRQ）评价磺胺类、大环内酯类、喹诺酮类、β-内酰胺类、林可霉素（LIN）等10种抗生素的生态风险情况.结果表明：氨苄西林（AMS）的检出浓度最高,浓度变化范围在ND~382.0 ng/L;其次为头孢氨苄（LEX）、诺氟沙星（NOR）、磺胺间甲氧嘧啶（SMM）、LIN、阿奇霉素（AZM）、磺胺噻唑（STZ）、磺胺甲恶唑（SMX）、泰乐菌素（TYL）和磺胺嘧啶（SDZ）,浓度范围分别为ND~283.0、ND~267.0、ND~219.0、31.50~209.0、ND~147.0、7.34~109.0、ND~104.0、ND~80.50和20.40~57.30 ng/L.月湖水体中10种目标抗生素的水平总体上高于自然湖泊,尤其β-内酰胺类和LIN在城市湖泊中广泛存在.生态风险评估的结果表明,LIN、TYL、SMX、NOR、AMS的生态风险值（RQ）值均大于1,具有高的生态风险;其余5种抗生素处于中或低的生态风险水平.本研究为城市湖泊抗生素生态风险问题的深入研究提供了一定的科学依据和基础.     

Presence of Semi‐Volatile Organic Contaminants in Shallow Groundwater of Selected Regions in China

A pioneering investigation of semi‐volatile organic compounds (SVOCs) in shallow groundwater in China was hereby reported. Representative groundwater samples were collected from three selected regions: Eastern Hai River Plain, Yangtze River Delta, and Yunnan‐Guizhou Plateau, and analyzed for 103 SVOCs linked to agricultural and industrial practices. Analytical results showed that 70 of the 103 SVOCs were present in the groundwater samples, a detection frequency of approximately 86%. Compounds detected most frequently included P,P′‐DDT (53.49%, MDL 0.0007 µg/L), 2,4‐dinitrotoluene (51.16%, MDL 0.02 µg/L), and phenol (51.16%, MDL 0.02 µg/L). Fifteen SVOCs, such as P,P′‐DDT, 2,4‐dinitrotoluene, heptachlor, and aldrin, were detected at concentrations exceeding the USA National Recommended Water Quality Criteria‐2009 (USNRWQC‐2009). Most of these 15 SVOCs belong to polycyclic aromatic hydrocarbons and organochlorine pesticides. The detection of SVOCs in the Yunnan‐Guizhou Plateau warrants special concern, since this region has limited human activities and been assumed as an environmentally pristine area. The data from this work are expected to contribute to the database of contemporary groundwater quality in China.     

The Occurrence and Persistence of MTBE in Groundwater in Windham,Maine, USA

A study was conducted from July 1998 through November 2007 on the occurrence and distribution of the fuel oxygenate methyl tert-butyl ether (MTBE) in a large sand and gravel aquifer located in southern Maine. MTBE was detected in 44% of 129 water samples collected from monitoring wells in concentrations up to 38.7 µg/L (reporting limit = 0.1 µg/L). The number of wells with detectable quantities of MTBE declined slightly between 1999 and 2007, but in general MTBE persisted throughout the period of study. Overall, MTBE was detected more frequently in the shallow and more transmissive parts of the aquifer. There was a statistically significant difference (p < 0.001) for MTBE concentrations relative to nearby land uses. MTBE was detected in 83% of the samples collected from wells in low-density residential areas, in 50% of samples from urban areas, and in 60% of samples from undeveloped areas. The concentrations of MTBE in the test wells were compared across the sample dates for trends and seven wells had a positive trend (Mann–Kendall statistic), but none was significant at p < 0.05. Nine wells had a negative trend, but only one was significant at p < 0.05. Three wells had no trend. The absence of strong or even consistent trends indicates that MTBE persists in shallow groundwater, even after gasoline formulations were changed to reduce or eliminate MTBE.     

Surveying Upstate NY Well Water for Pesticide Contamination: Cayuga and Orange Counties

Private wells in Cayuga and Orange counties in New York were sampled to determine the occurrence of pesticide contamination of groundwater in areas where significant pesticide use coincides with shallow or otherwise vulnerable groundwater. Well selection was based on local groundwater knowledge, risk modeling, aerial photo assessments, and pesticide application database mapping. Single timepoint samples from 40 wells in each county were subjected to 93‐compound chromatographic scans. All samples were nondetects (reporting limits ≤1 μg/L), thus no wells from either county exceeded any of 15 state groundwater standards or guidance values. More sensitive enzyme‐linked immunosorbent assays (ELISA) found two wells with quantifiable atrazine in each county (0.1–0.3 μg/L), one well with quantifiable diazinon (0.1 μg/L) in Orange County, and one well with quantifiable alachlor (0.2 μg/L) in Cayuga County. Trace detections (<0.1 μg/L) in Cayuga County included atrazine (five wells), metolachlor (six wells), and alachlor (one well), including three wells with multiple detections. All 12 Cayuga County wells with ELISA detections had either corn/grain or corn/forage rotations as primary surrounding land uses (although 20 other wells with the same land uses had no detections) and all quantified detections and most trace detections occurred in wells up to 9‐m deep. Orange County trace (<0.1 μg/L) ELISA detections (atrazine three wells, diazinon one well, and metolachlor five wells) and quantified detections were only generally associated with agricultural land uses. Finding acceptable drinking water quality in areas of vulnerable groundwater suggests that water quality in less vulnerable areas will also be good.     

Isotope Approach to Assess Hydrologic Connections During Marcellus Shale Drilling

Water and gas samples were collected from (1) nine shallow groundwater aquifers overlying Marcellus Shale in north‐central West Virginia before active shale gas drilling, (2) wells producing gas from Upper Devonian sands and Middle Devonian Marcellus Shale in southwestern Pennsylvania, (3) coal‐mine water discharges in southwestern Pennsylvania, and (4) streams in southwestern Pennsylvania and north‐central West Virginia. Our preliminary results demonstrate that the oxygen and hydrogen isotope composition of water, carbon isotope composition of dissolved inorganic carbon, and carbon and hydrogen isotope compositions of methane in Upper Devonian sands and Marcellus Shale are very different compared with shallow groundwater aquifers, coal‐mine waters, and stream waters of the region. Therefore, spatiotemporal stable isotope monitoring of the different sources of water before, during, and after hydraulic fracturing can be used to identify migrations of fluids and gas from deep formations that are coincident with shale gas drilling.     

Assessing Methane in Shallow Groundwater in Unconventional Oil and Gas Play Areas,Eastern Kentucky

The expanding use of horizontal drilling and hydraulic fracturing technology to produce oil and gas from tight rock formations has increased public concern about potential impacts on the environment, especially on shallow drinking water aquifers. In eastern Kentucky, horizontal drilling and hydraulic fracturing have been used to develop the Berea Sandstone and the Rogersville Shale. To assess baseline groundwater chemistry and evaluate methane detected in groundwater overlying the Berea and Rogersville plays, we sampled 51 water wells and analyzed the samples for concentrations of major cations and anions, metals, dissolved methane, and other light hydrocarbon gases. In addition, the stable carbon and hydrogen isotopic composition of methane (δ¹³C‐CH₄ and δ²H‐CH₄) was analyzed for samples with methane concentration exceeding 1 mg/L. Our study indicates that methane is a relatively common constituent in shallow groundwater in eastern Kentucky, where methane was detected in 78% of the sampled wells (40 of 51 wells) with 51% of wells (26 of 51 wells) exhibiting methane concentrations above 1 mg/L. The δ¹³C‐CH₄ and δ²H‐CH₄ ranged from ?84.0‰ to ?58.3‰ and from ?246.5‰ to ?146.0‰, respectively. Isotopic analysis indicated that dissolved methane was primarily microbial in origin formed through CO₂ reduction pathway. Results from this study provide a first assessment of methane in the shallow aquifers in the Berea and Rogersville play areas and can be used as a reference to evaluate potential impacts of future horizontal drilling and hydraulic fracturing activities on groundwater quality in the region.     

Using Na/K Ratios to Identify the Potential Impacts of Sewage Effluent on Groundwater Quality in Sohag,Egypt

Improper disposal of wastewater is an important source of groundwater contamination, as it poses serious threats to the environment and human health. In this case study, 18 groundwater and 3 sewage effluent samples were collected from the area adjacent to a wastewater treatment plant in Sohag, Egypt. These samples were subjected to detailed chemical and bacteriological analyses to quantify the potential impact of sewage effluent on the groundwater quality using geochemical indicators. The groundwater aquifer in the study area is represented by the highly permeable Qena Sands that are composed of sands and gravels. The bacteriological analyses indicated the presence of fecal coliform in groundwater at wells nearby the wastewater ponds and farm lands. NH₄ concentration of the contaminated groundwater samples ranged from 0.36 to 5.70 mg/L (78% of the samples > 1.20 mg/L) and the NH₄ in the non‐impacted samples ranged from 0.40 to 2.23 mg/L (22% > 1.20 mg/L). Variations in NH₄ concentrations are due to the transformation processes occurring in the aquifer. The groundwater samples were categorized based on the Na/K ratio into two classes. The first class shows the Na/K ratios vary from 2.52 to 12.19 for sewage effluent and contaminated samples, while in the second class they range from 12.85 to 31.60 for non‐impacted samples. As a result, the Na/K ratio in combination with other chemical and microbiological indicators is a useful screening tool for assessing possible sewage influence on shallow groundwater from shallow wells.     

Analysis of Endocrine Disrupting Steroids: Investigation of Their Release into the Environment and Their Behavior During Bank Filtration

A reliable and sensitive analytical method for the determination of estrone (E1), 17β-estradiol (E2), and the synthetic hormone 17α-ethinylestradiol (EE2) has been established. Samples are concentrated using automated solid-phase extraction and analysis is performed by liquid chromatography with detection by tandem mass spectrometry. Recoveries of all analytes were between 93% and 107%, and limits of quantification (LOQs) between 0.1 and 0.4 ng/L for purified sewage, and surface, ground, and drinking water, and between 1 and 2 ng/L in case of raw sewage. For the investigation of estrogen release into the environment and its behavior during sewage and surface water treatment, and during ground water recharge, samples from municipal waste water treatment plants (WWTPs), a surface water treatment plant, a bank filtration site, and a ground water enrichment (GWE) pond were analyzed. El was found in the raw waste water with an average concentration of 157 ng/L, whereas E2 and EE2 were found with mean concentrations of only 18 and 9 ng/L, respectively. Sewage treatment by municipal WWTPs affected a removal of EE2 (76%), El (92%), and E2 (94%). In the investigated surface water of Berlin, only E1 could be detected at concentrations around or below 1 ng/L. E2 and EE2 were not present in the Berlin surface water above the LOQ of 0.2 ng/L, respectively. Surface water treatment also leads to a significant removal of E1 (> 80%). In the ground water samples from the GWE site near Lake Tegel, only a few samples contained detectable concentrations of E1. These samples were collected from a shallow monitoring well located very close to the bank of the pond. Even a short distance between the bank and observation wells led to concentrations of El below the LOQ showing the potential of ground water recharge systems for the retention of estrogenic steroids depending on the environmental setting.     

Screening of Emerging Volatile Organic Contaminants in Shallow Groundwater in East China

In order to collect baseline information on the environmental occurrence of volatile organic compounds (VOCs) in groundwater in East China, shallow groundwater samples were collected from five alluvial plains in East China in 2008 to 2009. All samples were analyzed for 54 VOCs representing a wide variety of uses and origins. Sampling sites were mainly selected in the areas to be susceptible to contamination from human activities in terms of previous hydrogeological survey. The data of all samples showed a variety of different hydrogeological systems with potential sources of VOCs, with 36 of the 54 VOCs being found. The most frequently detected compounds include naphthalene (56.9%), chloroform (16.9%), 1,2‐dichloroethane (16.2%), 1,2‐dichloropropane (13.1%), and 1,2,3‐trichlorobenzene (12.3%). The concentrations of methylene chloride, 1,2‐dichloroethane, carbon tetrachloride, trichloroethene, 1,2‐dichloropropane, and tetrachloroethene exceeded the relating drinking water standards. Future work will be needed to identify those factors that are most important in determining the occurrence and concentrations of VOCs in groundwater in China.     

Experimental evidence of fast groundwater responses in a hillslope/floodplain area in the Black Forest Mountains,Germany

Analysis of water flow pathways from hillslopes to streams is essential for the optimal protection of water resources as well as for ecohydrological studies. This study addresses runoff generation processes at a hillslope and near‐stream shallow groundwater system in the Black Forest Mountains, southwestern Germany. The changing spatial and temporal flow patterns during differing hydrological situations were examined using a combined hydraulic and hydrochemical approach. Groundwater levels at 10 wells, discharge at a near‐stream saturated area, and several natural tracers (deuterium, dissolved silica, and major anions and cations) were observed at different locations during high and low flows. The importance of the groundwater component during flood formation was clearly demonstrated: its contribution was about 80% during a double peak flood event at the saturated area. In addition, a rapid change of the shallow groundwater levels was observed along two transects of groundwater wells in the floodplain. This led to an enhanced groundwater discharge into the saturated area located at the end of one study transect. The amount of groundwater additionally activated during the event was about 30% of total discharge recorded at the outlet of the saturated area. Two alternative hypotheses are discussed to explain this phenomenon: the establishment of locally confined conditions and the development of a pressure wave (hypothesis A), or the significant change of the three‐dimensional groundwater flow lines that caused a large increase of the groundwater catchment at the saturated area during the investigated event (hypothesis B). Even if the exact flow paths and mechanisms could not be clearly identified, the importance of rapid responding hillslope groundwater was undoubtedly demonstrated by a combination of tracer and hydrometric methods. Copyright © 2004 John Wiley & Sons, Ltd.     

Contrasting Influence of Geology on E. coli and Arsenic in Aquifers of Bangladesh

Arsenic in groundwater has been a concern in South and Southeast Asia for more than a decade. We explore here the possibility that hydrogeologic factors recently shown to influence the distribution of arsenic might also affect the level of contamination of shallow (<20 m) wells with microbial pathogens. A total of 96 shallow tube wells in two nearby villages of Bangladesh were surveyed during the wet and dry seasons, along with 55 deeper wells in neighboring villages. One of the two villages is located in a particularly sandy environment where recharge is rapid and shallow wells contain little arsenic. Shallow aquifers in the other village are capped with an impermeable clay layer, recharge is an order of magnitude slower, and arsenic levels are high. The fecal indicator E. coli was detected in 43% of shallow wells, compared with 12% of deeper wells. More shallow wells contained E. coli during the wet season (61%) than during the dry season (9%). In the wet season, a higher proportion of shallow wells in the village with low arsenic levels (72%) contained E. coli compared with the village having high arsenic levels (43%). Differences in arsenic and E. coli distributions between the two sites are likely due to the differences in permeability of near‐surface sediments although differences in average well‐depth between the two villages (9 ± 4 vs. 15 ± 3 m) may play a role as well. Hydrogeologic conditions that favor high levels of fecal contamination but low levels of arsenic in shallow groundwater should be taken into account during arsenic mitigation throughout South and Southeast Asia.     

Seasonality of Coliform Bacteria Detection Rates in New Jersey Domestic Wells

It is important that indicators of fecal pollution are reliable. Coliform bacteria are a commonly used indicator of fecal pollution. As other investigators have reported elsewhere, we observed a seasonal pattern of coliform bacteria detections in domestic wells in New Jersey. Examination of a statewide database of 10 years of water quality data from 93,447 samples, from 78,207 wells, generated during real estate transactions, revealed that coliform bacteria were detected in a higher proportion of wells during warm weather months. Further examination of the seasonal pattern of other data, including well water pH, precipitation, ground and surface water temperatures, surface water coliform bacteria concentrations, and vegetation, resulted in the hypothesis that these bacteria may be derived from nonfecal (or environmentally adapted) as well as fecal sources. We provide evidence that the coliform seasonality may be the result of seasonal changes in groundwater extraction volumes (and to a lesser extent precipitation), and temperature‐driven changes in the concentration of surface or near‐surface coliform sources. Nonfecal coliform sources may not indicate the presence of fecal wastes and hence the potential presence of pathogens, or do so in an inconsistent fashion. Additional research is needed to identify the sources of the coliforms detected in groundwater.     

Emerging organic contaminants in coastal waters: Anthropogenic impact,environmental release and ecological risk

This study provides a first estimate of the sources, distribution, and risk presented by emerging organic contaminants (EOCs) in coastal waters off southwestern Taiwan. Ten illicit drugs, seven nonsteroidal anti-inflammatory drugs (NSAIDs), five antibiotics, two blood lipid regulators, two antiepileptic drugs, two UV filters, caffeine, atenolol, and omeprazole were analyzed by solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry (SPE–LC–MS/MS). Thirteen EOCs were detected in coastal waters, including four NSAIDs (acetaminophen, ibuprofen, ketoprofen, and codeine), three antibiotics (ampicillin, erythromycin, and cefalexin), three illicit drugs (ketamine, pseudoephedrine, and MDMA), caffeine, carbamazepine, and gemfibrozil. The median concentrations for the 13 EOCs ranged from 1.47 ng/L to 156 ng/L. Spatial variation in concentration of the 13 EOCs suggests discharge into coastal waters via ocean outfall pipes and rivers. Codeine and ampicillin have significant pollution risk quotients (RQ > 1), indicating potentially high risk to aquatic organisms in coastal waters.     

新疆赛里木湖近岸表层水典型抗生素的赋存与风险评价

利用超高效液相色谱串联质谱联用技术(UPLC-MS/MS)检测了2019年3月份和7月份新疆赛里木湖近岸表层水中12种抗生素的浓度水平,分析了赛里木湖表层水中典型抗生素的时空分布特征及生态风险.结果表明,氧氟沙星和磺胺甲恶唑为赛里木湖中主要抗生素污染物,春季最高检出浓度分别为2.7×104和1.8×103 ng/L,其...     

广西青狮潭水库水体喹诺酮类抗生素的分布特征及生态风险评价

利用高效液相色谱法对桂林市青狮潭水库喹诺酮类抗生素（氧氟沙星（OFX）、诺氟沙星（NOR）、环丙沙星（CIP）、恩诺沙星（ENR））进行监测,并分析其污染来源和生态风险.结果表明：青狮潭水库水体中氧氟沙星、诺氟沙星、环丙沙星和恩诺沙星的检出浓度范围分别为50.00~660.13、3.70~5.00、3.49~6.22和4.59~6.06 ng/L;与国内河流抗生素浓度水平相比,青狮潭水库水体中喹诺酮类抗生素浓度处于中等偏低水平;青狮潭水库水体喹诺酮类抗生素浓度与水体理化性质的相关性分析表明：NOR浓度与pH相关性极显著、与浊度相关性显著,CIP浓度与总磷浓度相关性显著,OFX和ENR浓度与理化指标无显著相关性;生态风险评价结果表明青狮潭水库东湖区、西湖区水体中OFX存在高风险,NOR、CIP与ENR处于中等风险水平.     

Field verification of stable perched groundwater in layered bedrock uplands

Data substantiating perched conditions in layered bedrock uplands are rare and have not been widely reported. Field observations in layered sedimentary bedrock in southwestern Wisconsin, USA, provide evidence of a stable, laterally extensive perched aquifer. Data from a densely instrumented field site show a perched aquifer in shallow dolomite, underlain by a shale-and-dolomite aquitard approximately 25 m thick, which is in turn underlain by sandstone containing a 30-m-thick unsaturated zone above a regional aquifer. Heads in water supply wells indicate that perched conditions extend at least several kilometers into hillsides, which is consistent with published modeling studies. Observations of unsaturated conditions in the sandstone over a 4-year period, historical development of the perched aquifer, and perennial flow from upland springs emanating from the shallow dolomite suggest that perched groundwater is a stable hydrogeologic feature under current climate conditions. Water-table hydrographs exhibit apparent differences in the amount and timing of recharge to the perched and regional flow systems; steep hydraulic gradients and tritium and chloride concentrations suggest there is limited hydraulic connection between the two. Recognition and characterization of perched flow systems have practical importance because their groundwater flow and transport pathways may differ significantly from those in underlying flow systems. Construction of multi-aquifer wells and groundwater withdrawal in perched systems can further alter such pathways.     

Permeable Asphalt: A New Tool to Reduce Road Salt Contamination of Groundwater in Urban Areas

Chloride contamination of groundwater in urban areas due to deicing is a well‐documented phenomenon in northern climates. The objective of this study was to evaluate the effects of permeable pavement on degraded urban groundwater. Although low impact development practices have been shown to improve stormwater quality, no infiltration practice has been found to prevent road salt chlorides from entering groundwater. The few studies that have investigated chlorides in permeable asphalt have involved sampling directly beneath the asphalt; no research has looked more broadly at surrounding groundwater conditions. Monitoring wells were installed upgradient and downgradient of an 860 m² permeable asphalt parking lot at the University of Connecticut (Storrs, Connecticut). Water level and specific conductance were measured continuously, and biweekly samples were analyzed for chloride. Samples were also analyzed for sodium (Na), calcium (Ca), and magnesium (Mg). Analysis of variance analysis indicated a significantly (p < 0.001) lower geometric mean Cl concentration downgradient (303.7 mg/L) as compared to upgradient (1280 mg/L). Concentrations of all alkali metals increased upgradient and downgradient during the winter months as compared to nonwinter months, indicating that cation exchange likely occurred. Despite the frequent high peaks of chloride in the winter months as well as the increases in alkali metals observed, monitoring revealed lower Cl concentrations downgradient than upgradient for the majority of the year. These results suggest that the use of permeable asphalt in impacted urban environments with high ambient chloride concentrations can be beneficial to shallow groundwater quality, although these results may not be generalizable to areas with low ambient chloride concentrations.     

Weather-induced temporal variations in nitrate concentrations in shallow groundwater

For the evaluation of policy action programs to improve groundwater quality, research institutes and governments intensively monitor nitrate concentrations in shallow or near surface groundwater. However, trend detection is often hampered by the large seasonal and multi-annual temporal variability in nitrate concentrations, especially in shallow groundwater within 0–5 m below the surface in relatively humid regions. This variability is mainly caused by variations in precipitation excess (precipitation minus evapotranspiration) that results in strong variability in groundwater recharge. The objective of this study was to understand and quantify this weather-induced variability in shallow groundwater nitrate concentrations.We present an example of measured weather related variations in shallow groundwater nitrate concentrations from De Marke, an intensively monitored experimental farm in The Netherlands. For the quantification of the weather-induced variability, concentration-indices were calculated using a 1D model for water and solute transport. The results indicate that nitrate concentrations in the upper meter of groundwater at De Marke vary between 55% and 153% of the average concentration due to meteorological variability. The concentration-index quantification method was successfully used to distinguish weather related variability from human-induced trends in the nitrate concentration monitoring data from De Marke. Our model simulations also shows that sampling from fixed monitoring wells produces less short term variability than measuring from open boreholes. In addition, using larger screen depths and longer screens filters out short term temporal variability at the cost of a more delayed detection of trends in groundwater quality.