Occurrence, distribution, and attenuation of pharmaceuticals and personal care products in the riverside groundwater of the Beiyun River of Beijing, China

Managed aquifer recharge as a potential pathway of contaminants of emerging concern into groundwater systems - A systematic review

Groundwater is an often-overlooked resource, while its declining quantity and quality is of global concern. To protect and ensure stable quantity and quality of groundwater systems used as drinking water supplies, a common method is to artificially recharge these groundwater supplies with surface water, a process called managed aquifer recharge (MAR), that has been used globally for decades. However, surface waters used for MAR often contain elevated concentrations of anthropogenic chemicals of emerging concern (CECs), such as plastics, pesticides, pharmaceuticals and personal care products (PPCPs), or per- and polyfluoroalkyl substances (PFAS). When infiltrating this surface water, MAR can thus act as a shortcut for CECs into groundwater systems and eventually drinking water supplies. Especially PFAS are an example of very persistent contaminants showing atypical transport patterns during MAR and thus posing a risk for ground- and drinking water contamination. This systematic review addresses the transport process of CECs through MAR systems by looking at (1) common CEC concentrations in surface waters, (2) factors affecting CEC transport and possible retention during MAR, such as sorption and other physio-chemical mechanisms of CECs, biological and chemical decomposition, or hydrogeological properties of the MAR system, and (3) key contaminants leaching through the MAR systems as well as possible treatment options to improve the retention of CECs during MAR. Since we are facing increasing needs for high quality drinking water, lower CEC drinking water guidelines as well as an increasing number of identified CECs in surface waters, we conclude with a series of recommendations and future research directions to address these issues. Those include the need for regular monitoring programs specifically addressing CECs and especially not yet regulated, (very) persistent and (very) mobile contaminants, such as PFAS, as well as redesigned MAR systems to ensure stable ground- and drinking water quantity and quality.

Occurrence, efficiency of treatment processes, source apportionment and human health risk assessment of pharmaceuticals and xenoestrogen compounds in tap water from some Ghanaian communities

The occurrence of pharmaceuticals and xenoestrogen compounds (PXCs) in drinking water presents a dire human health risk challenge. The problem stems from the high anthropogenic pollution load on source water and the inefficiencies of the conventional water treatment plants in treating PXCs. This study assessed the PXCs levels and the consequential health risks of exposure to tap water from selected Ghanaian communities as well as that of raw water samples from the respective treatment plants. Thus the PXCs treatment efficiency of two drinking water treatment plants in the metropolises studied was also assessed. The study also conducted source apportionment of the PXCs in the tap water. Twenty six (26) tap and raw water samples from communities in the Cape Coast and Sekondi-Takoradi metropolises were extracted using SPE cartridges and analysed for PXCs using Ultra-fast-HPLC-UV instrument. Elevated levels of PXCs up to 24.79 and 22.02 μg/L were respectively recorded in raw and tap water samples from the metropolises. Consequently, elevated non-cancer health risk (HI > 1) to residential adults were found for tap water samples from Cape Coast metropolis and also for some samples from Sekondi-Takoradi metropolis. Again, elevated cumulative oral cancer risks >10-5 and dermal cancer risk up to 4 × 10-5 were recorded. The source apportionment revealed three significant sources of PXCs in tap water samples studied. The results revealed the inefficiency of the treatment plants in removing PXCs from the raw water during treatments. The situation thus requires urgent attention to ameliorate it, safeguarding public health. It is recommended that the conventional water treatment process employed be augmented with advanced treatment technologies to improve their efficacy in PXCs treatment.

Analysis on the attenuation characteristics of PPCPs in surface water and their influencing factors based on a compilation of literature data

The attenuation characteristics of PPCPs play an important part in predicting their environmental concentrations. However, considerable uncertainty remains in reported laboratory data on the attenuation characteristics of PPCPs. In this analysis, we compile information on laboratory-observed photodegradation half-lives (t1/2), biodegradation t1/2, the organic carbon normalized adsorption constant (KOC) and field-observed overall attenuation t1/2 for PPCPs in water bodies from more than 200 peer-reviewed studies. To mitigate the effects of such uncertainty, we derive representative values (RV) for PPCP degradability from these records to better compare the characteristics of different PPCPs. We further examine the influence of experimental conditions and environmental drivers on the determination of t1/2 using difference analysis and correlation analysis. The results indicate that for laboratory photodegradation tests, different light sources, initial concentration and volume significantly affect t1/2, whereas there is no significant difference between values obtained from tests conducted in pure water and natural water. For biodegradation, laboratory-measured t1/2 values in batch, flume and column studies gradually decrease, marking the controlling role of experimental setup. Redox condition, initial concentration and volume are also recognized as important influencing factors. For adsorption, water-sediment ratio is the primary reaction parameter. As two frequently investigated factors, however, pH and temperature are not significant factors in almost all cases. In field observations, the persistence of carbamazepine, typically used as a tracer, is in doubt. Water depth and latitude are the most correlated drivers of t1/2, indicating the predominant status of photodegradation in the overall attenuation rates. These findings call for caution when selecting experimental parameters and environmental drivers in determining PPCP's attenuation rates and establishing PPCP fate models in the field.

Utility and mechanism of magnetic nano-MnFe2O4/MWNT activation for oxidative degradation of tetracycline by persulfate

A magnetic MnFe₂O₄/MWNT nanocomposite activated with sodium persulfate (PDS) was investigated for the removal of the widely used antibiotic tetracycline (TC). The best-performing 80 wt.% MnFe₂O₄/MWNT nanocomposite was screened for catalytic degradation of TC by comparing the catalytic and adsorption processes. The nanocomposite was evaluated using a series of physical characterizations. The effects of catalyst dosage, PDS dosage, temperature, initial pH, and initial concentration of TC on TC removal were investigated. After the reaction for 90 min, the addition of 4 mM PDS to the 80 wt.% MnFe₂O₄/CNT catalyst at 0.5 g/L degraded 78.85% of TC and 51.97% of TOC at an initial TC concentration of 40 mg/L. The reusability of MnFe₂O₄/MWNT nanocomposite was evaluated and the structural stability of the material was verified. It was demonstrated that multiple active species (SO₄^-, ·OH, ·O₂^-, ¹O₂) were produced in the MnFe₂O₄/MWNT/PDS system. The catalytic mechanism was analyzed based on the XPS results. Total organic carbon (TOC) measurement indicated partial TC had completely mineralized. The presumable degradation pathway of TC was proposed according to intermediate products by the LC-MS method.

Distinct structural strategies with similar functional responses of abundant and rare subcommunities regarding heavy metal pollution in the Beiyun river basin

Bacteria within a metacommunity could be partitioned into different subcommunities ecological assemblages in light of potential importance for the community function. It is unknown how abundant and rare microbial subcommunities in urban river sediments respond to heavy metal pollutants. Using high-throughput sequencing, we analyzed these response patterns in the heavliy polluted (Beijing, China). We found that this river faces substantial ecological risks, owing to high rates of Cd and Hg pollution from urban activities. Surprisingly, abundant and rare subcommunity structures showed opposite responses to heavy metals. Abundant taxa, such as Crenarchaeota and Euryarchaeota, are resistant to heavy metal pollution through the synergistic of ammonia nitrogen (NH₄⁺-N) and total phosphorus (TP). By contrast, rare taxa, such as Verrucomicrobia, Fibrobacteres, Berkelbacteria, and Euryarchaeota, had a high synergy with NH₄⁺-N and TP with high a resilience to heavy metal pollution. However, the functions of both abundant and rare subcommunities showed a similar response to heavy metal pollutants, especially in denitrification processes. The abundant taxa responded to heavy metal pollution through methanogenesis by CO₂ reduction with H₂, human pathogens nosocomia, sulfate respiration, photoheterotrophy, and dark sulfide oxidation synergy with NH₄⁺-N and TP. The rare taxa responded to heavy metals through methanogenesis by CO₂ reduction with H₂, cellulolysis, sulfate respiration, intracellular parasites, nitrate reduction and plant pathogen. We observed distinct patterns between the structural and functional responses of microbial subcommunities to heavy metal pollutants. Our findings support the concept that denitrification processes are sensitive to but not inhibited by high levels of heavy metals pollution. We propose that the structures and functions of the abundant and rare microbial subcommunities could inform the management of pollutants in heavily polluted urban river ecosystems at fine geographical scales.

Efficiency of the bank filtration technique for diclofenac removal: A review

Bank filtration (BF) has been employed for more than a century for the production of water with a better quality, and it has been showing satisfactory results in diclofenac attenuation. Considered the most administered analgesic in the world, diclofenac has been frequently detected in water bodies. Besides being persistent in the environment, this compound is not completely removed by the conventional water treatments, drinking water treatment plants (DWTPs) and wastewater treatment plant (WWTPs). BF has a high complexity, whose efficiency depends on the characteristics of the observed pollutant and on the environment where the system in installed, which is why this is a topic that has been constantly studied. Nevertheless, studies present the behavior of diclofenac during the BF process. In this context, this research performed the evaluation of the factors and the biogeochemical processes that influence the efficiency of the BF technique in diclofenac removal. The aerobic conditions, higher temperatures, microbial biomass density, hydrogen potential close to neutrality and sediments with heterogeneous fractions are considered the ideal conditions in the aquifer for diclofenac removal. Nonetheless, there is no consensus on which of these factors has the greatest contribution on the mechanism of attenuation during BF. Studies with columns in laboratory and modeling affirm that the highest degradation rates occur in the first centimeters (5-50 cm) of the passage of water through the porous medium, in the environment known as hyporheic zone, where intense biogeochemical activities occur. Research has shown 100% removal efficiency for diclofenac persistent to compounds not removed during the BF process. However, half of the studies had removal efficiency that ranged between 80 and 100%. Therefore, the performance of more in-depth studies on the degradation and mobility of this compound becomes necessary for a better understanding of the conditions and biogeochemical processes which act in its attenuation.

Influence of physicochemical parameters on PPCP occurrences in the wetlands

There have been many global studies on the occurrence and distribution of pharmaceuticals and personal care products (PPCPs) in the aquatic resources, but reports on the effects of physicochemical properties of water on their concentrations are very scarce. The amounts and removal of these contaminants in various environmental media are dependent on these physicochemical properties, which include pH, temperature, electrical conductivity, salinity, turbidity, and dissolved oxygen. Here, we reviewed the influence of these properties on determination of PPCPs. Reports showed that increase in turbidity, electrical conductivity, and salinity gives increase in concentrations of PPCPs. Also, neutral pH gives higher PPCP concentrations, while decrease in temperature and dissolved oxygen gives low concentration of PPCPs. Nevertheless, it is quite challenging to ascertain the influence of water quality parameters on the PPCP concentration, as other factors like climate change, type of water, source of pollution, persistence, and dilution factor may have great influence on the concentration of PPCPs. Therefore, routine monitoring is suggested as most water quality parameters vary because of effects of climate change.

Effects of Al substitution on sorption of diclofenac to Fe(III) (hydr)oxides: roles of phase transition and sorption mechanisms

Fe(III) (hydr)oxides commonly contained many metal impurities such as Al. The incorporation of Al might change the properties of minerals and consequently affect sorption behaviors of pollutants with polar functional groups (e.g., diclofenac (DCF)). In this study, batch experiments and microscale characterization were conducted to investigate the DCF sorption mechanisms to goethite and Al-substituted minerals. Goethite and Al-substituted products (including Al-goethite, Al-goethite-hematite, and Al-hematite) were synthesized with different Al contents (i.e., 0%, 5%, 10%, and 15% (in mol)) by co-precipitation method. Due to difference of ionic radius between Al and Fe and formation of excessive -OH, Al substitution resulted in deviation of cell parameters from the Vegard line. Al substitution caused increasing -OH in Al-goethite and phase transformation caused decreasing -OH in Al-hematite. The total -OH in minerals was positively related to DCF sorption capacity. In the lower initial concentration range (0.4-9 mg/L), the sorption distribution coefficient (Kd) values of goethite, Al-goethite, and Al-hematite were 21.98, 22.25, and 21.18 L/kg, respectively. Desorption characteristics and ion strength effects indicated that DCF sorption to minerals occurred mainly through outer-sphere complexation. Fourier transform infrared analyses revealed that H-bonds could be formed through -OH of minerals and -COOH of DCF, and the H-bond strength on Al-hematite was stronger than that on goethite/Al-goethite. In the normal environmental pH (e.g., 6.0 to 8.0), Kd values of DCF decreased linearly with increasing pH. These findings are helpful for understanding of DCF migration in environment involving Al-substituted minerals.

Environmental Risk Assessment of Active Human Pharmaceutical Ingredients in Urban Rivers in Japan

Active pharmaceutical ingredients (APIs) have become a public concern owing to their possible adverse effects on aquatic organisms. Ministry of Health, Labor and Welfare in Japan (MHLW) issued "Guidance on the Environmental Risk Assessment (ERA) in new pharmaceutical development" in 2016. To evaluate the validity of phase 1 in the MHLW's ERA guidance, we monitored the measured environmental concentrations (MECs) of approved APIs in urban rivers and sewage treatment plants (STPs) in Japan and compared these MECs with the predicted environmental concentration (PEC). We collected water samples from urban seven rivers and three STPs during each season. Fifty-one APIs for human and veterinary use and the artificial sweetener sucralose were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Forty-four APIs were observed in the rivers and 42 were found in the influent and effluent of STPs, with levels ranging from nanograms to micrograms per liter. The action limit in phase I of the MHLW's guidance was set to 10 ng/L, and there was no API except for ketoprofen, for which PEC of the MHLW's guidance (PECjapan) was lower than 10 ng/L and the maximum MEC (MECmax) was 10 ng/L or greater. Almost all APIs also had median MECs that were lower than those of the respective PECjapan. These results indicate that the PECjapan values in phase I of the MHLW's guidance were appropriate. However, some APIs had MECmax values that were greater than those of the respective PECjapan due to overestimation of the dilution factor of river water and/or underestimation of API production.

Evaluation of the Acute Effects and Oxidative Stress Responses of Phenicol Antibiotics and Suspended Particles in Daphnia magna

Suspended particles (SP) exist widely in various water systems and are able to adsorb other pollutants in water, producing ecotoxic effects on aquatic nontarget species. Until now, however, few studies have focused on the effects of SP on antibiotics. Therefore, the present study investigated the effects of the mixtures of SP and phenicol antibiotics (chloramphenicol [CAP], thiamphenicol [TAP]) on acute toxicity and oxidative stress responses in Daphnia magna. The results indicated that the acute toxicity of phenicol antibiotics in D. magna was increased when combined with SP. Besides, the immobilization of daphnids caused by phenicol drugs in the presence of 10 mg/L of SP was more intense than that with 200 mg/L of SP. Furthermore, the impact of SP with diverse concentrations on the activity of catalase and the level of reduced glutathione in D. magna was different. Notably, almost all CAP + TAP + SP treatments markedly increased malondialdehyde content in D. magna, causing potential cellular oxidative damage in D. magna. In summary, the present study provides insights into the toxic effects of phenicol antibiotic and SP mixtures on aquatic organisms. Environ Toxicol Chem 2021;40:2463-2473. © 2021 SETAC.

Consequences of combined exposure to thermal stress and the plasticiser DEHP in Mytilus spp. differ by sex

Little is known about the combined effect of environmental factors and contaminants on commercially important marine species, and whether this effect differs by sex. In this study, blue mussels were exposed for seven days to both single and combined stressors (i.e., +3 °C elevated temperature and two environmentally relevant concentrations of the plastic softener DEHP, 0.5 and 50 μg/l) in a factorial design. Males were observed to be more sensitive to high temperature, demonstrated by the significant increase in out-of-season spawning gonads and higher gene expression of the antioxidant catalase and the estrogen receptor genes. On the other hand, while the gametogenesis cycle in females was more resilient than in males, DEHP exposure altered the estrogen-related receptor gene expression. We show that the combined stressors DEHP and increased temperature, in environmentally relevant magnitudes, have different consequences in male and female mussels, with the potential to impact the timing and breeding season success in Mytilus spp.

A review of distribution and risk of pharmaceuticals and personal care products in the aquatic environment in China

Due to the extensive use and pseudo-persistence of pharmaceuticals and personal care products (PPCPs), they are frequently detected in the aqueous environment, which has attracted global attention. In this paper, accumulation data of 81 PPCPs in surface water or sediment in China were reported. In addition, 20 kinds of PPCPs with high frequency were selected and their ecological risk assessment was conducted by risk quotient (RQs). The results indicated that the concentration detected in surface water and sediment ranged from ng/L (ng/kg) to μg/L (μg/kg) in China, which was similar to concentrations reported globally. However, contamination by certain PPCPs, such as caffeine, oxytetracycline, and erythromycin, was relatively high with a maximum concentration of more than 2000 ng/L in surface water. RQs revealed that 14 kinds of PPCPs pose no significant risk or low risk to aquatic organisms, while 6 kinds of PPCPs pose a high risk. Additionally, the pollution characteristics of PPCPs in each watershed are different. The Haihe River watershed and the central and lower Yangtze River were the regions of high concern for erythromycin. Triclosan has potential risks in the Pearl River watershed. This study determined the occurrence and risk of PPCPs in China in the past decade, providing a scientific basis for PPCPs pollution control and risk prevention.

Kinetic removal of acetaminophen and phenacetin during LED-UV365 photolysis of persulfate system: Reactive oxygen species generation

Acetaminophen (ACT) and phenacetin (PNT) removal during light-emitting diode (LED)-UV photolysis of persulfate (PS) was evaluated with a typical wavelength of 365 nm. Decay of PNT and ACT in pH ranges of 5.5-8.5 followed pseudo-first order kinetics. Maximum pseudo-first order rate constants (k_obs) of ACT and PNT decomposition of 1.8 × 10^-1 and 1.2 × 10^-1 min^-1, respectively, were obtained at pH 8.5. Hydroxyl radicals (·OH), sulfate radicals (SO₄·^-), superoxide radicals (O₂^-·), and singlet oxygen (¹O₂) were determined in-situ electron paramagnetic resonance (EPR) and alcohol scavenging tests. The average contributions of ·OH and SO₄·^- were 23.5% and 53.0% for PNT removal, and 15.9% and 53.0% for ACT removal at pH ranges of 5.5-8.5. In samples subjected to chlorination after LED-UV₃₆₅/PS pre-oxidation, a relatively small total concentration of five halogenated disinfection by-products (DBPs) was obtained of 90.9 μg L^-1 (pH 5.5) and 126.7 μg L^-1 (pH 7.0), which is 58.5% and 30.2% lower than that in system without LED-UV₃₆₅/PS pre-oxidation. Meanwhile, a higher maximum value of total DBP concentration was obtained at pH 8.5 (445.6 μg L^-1) following LED-UV₃₆₅/PS pre-oxidation. The results of economy evaluation showed that UV₃₆₅ was more cost-effective in application for organic contaminant removal compared with UV₂₅₄.

Occurrence, seasonal variations, and ecological risk of pharmaceuticals and personal care products in River Ganges at two holy cities of India

Occurrence of 15 different pharmaceuticals and personal care products (PPCPs) (ibuprofen, diclofenac, ketoprofen, acetaminophen, ciprofloxacin, erythromycin, amoxicillin, ofloxacin, tetracycline, metoprolol, triclosan, salicylic acid, N, N diethyl-meta-toluamide, caffeine and β-Estradiol) belongs to eight different classes in an urban stretch of River Ganges were detected for three seasons in two holy cities Rishikesh and Haridwar (India). The overall concentration of PPCPs in the River Ganges ranged between Below Detectable Limit (BDL) to 1104.84 ng/L, with higher concentrations at anthropogenically influenced lower reaches of the River Ganges at Haridwar. Acetaminophen, triclosan, N, N diethyl-meta-toluamide (DEET), tetracycline, and caffeine showed the highest detection frequency (>90-100%) in the river. PPCPs concentration, especially for NSAIDs (Ibuprofen, ketoprofen and acetaminophen), antibiotics (ciprofloxacin, tetracycline and ofloxacin) and metabolite (salicylic acid) was found to be higher in winter compared to summer in the Ganges, possibly due to the lower biodegradation efficiency related to lesser temperatures and inadequate sunlight. While metoprolol (beta-blockers), triclosan (antibacterial), DEET (insect repellent) and caffeine (human indicator) showed a higher load in summer, possibly due to their intense uses during this period. Results of risk quiescent (RQ) revealed higher ecological risk for algae while the moderate risk for river fish biota.

A chronicle of SARS-CoV-2: Seasonality, environmental fate, transport, inactivation, and antiviral drug resistance

In this review, we present the environmental perspectives of the viruses and antiviral drugs related to SARS-CoV-2. The present review paper discusses occurrence, fate, transport, susceptibility, and inactivation mechanisms of viruses in the environment as well as environmental occurrence and fate of antiviral drugs, and prospects (prevalence and occurrence) of antiviral drug resistance (both antiviral drug resistant viruses and antiviral resistance in the human). During winter, the number of viral disease cases and environmental occurrence of antiviral drug surge due to various biotic and abiotic factors such as transmission pathways, human behaviour, susceptibility, and immunity as well as cold climatic conditions. Adsorption and persistence critically determine the fate and transport of viruses in the environment. Inactivation and disinfection of virus include UV, alcohol, and other chemical-base methods but the susceptibility of virus against these methods varies. Wastewater treatment plants (WWTPs) are major reserviors of antiviral drugs and their metabolites and transformation products. Ecotoxicity of antiviral drug residues against aquatic organisms have been reported, however more threatening is the development of antiviral resistance, both in humans and in wild animal reservoirs. In particular, emergence of antiviral drug-resistant viruses via exposure of wild animals to high loads of antiviral residues during the current pandemic needs further evaluation.

Impact of long-duration CSO events under different tidal change conditions on distribution of microbial indicators and PPCPs in Sumida river estuary of Tokyo Bay, Japan

The Sumida river estuary of Tokyo bay is often affected by fecal contamination from combined sewer overflows (CSOs). This study monitored the surface water quality from the upstream of the Sumida river to the estuary in October 2017, June 2018, and July 2018 after three long-duration rainfall events. Several types of sewage markers, including fecal bacteria and two types of bacteriophages as microbial markers, and five pharmaceuticals and personal care products (PPCPs) as chemical markers were used to evaluate fecal contamination. CSO discharge was estimated separately from pumping stations and overflow chambers. The dominant contribution from overflow chambers was estimated to be as high as 86 - 91% of total discharge volume indicating their significance in controlling CSO pollution. High concentrations of sewage marker were observed in a wide area due to CSO discharge of more than 30 h in all 3 events. Escherichia coli was found to be as high as 4.00 - 4.57 log₁₀ (CFU/100 mL). Meanwhile, caffeine showed the highest concentration of 2105 ng/L among PPCPs. It was found to be a useful indicator of recent contamination that captured a unique spatial distribution tendency. On the other hand, crotamiton, a conservative PPCP, was found to be highly diluted and might not be appropriate for tracking pollutants under heavy rainfall events. The effect of CSO discharge pattern and tidal change on the distribution of sewage markers, including dispersion degree and pollutants travel time, was described. CSO pollutants were found to accumulate in the river mouth areas during high tide before being discharged into the estuary.

Pollutant toxicology with respect to microalgae and cyanobacteria

Microalgae and cyanobacteria are fundamental components of aquatic ecosystems. Pollution in aquatic environment is a worldwide problem. Toxicological research on microalgae and cyanobacteria can help to establish a solid foundation for aquatic ecotoxicological assessments. Algae and cyanobacteria occupy a large proportion of the biomass in aquatic environments; thus, their toxicological responses have been investigated extensively. However, the depth of toxic mechanisms and breadth of toxicological investigations need to be improved. While existing pollutants are being discharged into the environment daily, new ones are also being produced continuously. As a result, the phenomenon of water pollution has become unprecedentedly complex. In this review, we summarize the latest findings on five kinds of aquatic pollutants, namely, metals, nanomaterials, pesticides, pharmaceutical and personal care products (PPCPs), and persistent organic pollutants (POPs). Further, we present information on emerging pollutants such as graphene, microplastics, and ionic liquids. Efforts in studying the toxicological effects of pollutants on microalgae and cyanobacteria must be increased in order to better predict the potential risks posed by these materials to aquatic ecosystems as well as human health.

Transition element doped octahedral manganese molecular sieves (Me-OMS-2) as diclofenac adsorbents

Diclofenac (DCF) control measures have become an area of increased interest for environmental researchers due to the high environmental concentration and risk of DCF. Adsorption seems to be promising for DCF removal from the aqueous phase because of its specific superiority in comparison with biodegradation, membrane separation, and advanced oxidation or reduction. In this study, OMS-2 and metal-doped OMS-2 ((Me-OMS-2, with Me = Co, Cu or Ce) were prepared and tested as adsorbents for the removal of DCF. It was evident that the maximum adsorption capacity and rate of Ce-OMS-2 were much higher than those of the other adsorbents, which could be attributed to its large specific surface area and stereoscopic aperture structure. The experimental data are fitted the pseudo-second-order model, the Elovich equation and the Langmuir model well; moreover, the process is an endothermic and spontaneous thermodynamic process, during which the entropy increased, based on the experimental results, indicating that chemisorption was dominant during the DCF adsorption process onto Ce-OMS-2. By the integral of the peak deconvoluted from the XPS spectrum, the ratio of Mn³⁺/Mn⁴⁺ increased from 0.393 to 0.407, revealing that Mn(IV) is rarely reduced into Mn(III) during the DCF adsorption process.

Diclofenac Degradation-Enzymes, Genetic Background and Cellular Alterations Triggered in Diclofenac-Metabolizing Strain Pseudomonas moorei KB4

Diclofenac (DCF) constitutes one of the most significant ecopollutants detected in various environmental matrices. Biological clean-up technologies that rely on xenobiotics-degrading microorganisms are considered as a valuable alternative for chemical oxidation methods. Up to now, the knowledge about DCF multi-level influence on bacterial cells is fragmentary. In this study, we evaluate the degradation potential and impact of DCF on Pseudomonas moorei KB4 strain. In mono-substrate culture KB4 metabolized 0.5 mg L⁻¹ of DCF, but supplementation with glucose (Glc) and sodium acetate (SA) increased degraded doses up to 1 mg L⁻¹ within 12 days. For all established conditions, 4′-OH-DCF and DCF-lactam were identified. Gene expression analysis revealed the up-regulation of selected genes encoding biotransformation enzymes in the presence of DCF, in both mono-substrate and co-metabolic conditions. The multifactorial analysis of KB4 cell exposure to DCF showed a decrease in the zeta-potential with a simultaneous increase in the cell wall hydrophobicity. Magnified membrane permeability was coupled with the significant increase in the branched (19:0 anteiso) and cyclopropane (17:0 cyclo) fatty acid accompanied with reduced amounts of unsaturated ones. DCF injures the cells which is expressed by raised activities of acid and alkaline phosphatases as well as formation of lipids peroxidation products (LPX). The elevated activity of superoxide dismutase (SOD) and catalase (CAT) testified that DCF induced oxidative stress.

Characteristics of pharmaceutically active compounds in surface water in Beijing, China: Occurrence, spatial distribution and biennial variation from 2013 to 2017

Pharmaceutically active compounds (PhACs) are widely found in the environment due to vast human consumption. Lots of work has been devoted to investigating the occurrence and seasonal variations globally. To fully understand characteristics and cross-year variation of PhACs in Beijing, 35 PhACs were analyzed in 46 sites across Beijing from both urban and suburban areas. Concentrations of target PhACs were ranged from levels of ng L^-1 to μg L^-1. Metoprolol (524 ng L^-1), caffeine (390 ng L^-1) and acetaminophen (156 ng L^-1) were the three most abundant non-antibiotics with the highest median concentration, and nalidixic acid (135 ng L^-1), erythromycin (64 ng L^-1) and sulfamethoxazole (77 ng L^-1) were the most abundant antibiotics. Urban and suburban areas are distinguished by PhAC composition in cluster analysis due to different wastewater collection rate. The ratio of easily removable compound group and hardly removable group was then proposed to reflect the wastewater collection rate. The compositional comparison of PhACs in WWTPs' effluents and their receiving rivers further illustrates the impact of WWTPs in urban area. Higher proportion of antibiotics (>30%) in suburban area reflected the impact of presence of livestock farms, which should be concerned. Further statistical analyses show an improving trend of wastewater collection rate, and excluding metoprolol, an anti-hypertension medicine, the total concentration of 13 target PhACs was reduced by 72% during 2013-2017.

Occurrence, distribution, and health risk assessment of 20 personal care products in indoor and outdoor swimming pools

The distribution of 20 personal care products (PCPs), including seven preservatives, six UV filters, five anticorrosion agents, and two antimicrobials, were determined in 40 swimming pools using solid phase extraction followed by liquid chromatography-tandem mass spectrometry. Among 14 targets detected, 1H-benzotriazole and triclocarban were observed in all samples. The detected concentrations of preservatives, UV filters, anticorrosion agents, and antimicrobials were in the ranges of not detected (nd)-179 ng L^-1, nd-289 ng L^-1, nd-58.4 ng L^-1, and nd-56.9 ng L^-1, respectively. The presence of preservatives, UV filters and antimicrobials in pool waters might be mainly brought in by human activities while anticorrosion agents were mainly from the source water. Furthermore, the concentrations of methylparaben, ethylparaben, 1H-benzotriazole, 5-methyl-1H-benzotriazole, 5-chloro-1H-benzotriazole, and 5,6-dimethyl-1H-benzotriazole in indoor pools were found higher than those in outdoor pools. The longer opening time and weaker light intensity for indoor pools might cause the difference. The redundancy analysis showed significantly negative correlations between the concentrations of parabens and the contents of residual chlorine in the pool waters. A higher chlorine residue may promote the decomposition of parabens. Health risk assessment showed that skin penetration would be the main approach for the intake of PCPs by swimmers while swimming. Compared with the non-athletic swimmers, the athletic swimmers might be more sensitive, but the health risks for both groups of swimmers could be negligible.

Widespread monitoring of chiral pharmaceuticals in urban rivers reveals stereospecific occurrence and transformation

The present work aimed to discuss the enantiomeric occurrence of chiral pharmaceuticals including 5 parent compounds (PCs) metoprolol, propranolol, atenolol, venlafaxine and fluoxetine as well as 6 of their transformation products (TPs) in surface water in Beijing. Among which, 9 out of 11 were detected during the two sampling campaigns with N-O-Didesmethylvenlafaxine (NODDV) and α-hydroxymetoprolol confirmed in the catchment for the first time. Metoprolol acid (MTPA) was the most abundant up to 1508 ng L^-1, followed by metoprolol and O-desmethylvenlafaxine (ODV). Most compounds showed 100% detection frequency or nearly, while norfluoxetine (the main metabolite of fluoxetine) and 4-hydroxypropranololone (one TP of propranolol) were not detected. Metoprolol (MTP) and venlafaxine (VFX) did not vary significantly between two sampling periods with mean concentrations of 280.7 and 22.9 ng L^-1, respectively. Enantiomeric enrichment was observed for venlafaxine, metoprolol and NODDV, where R-venlafaxine was preferentially biotransformed than the S-form through O-desmethylation. Risk assessment indicated that fluoxetine and atenolol could pose harmful effects to aquatic organisms. This work provides enantiospecific profiles of pharmaceutically active compounds (PhACs), and extended the concept of applying the ratio of TPs vs. parent compound plus their enantiomeric traits for quantitative assessment of in situ biodegradation. Due to the considerable contribution by TPs (64% in present study) as well as the unexpected impacts from enantiomeric existence, the stereoselectivity of chiral pollutants during environmental process should be taken into account in future study. To the best of the authors' knowledge, it is the first comprehensive evaluation of chiral pharmaceuticals and transformation products at enantiomeric level in aquatic environment in China, which would facilitate better understanding of their environmental fate.

Contamination profile of antibiotic resistance genes in ground water in comparison with surface water

Dissemination of antibiotic resistance genes (ARGs) in the water environment has become an increasing concern. There have been many reports on ARGs in surface water, but little is known about ARGs in groundwater. In this study, we investigated the profiles and abundance of ARGs in groundwater in comparison with those in surface water of Maozhou River using high-throughput quantitative PCR (HT-qPCR). Totally 127 ARGs and 10 MGEs were detected by HT-qPCR, and among them the sulfonamides, multidrug and aminoglycosides resistance genes were the dominant ARG types. According to the results of HT-qPCR, 18 frequently detected ARGs conferring resistance to 6 classes of antibiotics and 3 MGEs were further quantified by qPCR in the wet season and dry season. The absolute abundance ranged from 1.23 × 10⁵ to 8.89 × 10⁶ copies/mL in wet season and from 8.50 × 10² to 2.65 × 10⁶ copies/mL in the dry season, with sul1 and sul2 being the most abundant ARGs. The absolute abundance of ARGs and MGEs has no significant difference between the wet season and dry season while the diversity of ARGs in the dry season was higher than that in the wet season (p < 0.05). Totally 141 and 150 ARGs were detected in the water and sediments of Maozhou River, respectively. A total of 116 ARGs were shared among the groundwater, river water, and sediment, which accounted for 67.1% of all detected genes. Redundancy analysis further demonstrated that the environmental factors contributed 70.7% of the total ARG variations. The findings of large shared ARGs, abundant Total Coliforms and large wastewater burden in the groundwater provide a clear evidence that anthropogenic activities had a significant impact on groundwater.

Distribution of micropollutants in estuarine and sea water along the Portuguese coast

This work provides the first spatial distribution report of micropollutants (MPs) in the entire Portuguese coast, comprising the ocean shore (sea water, SW) and whenever possible the nearest river discharging on it (estuarine water, EW). This surface water monitoring programme aimed to assess the spatial distribution of 37 MPs with a wide chemical nature, including some substances prioritized by the European Union Directive 39/2013/EU and contaminants of emerging concern targeted in the Watch List of Decisions 495/2015/EU and 840/2018/EU. The risk quotients were estimated in each sampling point for the detected MPs. High concentrations of diclofenac, tramadol and carbamazepine were determined, the latter with medium to high risk for algae. Some pharmaceuticals and perfluorooctanesulfonic acid (PFOS) were broadly distributed, maybe due to the direct discharge into the sea. Atrazine and alachlor were found in the majority of the samples, with alachlor levels often considered as medium to high risk.

Pharmaceuticals, pesticides, personal care products and microplastics contamination assessment of Al-Hassa irrigation network (Saudi Arabia) and its shallow lakes

This study assess the presence of pharmaceutical and personal care products (PPCPs) and pesticides in different environmental compartments and microplastics in water of a characteristic lagoon wetland in Saudi Arabia to establish the transport, accumulation and fate of these pollutants in a water-stressed area under high anthropogenic pressure. In water, diazinon (up to 1016 ng L^-1), caffeine (up to 20,663 ng L^-1), diclofenac (up to 1390 ng L^-1) and paracetamol (up to 3069 ng L^-1) were at the highest concentrations. The substances with the highest frequency of detection were carbendazim, atorvastatin, caffeine, etoricoxib, lorazepam, metformin, ofloxacin, paracetamol, salicylic acid and tramadol. Considerably less pesticides and PPCPs at concentrations ranging from 0.01 to 126 ng g^-1 dry weight (d.w.) were detected in the other matrices (sediment ≫ soil > plants). The concentration of microplastics in water ranged from 0.7 to 7.8 items/L in the Al-Asfar lake and from 1.1 to 9.0 items/L in the Al-Hubail lake. Risk assessment [using hazards quotients (HQ)] was used to highlight pesticides and PPCPs of major ecological concern that should be closely monitored to avoid adverse effects.

Adsorption site-dependent transport of diclofenac in water saturated minerals and reference soils

Use of reclaimed water for irrigation is a main way for pharmaceutical compounds such as diclofenac getting into the soil environment. However, the role of minerals, especially iron oxides, in the diclofenac adsorption to soils with low soil organic matter (SOM) is still in the lack of evaluation. In this study, adsorption of diclofenac onto six minerals (five nature minerals-hematite, goethite, magnetite, kaolinite and aluminium oxide and one engineered mineral-activated aluminia) and five reference soils was investigated by column chromatography. Adsorption of diclofenac onto minerals and soils was totally reversible and interactions such as H-bonding were the primary mechanisms. Adsorption affinity of iron oxides was much higher than that of nature silicon and aluminum oxides. Diclofenac tended to be adsorbed by mineral surface -OH groups with high thermodynamic stability, which were dehydroxylated at high temperature. Compared with the SOM-dominated sorption of naphthalene, adsorption of diclofenac onto soils was controlled by bonding with surface -OH groups of iron oxides. Adsorption coefficients of diclofenac onto soils can be well predicted by contents of extracted Fe by diethylenetriamine pentaacetic acid (DTPA) instead of total iron oxides contents, suggesting that the bonding was adsorption site-dependent. These findings highlighted the importance of iron oxides in the adsorption of diclofenac (an anionic pharmaceutical compound) in soils with relatively low SOM (e.g., 1.03-3.45%). It also indicated that contents of effective surface -OH groups and DTPA-Fe were the promising parameters to develop the predictive models for diclofenac adsorption onto minerals and soils, respectively.

Risk assessment of soil heavy metals associated with land use variations in the riparian zones of a typical urban river gradient

Urbanization-induced land use changes in riparian area alter soil and water regimes in complex ways, which may also affect the migration and transformation of soil heavy metals and increase the risk of release. In this study, soil samples from the riparian zone of Beiyun River, which located in the rapidly urbanized Beijing metropolis, were collected and analyzed for heavy metals (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn). Then their zoning distribution pattern along river (section 1 to section 4 from upper to low reaches) and the correlation of heavy metals between riparian soils and riverine sediments were investigated. Results showed that the average soil heavy metal concentrations of Cd, Cr, Cu and Zn in riparian zone were approximately 2.2, 1.7, 1.9 and 2.0 times higher than the background values. Sectionally, the concentrations of Cd, Ni, Pb and Zn displayed a decreasing order with section 2 > section 3 > section 4 > section 1, while the highest values of Cr and Cu were found in section 3. The concentrations of all heavy metals except Cr in artificial garden land were higher than those in other land use types, and the concentrations of Cr among five land use types were in the order of grass land > farmland > artificial garden land > forest land > forest-grass land. Generally, most of the heavy metals in the riverine sediments had higher contents than those in riparian zones, especially Cu and Zn. There was a decreasing order for the average geo-accumulation index (I_geo) of measured heavy metals in the soils of riparian zone: Zn (0.15) > Cr (0.08) > Cu (0.07) > Cd (-0.08) > As (-0.57) > Pb (-0.67) > Mn (-0.75) > Ni (-0.86), whereas they had different "high-low" orders in different land use types. The I_geo index indicated most regions of riparian zone were moderately polluted with Cd, Cr, Cu and Zn, especially in grass land and forest land. Also, Cd, Cr and Zn in riparian zone have positive relationships with the concentrations in riverine sediments. Health risk assessment showed that the contribution of ingestion HQ to HI was the highest among the three exposure pathways (ingestion, inhalation and dermal contact), and children had higher non-carcinogenic risk and carcinogenic risk index than adult. Our findings suggest that land use and soil in riparian zone should be protected and managed scientifically to control the riverine pollution and ensure human health.

Spatial and seasonal variations of antibiotics in river waters in the Haihe River Catchment in China and ecotoxicological risk assessment

Concentrations of widely used antibiotics were predicted to be the highest in the Haihe River Catchment across China previously, potentially resulting in high ecotoxicological risks in this region. As a result of growing usage and regulation of antibiotic use in animals, the pattern of use may have altered temporally for different antibiotics. It is important to monitor the occurrence of antibiotics within different categories for understanding their mass loading to the catchment and the potential ecotoxicological risks involved. This study investigated the seasonal occurrence and spatial variation of 15 antibiotics in the Haihe River Catchment during 2016-2017. The investigated compounds included veterinary antibiotics, human-use antibiotics, and those intended for both human and animal use. Measurements reported from previous studies were compared with the results of this study and indicated that the use of veterinary antibiotics is probably increasing around the catchment. The ∑antibiotics concentration (i.e. the summed concentration of the 15 target antibiotics) ranged from 414 to 1951 ng/L, with an average of 821 ng/L. Discharges from wastewater treatment plants were the main sources of these compounds. The mass loading of antibiotics to the river waters was higher during wet seasons than during dry seasons. The mass fluxes of the antibiotics continuously increased towards the lower reaches of the rivers. The total annual input of the antibiotics from the Haihe River and Yongdingxin River into the Bohai Bay was 5008 kg/yr. Ofloxacin, trimethoprim, leucomycin, anhydro erythromycin and florfenicol were the predominant antibiotics, whilst amoxicillin, anhydro erythromycin, ofloxacin, norfloxacin and enrofloxacin may pose high ecotoxicological risks to the investigated aquatic ecosystem. Several antibiotics selected in this study were reported for the first time in this catchment. This study provides important information for chemical management and indicates that further monitoring is needed on the more harmful and veterinary antibiotics in the catchment.

Features of diclofenac biodegradation by Rhodococcus ruber IEGM 346

This study investigated the ability of rhodococci to biodegrade diclofenac (DCF), one of the polycyclic non-steroidal anti-inflammatory drugs (NSAIDs) most frequently detected in the environment. Rhodococcus ruber strain IEGM 346 capable of complete DCF biodegradation (50 µg/L) over 6 days was selected. It is distinguished by the ability to degrade DCF at high (50 mg/L) concentrations unlike other known biodegraders. The DCF decomposition process was accelerated by adding glucose and due to short-term cell adaptation to 5 µg/L DCF. The most typical responses to DCF exposure observed were the changed ζ-potential of bacterial cells; increased cell hydrophobicity and total cell lipid content; multi-cellular conglomerates formed; and the changed surface-to-volume ratio. The obtained findings are considered as mechanisms of rhodococcal adaptation and hence their increased resistance to toxic effects of this pharmaceutical pollutant. The proposed pathways of bacterial DCF metabolisation were described. The data confirming the C-N bond cleavage and aromatic ring opening in the DCF structure were obtained.

Mechanisms and quantification of adsorption of three anti-inflammatory pharmaceuticals onto goethite with/without surface-bound organic acids

Nowadays non-steroidal anti-inflammatory drugs (NSAIDs) are often detected in surface water and groundwater. In this study, effects of environmental factors, i.e., solution pH, ionic strength, temperature and surface-bound organic acids, on bonding of three typical NSAIDs (ketoprofen, naproxen and diclofenac) onto goethite were systematically investigated. Column chromatography, batch experiments, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and surface complexation modeling were used to probe the adsorption mechanisms. Bonding of three NSAIDs onto goethite was totally reversible, ionic strength-dependent and endothermic (adsorption enthalpy 2.86-9.75 kJ/mol). These evidences supported H-bonding mechanism, which was further explained by ATR-FTIR observation and a triple planes model. Surface-bound organic acids (phthalic acid, trimellitic acid and pyromellitic acid) by inner-sphere complexation with goethite were hard to be desorbed. Surface-bound phthalic acid increased the uptake of NSAIDs but surface-bound trimellitic acid and pyromellitic acid reduced their adsorption. The reason is that the adsorbed phthalic acid can result in a more hydrophobic surface while adsorbed trimellitic acid and pyromellitic acid increased the surface negative charge and polarity. Finally, adsorption of NSAIDs onto goethite with/without surface-bound organic acids was well described by a free energy model, in which contributions of interactions (e.g., H-bonding and van der Waals) were evaluated.

Bonding of monocarboxylic acids, monophenols and nonpolar compounds onto goethite

Adsorption of a diverse set of chemicals onto goethite was evaluated by column chromatography. The pH of the effluents was 4.7-5.2. Van der Waals forces dominate the exothermic adsorption of 8 nonpolar compounds (e.g., PAHs and chlorobenzenes). H-bonding is responsible for the adsorption of 32 monocarboxylic acids (i.e., benzoic acids, naphthoic acids and acidic pharmaceuticals) and their adsorption tends to be endothermic. Steric effects significantly decreased the bonding of monocarboxylic acids with ortho-substitutions. Exothermic adsorption of 10 monophenols is controlled by weak H-bonding. Bonding of these 50 solutes onto goethite is totally reversible. In contrast, inner-sphere complexation of phthalic acid and chlortetracycline with goethite occurred according to their low desorption ratio (1.1%-54.4%). Polyparameter linear free energy relationship (PP-LFER) models were established to provide acceptable fitting results of the goethite-solute distribution coefficients (RMSE = 0.32 and 0.30 at 25 °C and 5 °C, respectively). It is worthy to note that steric effects must be considered to get a better prediction for compounds with ortho-substitutions.

Roles of hydrophobic and hydrophilic fractions of dissolved organic matter in sorption of ketoprofen to biochars

Hydrophobic acid (HoA) and hydrophilic neutral (HiN) are two major fractions of dissolved organic matter (DOM). Their role in the sorption of ketoprofen (KTP) to wheat straw-derived biochars pyrolyzed at 300 °C (WS300) and 700 °C (WS700) was investigated to further probe the mechanisms responsible. WS700 has much higher pore volume and specific surface area (SSA) than WS300. Loading of HoA and HiN resulted in surface coverage of biochars. HoA with larger molecular size led to more pore blockage of biochars than HiN. Higher HoA binding affinity also caused a stronger competition with KTP on biochars. These factors reduced the accessibility of sorption sites for KTP, and significantly inhibited KTP sorption to biochar of lower SSA (i.e., WS300) by HoA. Water solubility (S_w) of KTP was slightly enhanced (3%) in the presence of HoA. In contrast, the presence of HiN reduced (22%) S_w of KTP. The decreased S_w of KTP by HiN exerted a more dominant influence than its competitive and loading effects, thus led to apparent enhanced sorption of KTP, especially to biochar of higher SSA (i.e., WS700). The results demonstrated the diverse effects of HoA and HiN on KTP sorption, which is helpful in understanding pharmaceutical-DOM-biochar interactions and environmental behaviors of pharmaceuticals.

A review on environmental monitoring of water organic pollutants identified by EU guidelines

The contamination of fresh water is a global concern. The huge impact of natural and anthropogenic organic substances that are constantly released into the environment, demands a better knowledge of the chemical status of Earth's surface water. Water quality monitoring studies have been performed targeting different substances and/or classes of substances, in different regions of the world, using different types of sampling strategies and campaigns. This review article aims to gather the available dispersed information regarding the occurrence of priority substances (PSs) and contaminants of emerging concern (CECs) that must be monitored in Europe in surface water, according to the European Union Directive 2013/39/EU and the Watch List of Decision 2015/495/EU, respectively. Other specific organic pollutants not considered in these EU documents as substances of high concern, but with reported elevated frequency of detection at high concentrations, are also discussed. The search comprised worldwide publications from 2012, considering at least one of the following criteria: 4 sampling campaigns per year, wet and dry seasons, temporal and/or spatial monitoring of surface (river, estuarine, lake and/or coastal waters) and ground waters. The highest concentrations were found for: (i) the PSs atrazine, alachlor, trifluralin, heptachlor, hexachlorocyclohexane, polycyclic aromatic hydrocarbons and di(2-ethylhexyl)phthalate; (ii) the CECs azithromycin, clarithromycin, erythromycin, diclofenac, 17α-ethinylestradiol, imidacloprid and 2-ethylhexyl 4-methoxycinnamate; and (iii) other unregulated organic compounds (caffeine, naproxen, metolachlor, estriol, dimethoate, terbuthylazine, acetaminophen, ibuprofen, trimethoprim, ciprofloxacin, ketoprofen, atenolol, Bisphenol A, metoprolol, carbofuran, malathion, sulfamethoxazole, carbamazepine and ofloxacin). Most frequent substances as well as those found at highest concentrations in different seasons and regions, together with available risk assessment data, may be useful to identify possible future PS candidates.