Characterizing pharmaceutical, personal care product, and hormone contamination in a karst aquifer of southwestern Illinois, USA, using water quality and stream flow parameters

Mitigation of Triclocarban Inhibition in Microbial Electrolysis Cell-Assisted Anaerobic Digestion

Triclocarban (TCC), as a widely used antimicrobial agent, is accumulated in waste activated sludge at a high level and inhibits the subsequent anaerobic digestion of sludge. This study, for the first time, investigated the effectiveness of microbial electrolysis cell-assisted anaerobic digestion (MEC-AD) in mitigating the inhibition of TCC to methane production. Experimental results showed that 20 mg/L TCC inhibited sludge disintegration, hydrolysis, acidogenesis, and methanogenesis processes and finally reduced methane production from traditional sludge anaerobic digestion by 19.1%. Molecular docking revealed the potential inactivation of binding of TCC to key enzymes in these processes. However, MEC-AD with 0.6 and 0.8 V external voltages achieved much higher methane production and controlled the TCC inhibition to less than 5.8%. TCC in the MEC-AD systems was adsorbed by humic substances and degraded to dichlorocarbanilide, leading to a certain detoxification effect. Methanogenic activities were increased in MEC-AD systems, accompanied by complete VFA consumption. Moreover, the applied voltage promoted cell apoptosis and sludge disintegration to release biodegradable organics. Metagenomic analysis revealed that the applied voltage increased the resistance of electrode biofilms to TCC by enriching functional microorganisms (syntrophic VFA-oxidizing and electroactive bacteria and hydrogenotrophic methanogens), acidification and methanogenesis pathways, multidrug efflux pumps, and SOS response.

Predicting environmental risks of pharmaceutical residues by wastewater surveillance: An analysis based on pharmaceutical sales and their excretion data

Pharmaceutical residues are increasingly becoming a significant source of environmental water pollution and ecological risk. This study, leveraging official national pharmaceutical sales statistics, predicts the environmental concentrations of 33 typical pharmaceuticals in the Tianjin area. The results show that 52 % of the drugs have a PEC/MEC (Predicted Environmental Concentration/Measured Environmental Concentration) ratio within the acceptable range of 0.5-2, including atenolol (1.21), carbamazepine (1.22), and sulfamethoxazole (0.91). Among the selected drugs, tetracycline, ciprofloxacin, and acetaminophen had the highest predicted concentrations. The EPI (Estimation Programs Interface) biodegradation model, a tool from the US Environmental Protection Agency, is used to predict the removal efficiency of compounds in wastewater treatment plants. The results indicate that the EPI predictions are acceptable for macrolide antibiotics and β-blockers, with removal rates of roxithromycin, spiramycin, acetaminophen, and carbamazepine being 14.1 %, 61.2 %, 75.1 %, and 44.5 %, respectively. However, the model proved to be less effective for fluoroquinolone antibiotics. The ECOSAR (Ecological Structure-Activity Relationships) model was used to supplement the assessment of the potential impacts of drugs on aquatic ecosystems, further refining the analysis of pharmaceutical environmental risks. By combining the concentration and detection frequency of pharmaceutical wastewater, this study identified 9 drugs with significant toxicological risks and marked another 24 drugs as substances of potential concern. Additionally, this study provides data support for addressing pharmaceutical residues of priority concern in subsequent research.

Environmentally relevant concentrations of triclocarban affect behaviour, learning, and brain gene expression in fish

Many chemicals spilled in aquatic ecosystems can interfere with cognitive abilities and brain functions that control fitness-related behaviour. Hence, their harmful potential may be substantially underestimated. Triclocarban (TCC), one of the most common aquatic contaminants, is known to disrupt hormonal activity, but the consequences of this action on behaviour and its underlying cognitive mechanisms are unclear. We tried to fill this knowledge gap by analysing behaviour, cognitive abilities, and brain gene expression in zebrafish larvae exposed to TCC sublethal concentrations. TCC exposure substantially decreased exploratory behaviour and response to stimulation, while it increased sociability. Additionally, TCC reduced the cognitive performance of zebrafish in a habituation learning task. In the brain of TCC-exposed zebrafish, we found upregulation of c-fos, a gene involved in neural activity, and downregulation of bdnf, a gene that influences behavioural and cognitive traits such as activity, learning, and memory. Overall, our experiments highlight consistent effects of non-lethal TCC concentrations on behaviour, cognitive abilities, and brain functioning in a teleost fish, suggesting critical fitness consequences of these compounds in aquatic ecosystems as well as the potential to affect human health.

Seasonal variations of microbial community structure, assembly processes, and influencing factors in karst river

The physicochemical properties and microbial communities have significant annual and seasonal changes in karst aquifers. To explore the changes of microbial community and their relationships with environmental factors, water samples were collected from a typical karst river. Microbial communities in winter (Jan-2017 and Jan-2019) were stable with high similarity in spite of the 2 years sampling interval, but the microbial communities in Aug-2017 was different from that in Aug-2018. In four sampling times, there were 275 shared genera, whose average relative abundance ranging from 89.04 to 96.27%. The winter and summer specific genera were mainly from the recharge of tributary site K6 and discharge of waste water treatment plant (K2 and K3), respectively. The deterministic processes had a more significant effect on the microbial community assembly in winter than that in summer, which was affected by environmental pressure from pollution. Furthermore, antibiotics and inorganic nitrogen pollution affected element cycles of nitrogen and sulfur indirectly through microbial ecological modules in karst river, and the denitrification and desulfurization processes were potentially inhibited. These findings contributed to understand the changes and its assembly mechanism of microbial community, as well as the feedback to environment in polluted karst river.

Distribution and health risks of organic micropollutants from home dusts in Malaysia

Indoor dust is an important medium to evaluate human exposure to emerging organic contaminants. The principal aim of this study was to determine overall status of organic micropollutants (OMPs) of indoor dust in Kuala Lumpur, Malaysia and assess their corresponding health risks. One hundred thirty-three OMPs, ascribed to 13 chemical groups, were screened by Automated Identification and Quantification System with a GC-MS database. The concentrations of OMPs ranged between 460 and 4000 μg/g, with the median concentration of 719 μg/g. The dominant chemical groups were ascribed to n-alkanes (median: 274 μg/g), plasticizers (151 μg/g), sterols (120 μg/g), and pesticides (42.6 μg/g). Cholestrol was the most abundant compound (median: 115 μg/g). Different sources and usage patterns of OMPs in various houses were expected. Toxicity values of OMPs were obtained from existing databases or predicted by quantitative structure-activity relationship models. Cumulative hazard quotients for OMPs through ingestion route were lower than one for all the dust samples, demonstrating that there was no remarkable non-cancer risk. The cancer risks of these OMPs were greater than 10^-4, with cholestrol dominating 99.1% of the carcinogenic risks, which suggested that there was a significant cancer risk. This study might offer a benchmark to ensure the safety of chemical usages in future in Malaysia.

Life history observations of the Illinois state endangered Enigmatic Cavesnail, Fontigens antroecetes (Hubricht, 1940) made under simulated cave conditions

The Enigmatic Cavesnail, Fontigens antroecetes (Hubricht, 1940), is a cave adapted hydrobioid snail listed as state endangered in Illinois. It is known from only one cave in Illinois, Stemler Cave, and from several caves in the eastern Ozark ecoregion of Missouri. Little is known about the snail’s reproductive habits, embryological development, or growth rates. I attempted to gain basic life history information by breeding Enigmatic Cavesnails under simulated cave conditions in the laboratory. Six adult snails were collected from Stemler Cave and held in aerated containers of cave water with one or two cobbles from the cave stream. Containers of snails were housed in incubators set at the average cave water temperature of 13 °C. The snails produced 49 embryos in captivity over the course of 34 weeks. Eggs were deposited singly, attached to the underside of rocks within small pits or crevices. Nearly 82% of embryos developed to hatching. Mean estimated development time of embryos was 70.7 days. Survival of hatchling snails was poor. Limited data available from surviving hatchling snails suggests slow growth rates. The process was replicated with nine Enigmatic Cavesnails collected from Cliff Cave in St. Louis County MO. Captive Cliff Cave snails produced 34 embryos over 46 weeks and varied from the Stemler population in their oviposition behavior, with a majority of eggs deposited on the top surface of rocks. Cliff Cave snail embryos also had longer mean estimated development times (82.17 days).

Unraveling the occurrence of contaminants of emerging concern in groundwater from urban setting: A combined multidisciplinary approach and self-organizing maps

In recent decades, changes in human behavior and new technologies have introduced thousands of new compounds into the environment called "contaminants of emerging concern" (CEC). These compounds have been detected in different environmental compartments such as soil, surface water, air, and groundwater. The presence of these contaminants in groundwater may pose risks to human health when used as potable water. In some urban areas in Brazil, groundwater is normally consumed without previous treatment. This study aimed to use statistical analysis by self-organizing maps (SOM) to evaluate the trends of CEC in urban groundwater systems. A total of 23 CEC compounds including pesticides, pharmaceuticals, and hormones were determined in groundwater samples using solid phase extraction and liquid chromatography-mass spectrometry. The CEC most frequently detected were atrazine and degradation products, fipronil, simazine, tebuconazole, hexazinone, and caffeine in concentrations up to 300 ng L^-1. All studied compounds were detected in groundwater at least in one sample. Patterns in the data through SOM have shown a strong positive correlation between atrazine, hexazinone, simazine, tebuthiuron, 2-hydroxyatrazine, and 17β-estradiol. The hormones estrone and testosterone also show a positive correlation due to their similar chemical properties. On the other hand, caffeine was detected in 90% of the samples, likely due to a population habit of taking daily a hot drink made of yerba mate associated with low rates of treated domestic sewage in the study area.

Antimicrobial Resistance Development Pathways in Surface Waters and Public Health Implications

Human health is threatened by antibiotic-resistant bacteria and their related infections, which cause thousands of human deaths every year worldwide. Surface waters are vulnerable to human activities and natural processes that facilitate the emergence and spread of antibiotic-resistant bacteria in the environment. This study evaluated the pathways and drivers of antimicrobial resistance (AR) in surface waters. We analyzed antibiotic resistance healthcare-associated infection (HAI) data reported to the CDC's National Healthcare Safety Network to determine the number of antimicrobial-resistant pathogens and their isolates detected in healthcare facilities. Ten pathogens and their isolates associated with HAIs tested resistant to the selected antibiotics, indicating the role of healthcare facilities in antimicrobial resistance in the environment. The analyzed data and literature research revealed that healthcare facilities, wastewater, agricultural settings, food, and wildlife populations serve as the major vehicles for AR in surface waters. Antibiotic residues, heavy metals, natural processes, and climate change were identified as the drivers of antimicrobial resistance in the aquatic environment. Food and animal handlers have a higher risk of exposure to resistant pathogens through ingestion and direct contact compared with the general population. The AR threat to public health may grow as pathogens in aquatic systems adjust to antibiotic residues, contaminants, and climate change effects. The unnecessary use of antibiotics increases the risk of AR, and the public should be encouraged to practice antibiotic stewardship to decrease the risk.

Pharmaceutical and Antibiotic Pollutant Levels in Wastewater and the Waters of the Zarqa River, Jordan

Assamra wastewater treatment plant (WWTP) is the largest treatment facility in Jordan. Treated wastewater is discharged into the Zarqa River (ZR) and used to irrigate fodder and vegetables. ZR also includes surface runoff, stormwater, and raw wastewater illegally discharged into the river. This study examined pharmaceutically active compounds (PhAC) in water resources in the ZR basin. Samples of WWTP influent and effluent and river water from four sites along ZR were collected. Concentrations of 18 target antibiotics, one stimulant, and 15 other PhACs were determined in the samples. Five antibiotics were detected in WWTP influent (510–860 ng L−1 for ∑Antibiotics) and six in the effluent (2300–2600 ng L−1 for ∑Antibiotics). Concentrations in the effluent of all antibiotics except clarithromycin increased by 2- to 5-fold compared with those in influent, while clarithromycin concentration decreased by around 4- fold (from 308 to 82 ng L−1). WWTP influent and effluent samples contained 14 non-antibiotic PhACs, one simulant, and six antibiotics at detectable concentrations. The dominant PhACs were paracetamol (74% of ∑PhACs) in the influent and carbamazepine (78% of ∑PhACs) in the effluent. At ZR sampling sites, carbamazepine was the dominant PhAC in all cases (800–2700 ng L−1). The antibiotics detected in WWTP effluent were also detected at the ZR sites. In summary, water in ZR is contaminated with PhACs, including antibiotics, and wastewater discharge seems to be the main pathway for this contamination. The occurrence of antibiotics and other PhACs in the irrigated soil requires investigation to assess their fate.

Presencia de productos farmacéuticos en el agua y su impacto en el ambiente

Los productos farmacéuticos (PFs) constituyen un grupo importante de los contaminantes emergentes (CE), debido a su potencial para inducir efectos fisiológicos adversos a bajas concentraciones en humanos y animales. Muchos estudios alrededor del mundo han reportado la presencia de un sin número de estos compuestos en diferentes medios acuáticos, lo que genera preocupación por los posibles efectos negativos que se producen en el agua, en la salud humana y la vida silvestre. En este contexto, este artículo tiene por objetivo presentar una revisión de los aspectos más relevantes sobre la presencia de PFs en el agua en un ámbito global desde el año 2010 hasta el 2019. El mayor número de estudios reportan presencia de contaminantes emergentes incluyendo fármacos de diferentes tipos en aguas superficiales, aguas subterráneas, aguas residuales y agua potable. Las principales fuentes de ingreso de fármacos en los sistemas acuáticos provienen de las aguas residuales que recogen aguas domésticas, efluentes hospitalarios y efluentes de fábricas sin tratamiento o inadecuadamente tratadas antes de ser liberadas a ríos y mares. La presencia de PFs en el ambiente acuático preocupa por su persistencia, la bioacumulación, la toxicidad y la generación de resistencia a antibióticos de muchos microorganismos, entre otras consecuencias aún no estudiadas en el ambiente.

Source identification and management of perennial contaminated groundwater seepage in the highly industrial watershed, south India

Perennial contaminated groundwater seepage is threatening the downstream ecosystem of the Kazipally Pharmaceutical industrial area located in South India. The sources of seepage are unknown for the last three decades that challenging the regulatory authorities and industries. In general, water quality monitoring and geophysical techniques are applied to identify the sources. However, these techniques may lead to ambiguous results and fail to identify the seepage sources, especially when the area is urbanized/paved, and groundwater is already contaminated with other leakage sources that have similar chemical compounds. In the present study, a novel and multidisciplinary approach were adopted that includes satellite-based Land Surface Temperature (LST) observations, field-based Electrical Resistivity Tomography (ERT), continuous Soil Electrical Conductivity (SEC) and Volumetric Soil Moisture (VSM%) measurements along with groundwater levels monitoring to identify the sources and to control the seepage. The integrated results identified that the locations with the Standard Thermal Anomaly (STA) in the range of -0.5 to -1 °C, VSM% >50%, SEC > 1.5 mS/cm, bulk resistivity < 12 Ω m with shallow groundwater levels < 3 m below ground level (bgl) are potentially contaminated perennial seepage sources. Impermeable sheet piles have been installed across the groundwater flow direction to control the seepage up to 1.5 m bgl, where groundwater frequently intercepts land surface. The quantity of dry season groundwater seepage has been declined by 79.2% after these interventions, which in turn minimized the treatment cost of 1,96,283 USD/year and improved the downstream ecosystem.

Occurrence and Health Risks of Organic Micro-Pollutants and Metals in Groundwater of Chinese Rural Areas

BACKGROUND

Groundwater is a main drinking-water source for Chinese rural residents. The overall pollution status of organic micropollutants (OMPs) and metals in the groundwater and corresponding health risks are unknown.

OBJECTIVES

Our objective was to comprehensively screen for and assess the health risks of OMPs and metals in groundwater of rural areas in China where groundwater is used for drinking so as to provide a benchmark for monitoring and improving groundwater quality in future developments.

METHODS

One hundred sixty-six groundwater samples were collected in the rural areas of China, and 1,300 OMPs and 25 metals were screened by GC-MS, LC-QTOF/MS, and ICP-MS analysis. To assess the noncarcinogenic and carcinogenic risks of the detected pollutants, missing toxicity threshold values were extrapolated from existing databases or predicted by quantitative structure-activity relationship (QSAR) models. Monte Carlo simulation was performed to account for uncertainties in the exposure parameters and toxicity thresholds.

RESULTS

Two hundred thirty-three OMPs and 25 metals were detected from the 166 samples. The concentration summation for the detected OMPs ranged from 2.9 to 1.7×105ng/L among the different sampling sites. Cumulative noncarcinogenic risks for the OMPs were estimated to be negligible. However, high metal risks were calculated in 23% of the sites. Forty-two carcinogens (including 38 OMPs) were identified and the cumulative carcinogenic risks in 34% of the sites were calculated to be >10-4 (i.e., one excess cancer case in a population of 10 thousand people). The carcinogenic risks were estimated to be mainly associated with exposures to the metals, which were calculated to contribute 79% (0-100%) of the cumulative carcinogenic risks.

DISCUSSION

The overall status of OMPs and metals pollution in the groundwater and the corresponding health risks were determined preliminarily, which may provide a benchmark for future efforts in China to ensure the safety of drinking water for the local residents in rural areas. The joint application of QSARs and Monte Carlo simulation provided a feasible way to comprehensively assess the health risks of the large and ever-increasing number of pollutants detected in the aquatic environment. https://doi.org/10.1289/EHP6483.

Occurrence of caffeine in the freshwater environment: Implications for ecopharmacovigilance

Owing to the substantial consumption of caffeinated food, beverages, and medicines worldwide, caffeine is considered the most representative pharmaceutically active compound (PhAC) pollutant based on its high abundance in the environment and its suitability as an indicator of the anthropogenic inputs of PhACs in water bodies. This review presents a worldwide analysis of 132 reports of caffeine residues in freshwater environments. The results indicated that more than 70% of the studies reported were from Asia and Europe, which have densely populated and industrially developed areas. However, caffeine pollution was also found to affect areas isolated from human influence, such as Antarctica. In addition, the maximum concentrations of caffeine in raw wastewater, treated wastewater, river, drinking water, groundwater, lake, catchment, reservoir, and rainwater samples were reported to be 3.60 mg/L, 55.5, 19.3, 3.39, 0.683, 174, 44.6, 4.87, and 5.40 μg/L, respectively. The seasonal variation in caffeine residues in the freshwater environment has been demonstrated. In addition, despite the fact that there was a small proportion of wastewater treatment plants in which the elimination rates of caffeine were below 60%, wastewater treatment is generally believed to have a high caffeine removal efficiency. From a pharmacy perspective, we proposed to adopt effective measures to minimize the environmental risks posed by PhACs, represented by caffeine, through a new concept known as ecopharmacovigilance (EPV). Some measures of EPV aimed at caffeine pollution have been advised, as follows: improving knowledge and perceptions about caffeine pollution among the public; listing caffeine as a high-priority PhAC pollutant, which should be targeted in EPV practices; promoting green design and production, rational consumption, and environmentally preferred disposal of caffeinated medicines, foods, and beverages; implementing intensive EPV measures in high-risk areas and during high-risk seasons; and integrating EPV into wastewater treatment programs.

Quantification of estrogen concentration in a creek receiving wastewater treatment plant effluent

Estrogen in streams threatens aquatic animals, especially where wastewater treatment plant (WWTP) effluent contributes to baseflow. We investigated total estrogen (E1+E2+E3) as estradiol equivalent (E2) and ethynylestradiol (EE2) concentration in Cibolo Creek (Cibolo), a groundwater-fed stream near San Antonio, TX, receiving effluent via two WWTP. We collected water samples bi-monthly from late spring to early fall 2018 in Cibolo and WWTP effluent, and used ELISA analysis and discharge measurements to determine concentrations and loads of estrogens. We measured several environmental variables to investigate what factors influenced estrogen concentrations in Cibolo downstream from WWTP inputs. Mean concentrations of WWTP effluent (E2, 41.43 ± 15.48; EE2, 11.40 ± 2.07 ng L^-1) were higher compared with concentrations in Cibolo, both downstream (E2, 30.09 ± 25.85; EE2, 6.33 ± 1.92 ng L^-1) and upstream (E2, 12.91 ± 11.12; EE2, 4.5 ± 1.38 ng L^-1) of WWTP inputs. Both E2 and EE2 concentrations decreased downstream from WWTP inputs, a section of stream without large quantities of fine sediments for sorption, indicating potential dilution or chemical and biological degradation. Effluent into Cibolo via the first, and older, WWTP contributed the most estrogen load in Cibolo. Median concentrations of E2 and EE2 were 19 and 5 ng L^-1, respectively, downstream of WWTP inputs, concentrations known to affect reproductive processes of aquatic biota and impair human health. Results suggest estrogens may pose a risk to aquatic ecosystems wherever WWTP effluent comprises a majority of baseflow, though further studies are required in this stream to verify biological impacts.

Occurrence, source estimation and risk assessment of pharmaceuticals in the Chaobai River characterized by adjacent land use

This study investigated the occurrence of 27 pharmaceuticals with diverse physicochemical properties in a year-long monitoring campaign in the Chaobai River, China. The correlation between the distribution of pharmaceuticals in the river and the adjacent sources was elucidated. The results indicate that the agriculture area was the most polluted area with a median summed pharmaceutical concentration of 225.3 ng L^-1, followed by the urban area and the mountain area with the corresponding values of 136.9 and 29.9 ng L^-1, respectively. In terms of individual compounds, 22 out of 27 compounds were detected with concentrations ranging from <1 to 1972 ng L^-1. Caffeine, carbamazepine, azithromycin, bezafibrate, metoprolol, sulfadiazine, sulfamethoxazole, clarithromycin, erythromycin, roxithromycin, and trimethoprim were pharmaceuticals with relatively high levels, with median concentrations ranging from 3.3 to 25.6 ng L^-1 and detection frequencies ranging from 40% to 97%. Higher concentrations were mainly observed during cold seasons, with mean concentrations 1 to 52 times as high as those during warm seasons. Spatial analysis reveals that the pharmaceutical concentrations in different areas were impacted by different sources. A wastewater treatment plant was an important source in the urban area, while the agriculture area was impacted by various treated and untreated wastewater sources. The species sensitivity distribution model and risk quotient (RQ) method were combined in the ecological risk assessment. The results indicate that the multi-substance potentially affected fraction (msPAF) values of the sampling sites were below 0.04%, whereas nearly half of RQ values were higher than 1. Caffeine was proposed as a priority compound due to its high contribution rate (i.e., 79%) to the cumulative msPAF value, which implies that increased control and management of untreated wastewater sources along the Chaobai River is necessary.

Cellulose Acetate/P4VP-b-PEO Membranes for the Adsorption of Electron-Deficient Pharmaceutical Compounds

The prevalence of pharmaceutical compounds in surface and groundwater presents a rising threat to human health. As such, the search for novel materials that serve to avoid their release into the environment or for the remediation once in the water effluent is of utmost importance. The present work describes the fabrication of a cellulose acetate membrane modified with the block copolymer poly(4-vinylpyridine-b-ethylene oxide) (P4VP-b-PEO) crafted for the specific targeting and adsorption of electron-deficient pharmaceuticals (EDPs). The EDPs under study were sulfamethoxazole, sulfadiazine, and omeprazole. The results as part of this work present a thorough characterization of the prepared membranes by FTIR, contact angle measurement, and SEM images. Moreover, results show that the adsorptive character of the membrane correlates with the relative electron deficiency and spatial orientation of the contaminant. Interestingly, the addition of nominal 1% P4VP-b-PEO to the cellulose matrix helps to increase the adsorption efficiency of the membranes by at least 2-fold in most cases. For the compounds studied, the prepared membrane has a higher efficiency toward omeprazole followed by sulfamethoxazole and sulfadiazine. This work may serve to inspire the design and fabrication of selective soft materials for the adsorption and remediation of contaminants of emerging concern.

Sorption of ionic and neutral species of pharmaceuticals to loessial soil amended with biochars

To clarify the impact of biochar amendment on soil sorption for coexisting pharmaceuticals, wheat straw-derived biochars pyrolyzed at 300 and 700 °C (labeled as WS300 and WS700, respectively) were prepared. Batch experiments on ketoprofen (KTP), atenolol (ATL) and carbamazepine (CBZ) sorption to biochars, loessial soil and biochar-amended soils were conducted. The results indicated that sorption affinity of different species of pharmaceuticals to WS300 and WS700 was in the order of cationic ATL > neutral CBZ > anionic KTP. Cationic ATL had the highest sorption to biochars due to electrostatic attraction. Coexisting ATL, CBZ and KTP competed for the shared adsorption sites on carbonized phase of biochars, and π-π interactions were proposed to be the main sorption mechanism. Sorption coefficients (K_d) and nonlinearity of ATL, CBZ and KTP to soil increased when biochar was added (5% by weight), especially for WS700 with higher specific surface area. K_d values of the three pharmaceuticals to WS700-amended soil in either single solute or bisolute system were one to two orders of magnitude higher than those to soil, indicating the promoting role of WS700 in sorption of coexisting pharmaceuticals in soil. The study demonstrated the enhanced and competitive sorption of ionic and neutral species of pharmaceuticals to soil amended with biochars, which is helpful in designing biochar as effective sorbents for immobilization of pharmaceuticals in soil remediation.

Tracing and quantifying contributions of end members to karst water at a coalfield in southwest China

Karst water, which provides 25% of the world's drinking water, is especially vulnerable to anthropogenic contamination. Such is the case in southwestern China with trace element pollution in important karst aquifers. Approximately 20% of the total study area consisted of abandoned mine tailings with elevated concentrations of Fe, S, Mn, As, Cu, and Cr. Acid mine drainage (AMD) water originating from pyrite oxidation of the tailings was characterized by low pH and high concentrations of Fe, SO₄^2-, and As. Concentrations of Fe, Mn, Al, SO₄^2-, As, Cd, and Pb in spring water in wet and dry seasons were greater than WHO and USEPA drinking water guidelines. Based on the results of mineral characterizations, hydrogeochemistry, and isotopic compositions (δ³⁴S_SO4, δ¹⁸O_SO4, and δ¹⁸O_H2O), the chemistry of AMD water was primarily controlled by pyrite oxidation, river water by atmospheric precipitation, and spring water by carbonate rock dissolution and mixing with river and AMD waters. A three-end-member mixing model identified the contributions of these different end members to spring water quality. Although AMD water was characterized by the lowest mixing percentages during the wet (14.1%) and dry (26.9%) seasons, it played a very important role in degrading spring water quality. Based on these findings, an investigation strategy was developed for illuminating seasonal water quality and potential remediation methods corresponding to the contaminants in the spring water are also proposed to manage this seriously polluted karst system. Results could benefit remediation planning for these distinctively complex and vulnerable systems in other regions of the world.

Attenuation, transport, and management of estrogens: A review

Overabundance of endocrine disruptors (EDs), such as steroid estrogens, in the natural environment disrupts hormone synthesis in aquatic organisms. Livestock and wastewater outflows contribute measurable quantities of steroid estrogens into the environment where they are picked up and transported via surface runoff and feedlot effluents into water matrices. E1, E2β, E2α, E3 and EE2 are the most prevalent estrogens in these environmental systems. Estrogens in soils and water undergo several concurrent attenuation processes including sorption to particles, biotransformation, photo-transformation, and plant uptake. This review summarizes current studies on the attenuation and transport of steroid estrogens with a focus on estrogen attenuation and transport modeling. The authors use this information to synthesize appropriate strategies for reducing estrogenicity in the environment.

Removal of pharmaceuticals and personal care products using constructed wetlands: effective plant-bacteria synergism may enhance degradation efficiency

Post-industrial era has witnessed significant advancements at unprecedented rates in the field of medicine and cosmetics, which has led to affluent use of pharmaceuticals and personal care products (PPCPs). However, this has exacerbated the influx of various pollutants in the environment affecting living organisms through multiple routes. Thousands of PPCPs of various classes-prescription and non-prescription drugs-are discharged directly into the environment. In this review, we have surveyed literature investigating plant-based remediation practices to remove PPCPs from the environment. Our specific aim is to highlight the importance of plant-bacteria interplay for sustainable remediation of PPCPs. The green technologies not only are successfully curbing organic pollutants but also have displayed certain limitations. For example, the presence of biologically active compounds within plant rhizosphere may affect plant growth and hence compromise the phytoremediation potential of constructed wetlands. To overcome these hindrances, combined use of plants and beneficial bacteria has been employed. The microbes (both rhizo- and endophytes) in this type of system not only degrade PPCPs directly but also accelerate plant growth by producing growth-promoting enzymes and hence remediation potential of constructed wetlands.

Micropollutants related to human activity in groundwater resources in Barbados, West Indies

Several micropollutants, including caffeine, artificial sweeteners, pharmaceuticals, steroid hormones and a current-use pesticide were analyzed in water samples collected from five groundwater pumping stations in Barbados. The presence of caffeine and three artificial sweeteners (i.e. acesulfame, sucralose, saccharin) in groundwater samples indicated that groundwater was being contaminated by infiltration of wastewater into the karst aquifer. An estrogen (i.e. estrone), three pharmaceuticals (i.e. carbamazepine, trimethoprim, ibuprofen) and a transformation product of the fungicide, chlorothalonil (i.e. 4-hydroxychlorothalonil) were also detected at ng/L concentrations in groundwater collected from two or more pumping sites. The concentrations of carbamazepine and trimethoprim were correlated with the concentrations of caffeine (R² values of 0.70 to 0.80), indicating pharmaceutical contamination of groundwater by infiltration from domestic wastewater. The concentrations of caffeine were generally higher in groundwater samples collected in June during the wet season relative to the concentrations in samples collected in February during the dry season, indicating that infiltration of contaminants is higher during periods of heavy rainfall. Rapid rates of degradation and relatively slow rates of infiltration may explain why several target analytes were not detected in groundwater. Elevated concentrations of 4-hydroxychlorothalonil > 0.1 μg/L in samples collected at two of the monitoring sites warrant further studies on the sources and the distribution of this compound and other pesticides used in agriculture and for turf-treatment (e.g. golf courses). Overall, more data are needed in order to implement mitigation strategies that are effective in reducing chemical contamination in groundwater in Barbados.

Assessment of groundwater quality and remediation in karst aquifers: A review

Karst aquifers, capable of storing and transmitting large amount of water, are the main source of drinking water in many regions worldwide. Their excessive permeability leads to an enhanced vulnerability to retain and spread the contamination accordingly. From sustainability perspective, the environmental, economic and social impacts of karst contamination on water resources management are gaining more attention. In this study, an overview of hydrogeological processes and concepts regarding groundwater flow and contaminant transport in karstic systems is presented, followed by a short discussion on surface water and groundwater interaction. Due to the complexity of karstic systems, different approaches have been developed by researchers for investigating and understanding hydrogeological processes and groundwater behavior in karst which are reviewed herein. Additionally, groundwater contamination issues and the most common and effective remediation techniques in karstic terrains are discussed. Lastly, modeling techniques and remote sensing methods, as beneficial and powerful tools for assessing groundwater flow and contaminant transport in karst terrains, are reviewed and evaluated. In each section, relevant research works conducted for Puerto Rico are discussed and some recommendations are presented to complement the ongoing hydrogeological investigations on this island.

Differentiation of Surface Water and Groundwater in a Karst System Using Anthropogenic Signatures

Surface water–groundwater interaction within a karstic system enhances contaminant transport, making karst aquifers susceptible to anthropogenic practices. Contaminated waters related to agricultural and animal husbandry in northwestern Illinois (USA) prompted this investigation. Six streams and five springs were sampled for 16 parameters to assess anthropogenic influences. Statistical analyses revealed differences in 13 of 16 parameters between the stream and spring waters. Rock–water interaction was identified as the dominant mechanism defining the chemistry for both waters, which were classified as Ca-Mg HCO3. Elevated nitrate as nitrogen (NO3-N), chloride (Cl−), sodium, and potassium concentrations indicate that human activities have influenced the quality of both water types. All streams and springs had NO3-N concentration exceeding background levels, with concentrations ranging from 2.9 to 14.5 mg/L and 2.9 to 30.1 mg/L, respectively. NO3-N/Cl relationships at individual locations showed elevated concentrations of NO3-N due to fertilizers, while the spring waters were influenced by manure, septic effluent, or mixed sources. The presence of coliform supports the likelihood of animal or human waste influences on waters. Dissimilarities within their chemical fingerprints can be traced to aid in differentiating sources within the waters.

Microplastic Contamination in Karst Groundwater Systems

Groundwater in karst aquifers constitutes about 25% of drinking water sources globally. Karst aquifers are open systems, susceptible to contamination by surface-borne pollutants. In this study, springs and wells from two karst aquifers in Illinois, USA, were found to contain microplastics and other anthropogenic contaminants. All microplastics were fibers, with a maximum concentration of 15.2 particles/L. The presence of microplastic was consistent with other parameters, including phosphate, chloride and triclosan, suggesting septic effluent as a source. More studies are needed on microplastic sources, abundance, and impacts on karst ecosystems.

Metabolomic responses to pre-chlorinated and final effluent wastewater with the addition of a sub-lethal persistent contaminant in Daphnia magna

Consumer products such as perfluorooctanesulfonic acid (PFOS) and pharmaceuticals (PCPPs) enter aquatic ecosystems through inefficient removal during wastewater treatment. Often, the sterilization process of wastewater includes the addition of sodium hypochlorite that can react with PCPPs and other organic matter (i.e., dissolve organic matter) to generate disinfection by-products and can cause the final effluent to be more harmful to aquatic organisms. Here, we exposed Daphnia magna to two stages of wastewater, the pre-chlorinated wastewater (PreCl) and the final effluent. In addition, we exposed D. magna, to the final effluent with a concentration gradient of added PFOS, to investigate if this persistent contaminant altered the toxicity of the final effluent. After 48 h of contaminant exposure, we measured the daphnids metabolic responses to the different stages of wastewater treatment, and with the addition of PFOS, utilizing proton nuclear magnetic resonance spectroscopy and liquid chromatography tandem mass spectrometry. We found few significant changes to the metabolic profile of animals exposed to the PreCl wastewater; however, animals exposed to the final effluent displayed increases in many amino acids and decreases in some sugar metabolites. With the addition of PFOS to the final effluent, the metabolic profile shifted from increased amino acids and decreased sugar metabolites and energy molecules especially at the low and high concentrations of PFOS. Overall, our results demonstrate the metabolome is sensitive to changes in the final effluent that are caused by sterilization, and with the addition of a persistent contaminant, the metabolic profile is further altered.

Antibiotics in a typical karst river system in China: Spatiotemporal variation and environmental risks

Karst aquifers are highly susceptible to contamination because compounds in water from the land surface are able to enter aquifers directly through sinkholes and travel rapidly through conduits. To investigate the occurrence and profiles of antibiotics in the typical karst river system in Kaiyang, southwest China, 34 aqueous samples were collected periodically to delineate seasonal trends in antibiotic levels. Thirty-five antibiotics, including nine sulfonamides, four tetracyclines, five macrolides, 16 quinolones and chloramphenicol, were analysed via solid phase extraction combined with ultra-performance liquid chromatography-tandem mass spectrometry. A total of 25 antibiotics were detected with the highest detection frequency reaching 94.1%, indicating the ubiquity of antibiotics in the study area. The total concentration of antibiotics ranged from 0.37 to 508.6 ng/L, with the dominating proportion including macrolides and quinolones based on the distribution profiles and seasonal variation. Due to the natural attenuation, the total concentration of antibiotics gradually decreased with the flow direction in the southern part of the river. The total concentrations of antibiotics in the mainstream were significantly higher in the dry season than in the rainy seasons. However, the distribution profiles were susceptible to anthropogenic activities, such as the leakage of septic tank wastewater. The dendrogram and heatmap revealed that three clusters of sample sites represented tributaries and the upstream areas, the downstream areas, and the potential pollutant source, and three clusters of antibiotics represented different concentration patterns. The high ecological risks of tetracycline, erythromycin and ciprofloxacin for algae and ofloxacin for plants were determined. These findings contributed to the establishment of a database for future monitoring and control of antibiotics in karst areas.

Removal of estrogenic hormones from manure-containing water by vegetable oil capture

Manure-containing water (MCW) is frequently used for agricultural amendment, a practice that introduces natural and synthetic hormones to the environment. Advanced treatment processes are not practical for most animal operations, so inexpensively removing hormones from MCW by capture with vegetable oils was evaluated. Estrone (E1) and 17β-estradiol (E2) were used as model hormones due to their high biological activity and prevalence in MCW. Eight vegetable-based oils were able to remove >94% of E1 and >87% of E2 from nanopure water (NPW), and tested oils had log₁₀K_oil-water values of 1.96-2.66 for E1 and 1.51-2.47 for E2. System parameters were optimized at 3min of shaking time and 1:10 corn oil:water (v/v). Removal from real MCW and NPW was assessed at several initial concentrations of E1 and E2. While E1 removal was comparable across all initial concentrations and both water types (>93%), E2 removal exhibited concentration-dependent interaction with MCW matrix. Treatment capacity was assessed by using the same oil for multiple batches of NPW or MCW. After 18 cycles, removal dropped to 50-64% of E1 and 35-37% for E2. Treating MCW with vegetable oils may be a promising approach to inexpensively remove microcontaminants before MCW is used for land application.

Geochemistry and microbial diversity of cave waters in the gypsum karst aquifers of Emilia Romagna region, Italy

Fifty-seven control points of waters (sinking streams, rivers in caves, and resurgences) hosted in gypsum karst areas in Emilia Romagna region (N-Italy) were sampled in the framework of a Project LIFE+08NAT/IT/000369 "Gypsum" in the period 2010-2014. The microbiology and chemistry of these waters have been analyzed to evaluate the impact of human activities or natural factors, in the gypsum karst systems. Waters have been analyzed for major chemistry (Ca, Mg, Na, K, SO₄, HCO₃, Cl, NO₃) and some minor constituents (F, Br, NH₄ and PO₄), measuring pH, electric conductivity (EC), total dissolved solids (TDS) and temperature (T) in situ. The same samples have been analyzed with traditional microbiology techniques focused on total microbial count and on fecal microbiota, as index of human and/or animal contamination, and molecular biology techniques (sequencing of 16S rRNA segment and PCR-DGGE), focused on the characterization of microbial populations in the different sampling sites and determination of their variations and/or changes during the five years of the project. As expected, waters tend to be increasingly mineralized from sinking streams to resurgences, with only local and temporarily high contents in nitrates and ammonium, often related to the presence of bat colonies. PCR-DGGE revealed ecological changes, in terms of microbial populations present in the bulk water samples, in different sampling sites within the same cave. Although the impact of fecal microorganisms only rarely exceeded 2 log UFC/ml, the results evidenced fluctuations of these microorganisms mainly correlated to the season and to the biological activity of bats.