Biochar obtained from recovered cellulose and its mixture with conventional sources: Assessment of its potential for the removal of pollutants in water.

Yearly thousands of tons of cellulose, in the form of toilet paper, end up in the wastewater treatment plants (WWTP) through the sewage. Cellulose was recovered with a 0.35 mm sieve and processed obtaining three different pellets: pure cellulose, straw mix (50 % cellulose-50 % straw) and wood mix (50 % cellulose-50 % wood). Those materials were carbonized at 750 °C for 210 min producing non-activated biochar. Then, a part of those biochars was biologically activated by fermentation adding minerals, nutrients and a mixture of bacteria. All biochar versions were characterized, assessing the surface, porosity and adsorption capacity for a dye (indigo carmine) and a selection of 5 micropollutants (MPs): benzotriazole, carbamazepine, clarithromycin, DEET, and diclofenac. However, results showed that conventional analysis for adsorbents was not adequate for biologically activated materials since biofilm can obstruct the pores of the supporting material hindering the pollutants' adsorption. Therefore, the biological degradation of the pollutants by the microorganisms was also tested. Finally, biologically activated WOW-Biochar straw mix was the selected material to be further applied in constructed wetlands (CW) due to its higher average MPs removal capacity. Validation test at mesocosm scale demonstrates the suitability of the material as an admixture in CW, reaching a MPs removal rate higher than the 90 % regarding the WWTP inlet.

Occurrence and potential risks of pharmaceutical contamination in global Estuaries: A critical review and analysis.

Input of pollutants to estuaries is one of the major threats to marine biodiversity and fishery resources, and pharmaceuticals are one of the most important contaminants of emerging concern in aquatic ecosystems. To synthesize pharmaceutical pollution levels in estuaries over the past 20 years from a global perspective, this review identified 3229 individual environmental occurrence data for 239 pharmaceuticals across 91 global estuaries distributed in 26 countries. The highest cumulative weighted average concentration level (WACL) of all detected pharmaceuticals in estuarine water was observed in Africa (145,461.86 ng/L), with 30 pharmaceuticals reported. North America (24,316.39 ng/L) was ranked second in terms of WACL, followed by South America (20,784.13 ng/L), Asia (5958.38 ng/L), Europe (4691.23 ng/L), and Oceania (2916.32 ng/L). Carbamazepine, diclofenac, and paracetamol were detected in all continents. A total of 41 functional categories of pharmaceuticals were identified, and analgesics, antibiotics, and stimulants were amongst the most ubiquitous groups in estuaries worldwide. Although many pharmaceuticals were observed to present lower than or equal to moderate ecological risk, 34 pharmaceuticals were identified with high or very high ecological risks in at least one continent. Pharmaceutical pollution in estuaries was positively correlated with regional unemployment and poverty ratios, but negatively correlated with life expectancy and GDP per capita. There are some limitations that may affect this synthesis, such as comparability of the sampling and pretreatment methodology, differences in the target pharmaceuticals for monitoring, and potentially limited number and diversity of estuaries covered, which prompt us to standardize methods for monitoring these pharmaceutical contaminants in future global studies.

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.

Wastewater reuse and pharmaceutical pollution in agriculture: Uptake, transport, accumulation and metabolism of pharmaceutical pollutants within plants.

The presence of pharmaceutical pollutants in water sources has become a growing concern due to its potential impacts on human health and other organisms. The physicochemical properties of pharmaceuticals based on their intended therapeutical application, which include antibiotics, hormones, analgesics, and antidepressants, is quite diverse. Their presence in wastewater, sewerage water, surface water, ground water and even in drinking water is reported by many researchers throughout the world. Human exposure to these pollutants through drinking water or consumption of aquatic and terrestrial organisms has raised concerns about potential adverse effects, such as endocrine disruption, antibiotic resistance, and developmental abnormalities. Once in the environment, they can persist, undergo transformation, or degrade, leading to a complex mixture of contaminants. Application of treated wastewater, compost, manures or biosolids in agricultural fields introduce pharmaceutical pollutants in the environment. As pharmaceuticals are diverse in nature, significant differences are observed during their uptake and accumulation in plants. While there have been extensive studies on aquatic ecosystems, the effect on agricultural land is more disparate. As of now, there are few reports available on the potential of plant uptake and transportation of pharmaceuticals within and between plant organs. This review summarizes the occurrence of pharmaceuticals in aquatic water bodies at a range of concentrations and their uptake, accumulation, and transport within plant tissues. Research gaps on pharmaceutical pollutants' specific effect on plant growth and future research scopes are highlighted. The factors affecting uptake of pharmaceuticals including hydrophobicity, ionization, physicochemical properties (pKa, logKow, pH, Henry's law constant) are discussed. Finally, metabolism of pharmaceuticals within plant cells through metabolism phase enzymes and plant responses to pharmaceuticals are reviewed.

Ultraviolet absorbents and industrial antioxidants in seabirds, mammals, and fish from the Canadian Arctic.

Ultraviolet (UV) absorbents and industrial antioxidants are two groups of plastic-derived contaminants of emerging environmental concern. However, their distribution and fate are poorly understood in Arctic wildlife. In the present study, 16 UV absorbents (10 benzotriazole UV stabilizers (BZT-UVs) and 6 organic UV filters (UVFs)) and 7 industrial antioxidants (6 aromatic secondary amines (Ar-SAs) and 2,6-di-tert-butylphenol (26DTBP)) were analyzed in the livers of thick-billed murre (Uria lomvia; n = 28), northern fulmar (Fulmarus glacialis; n = 4), black guillemot (Cepphus grylle; n = 11), polar bear (Ursus maritimus; n = 18), beluga whale (Delphinapterus leucas; n = 10), landlocked (n = 25) and sea-run (n = 10) Arctic char (Salvelinus alpinus) from the Canadian Arctic collected between 2017 and 2021. Compared to industrial antioxidants (median range: ΣAr-SAs: not calculated due to detection frequency < 30 % (NA)-4.06 ng/g, wet weight (ww); 26DTBP: NA-1.91 ng/g ww), UV absorbents (median range: ΣBZT-UVs: NA-8.71 ng/g ww; ΣUVFs: NA-48.3 ng/g ww) generally showed greater concentrations in the liver of these species. Seabirds accumulated higher levels of these contaminants (median range: ΣBZT-UVs: 3.38-8.71 ng/g ww; ΣUVFs: NA-48.3 ng/g ww; ΣAr-SAs: 0.07-4.06 ng/g ww; 26DTBP: NA-1.14 ng/g ww)) than the other groups (median range: ΣBZT-UVs: NA-1.31 ng/g ww; ΣUVFs: NA-4.22 ng/g ww; ΣAr-SAs: NA; 26DTBP: NA-1.91 ng/g ww), suggesting that seabirds may be useful indicator species for future long-term monitoring. The livers of Arctic char in the Canadian Arctic generally contain lower levels of these contaminants than those of freshwater fish in temperate regions. Spatial variations were found in the liver of black guillemots, Hudson Bay polar bears, and landlocked char for some target contaminants, indicating differences in the levels of these contaminants in their surrounding environment or diet. Consumption of liver tissues from these species may expose humans to varying levels of UV absorbents and industrial antioxidants. This study establishes a baseline for future research of the spatial and temporal trends of these contaminants in Arctic species. It provides the basis for elucidating the fate of these contaminants and assessing their adverse effects at environmental-relevant concentrations in the Arctic. Factors influencing the accumulation patterns of these contaminants in Arctic biota and their potential health risks require further investigation.

[Translated article] Pharmaceuticals in the environment: A hospital pharmacy perspective.

Drugs do not disappear once they have been excreted. In fact, 992 active principles have already been measured in the different environmental matrices. A recent study led by scientists from the University of York has studied the presence of drugs in the rivers of more than 100 different countries, showing that environmental contamination by pharmaceuticals is a global issue and that, concentrations found are frequently harmful to the environment. In this work, we have tried to briefly expose the problem of environmental contamination with medicines, but above all, we have tried to address the possible solutions, with a perspective from the field of hospital pharmacy. This is a very complex matter (a wicked problem), since it involves multiple stakeholders with different visions and interests regarding medicines. In order to find solutions, we will probably need to act at all steps of the drug's life cycle. Until now, health professionals have been part of the problem. It is time for us to be part of the solution.

Exploration of novel solid-phase extraction modes for analysis of multiclass emerging contaminants.

Solid-phase extraction (SPE) has gained an essential role in environmental analytical chemistry. Classic off-line SPE coupled with LC-MS/MS systems creates powerful analytical procedures for ultratrace analysis of contaminants of emerging concern (CECs) in water. But, being associated with tedious work and large consumption of materials, alternative SPE modes are becoming interesting. As so, the study focuses on development, evaluation, and overall comparison of established and novel SPE modes. Off-line SPE, dispersive micro SPE (DMSPE), and 'fast' single-pump on-line SPE were explored, using commercially available sorbents. Their efficiency was evaluated on their performance in water analysis of 20 multiclass CECs. Hydrophilic-lipophilic sorbent and mixture of C18/C8 sorbents were the best choice for off-line and DMSPE, respectively. All optimized SPE modes coupled with UHPLC-MS/MS reached environmentally-relevant limits of detection (LODs 0.1-12 ng L-1), acceptable repeatability (<20 % RSD), and exhibited less than ±30 % matrix effects in real river water sample. Among all, on-line SPE showed a potential to fully replace the well-established off-line SPE and even improve analytical performance. This was due to the best repeatability (<10 % RSD), automatization, simplicity, the highest multiplexing capacity, as well as comparable LODs of <2 ng L-1. DMSPE is, on the other hand, the most innovative and could be seen as a quick and green alternative to off-line SPE for determination of semi-to-nonpolar CECs, but within sub-10 ng L-1 range. Overall, the study shows workflow for the exploration of important and promising sample pretreatment techniques in water analysis. Comparison of the developed three SPE-UHPLC-MS/MS methods suggests that alternative SPE modes can compete with the well-established off-line SPE and can even improve the analysis quality if properly applied.

Legacy and novel contaminants in surface sediments of Admiralty Bay, Antarctica Peninsula.

Despite being one of the most remote areas on the planet, the Antarctic continent is subject to anthropogenic influences. The presence of various groups of contaminants, including persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs), has been documented in the region over the past decades. However, a significant knowledge gap remains regarding the detection of new pollutants, such as emerging contaminants (ECs), in Antarctic coastal environments. This study analyzed the occurrence and levels of selected POPs, PAHs, ECs in surface sediments from Admiralty Bay, Antarctica Peninsula. Non-target screening was employed to identify potential novel contaminants in the region. Samples (n = 17) were extracted using an accelerated solvent extraction (ASE) system and instrumental analyses were performed using gas chromatography coupled to a triple-quadrupole mass spectrometer (GC/MS-MS). Regarding regulated contaminants, concentrations of Σ5PCBs ranged from

Effect driven prioritization of contaminants in wastewater treatment plants across China: A data mining-based toxicity screening approach.

A diversity of contaminants of emerging concern (CECs) are present in wastewater effluent, posing potential threats to receiving waters. It is urgent for a holistic assessment of the occurrence and risk of CECs related to wastewater treatment plants (WWTP) on national and regional scales. A data mining-based risk prioritization method was developed to collect the reported contaminants and their respective concentrations in municipal and industrial WWTPs and their receiving waters across China over the past 20 years. A total of 10,781 chemicals were reported in 8336 publications, of which 1037 contaminants were reported with environmental concentrations. While contaminant categories varied across WWTP types (municipal vs. industrial) and regions, pharmaceuticals and cyclic hydrocarbons were the most studied CECs. Contaminant composition in receiving water was closer to that in municipal than industrial WWTPs. Publications on legacy pesticides and polycyclic aromatic hydrocarbons in WWTP decreased recently compared to the past, while pharmaceuticals and perfluorochemicals have received increasing attention, showing a changing concern over time. Detection frequency, concentration, removal efficiency, and toxicity data were integrated for assessing potential risks and prioritizing CECs on national and regional scales using an environmental health prioritization index (EHPi) approach. Among 666 contaminants in municipal WWTP effluent, trichlorfon and perfluorooctanesulfonic acid were with the highest EHPi scores, while 17ɑ-ethinylestradiol and bisphenol A had the highest EHPi scores among 304 contaminants in industrial WWTPs. The prioritized contaminants varied across regions, suggesting a need for tailoring regional measures of wastewater treatment and control.

Pharmaceuticals in the Environment: A hospital pharmacy's perspective. / El impacto ambiental de los medicamentos: una mirada desde la farmacia hospitalaria.

Drugs do not disappear once they have been excreted. In fact, 992 active principles have already been measured in the different environmental matrices. A recent study led by scientists from the University of York has studied the presence of drugs in the rivers of more than 100 different countries, showing that environmental contamination by pharmaceuticals is a global issue and that, concentrations found are frequently harmful to the environment. In this work, we have tried to briefly expose the problem of environmental contamination with medicines, but above all, we have tried to address the possible solutions, with a perspective from the field of hospital pharmacy. This is a very complex matter (a wicked problem), since it involves multiple stakeholders with different visions and interests regarding medicines. In order to find solutions, we will probably need to act at all steps of the drug's life cycle. Until now, health professionals have been part of the problem. It is time for us to be part of the solution.

Effects of functional groups of polyfluoroalkyl substances on their removal by nanofiltration.

Determining the reliability of nanofiltration (NF) membranes for the removal of contaminants of emerging concern, including polyfluoroalkyl substances (PFASs), pharmaceuticals, and personal care products (PPCPs), is important for ensuring drinking water safety. This study aimed to clarify the factors that influence the removal of nine major PFASs during submerged NF treatment via extrapolation based on the factors that influence PPCP removal. The rejection of nine PFASs in ultra-filtered dam water by a polypiperazine-amide (NF270) membrane increased from 71 % to 94 % at a low permeate flux of 5 L/m2 h as the PFAS molecular dimensions increased. PFASs with a carboxylic acid (-CO2H) were rejected to a greater extent than PFASs with a sulfo group (-SO3H). Further, negatively charged PFASs or PPCPs were rejected to a greater extent than uncharged and positively charged PPCPs. Our findings suggest that the rejection of PFASs can vary because of the (i) clearance distance between the PFASs' molecular dimensions and NF membrane pore diameter and (ii) intensity of electrostatic repulsion between the PFASs' functional groups and NF membrane surface. Our study indicates that submerged NF can achieve high PFAS rejection; however, variations in rejection among PFASs can become more prominent owing to a low permeate flux.

Novel brominated flame retardants relevant for European aquatic environments: ranking of analytes to monitor and focus on the French Eastern Mediterranean coastline.

Around a hundred of novel brominated flame retardants are currently being used to replace those regulated in the 2000s. However, data about their production, usage, and toxicity is still scarce, as well as their levels of contamination in the Mediterranean Sea and the subsequent risk. Our goal was to select the relevant novel brominated flame retardants to monitor and to apply it along the northeastern Mediterranean Sea. We proposed a ranking for novel brominated flame retardants based on their production or import, occurrence, and ecotoxicology, yielding to a selection of 21 priority molecules. From this list, 16 compounds were analyzed in ten coastal suspended matter samples, together with six related chemicals. To assess their occurrence in comparison to better documented flame retardants, eight legacy polybromodiphenyl ethers, seven polychlorobiphenyls, and short- and medium-chain chlorinated paraffins were also targeted. Novel brominated flame retardants and polychlorobiphenyls were detected in all the samples. Polybromodiphenyl ethers and chlorinated paraffins were detected in nine and seven samples, respectively. Out of the 22 novel brominated flame retardants analyzed, nine were detected, with total concentrations ranging from 0.4 to 18.5 ng.g-1 d.w., which was often higher than that of polybromodiphenyl ethers. A high risk for 2,4,6­tribromophenol and PCB 118 was assessed in two and six samples, respectively. To our knowledge, this is the first priority ranking and screening of most of the novel brominated flame retardants selected in the French Mediterranean Sea.

Estimating Octanol-Water Partition Coefficients of Novel Brominated Flame Retardants by Reversed-Phase High-Performance Liquid Chromatography and Computational Models.

Legacy brominated flame retardants, including polybrominated diphenyl ethers (PBDEs), have been classified as persistent organic pollutants and replaced with novel brominated flame retardants (NBFRs). The octanol-water partition coefficients (log KOW) of NBFRs have been computationally estimated, but the log KOW values provided by these methods can differ by 1 to 3 orders of magnitude. Given the importance of this parameter in fate and toxicity models, we indirectly measured the log KOW values of eight NBFRs by their capacity factor (k') on a reversed-phase high-performance liquid chromatography (HPLC) C18 column by isocratic elution and compared these measured values with those estimated by nine computational models. Log KOW values were obtained for the NBFRs 1,2-bis(2,4,6-tribromophenoxy) ethane, pentabromobenzene, pentabromoethylbenzene, pentabromotoluene, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate, allyl 2,4,6-tribromophenylether, 2,3-dibromopropyl-2,4,6-tribromophenyl ether, and bis(2-ethylhexyl) tetrabromophthalate. A training set of phthalates, polychlorinated biphenyls, PBDEs, and halogenated benzenes were chosen to obtain the log k'-log KOW calibration for the NBFRs. The computational models KowWIN, XLogP3, EAS-E Suite, COSMOtherm, DirectML, and Abraham polyparameter linear free energy relationships all predicted the log KOW values of the calibration compounds to within 1 order of magnitude without significant bias. The median of these models predicted log KOW values for the calibration compounds that were close to those known in the literature with root mean square error (RMSE) = 0.224 and for the NBFRs that were close to those measured by HPLC (RMSE = 0.334). Environ Toxicol Chem 2024;43:2105-2114. © 2024 SETAC.

Aggravating Pollution of Emerging Aryl Organophosphate Esters in Urban Estuarine Sediments of South China.

Emerging aryl organophosphate esters (aryl-OPEs) have been employed as substitutes for organohalogen flame retardants in recent years; however, their environmental occurrence and associated impacts in urban estuarine sediments have not been adequately investigated, impeding regulatory decision-making. Herein, field-based investigations and modeling based on surface sediment and sediment core analysis were employed to uncover the historical pollution and current environmental impacts of aryl-OPEs in the Pearl River Estuary, South China. Our results revealed a substantial increase in aryl-OPE emission, particularly emerging aryl-OPEs, through sediment transport to the estuary since the 2000s. The emerging aryl-OPEs comprised 83% of the total annual input in the past decade, with an average annual input of 155,000 g. Additionally, the emerging-to-traditional aryl-OPE concentration ratios increased with decreasing distance from the shore, peaking in the highly urbanized riverine outlets. These findings indicate that inventories of emerging aryl-OPEs are likely increasing in estuarine sediments and their emissions are surpassing those of traditional aryl-OPEs. Our risk-based priority screening approach indicates that some emerging aryl-OPEs, particularly bisphenol A bis(diphenyl phosphate), can pose a higher environmental risk than traditional aryl-OPEs in estuarine sediments. Overall, our study highlights the importance of recognizing the environmental impacts of emerging aryl-OPEs.

Factors in the decline of the African penguin: Are contaminants of emerging concern (CECs) a potential new age stressor?

The African penguin is currently experiencing a significant decline, with just over 10,000 breeding pairs left. A substantial body of research reflects the impacts of contaminants of emerging concern (CECs) on the marine environment, with wastewater treatment plants reported as one of the main sources of CEC release. In South Africa, CECs were identified contaminating the marine environment and bioaccumulating in several marine species. Approximately 70 % of all African penguin colonies breed in close proximity to cities and/or harbors in South Africa. Currently, the impact of CECs as a stressor upon the viability of African penguin populations is unknown. Based on the search results there was a clear lack of information on CECs' bioaccumulation and impact on the African penguin. This narrative review will thus focus on the prevalent sources and types of CECs and examine the reported consequences of constant exposure in seabirds, particularly African penguins.

"Cocaine Shark": First report on cocaine and benzoylecgonine detection in sharks.

Cocaine (COC) and benzoylecgonine (BE), the main COC metabolite, have been detected in aquatic ecosystems. Studies focusing on wild fish are, however, very limited, and no reports concerning elasmobranchs are available. This study investigated COC and BE levels in Brazilian Sharpnose sharks (Rhizoprionodon lalandii) (n = 13) using LC-MS/MS. All samples (13/13) tested positive for COC, with 92 % (12/13) testing positive for BE. COC concentrations (23.0 µg kg-1) were over 3-fold higher than BE (7.0 µg kg-1). COC levels were about three-fold significantly higher in muscle (33.8 ± 33.4 g kg-1) compared to liver (12.2 ± 14.2 µg kg-1). Females presented higher COC concentrations in muscle (40.2 ± 35.8 µg kg-1) compared to males (12.4 ± 5.9 µg kg-1). Several positive statistical correlations were noted between COC and BE (rho = 0.84) in females, indicating systemic COC transport and metabolization, as well as between BE and weight (rho = 0.62), and between COC and the Condition Factor (rho = 0.73). A strong correlation was noted between BE and COC in the muscle of non-pregnant females (rho = 1.00). This study represents the first COC and BE report in free-ranging sharks, and the findings point to the potential impacts of the presence of illicit drugs in environments.

Ultraviolet activation of monochloramine to treat contaminants of emerging concern: reactions, operating parameters, byproducts, and opportunities.

The presence of CECs in aquatic systems has raised significant concern since they are potentially harmful to the environment and human health. Eliminating CECs has led to the development of alternatives to treat wastewater, such as advanced oxidation processes (AOPs). The ultraviolet-mediated activation of monochloramine (UV/NH2Cl) is a novel and relatively unexplored AOPs for treating pollutants in wastewater systems. This process involves the production of amino radicals (•NH2) and chlorine radicals (Cl•) from the UV irradiation of NH2Cl. Studies have demonstrated its effectiveness in mitigating various CECs, exhibiting advantages, such as the potential to control the amount of toxic disinfection byproducts (TDBPs) formed, low costs of reagents, and low energy consumption. However, the strong influence of operating parameters in the degradation efficiency and existence of NH2Cl, the lack of studies of its use in real matrices and techno-economic assessments, low selectivity, and prolonged treatment periods must be overcome to make this technology more competitive with more mature AOPs. This review article revisits the state-of-the-art of the UV/NH2Cl technology to eliminate pharmaceutical and personal care products (PPCPs), micropollutants from the food industry, pesticides, and industrial products in aqueous media. The reactions involved in the production of radicals and the influence of operating parameters are covered to understand the formation of TDBPs and the main challenges and limitations of the UV/NH2Cl to degrade CECs. This review article generates critical knowledge about the UV/NH2Cl process, expanding the horizon for a better application of this technology in treating water contaminated with CECs.

Long-term impact of wastewater effluent discharge on groundwater: Identification of contaminant plume by geochemical, isotopic, and organic tracers' approach.

Infiltration of effluents from wastewater treatment plants (WWTP) into groundwater can be a source of Contaminants of Emerging Concern (CECs), such as pharmaceutical compounds, that are not fully removed during the treatment processes. A multi-tracer approach, based on hydrogeochemical, isotopic, and organic tracers, is applied in the Vistrenque Aquifer (Gard, France) to assess the dispersion of such unintentional plumes and its potential implication on groundwater quality for CECs in a small catchment area. In this area, a point source of WWTP effluent causes contaminant infiltration and unintentional transfer to the aquifer. This strong impact of an urban effluent was revealed from the Br/Cl ratio, boron concentrations and δ11B isotopic signature of the groundwater in the direct vicinity of the infiltration point. With increasing distance from that point, dilution with groundwater rapidly attenuates the urban signal from these hydrogeochemical and isotopic tracers. Nevertheless, a gadolinium anomaly, resulting from discharges of urban wastewater containing the contrast agents used for magnetic resonance imaging (MRI), highlights the presence of a wastewater plume further along the flow line, that comes with a series of organic molecules, including pharmaceutical residues. Monitoring persistent or reactive molecules along the plume provides a more detailed understanding of the transfer of CECs into groundwater bodies. This highlights the relevance of pharmaceutical compounds as co-tracers for WWTP plume delineation. The present multi-tracer approach for groundwater resource vulnerability towards CECs allows a more in-depth understanding of contaminant transfer and their fate in groundwater.

Apportioning sources of chemicals of emerging concern along an urban river with inverse modelling.

Concentrations of chemicals in river water provide crucial information for assessing environmental exposure and risks from fertilisers, pesticides, heavy metals, illicit drugs, pathogens, pharmaceuticals, plastics and perfluorinated substances, among others. However, using concentrations measured along waterways (e.g., from grab samples) to identify sources of contaminants and understand their fate is complicated by mixing of chemicals downstream from diverse diffuse and point sources (e.g., agricultural runoff, wastewater treatment plants). To address this challenge, a novel inverse modelling approach is presented. Using waterway network topology, it quantifies locations and concentrations of contaminant sources upstream by inverting concentrations measured in water samples. It is computationally efficient and quantifies uncertainty. The approach is demonstrated for 13 contaminants of emerging concern (CECs) in an urban stream, the R. Wandle (London, UK). Mixing (the forward problem) was assumed to be conservative, and the location of sources and their concentrations were treated as unknowns to be identified. Calculated CEC source concentrations, which ranged from below detection limit (a few ng/L) up to 1µg/L, were used to predict concentrations of chemicals downstream. Using this approach, >90% of data were predicted within observational uncertainty. Principal component analysis of calculated source concentrations revealed signatures of two distinct chemical sources. First, pharmaceuticals and insecticides were associated with a subcatchment containing a known point source of treated effluent from a wastewater treatment plant. Second, illicit drugs and salicylic acid were associated with multiple sources, interpreted as input from untreated sewage including Combined Sewer Overflows (CSOs), misconnections, runoff and direct disposal throughout the catchment. Finally, a simple algorithmic approach that incorporates network topology was developed to design sampling campaigns to improve resolution of source apportionment. Inverse modelling of contaminant measurements can provide objective means to apportion sources in waterways from spot samples in catchments on a large scale.

Response of Microbial Communities to Naturally Occurring Radioactive Material-Contaminated Sediments: A Microcosm-Based Study.

There is a growing need to understand the potential ecological impacts of contaminants in offshore oil and gas infrastructure, especially if that infrastructure is to be left in situ as a decommissioning option. Naturally occurring radioactive material (NORM) is one type of contaminant found in solid deposits on internal surfaces of infrastructure that poses potential ecological harm if released into the marine environment. Microbes are important components of marine sediment ecosystems because they provide ecosystem services, yet the impacts of NORM contamination to these communities are not well understood. The present study aimed to investigate the response of benthic microbial communities to NORM-contaminated scale, collected from an offshore oil and gas system, via controlled laboratory microcosm studies. Changes to microbial communities in natural sediment and sediments spiked with NORM at radium-226 activity concentrations ranging from 9.5 to 59.8 Bq/kg (in partial equilibria with progeny) over 7 and 28 days were investigated using high-throughput sequencing of environmental DNA extracted from experimental sediments. There were no significant differences in microbial community composition between control and scale-spiked sediments over 7 and 28 days. However, we observed a greater presence of Firmicutes in the scale-mixed treatment and Chloroflexi in the scale-surface treatments after 28 days. This could suggest selection for species with contaminant tolerance or potential resilience to radiation and metal toxicity. Further research is needed to explore microbial tolerance mechanisms and their potential as indicators of effects of radionuclide-contaminated sediments. The present study demonstrated that microcosm studies can provide valuable insights about the potential impacts of contamination from oil and gas infrastructure to sediment microbial communities. Environ Toxicol Chem 2024;43:1648-1661. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.