Fate Of Pharmaceuticals Research Articles

Predicting pharmaceutical concentrations and assessing risks in the aquatic environment using PERK: A case study of a catchment area in South-West England

The aim of this study was to introduce a model to predict pharmaceuticals concentrations in the aquatic environment and their environmental impacts using the Risk Quotient (RQ) approach. The model was trained using: (i) high resolution dataset on pharmaceuticals’ concentration in wastewater and receiving environment in a river catchment, (ii) understanding of pharmaceuticals’ discharge points in the catchment, (iii) fate of pharmaceuticals during wastewater treatment and in the receiving environment, (iv) high resolution per-postcode pharmaceutical prescription data. A total of 41 pharmaceuticals were evaluated, with successful predictions achieved for concentrations falling within the range of 0.7 (influent: 37 %, effluent: 39 %, river: 29 %) to 1 % (influent: 56 %, effluent: 58 %, river: 48 %) of the measured values. Importantly, our risk assessment demonstrates significant environmental risks associated with specific pharmaceuticals, with strong alignment (86 %) between assessments based on predicted and measured data, underscoring the reliability of our model in assessing environmental risks. The observed variability in predicted and measured concentrations underscores the necessity for ongoing model refinement, particularly in regions with notable discrepancies such as wastewater treatment plant (WWTP) C. Overall, our study illustrates the intricate dynamics of pharmaceutical contamination in aquatic ecosystems, emphasizing the crucial need for continued research in this field.

Differential tissue distribution of pharmaceuticals in a wild subtropical marine fish

To date, the presence of pharmaceuticals has been extensively documented across a wide range of aquatic systems and biota. Further, substantial progress has been made in transitioning from laboratory assessments of pharmaceutical fate and effects in fish to in situ assessments of exposure and effects; however, certain research areas remain understudied. Among these is investigation of differential accumulation across multiple internal tissues in wild marine fish beyond the species commonly sampled in laboratory and freshwater field settings. This study examined the presence of pharmaceuticals across four tissues (plasma, muscle, brain, and liver) in a wild marine fish, bonefish (Albula vulpes), throughout coastal South Florida, USA. Differential accumulation across tissues was assessed for the number and concentration, identity, and composition of accumulated pharmaceuticals by sampling 25 bonefish and analyzing them for 91 pharmaceuticals. The concentration of pharmaceuticals was highest in plasma > liver > brain > muscle, while the number of pharmaceuticals was highest in liver > brain > plasma > muscle. The identity of detected pharmaceuticals was tissue specific, and there was an inverse relationship between the number of detections for each pharmaceutical and its log Kow. The composition of pharmaceuticals was tissue specific for both pharmaceutical presence/absence and concentration. Across all tissues, the greatest similarity was between brain and liver, which were more similar to plasma than to muscle, and muscle was the most distinct tissue. For tissue compositional variability, muscle was the most diverse in accumulated pharmaceuticals, while plasma, brain, and liver were similarly variable. With the highest concentrations in plasma and highest number in liver, and documented variability in accumulated pharmaceuticals across tissues, our results highlight the importance of tissue selection when surveying exposure in wild fish, suggesting that multi-tissue analysis would allow for a more comprehensive assessment of exposure diversity and risk of adverse effects.

The fate of pharmaceuticals and personal care products (PPCPs) in sewer sediments:Adsorption triggering resistance gene proliferation

In recent years, large quantities of pharmaceuticals and personal care products (PPCPs) have been discharged into sewers, while the mechanisms of PPCPs enrichment in sewer sediments have rarely been revealed. In this study, three PPCPs (tetracycline, sulfamethoxazole, and triclocarban) were added consecutively over a 90-day experimental period to reveal the mechanisms of PPCPs enrichment and the transmission of resistance genes in sewer sediments. The results showed that tetracycline (TC) and triclocarban (TCC) have higher adsorption concentration in sediments compared to sulfamethoxazole (SMX). The absolute abundance of Tets and suls genes increased in sediments under PPCPs pressure. The increase in secretion of extracellular polymeric substances (EPS) and the loosening of the structure exposed a large number of hydrophobic functional groups, which promoted the adsorption of PPCPs. The absolute abundance of antibiotic resistance genes (ARGs), EPS and the content of PPCPs in sediments exhibited significant correlations. The enrichment of PPCPs in sediments was attributed to the accumulation of EPS, which led to the proliferation of ARGs. These findings contributed to further understanding of the fate of PPCPs in sewer sediments and opened a new perspective for consideration of controlling the proliferation of resistance genes.

Occurrence and fate of pharmaceuticals and personal care products in a wastewater treatment plant with Bacillus bio-reactor treatment

Pharmaceuticals and personal care products (PPCPs) have attracted wide attention due to their environmental impacts and health risks. PPCPs released through wastewater treatment plants (WWTPs) are estimated to be 80 %. Nevertheless, the occurrence of PPCPs in the WWTPs equipped with Bacillus spec.-based bioreactors (BBR) treatment system remains unclear. In this study, sludge and waste water samples were collected during separate winter and summer sampling campaigns from a typical BBR treatment system. The results indicate that out of 58 target PPCPs, 27 compounds were detected in the waste water (0.06–1900 ng/L), and 23 were found in the sludge (0.6–7755 ng/g dw). Paraxanthine was the chemical of the highest abundance in the influent due to the high consumption of the parent compounds caffeine and theobromine. The profile for PPCPs in the wastewater and sludge exhibited no seasonal variation. Overall, the removal of target PPCPs in summer is more effective than the winter. In the BBR bio-reactor, it was found that selected PPCPs (at ng/L level) can be completely removed. The efficiency for individual PPCP removal was increased from 1.0 % to 50 % in this unit, after target specific adjustments of the process. The effective removal of selected PPCPs by the BBR treatment system is explained by combined sorption and biodegradation processing. The re-occurrence of PPCPs in the wastewater was monitored. Negative removal efficiency was explained by the cleavage of Phase II metabolites after the biotransformation process, and the lack of equilibrium for PPCPs in the sludge of the second clarifier. A compound specific risk quotient (RQ) was calculated and applied for studying the potential environmental risks. Diphenhydramine is found with the highest environmental risk in wastewater, and 15 other PPCPs show negligible risks in sewage sludge.

Fate of pharmaceuticals and personal care products like metronidazole, naproxen, and methylparaben and their effect on the physiological characteristics of two wetland plants

Plants play a vital role in the phytoremediation process, attenuating various pollutants. However, the dynamic root uptake and fate of emerging pollutants in plants, along with their effects on plant characteristics, have received limited research attention. This study explores the potential of Chrysopogon zizanioides (Vetiver) and Colocasia esculenta (Taro) in mitigating pharmaceutical and personal care products (PPCPs) - metronidazole (MNZ), naproxen (NAP), and methylparaben (MeP), under hydroponic conditions. Both plants demonstrated similar specific uptake potentials for the target pollutants (5.23 to 5.76 mg/g of biomass dry weight), with pollutant accumulation in plants remaining very low (<10 %). Notably, a substantial fraction of pollutants (66.27 % to 78.42 %) underwent metabolism. Qualitative analysis identified five MNZ and NAP metabolites and six MeP metabolites in plant tissues. Over a 28-day PPCPs exposure, accumulation of reactive oxygen species (ROS) resulted in reduced chlorophyll content, root activity, protein, and carbohydrates, alongside increased oxidative stress levels. The study highlighted distinct accumulation patterns, with NAP (anion) primarily in roots and MeP (cation) and MNZ (neutral) predominantly in aerial parts. Phloroglucinol staining confirmed the intact endodermis (Casparian Strips) in Vetiver roots, indicating symplastic transport of PPCPs to aerial parts. Moreover, significant morphological alterations were observed in plant roots exposed to target pollutants. During recuperation, a decrease in accumulated ROS indicates partial self-recovery from oxidative damage. In conclusion, both Vetiver and Taro emerge as promising candidates for removing specified PPCPs, emphasizing the critical role of addressing emerging contaminants for sustainable development and preserving the environment and human wellbeing.

Fate of pharmaceuticals in the Ebro River Delta region: The combined evaluation of water, sediment, plastic litter, and biomonitoring

The increasing consumption of pharmaceuticals, alongside their limited removal in wastewater treatment plants (WWTPs), have led to their ubiquitous occurrence in receiving aquatic environments. This study addresses the occurrence of 68 pharmaceuticals (PhACs) in the Ebro River Delta region (NE Spain), as well as their distribution in different environmental compartments, including surface water, sediments, biota (river biofilm and fish tissues), and field-collected plastic litter. In addition, their concentrations in serving WWTPs, as possible sources of environmental contamination, were also determined.Our study confirmed the widespread occurrence of PhACs in riverine and, to a more limited extent, coastal environments. Most frequently detected PhACs belonged to analgesics/anti-inflammatories (e.g., ibuprofen) and psychiatric drugs (e.g., venlafaxine) therapeutic groups, followed by antihypertensives (e.g., valsartan) and antibiotics (e.g., azithromycin). Seasonal differences in cumulative levels of PhACs were reported for water and sediments (winter>summer). Despite spatial gradients were not clear along the river, a non-negligible contribution of upstream Ebro sites (reference area) was highlighted, which was unexpected based on the low anthropogenic pressure. Sediments represented a minor attenuation pathway for the selected PhACs, whereas they were more heavily accumulated in biota: fish liver (up to 166 ng/g dw), river biofilms (up to 108 ng/g dw), fish plasma (up to 63 ng/mL), and fish muscle (up to 31 ng/g dw).These findings highlight the importance of biomonitoring in the characterization of polluted areas and prioritization of hazardous substances (e.g., psychiatric drugs) in aquatic systems, and a particular interest of fish plasma as non-destructive biomonitoring matrix. PhACs were also detected on plastic litter, demonstrating their role as environmental sinks for certain PhACs (e.g., analgesics/anti-inflammatories, psychiatric drugs). Overall, the widespread detection of PhACs in a variety of biotic and abiotic matrices from the lower Ebro River and Delta warns about their possible environmental implications.

Role of Soil Biofilms in Clogging and Fate of Pharmaceuticals: A Laboratory-Scale Column Experiment.

Contamination of groundwater with pharmaceutical active compounds (PhACs) increased over the last decades. Potential pathways of PhACs to groundwater include techniques such as irrigation, managed aquifer recharge, or bank filtration as well as natural processes such as losing streams of PhACs-loaded source waters. Usually, these systems are characterized by redox-active zones, where microorganisms grow and become immobilized by the formation of biofilms, structures that colonize the pore space and decrease the infiltration capacities, a phenomenon known as bioclogging. The goal of this work is to gain a deeper understanding of the influence of soil biofilms on hydraulic conductivity reduction and the fate of PhACs in the subsurface. For this purpose, we selected three PhACs with different physicochemical properties (carbamazepine, diclofenac, and metoprolol) and performed batch and column experiments using a natural soil, as it is and with the organic matter removed, under different biological conditions. We observed enhanced sorption and biodegradation for all PhACs in the system with higher biological activity. Bioclogging was more prevalent in the absence of organic matter. Our results differ from works using artificial porous media and thus reveal the importance of utilizing natural soils with organic matter in studies designed to assess the role of soil biofilms in bioclogging and the fate of PhACs in soils.

Occurrence, environmental impact and fate of pharmaceuticals in groundwater and surface water: a critical review.

In many nations and locations, groundwater serves as the population's primary drinking water supply. However, pharmaceuticals found in groundwater and surface waters may affect aquatic ecosystems and public health. As a result, their existence in natural raw waters are now more widely acknowledged as a concern. This review summarises the evidence of research on pharmaceuticals' occurrence, impact and fate, considering results from different water bodies. Also, various analytical techniques were reviewed to compare different pharmaceuticals' detection frequencies in water bodies. These include liquid chromatography-mass spectrometry (LC-MS), high-performance liquid chromatography (HPLC), ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and gas chromatography-mass spectrometry (GC-MS). However, owing to LC-MS's high sensitivity and specification, it is the most reported instrument used for analysis. The PRISMA reviewing methodology was adopted based on relevant literature in order to focus on aim of the review. Among other pharmaceuticals reviewed, sulfamethoxazole was found to be the most frequently detected drug in wastewater (up to 100% detection frequency). The most reported pharmaceutical group in this review is antibiotics, with sulfamethoxazole having the highest concentration among the analysed pharmaceuticals in groundwater and freshwater (up to 5600ng/L). Despite extensive study and analysis on the occurrence and fate of pharmaceuticals in the environment, appropriate wastewater management and disposal of pharmaceuticals in the water environment are not still monitored regularly. Therefore, there is a need for mainstream studies tailored to the surveillance of pharmaceuticals in water bodies to limit environmental risks to human and aquatic habitats in both mid and low-income nations.

Combined use of strictly anaerobic MBBR and aerobic MBR for municipal wastewater treatment and removal of pharmaceuticals

An integrated lab-scale wastewater treatment system consisting of an anaerobic Moving Bed Biofilm Reactor (AnMBBR) and an aerobic Membrane Bioreactor (AeMBR) in series was used to study the removal and fate of pharmaceuticals during wastewater treatment. Continuous-flow experiments were conducted applying different temperatures to the AnMBBR (Phase A: 35 °C; Phase B: 20 °C), while batch experiments were performed for calculating sorption and biotransformation kinetics. The total removal of major pollutants and target pharmaceuticals was not affected by the temperature of the AnMBBR. In Phase A, the average removal of dissolved chemical oxygen demand (COD), biological oxygen demand (BOD), and ammonium nitrogen (NH4–N) was 86%, 91% and 96% while in Phase B, 91%, 96% and 96%, respectively. Removal efficiencies ranging between 65% and 100% were observed for metronidazole (MTZ), trimethoprim (TMP), sulfamethoxazole (SMX), and valsartan (VAL), while slight (<30%) or no removal was observed for carbamazepine (CBZ) and diclofenac (DCF), respectively. Application of a mass balance model showed that the predominant mechanism for the removal of pharmaceuticals was biotransformation, while the role of sorption was of minor importance. The AeMBR was critical for VAL, SMX and TMP biodegradation; the elimination of MTZ was strongly enhanced by the AnMBBR. In both bioreactors, Bacteroidetes was the dominant phylum in both bioreactors over time. In the AnMBBR, Cloacibacterium and Bacteroides had a higher abundance in the biocarriers compared to the suspended biomass.

MDM-Pred: a freely available web application for predicting the metabolism of drug-like compounds by the gut microbiota

ABSTRACT The human gut microbiota (HGM) comprises a complex population of microorganisms that significantly affect human health, including their influence on xenobiotics metabolism. Many pharmaceuticals are taken orally and thus come into contact with HGM, which can metabolize them. Therefore, it is necessary to evaluate the effect of HGM on the fate of pharmaceuticals in the organism. We have collected information about over 600 compounds from more than eighty publications. At least half of them (329 compounds) are known to be metabolized by HGM. We have used PASS (Prediction of Activity Spectra for Substances) software to build three classification SAR models for HGM-mediated drug metabolism prediction. The first model with an accuracy of prediction 0.85 estimates whether compounds will be metabolized by HGM. The second model with an average accuracy of prediction 0.92 estimates which bacterial genera are responsible for the drug metabolism. The third model with an average accuracy of prediction 0.92 estimates the biotransformation reactions during HGM-mediated drug metabolism. The created models were used to develop the freely available web application MDM-Pred (http://www.way2drug.com/mdm-pred/).

Bioaccumulation and fate of pharmaceuticals in a Mediterranean coastal lagoon: Temporal variation and impact of a flash flood event

Coastal ecosystems are particularly vulnerable to terrestrial inputs from human-impacted areas. The prevalence of wastewater treatment plants, unable to remove contaminants such as pharmaceuticals (PhACs), leads to their continuous input into the marine environment. In this paper, the seasonal occurrence of PhACs in a semi-confined coastal lagoon (the Mar Menor, south-eastern Spain) was studied during 2018 and 2019 by evaluating their presence in seawater and sediments, and their bioaccumulation in aquatic organisms. Temporal variation in the contamination levels was evaluated by comparison to a previous study carried out between 2010 and 2011 before the cessation of permanent discharges of treated wastewater into the lagoon. The impact of a flash flood event (September 2019) on PhACs pollution was also assessed. A total of seven compounds (out of 69 PhACs analysed) were found in seawater during 2018–2019, with a limited detection frequency (<33%) and concentrations (up to 11 ng/L of clarithromycin). Only carbamazepine was found in sediments (ND–1.2 ng/g dw), suggesting an improved environmental quality in comparison to 2010–2011 (when 24 and 13 compounds were detected in seawater and sediments, respectively). However, the biomonitoring of fish and molluscs showed a still remarkable accumulation of analgesic/anti-inflammatory drugs, lipid regulators, psychiatric drugs and β-blocking agents, albeit not higher than in 2010. The flash flood event from 2019 increased the prevalence of PhACs in the lagoon, compared to the 2018–2019 sampling campaigns, especially in the upper water layer. After the flash flood the antibiotics clarithromycin and sulfapyridine yielded the highest concentrations ever reported in the lagoon (297 and 145 ng/L, respectively), alongside azithromycin in 2011 (155 ng/L). Flash flood events associated with sewer overflows and soil mobilisation, which are expected to increase under climate change scenarios, should be considered when assessing the risks posed by pharmaceuticals to vulnerable aquatic ecosystems in the coastal areas.

Environmental degradation of human metabolites of cyclophosphamide leads to toxic and non-biodegradable transformation products

The present study assessed the ready biodegradability of the prodrug cyclophosphamide (CPA) and its stable human metabolites in the closed bottle test (CBT). The results of the CBT showed that only the main human metabolite, carboxyphosphamide (CXP), was biodegradable to a certain extent (23 ± 2.4 % ThODNH3). All other metabolites showed neither biodegradation under these conditions nor were any toxic effects on the inoculum observed. Yet, HRMSn results revealed partial primary elimination of all human metabolites and formation of 25 new transformation products. Abiotic degradation via SNi and SN2 reactions was proposed as the main degradation pathway during the CBT. The main degradation products were assigned as 3-(2-chloroethyl)oxazolidin-2-one (COAZ), cytotoxic N-2-chloroethylaziridine (CEZ) and nor‑nitrogen mustard (NNM), an analogue of the chemical warfare agent HN2. While the acute ecotoxicity of the detected products is widely unknown, many have already been reported in medical literature to be either mutagenic, genotoxic, cytotoxic or carcinogenic and may therefore cause a greater risk than their precursors. QSAR models predicted that 16 of them are mutagenic and genotoxic, thus classifying the majority of the chemicals as potential environmental hazards. The central intermediates during the degradation process were proposed as CEZ and its corresponding aziridinium ion. However, other degradation products may occur depending on the type and strength of nucleophiles present in the matrices. Overall, the results demonstrated the importance to include human metabolites in the evaluation of the environmental fate of pharmaceuticals and their risk assessment especially when investigating prodrugs. The results underline the importance of identifying possible degradation products of metabolites, as they can be more toxic than related parent compounds and metabolites and can cause a greater risk to the environment and humans.

Transformation and fate of pharmaceuticals, personal care products, and per- and polyfluoroalkyl substances during aerobic digestion of anaerobically digested sludge

Post-anaerobic aerobic digestion (PAAD) is a promising strategy to further reduce the volume and improve the quality of anaerobically digested sludge (ADS). However, the effect of PAAD process on the fate of pharmaceuticals and personal care products (PPCPs) and per- and polyfluoroalkyl substances (PFAS) remains largely unknown. In this study, fourteen PPCPs and fifteen PFAS were detected in ADS and evaluated regarding their fate and transformation in a laboratory aerobic digester operated with a hydraulic retention time of 13 days under 22 ℃. Twelve PPCPs demonstrated significant (p < 0.05) decrease in their total concentrations (dissolved and adsorbed fractions combined) with six compounds presenting substantial transformation (> 80%) after aerobic digestion. On the contrary, PFAS were not removed and their concentrations were either increased (increasing ratio: 91 – 571%) or consistent in the sludge during PAAD process, suggesting their recalcitrance to post aerobic digestion. More than half of PPCPs and PFAS demonstrated medium to strong sorption onto solids with their solid fraction higher than 50% in the ADS. After PAAD process, sorption of four PPCPs and three PFAAs to solids was enhanced in sludge.

Anxiety in Duckweed–Metabolism and Effect of Diazepam on Lemna minor

The fate of pharmaceuticals in the human body, from their absorption to excretion is well studied. However, medication often leaves the patient’s body in an unchanged or metabolised, yet still active, form. Diazepam and its metabolites, ranging up to 100 µg/L, have been detected in surface waters worldwide; therefore, the question of its influence on model aquatic plants, such as duckweed (Lemna minor), needs to be addressed. Lemna was cultivated in a Steinberg medium containing diazepam in three concentrations—0.2, 20, and 2000 µg/L. The activity of superoxide dismutase (SOD) and catalase (CAT), leaf count, mass, and the fluorescence quantum yield of photosynthesis were assessed. The medium was also analysed by LC-MS/MS to determine the concentration of diazepam metabolites. Our results show no negative impact of diazepam on Lemna minor, even in concentrations significantly higher than those that are ecotoxicologically relevant. On the contrary, the influence of diazepam on Lemna suggests growth stimulation and a similarity to the effect diazepam has on the human body. The comparison to the human body may be accurate because γ-Aminobutyric acid-like (GABA-like) receptors responsible for the effect in humans have also been recently described in plants. Therefore, our results can open an interesting scientific area, indicating that GABA receptors and interference with benzodiazepines are evolutionarily much older than previously anticipated. This could help to answer more questions related to the reaction of aquatic organisms to micropollutants such as psychopharmaceuticals.

Marine bacteria-mediated abiotic-biotic coupling degradation mechanism of ibuprofen

Knowledge on the behavior and fate of pharmaceuticals and personal care products (PPCPs) is poorly explored in marine aphotic environment. In this study, the degradation mechanism of a typical PPCPs—ibuprofen (IBP) by a ubiquitous marine Pseudoalteromonas sp. was investigated based on transcriptome and key enzymes analysis. More importantly, a novel enzymatic-nonenzymatic coupling degradation mechanism was uncovered for the first time, namely, the degradation of IBP was firstly initiated by extracellular reactive oxygen species (ROS), then the intermediate (e.g.4-ethylresorcinol) was further degraded by intracellular enzymes. It was showed that biogenic •OH, O2•−and H2O2 were responsible for extracellular nonenzymatic degradation, in which IBP was degraded to 4-ethylresorcinol through hydrogenation, isobutyl moiety cleavage, oxidation and decarboxylation. 4-Hydroxyphenylpyruvate dioxygenase, homogentisate 1,2-dioxygenase, long-chain acyl-CoA synthetase, acetyl-CoA acyltransferase and enoyl-CoA hydratase were identified to be involved in intracellular degradation, leading 4-ethylresorcinol cracked and eventually mineralized. Ultimately, this novel degradation mechanism was demonstrated to be amino acids-driven through KEGG enrichment analysis and experimental data. Overall, our work uncovered a yet undiscovered abiotic-biotic coupling degradation mechanism in PPCPs biotransformation, thereby updating the conventional concept that contaminants transformation is solely accomplished by enzymes or non-enzymes, which can also provide new insights into PPCPs environmental behavior and fate.

Fate of pharmaceuticals and PFASs during the electrochemical generation of a nitrogen-rich nutrient product from real reject water

Recycling vital macronutrients, such as nitrogen, from wastewaters back to fertiliser use is becoming essential to ensure sustainable agricultural practices. Technologies developed for such purposes are typically evaluated for their capacity to recover nutrients; however, the presence of contaminants of emerging concern (CECs) in these waste-derived nutrient products must not be overlooked. In this study, nitrogen was recovered from real anaerobically digested municipal sewage sludge reject water using a novel set-up combining membrane-based electroconcentration (EC) with electrochemical advanced oxidation processes (EAOPs). Simultaneously, the fate of five spiked pharmaceuticals (carbamazepine, ciprofloxacin, diclofenac, erythromycin and metoprolol) as well as ten indigenous perfluoroalkyl substances (PFASs) was investigated. The EC-EAOP system was effective in up-concentrating nitrogen ca. 13 times to a final concentration of 12.7 ± 0.8 g L−1 in the nutrient product. At the same time, no up-concentration was observed for the pharmaceuticals and their concentrations in the recovered concentrated remained at ≤ 3.4 ± 1.3 µg L−1. The EAOPs were the main transformation mechanism for all the pharmaceuticals at 33–88% efficiency, while diclofenac also notably adsorbed in the system (30 ± 1.4%). Out of the ten studied PFASs, only three were found in the recovered nutrient concentrate, albeit at very limited concentrations of ≤ 0.024 ± 0.013 µg L−1. The EAOPs were found to degrade longer-chain PFASs into their shorter-chain counterparts. The low contaminant concentrations in the nutrient product pose a reduced risk for soil contamination compared to, e.g., biosolids that are more typically used as fertilisers.

Influence of Conjugation on the Fate of Pharmaceuticals and Hormones in Canadian Wastewater Treatment Plants

Influence of Conjugation on the Fate of Pharmaceuticals and Hormones in Canadian Wastewater Treatment Plants

Target and Suspect Screening of Pharmaceuticals and their Transformation Products in the Klip River, South Africa, using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry.

In spite of recent reports about the presence of pharmaceuticals in African water bodies, their prevalence has still not been sufficiently quantified. The few available studies have mostly focused on a limited number of pharmaceuticals. In the present study, a suspect screening of 92 compounds (mainly pharmaceuticals and their transformation products) along the Klip River, South Africa was conducted, followed by target monitoring of 21 of the detected pharmaceuticals. The experimental approach was based on solid-phase extraction followed by analysis with ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS). The results revealed 47 pharmaceuticals, 31 of which were detected for the first time in South African waters. Seven detected pharmaceuticals (propyphenazole, sulfamerazine, levamisole, tryptophan, dibucaine, albuterol, and fenpropimorph) are not approved medications in South Africa. Six pharmaceutical metabolites were detected for the first time in South Africa. Pharmaceuticals with the highest concentrations in river water were flumequine (0.257 µg L-1 ), oxolinic acid (0.355 µg L-1 ), and acetaminophen (0.432 µg L-1 ). Oxolinic acid presented the highest hazard quotient, 48.6, indicating a risk of toxicity to aquatic organisms. Hazard quotients for other pharmaceuticals were below 1, except that of flumequine, which reached 1.285. These results suggest a need for further research into the fate of pharmaceuticals in surface waters, and a quantification of the risks associated with the identified drugs because they are likely to accumulate in the tissues of fish/aquatic organisms, thus affecting humans. Environ Toxicol Chem 2022;41:437-447. © 2021 SETAC.

Fate evaluation of pharmaceuticals in solid and liquid phases at biological process of full-scale municipal wastewater treatment plants

In the last few decades, pharmaceuticals have saved millions of lives. However, their overconsumption is causing several negative impacts on human and wildlife endocrine systems. To date, numerous studies have investigated the occurrence and fate of pharmaceutical in municipal wastewater treatment plants (WWTPs). However, efforts to understand the removal mechanism of pharmaceuticals in WWTPs by simultaneously investigating pharmaceuticals in liquid and solid phases are limited. In this study, a simultaneous assessment of pharmaceuticals in liquid and solid phases was performed using samples collected from biological processes of three municipal WWTPs that adopted different treatment configurations. Among the three WWTPs, noticeable mitigation of macrolide antibiotics was observed in WWTP_A, which adopted membrane bioreactor. 12 pharmaceuticals, which showed positive removal in all sampling campaigns, were selected to evaluate the removal mechanism. The removal of acetylsalicylic acid, ciprofloxacin, ibuprofen, and ofloxacin by sorption in each WWTP seems to be acceptable as per the calculated sorption coefficient (Kd) value and qualitative detection. However, it is inadequate to only evaluate using the Kd values of acetaminophen, caffeine, and cefradine of WWTP_B owing to their lower qualitative detection in the solid phase. Interestingly, the calculated biodegradation constant value of ciprofloxacin (0.41–5.07 L/gMLSS·d) (mitigation pathway of electrostatic interaction) in the anaerobic reactor of WWTP_A was similar to that of caffeine (0.84–5.20 L/gMLSS·d) indicating a high biodegradability in wastewater treatment. Therefore, the simultaneous analysis of both liquid and solid phases provides valuable information for the detailed evaluation of the fate of pharmaceuticals in biological processes of municipal WWTPs.

Fate of Pharmaceuticals in a Submerged Membrane Bioreactor Treating Hospital Wastewater

The fate of 12 pharmaceutical pollutants was investigated to understand their removal mechanism during hospital wastewater (HWW) treatment in submerged membrane bioreactor (SMBR). High concentrations of anti-depressant (venlafaxine and desvenlafaxine), analgesic (ibuprofen and hydroxy-ibuprofen), and caffeine were detected in the HWW during the entire study period. The SMBR showed high removal &amp;gt;70% of antibiotics (sulfamethoxazole and clarithromycin), beta-blocker (acebutolol), hormone (estrone), and caffeine via biodegradation. The partial degradation of diclofenac, venlafaxine, and desvenlafaxine in SMBR indicates the growth promoter or agent requirement, which could facilitate the metabolism and co-metabolism of these pharmaceuticals by microorganisms. The study demonstrated that the major removal mechanism of pharmaceuticals in SMBR at optimized treatment conditions was biodegradation for the majority of examined pharmaceuticals. The assessment of SMBR performance at the low temperature of 15 and 10°C resulted in the drop of biodegradation efficiency of SMBR, affecting overall pharmaceuticals removal.