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The use of reclaimed water from wastewater treatment plants for irrigation has a risk of introducing micropollutants such as microplastics (MPs) and antimicrobials (AMs) into the agroecosystem. This study was conducted to investigate the effects of single and combined treatment of 0.1 % polyamide (PA ∼15 μm), and varying sulfamethoxazole (SMX) levels 0, 10, 50, and 150 mg/L on rice seedlings (Oryza sativa L.) for 12 days. The study aimed to assess the impact of these contaminants on the morphological, physiological, and biochemical parameters of the rice plants. The findings revealed that rice seedlings were not sensitive to PA alone. However, SMX alone or in combination with PA, significantly inhibited shoot and root growth, total biomass, and affected photosynthetic pigments. Higher concentrations of SMX increased antioxidant enzyme activity, indicating oxidative stress. The roots had a higher SMX content than the shoots, and the concentration of minerals such as iron, copper, and magnesium were reduced in roots treated with SMX. RNA-seq analysis showed changes in the expression of genes related to stress, metabolism, and transport in response to the micropollutants. Overall, this study provides valuable insights on the combined impacts of MPs and AMs on food crops, the environment, and human health in future risk assessments and management strategies in using reclaimed water., Competing Interests: Declaration of competing interest All the authors declare that there is no conflict of interest., (Copyright © 2024. Published by Elsevier B.V.)

The increasing use of antibiotics has attracted widespread attention to their environmental risks. However, the phototoxicity of sulfonamide antibiotics to plants remain unclear. In this study, the mechanism of the effect of sulfamethoxazole on photosynthesis of pakchoi cabbage (Brassica rapa var. chinensis) was investigated. The results showed that sulfamethoxazole inhibited the growth of pakchoi cabbage and produced photosynthetic toxicity. The growth inhibition rates increased with concentration, the root and shoot weight were 76.02 % and 47.04 % of the control, respectively, with stay-greens phenomenon in 4 mg·L -1 sulfamethoxazole treatment. Chlorophyll precursors (protoporphyrin IX (Proto IX), Mg-proto IX, and protochlorophyllide (Pchlide), 5-aminolevulinic acid (ALA), and porphobilinogen (PBG)) were 1.38-, 1.26-, 1.12-, 1.71-, and 0.96-fold of the control, respectively; photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoids) were 1.26-, 1.39-, and 1.03-fold of the control, respectively. Respiration rate was 271.42 % of the control, whereas the net photosynthetic rate was 50.50 % of the control. The maximum photochemical quantum yield of PSII (F v /F m ), the actual photosynthetic efficiency (Y(II)), the quantum yield of non-regulated energy dissipation (Y(NO)), the apparent electron transfer efficiency of PSII (ETR) under actual light intensity were affected, and chloroplast swelling was observed. Proteomic analysis showed that photosynthesis-related pathways were significantly up-regulated, biological processes such as light response, carbohydrates, and reactive oxygen species were activated. Metabolomic analysis revealed that the tricarboxylic acid cycle (TCA cycle) and carbohydrate catabolism were stimulated significantly (p < 0.05), sugars and amino acids were increased to regulate and enhance the resilience of photosynthesis. While folate biosynthesis and ribosomal pathways were significantly down-regulated, the synthesis and translation processes of amino acids and nucleotides were inhibited., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Microplastics and antibiotics are emerging contaminants in agricultural soil that can have negative effects on crops. However, limited research has been conducted on the effects of the polypropylene (PP) microplastic and sulfamethoxazole (SMX) co-exposure on crops, specifically regarding the impact of PP microplastics on SMX uptake and transport in crops. In this study, hydroponic experiments were carried out using lettuce (Lactuca sativa L.), PP microplastics (1.0 g L -1 ), and SMX (0.5 mg L -1 or 2.5 mg L -1 ) to investigate the individual and co-exposure effects of PP microplastics and SMX on Lettuce growth, explore the uptake and translocation of SMX in lettuce and elucidate the underlying mechanism of PP microplastic impact on SMX uptake. Results demonstrated that co-exposure to 1.0 g L -1 of PP microplastics and 0.5 mg L -1 of SMX resulted in an enhanced toxic effect. However, no intensified toxic effect on the lettuce was observed when 1.0 g L -1 PP microplastics were added in the presence of 2.5 mg L -1 SMX, indicating that the SMX dominated the toxic effect on lettuce at high concentrations. Additionally, the study found that the water absorption process controlled by the aquaporin and transpiration contributed to the uptake and translocation of SMX in lettuce. When exposed to PP microplastics, no impact was observed on the aquaporin contents of the lettuce while the transpiration rate was significantly decreased by 31.6 % - 44.2 % resulting from microplastics adhered to the root surface. Therefore, in the presence of 2.5 mg L -1 SMX, the SMX uptake in the lettuce root was inhibited by 35.9 % (P < 0.05) when exposed to 1.0 g L -1 PP microplastic. This work deepens our understanding of the behaviour of microplastics and antibiotics in the terrestrial environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The escalating occurrence of the antibiotic Sulfamethoxazole (SMX) in the environment presents a significant global threat to ecological systems and human health. Despite the growing interest in using microalgae for antibiotic biodegradation, strategies to enhance SMX elimination remain underexplored. In this study, we isolated a novel aggregation-algae consortium (AAC) from a municipal wastewater treatment plant (WWTP) and examined its potential for SMX removal, optimized culture conditions, SMX metabolite fate and the physicochemical impact on microalgal cells. The findings revealed that the AAC demonstrated remarkable resistance to SMX, even at concentrations as high as 10 mg/L, and could degrade SMX via free radical reactions. Although ion repulsion limited the biodegradation of AAC, the addition of peptone and yeast extract resulted in a significant enhancement, increased by 16.71%, 39.12% and 46.77% of three SMX groups. Moreover, AAC exhibited exceptional adaptability in real wastewater, achieving removal of 87.05%, 97.39% and 20.80% for total dissolved nitrogen, total dissolved phosphorus and SMX, respectively. The decreased degradation toxicity of SMX following AAC treatment was further validated by ECOSAR software and in vitro tests using Caenorhabditis elegans. This study advanced our understanding of SMX biodegradation and provided a novel approach for treating wastewater contaminated with SMX., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study developed a continuous reactor system employing a hybrid hydrogel composite synthesized using a complex sludge microbiome and an adsorbent (HSA). This HSA-based system effectively eliminated the environmental risks associated with a mixture of the antibiotics ciprofloxacin and sulfamethoxazole, which exhibited higher toxicity in combination than individually at environmentally relevant levels. Analytical chemistry experiments revealed the in-situ generation of various byproducts (BPs) within the bioreactor system, with two of these BPs recording toxicity levels that surpassed those of their parent compound. The HSA approach successfully prevented the functional microbiome from being washed out of the reactor, while HSA efficiently removed antibiotic residues in their original and BP forms through synergistic adsorptive and biotransformation mechanisms, ultimately reducing the overall ecotoxicity. The use of HSA thus demonstrates promise not only as a mean to reduce the threat posed by toxic antibiotic residues to aquatic ecosystems but also as a practical solution to operational challenges, such as biomass loss/washout, that are frequently encountered in various environmental bioprocesses., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study aimed to assess the ecological risks posed by sulfamethoxazole (SMX) at environmentally relevant concentrations. Specifically, its effects on the growth and biochemical components (total protein, total lipid, and total carbohydrate) of two marine microalgae species, namely Skeletonema costatum (S. costatum) and Phaeodactylum tricornutum (P. tricornutum), were investigated. Our findings revealed that concentrations of SMX below 150 ng/L stimulated the growth of both microalgae. Conversely, at higher concentrations, SMX inhibited their growth while promoting the synthesis of photosynthetic pigments, total protein, total lipid, and total carbohydrate (P < 0.05). Transmission electron microscope (TEM) observations demonstrated significant alterations in the ultrastructure of algal cells exposed to SMX, including nuclear marginalization, increased chloroplast volume, and heightened vacuolation. In addition, when SMX was lower than 250 ng/L, there was no oxidative damage in two microalgae cells. However, when SMX was higher than 250 ng/L, the antioxidant defense system of algal cells was activated to varying degrees, and the level of malondialdehyde (MDA) increased, indicating that algae cells were damaged by oxidation. From the molecular level, environmental concentration of SMX can induce microalgae cells to produce more energy substances, but there are almost no other adverse effects, indicating that the low level of SMX at the actual exposure level was unlikely to threaten P. tricornutum, but a higher concentration can significantly reduce its genetic products, which can affect the changes of its cell structure and damage P. tricornutum to some extent. Therefore, environmental concentration of SMX still has certain potential risks to microalgae. These outcomes improved current understanding of the potential ecological risks associated with SMX in marine environments., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The ubiquitous presence of sulfonamides (SAs) in wastewater poses serious risks to human health and ecosystem safety. This study evaluated the performance of a falling film dielectric barrier discharge (DBD) system on the removal of five SAs, namely sulfamethoxazole (SMX), sulfisoxazole (SIZ), sulfathiazole (STZ), sulfadiazine (SDZ) and sulfamerazine (SMR). Removal efficiencies >99 % were observed for all target SAs within 30 min of treatment, with pseudo-first order rate constants varying between 0.17 and 0.27 min -1 . Superior removal efficiencies were achieved under acidic conditions compared to neutral and alkaline conditions. Using SMX as a model compound, mechanistic investigations revealed that the synergy of reactive oxygen species (ROS) and reactive nitrogen species (RNS) led to its efficient degradation, with peroxynitrites (ONOO - /ONOOH) and hydroxyl radical (OH) playing pivotal roles. SMX degradation pathways encompassing nitration/nitrosation, hydroxylation, deamination, CS and SN bond cleavage were proposed. The toxicity evaluation results demonstrated that the solution toxicity diminished following the plasma treatment under specific conditions. In particular, the solution treated with air or oxygen discharge enhanced the growth of wheat seedlings, suggesting the potential for reusing plasma-treated wastewater in agriculture. This study enhances our understanding of the underlying mechanisms involved in the plasma degradation of SAs and reveals the significant potential of plasma technology as a sustainable approach for treating wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Microplastics (MPs) and antibiotics often coexist in complex marine environments, yet their combined detrimental effects on marine organisms remain underexplored. This study evaluated the effects of polyethylene microplastics (PE, 200 μg/L) and sulfamethoxazole (SMX, 50 μg/L), both individually and in combination, on Mytilus galloprovincialis. The exposure lasted 6 days, followed by a 6-day recovery period. Bioaccumulation, DNA damage, pollutants transport/metabolism related responses and responding alterations of mitogen-activated protein kinase (MAPK) signaling pathway were detected in gills and digestive glands. Bioaccumulation of SMX/PE in mussels occurred in a tissue-specific manner, co-exposure altered SMX contents in investigated tissues. Co-exposure did not induce extra DNA damage, elevated DNA damage was alleviated during the recovery period in all treated groups. The exposure of SMX/PE exerted different alterations in pollutants transport/metabolism related responses, characterized by multixenobiotic resistance and relative expression of key genes (cytochrome P450 monooxygenase, glutathione S-transferase, ATP-binding cassette transporters). Key molecules (p38 MAPK, c-jun N-terminal kinase, extracellular regulated protein kinase, nuclear factor-κB and tumor protein p53) in MAPK signaling pathway were activated at transcriptional and translational levels after SMX/PE and co-exposure. Co-regulation between MAPK members and pollutants transport/metabolism related factors was revealed, suggesting MAPK signaling pathway served as a regulating hub in exposed mussels to conquer SMX/PE stress. Overall, this study provides new insights on SMX/PE induced health risks in marine mussels and potential mechanism through MAPK cascades regulation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Sulfamethoxazole (SMX) and trimethoprim (TRIM) are two of the most used antibiotics in the last 50 years, to prevent and treat bacterial infections; however, the available literature about toxicity to non-target organisms is quite discrepant and incomplete. This study aims to assess the SMX and TRIM ecotoxicological effects in standard species: Aliivibrio fischeri (bioluminescence inhibition), Escherichia coli ATCC 25922 (growth inhibition), Lemna minor (growth inhibition and biochemical biomarkers), Daphnia magna (immobilization/mortality, life history traits, and biochemical biomarkers), and Danio rerio (survival, hatching, abnormalities, and biochemical biomarkers). The species tested showed different acute sensitivities to SMX (A. fischeri < D. magna < E. coli < L. minor) and TRIM (L. minor < A. fischeri < D. magna < E. coli). Overall, TRIM reveals less toxicity than SMX, except for E. coli (Ecotoxicological approach based on Antimicrobial Susceptibility Testing - EcoAST procedure). Both antibiotics affect individually (e.g., growth and survival) and sub-individually (e.g., antioxidant defenses) L. minor, D. magna, and D. rerio. This study allowed us to generate relevant data and fill gaps in the literature regarding the effects of SMX and TRIM in aquatic organisms. The here-obtained results can be used to (i) complete and re-evaluate the Safety Data Sheet to improve the assessment of environmental safety and management of national and international entities; (ii) clarify the environmental risks of these antibiotics in aquatic ecosystems reinforcing the inclusion in the 4th Watch List of priority substances to be monitored in whole inland waters by the Water Framework Directive; and (iii) combat the development of antimicrobial resistance, as well as supporting the definition of environmental measurements in the context of European One Health Action Plan. However, it is essential to continue studying these antibiotics to better understand their toxicity at ecologically relevant concentrations and their long-term effects under different climatic change scenarios., (© 2024. The Author(s).)

Cadmium (Cd) and sulfamethoxazole (SMX) frequently coexist in farmlands, yet their synergistic toxicological impacts on terrestrial invertebrates remain unexplored. In this study, earthworms were exposed to artificial soils percolated with Cd (5 mg/kg), SMX (5 mg/kg) or combination of them for 7 days, followed by a 12-day elimination phase in uncontaminated soil. The uptake of Cd and SMX by the earthworms, along with their subcellular distribution, was meticulously analyzed. Additionally, a suite of biomarkers-including superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and weight loss-were evaluated to assess the health status of the earthworms and the toxicological effects of the Cd and SMX mixture. Notably, the cotreatment with Cd and SMX resulted in a significantly higher weight loss in Eisenia fetida (41.25 %) compared to exposure to Cd alone (26.84 %). Moreover, the cotreatment group exhibited substantially higher concentrations of Cd in the total internal body, fraction C (cytosol), and fraction E (tissue fragments and cell membranes) in Eisenia fetida compared to Cd alone counterparts. The combined exposure also significantly elevated the SMX levels in the total body and fraction C compared with the SMX-only treated earthworms. Additionally, Eisenia fetida subjected to the combined treatment showed markedly increased activities of SOD, CAT, and MDA compared to those treated with Cd alone. The effect addition indices (EAIs), ranging from 1.00 to 2.23, unequivocally demonstrated a synergistic effect of the combined treatments. Interestingly, relocating the earthworms to clean soil did not mitigate the observed adverse effects. These findings underscore the increased risk posed by the Cd-SMX complex to terrestrial invertebrates in agricultural areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sulfamethoxazole (SMZ) is a commonly used antibiotic in aquaculture, and its residues in water bodies pose a significant threat to aquatic organisms in the water environment. In the present study, epigallocatechin-3-gallate (EGCG), a catecholamine, was used to mitigate the immunotoxicity caused by SMZ exposure in Procambarus clarkii. EGCG reduced the apoptosis rate, which was elevated by SMZ exposure, and increased the total hemocyte count. Simultaneously, EGCG enhanced the activities of enzymes related to antibacterial and antioxidant activities, such as superoxide dismutase (SOD), catalase (CAT), lysozyme (LZM), acid phosphatase (ACP), and GSH, which were decreased following SMZ exposure. Hepatopancreatic histology confirmed that EGCG ameliorated SMZ-induced tissue damage caused by SMZ exposure. In addition to EGCG attenuating SMZ-induced immunotoxicity in crayfish, we determined that EGCG can effectively reduce SMZ residues in crayfish exposed to SMZ. In addition, at the genetic level, the expression levels of genes related to the immune response in hemocytes were disrupted after SMZ exposure, and EGCG promoted their recovery and stimulated an increase in the expression levels of metabolism-related transcripts in hemocytes. The transcriptome analysis was conducted, and "phagosome" and "apoptosis" pathways were shown to be highlighted using Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. To the best of our knowledge, this is the first study to confirm that EGCG attenuates SMZ-induced immunotoxicity in aquatic animals and reduces SMZ residues in aquatic animals exposed to SMZ. Our study contributes to the understanding of the mechanisms by which EGCG reduces the immunotoxicity of antibiotic residues in aquatic animals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The combined pollution of microplastics (MPs) and sulfamethoxazole (SMZ) often occurs in aquatic ecosystems, posing a serious threat to animal and human health. However, little is known about the liver damage caused by the single or co-exposure of MPs and SMZ, and its specific mechanisms are still poorly understood. In this study, we investigated the effects of co-exposure to 20 μm or 80 nm MPs and SMZ in both larval and adult zebrafish models. Firstly, we observed a significant decrease in the number of hepatocytes and the liver damage in larval zebrafish worsened following co-exposure to SMZ and MPs. Additionally, the number of macrophages and neutrophils decreased, while the expression of inflammatory cytokines and antioxidant enzyme activities increased after co-exposure in larval zebrafish. Transcriptome analysis revealed significant changes in gene expression in the co-exposed groups, particularly in processes related to oxidation-reduction, inflammatory response, and the MAPK signaling pathway in the liver of adult zebrafish. Co-exposure of SMZ and MPs also promoted hepatocyte apoptosis and inhibited proliferation levels, which was associated with the translocation of Nrf2 from the cytoplasm to the nucleus and an increase in protein levels of Nrf2 and NF-kB p65 in the adult zebrafish. Furthermore, our pharmacological experiments demonstrated that inhibiting ROS and blocking the MAPK signaling pathway partially rescued the liver injury induced by co-exposure both in larval and adult zebrafish. In conclusion, our findings suggest that co-exposure to SMZ and MPs induces hepatic dysfunction through the ROS-mediated MAPK signaling pathway in zebrafish. This information provides novel insights into the potential environmental risk of MPs and hazardous pollutants co-existence in aquatic ecosystems., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The increase in antibiotic residues poses a serious threat to ecological and aquatic environments, necessitating the development of cost-effective, convenient, and recyclable adsorbents. In our study, we used cellulose-based layered double hydroxide (LDH) as an efficient adsorbent and nanocarrier for both sulfamethoxazole (SMX) and cefixime (CFX) residues due to their biodegradability and biocompatibility. Chemical processes are measured according to green chemistry metrics to identify which features adhere to the principles. A GREEnness Assessment (ESA), Analytical GREEnness Preparation (AGREEprep), and Analytical Eco-Scale Assessments (ESA) were used to assess the suitability of the proposed analytical method. We extensively analyzed the synthesized CoFe LDH/cellulose before and after the adsorption processes using XRD, FTIR, and SEM. We investigated the factors affecting the adsorption process, such as pH, adsorbent dose, concentrations of SMX and CFX and time. We studied six nonlinear adsorption isotherm models at pH 5 using CoFe LDH, which showed maximum adsorption capacities (qmax) of 272.13 mg/g for SMX and 208.00 mg/g for CFX. Kinetic studies were also conducted. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was performed on Vero cells in direct contact with LDH nanocomposites to evaluate the cytotoxicity and side effects of cellulose-based CoFe LDH. The cellulose-based CoFe LDH nanocomposite demonstrated excellent cytocompatibility and less cytotoxic effects on the tested cell line. These results validate the potential use of these unique LDH-based cellulose cytocompatible biomaterials for water treatment applications. The cost of the prepared adsorbents was investigated., Competing Interests: Declaration of competing interest None of the authors have conflicts of interest to disclose., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study evaluated the impacts of sulfamethoxazole (SMX) on antioxidant, immune, histopathological dynamic changes, and gut microbiota of zebrafish. SMX was carried out five groups: 0 (C), 3 mg/L (T3), 6 mg/L (T6), 12 mg/L (T12), and 24 mg/L (T24), with 5 replicates per group for an 8-weeks chronic toxicity test. It was found that SMX is considered to have low toxicity to adult zebrafish. SMX with the concentration not higher than 24 mg/L has no obvious inhibitory effect on the growth of fish. Under different concentrations of SMX stress, oxidative damage and immune system disorder were caused to the liver and gill, with the 12 and 24 mg/L concentration being the most significant. At the same time, it also causes varying degrees of pathological changes in both intestinal and liver tissues. As the concentration of SMX increases, the composition and abundance of the gut microbiota in zebrafish significantly decrease., (© 2024. The Author(s).)

Sulfonamide antibiotics, extensively used in human and veterinary therapy, accumulate in agroecosystem soils through livestock manure and sewage irrigation. However, the interaction between sulfonamides and rice plants remains unclear. This study investigated the transformation behavior and toxicity of sulfamethoxazole (SMX) and its main metabolite, N4-acetyl-sulfamethoxazole (NASMX) in rice. SMX and NASMX were rapidly taken up by roots and translocated acropetally. NASMX showed higher accumulating capacity, with NASMX concentrations up to 20.36 ± 1.98 μg/g (roots) and 5.62 ± 1.17 μg/g (shoots), and with SMX concentrations up to 15.97 ± 2.53 μg/g (roots) and 3.22 ± 0.789 μg/g (shoots). A total of 18 intermediate transformation products of SMX were identified by nontarget screening using Orbitrap-HRMS, revealing pathways such as deamination, hydroxylation, acetylation, formylation, and glycosylation. Notably, NASMX transformed back into SMX in rice, a novel finding. Transcriptomic analysis highlights the involvements of cytochrome P450 (CYP450), acetyltransferase (ACEs) and glycosyltransferases (GTs) in these biotransformation pathways. Moreover, exposure to SMX and NASMX disrupts TCA cycle, amino acid, linoleic acid, nucleotide metabolism, and phenylpropanoid biosynthesis pathways of rice, with NASMX exerting a stronger impact on metabolic networks. These findings elucidate the sulfonamides' metabolism, phytotoxicity mechanisms, and contribute to assessing food safety and human exposure risk amid antibiotic pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The neurotoxic effects and mechanisms of low-dose and long-term sulfamethoxazole (SMZ) exposure remain unknown. This study exposed zebrafish to environmental SMZ concentrations and observed behavioral outcomes. SMZ exposure increased hyperactivity and altered the transcript levels of 17 genes associated with neurological function. It impaired intestinal function by reducing the number of intestinal goblet cells and lipid content. Metabolomic results indicated that the contents of several lipids and amino acids in the gut were altered, which might affect the expression levels of neurological function-related genes. Metagenomic results demonstrated that SMZ exposure substantially altered the composition of the gut microbiome. Zebrafish receiving a transplanted fecal microbiome from the SMZ group were also found to exhibit abnormal behavior, suggesting that the gut microbiome is an important target for SMZ exposure-induced neurobehavioral abnormalities. Multi-omics correlation analysis revealed that gut micrometabolic function was related to differential gut metabolite levels, which may affect neurological function through the gut-brain-axis. Reduced abundance of Lefsonia and Microbacterium was strongly correlated with intestinal metabolic function and may be the key bacterial genera in neurobehavioral changes. This study confirms for the first time that SMZ-induced neurotoxicity in zebrafish is closely mediated by alterations in the gut microbiome., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that influenced the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Sulfamethoxazole (SMZ) is a frequently detected antibiotic in the environment, and there is a growing concern about its potential toxic effects on aquatic organisms. sea cucumber (Apostichopus japonicas) is a benthic invertebrate whose gut acts as a primary immune defense and serves critical protective barrier. In this study, growth performance, histology, gut microbiota, and metabolomics analyses were performed to investigate the toxic response in the intestine of sea cucumber effects caused by SMZ stress for 56 d by evaluating with different concentrations of SMZ (0, 1.2×10 -3 , and 1.2 mg/L). The weight gain rate of sea cucumbers under SMZ stress showed significant decrease, indicating that the growth of sea cucumbers was hindered. Analysis of the intestinal morphological features indicated that SMZ stimulation resulted in atrophy of the sea cucumber gut. In the 1.2×10 -3 mg/L concentration, the thickness of muscle and mucosal layers was reduced by 12.40% and 21.39%, while in the 1.2 mg/L concentration, the reductions were 35.08% and 26.98%. The abundance and diversity of sea cucumber intestinal bacteria decreased significantly (P < 0.05) under the influence of SMZ. Notably, the intestinal bacteria of sea cucumber became homogenized with the increase in SMZ concentration, and the relative abundance of Ralstonia reached 81.64% under the stress of 1.2 mg/L concentration. The SMZ stress significantly impacted host metabolism and disrupted balance, particularly in L-threonine, L-tyrosine, neuronic acid, piperine, and docosapentaenoic acid. SMZ leads to dysregulation of metabolites, resulting in growth inhibition and potential inflammatory responses that could adversely affect the normal activities of aquatic organisms. Further metabolic pathway enrichment analyses demonstrated that impaired biosynthesis of unsaturated fatty acids and aminoacyl-tRNA biosynthesis metabolic pathway were major reasons for SMZ stress-induced intestinal bacteria dysbiosis. This research aims to provide some theoretical evidence for the ecological hazard assessment of antibiotics in water., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The misuse of antibiotics has brought potential ecological risks to marine ecosystems, especially under a changing climate. Laboratory experiments were conducted to understand the impact of rising temperatures and antibiotic sulfamethoxazole (SMX) abuse on marine diatom Phaeodactylum tricornutum. Temperatures of 21 and 24 °C were optimal for the growth and photosynthetic characteristics of P. tricornutum. When exposed to higher temperatures (≥27 °C), the growth and photosynthesis were inhibited. High concentrations of SMX (≥100 mg/L) caused rapid and acute toxicological effects on the phytoplankton. In contrast, low concentrations of SMX (1 mg/L) exhibited hormesis. When P. tricornutum was exposed to SMX at high temperatures, the stress on the phytoplankton was even more pronounced. This suggests that the combination of rising temperatures and antibiotic pollution may have a more significant negative impact on marine phytoplankton than either stressor alone. Neglecting the interaction between these stressors may lead to underestimating their combined effects on marine ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The widespread application of sulfonamide antibiotics in aquaculture has raised concerns about their adverse environmental impacts. Periphyton plays a crucial role in the aquatic ecosystem. In this study, we examined sulfamethoxazole (SMX) effects on the community structure and interactions of periphyton in simulated aquaculture water. Our findings indicated that the total biomass of periphyton decreased, while the biomass of periphytic algae and the secretion of extracellular polymeric substances (EPS) increased at 0.7 × 10 -3  mg/L. Under higher SMX concentrations (5 mg/L and 10 mg/L), periphyton growth was severely inhibited, the microbial community structure of periphyton were sharply altered, characterized by the cyanobacteria growth suppression and decrease in the diversity index of community. Furthermore, elevated SMX concentrations (5 mg/L and 10 mg/L) increased the ratio of negative relationships from 45.4% to 49.4%, which suggested that high SMX concentrations promoted potential competition among microbes and disrupted the microbial food webs in periphyton. The absolute abundance of sul1 and sul2 genes in T2 and T3 groups were 2-3 orders of magnitude higher than those in control group after 30 days of SMX exposure, which elevated the risk of resistance gene enrichment and dissemination in the natural environment. The study contributes to our understanding of the detrimental effects of antibiotic pollution, which can induce changes in the structure and interaction relationship of microbial communities in aquaculture water., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Pyrite has been extensively tested for oxidizing contaminants via the activation of water molecule or dissolved oxygen, while the changing of oxidation species induced by contaminant's concentration has been largely underestimated. In this study, we revealed a self-acclimation mechanism of pyrite in terms of • OH conversion to 1 O 2 during the sulfamethoxazole (SMX) degradation process under oxic conditions. Two reaction stages of SMX degradation by pyrite were observed. The SMX concentration decreased by 70% rapidly in the first 12 h after the reaction was initiated, then, the removal rate began to decrease as the SMX concentration decreased. Importantly, • OH and O 2 •- were the dominant oxidizing species in stage one, while 1 O 2 was responsible for the further degradation of SMX in stage two. The self-acclimated mechanism of pyrite was proven to be caused by the conversion of oxidative species at the surface of pyrite. This process can overcome the shortages of • OH such as ultrashort lifetime and limited effective diffusion in the decontamination of micropollutant. Moreover, different reactive oxygen species will lead to different degradation pathways and environmental toxicity while degrading pollutants. This finding of oxidizing species' self-acclimation mechanism should be of concern when using pyrite for water treatment., Competing Interests: Declaration of Competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Antibiotics are a contaminant class of worldwide concern as they are frequently detected in aquatic ecosystems. To better understand the impacts of antibiotics on aquatic ecosystems, we conducted an outdoor mesocosm experiment in which aquatic communities were exposed to different concentrations of the antibiotic sulfamethoxazole (0, 0.15, 1.5, 15 and 150 μg/L). These concentrations include mean (0.15 μg/L) and maximum detected concentrations (15 and 150 μg/L) in aquatic ecosystems worldwide. Sulfamethoxazole was applied once a week for eight consecutive weeks to 1530 L outdoor mesocosms in the Netherlands, followed by an eight-week recovery period. We evaluated phytoplankton-, bacterial- and invertebrate responses during and after sulfamethoxazole exposure and assessed impacts on organic matter decomposition. Contrary to our expectations, consistent treatment-related effects on algal and bacterial communities could not be demonstrated. In addition, sulfamethoxazole did not significantly affect zooplankton and macroinvertebrate communities. However, some effects on specific taxa were observed, with an increase in Mesostoma flatworm abundance (NOEC of <0.15 μg/L). In addition, eDNA analyses indicated negative impacts on the insects Odonata at a sulfamethoxazole concentration of 15 μg/L. Overall, environmentally relevant sulfamethoxazole concentration did not result in direct or indirect impairment of entire aquatic communities and ecological processes in our mesocosms. However, several specific macroinvertebrate taxa demonstrated significant (in)direct effects from sulfamethoxazole. Comparison of the results with the literature showed inconsistent results between studies using comparable, environmentally relevant, concentrations. Therefore, our study highlights the importance of testing the ecological impacts of pharmaceuticals (such as sulfamethoxazole) across multiple trophic levels spanning multiple aquatic communities, to fully understand its potential ecological threats., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Sulfamethoxazole (SMZ) is commonly used in aquaculture to treat bacterial infections, but its long-term residual properties in natural water can pose a direct threat to aquatic animals. This study is to investigate the effects of continuous exposure to SMZ on mud crabs (Scylla paramamosain) at four different concentrations (0, 10, 100, and 1000 ng/L) that reflect the range found in natural aquatic environments. The results confirmed that SMZ exposure reduced the expression levels of genes related to the innate immunity in mud crabs, including JAK, Astakine, TLR, and Crustin. It also stimulated oxidative stress, caused the production of reactive oxygen species and lower activities of antioxidant enzymes such as peroxidase, superoxide dismutase, catalase, and glutathione. SMZ exposure damaged the DNA of crab hemocytes and hepatopancreas tissue, and reduced the phagocytosis, ultimately leading to a decreased survival rates of mud crabs infected with Vibrio alginolyticus. These findings demonstrate that SMZ exposure has immunotoxic effects on mud crabs' innate immunity and reduces the ability to resist pathogen infections., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The increasing global water demand has prompted the reuse of treated wastewater. However, the persistence of organic micropollutants in inefficiently treated effluents can have detrimental effects depending on the scope of the reclaimed water usage. One example is the presence of sulfamethoxazole, a widely used antibiotic whose interference with the folate synthesis pathway negatively affects plants and microorganisms. The goal of this study is to assess the suitability of a non-thermal plasma-ozonation technique for the removal of the organic pollutant and reduction of its herbicidal effect. Fast sulfamethoxazole degradation was achieved with apparent reaction rate constants in the range 0.21-0.49 min -1 , depending on the initial concentration. The highest energy yield (64.5 g/kWh at 50 % removal) exceeds the values reported thus far in plasma degradation experiments. During treatment, 38 degradation intermediates were detected and identified, of which only 9 are still present after 60 min. The main reactive species that contribute to the degradation of sulfamethoxazole and its intermediate products were hydroxyl radicals and ozone, which led to the formation of several hydroxylated compounds, ring opening and fragmentation. The herbicidal effect of the target compound was eliminated with its removal, showing that the remanent intermediates do not retain phytotoxic properties., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Agricultural waterways are often contaminated with herbicide and antibiotic residues due to the widespread use of these chemicals in modern agriculture. The search for resistant bacterial strains that can adapt to and degrade these mixed contaminants is essential for effective in situ bioremediation. Herein, by integrating chemical and transcriptomic analyses, we shed light on mechanisms through which Paenarthrobacter sp. AT5, a well-known atrazine-degrading bacterial strain, can adapt to sulfamethoxazole (SMX) while degrading atrazine. When exposed to SMX and/or atrazine, strain AT5 increased the production of extracellular polymeric substances and reactive oxygen species, as well as the rate of activity of antioxidant enzymes. Atrazine and SMX, either alone or combined, increased the expression of genes involved in antioxidant responses, multidrug resistance, DNA repair, and membrane transport of lipopolysaccharides. Unlike atrazine alone, co-exposure with SMX reduced the expression of genes encoding enzymes involved in the lower part of the atrazine degradation pathway. Overall, these findings emphasize the complexity of bacterial adaptation to mixed herbicide and antibiotic residues and highlight the potential of strain AT5 in bioremediation efforts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The incorrect use of antibiotics and pesticides poses significant risks of biological toxicity. Their simultaneous exposure could jeopardize fish health and hinder sustainable aquaculture. Here, we subjected grass carp to waterborne cypermethrin (0.65 μg/L) or/and sulfamethoxazole (0.30 μg/L) treatments for a duration of 6 weeks. We closely monitored the effects on intestinal function, the intestinal microbiome, and the liver metabolome. The results revealed that exposure to waterborne cypermethrin or/and sulfamethoxazole compromised intestinal barrier function and decreased the expression of intestinal tight junction proteins. Additionally, heightened levels of pro-inflammatory cytokines in the intestines and reduced antioxidant levels indicated systemic inflammation and oxidative stress, with more severe effects observed in the combined exposure group. 16S rRNA sequencing of intestinal tissues suggested Firmicutes play a key role in the intestinal microbiota. GC/MS metabolomics of the liver showed more differential metabolites (56) in the co-exposure group compared to cypermethrin (45) or sulfamethoxazole (32) alone, indicating greater toxicological effects with combined exposure. Our analyses also suggest that ATP-binding cassette transporters could serve as a novel endpoint for assessing the risk of pesticide and antibiotic mixtures in grass carp. In summary, this study underscores the potential ecological risks posed by antibiotics and pesticides to aquatic environments and products. It emphasizes the importance of the gut-liver axis as a comprehensive pathway for assessing the toxicity in fish exposed to environmental contaminants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Sulfamethoxazole (SMZ) and zinc (Zn) are widespread harmful materials in aquatic ecosystems and cause toxic effects to aquatic animals under their individual exposure. Although they often co-exist in aquatic environments, little is known about their joint effects and mechanism influencing aquatic animals. Herein, SMZ induced mitochondrial and lysosomal dysfunction, inhibited autophagy flux, and induced lipotoxicity. However, SMZ-induced changes of these physiological and metabolic processes above were reversed by Zn exposure, indicating the antagonism between Zn and SMZ. SOD1-knockdown abrogated the reversing effects of Zn on mitochondria dysfunction and autophagy flux blockage induced by SMZ, suggesting that SOD1 was essential for Zn to reverse SMZ-induced mitochondria dysfunction and autophagy impairment. Our further investigation found that Zn regulated STAT3 translocation to lysosomes and mitochondria to attenuate SMZ-induced lipotoxicity, and SOD1 was required for these processes. Mechanistically, STAT3 was associated with ATP6V1 A in a coiled-coil domain-dependent manner, and pS710-STAT3-and pY753-STAT3-independent manners. Moreover, SMZ suppressed autophagic degradation of damaged mitochondria via inhibiting interaction between STAT3 and ATP6V1 A and increasing pS710-STAT3 level; SMZ impaired mitochondrial β-oxidation via decreasing pY753-STAT3 level and STAT3 mitochondrial localization. Zn reversed these SMZ-induced effects to alleviate SMZ-induced lipotoxicity. Taken together, our data showed that SMZ impaired mitochondrial β-oxidation and lysosomal acidification via the downregulation of SOD1, leading to lipotoxicity, and that Zn reversed SMZ-induced changes of these important biological processes and attenuated SMZ-induced lipotoxicity. Thus, our study identified previously unidentified mechanisms for the antagonistic mechanisms of Zn and SMZ on aquatic animals, which provided novel insights into the environmental risk assessments of the joint exposure between heavy metals and antibiotics in the aquatic organisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

In recent years, the biodegradable plastics has extensively used in industry, agriculture, and daily life. Herein, the effects of two biodegradable microplastics (BMPs), poly(butyleneadipate-co-terephthalate) (PBAT) and polyhydroxyalkanoate (PHA), on soil sulfamethoxazole (SMX) degradation and sul genes development were comparatively studied based on the type, dosage, and state. The addition of virgin BMPs significantly increased soil DOC following a sequential order PBAT > PHA and high dose > low dose. Meanwhile virgin PBAT significantly reduced soil pH. In general, the addition of BMPs not only promoted soil SMX degradation but also increased the abundance of sul genes, with an exception that pH reduction in virgin PBAT inhibited the proliferation of sul genes. The driving effects of BMPs on soil microbial diversity following the same order as that on DOC. Specific bacteria stimulated by BMPs, such as Arthrobacter and two genera affiliated with phylum TM7, accounted for the accelerated degradation of SMX. Intriguingly, UV-aging hindered the release of DOC from BMPs and the reduction in pH, mitigated the stimulation of microbial communities, and ultimately reduced the promotion effect of BMPs on SMX degradation and sul genes proliferation. Our results suggest that more attention should be paid to the proliferation risk of ARGs in the environment affected by BMPs and UV-aging can be employed sometimes to reduce this risk., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Incomplete mineralization of sulfamethoxazole (SMX) in wastewater treatment systems poses a threat to ecological health. The toxicity and environmental risk associated with SMX biodegradation in the sulfur-mediated biological process were examined for the first time through a long-term (180 days) bioreactor study and a series of bioassays. The results indicated that the sulfur-mediated biological system was highly resistant and tolerant to SMX toxicity, as evidenced by the enrichment of sulfate-reducing bacteria (SRB), the improved microbial metabolic activity, and the excellent performance on pollutants removal under long-term SMX exposure. SMX can be effectively biodegraded by the cleavage and rearrangement of the isoxazole ring, hydrogenation and hydroxylation reactions in sulfur-mediated biological wastewater system. These biodegradation pathways effectively reduced the acute toxicity, antibacterial activity, and ecotoxicities of SMX and its biotransformation products (TPs) in the effluent of the sulfur-mediated biological system. The TPs produced via hydrogenation (TP1), hydroxylation, and isoxazole ring cleavage (TP3, TP4, TP5, TP8, and TP9) exhibited lower toxicity than SMX. Under SMX stress, although the abundance of sulfonamide resistance genes increased, the total abundance of ARGs decreased due to the extrusion of some intracellular SMX by the efflux pump genes and the inactivation of some SMX through the biodegradation process. Efflux pump and inactivation, as the main resistance mechanisms of antibiotics in the sulfur-mediated biological system, play a crucial role in microbial self-defense. The findings of this study demonstrate the great potential of the sulfur-mediated biological system in SMX removal, detoxication, and ARGs environmental risk reduction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The Aliivibrio fischeri bioassay was successfully applied in order to evaluate the acute effect of sulfamethoxazole (SMX), ciprofloxacin (CIP), chlortetracycline (CTC) and copper (Cu), alone or in binary, ternary, and overall mixture. The toxicity results are reported in terms of both effective concentrations, which inhibited 50% of the bacterium bioluminescence (EC50%), and in Toxic Units (TUs). The TUs were compared with predicted values obtained using the Concentration Addition model (CA). Finally, the toxicity of water extracts from a soil contaminated by the three antibiotics (7 mg Kg-1 each) in the presence/absence of copper (30 mg Kg-1) was also evaluated. Copper was the most toxic chemical (EC50: 0.78 mg L-1), followed by CTC (EC50: 3.64 mg L-1), CIP (96 mg L-1) and SMX (196 mg L-1). Comparing the TU and CA values of the mixtures, additive effects were generally found. However, a synergic action was recorded in the case of the CIP+Cu co-presence and antagonistic effects in the case of CTC+Cu and the ternary mixture (containing each antibiotic at 0.7 mg L-1), were identified. Soil water extracts did not show any toxicity, demonstrating the buffering ability of the soil to immobilize these chemicals., (© The Author(s) 2023. Published by Oxford University Press on behalf of FEMS.)

Antibiotics and nanoplastics are widely detected in the coastal ecosystem. However, the transcriptome mechanism elucidating the effect of antibiotics and nanoplastics co-exposure on the gene expression of aquatic organisms in coastal environment is still unclear. Here, single and joint effects of sulfamethoxazole (SMX) and polystyrene nanoplastics (PS-NPs) on the intestinal health and gene expression of medaka juveniles (Oryzias melastigma), which live in coastal environment, were investigated. The SMX and PS-NPs co-exposure decreased intestinal microbiota diversity compared to the PS-NPs, and caused more adverse effect on the intestinal microbiota composition and intestinal damage compared to the SMX, indicating that PS-NPs might enhance the toxicity of SMX on the medaka intestine. The increased abundance of Proteobacteria in the intestine was observed in the co-exposure group, which might induce the intestinal epithelium damage. In addition, the differentially expressed genes (DEGs) were mainly involved in the drug metabolism-other enzymes, drug metabolism-cytochrome P450, metabolism of xenobiotics by cytochrome P450 pathways in visceral tissue after the co-exposure. The expression of the host immune system genes (e.g., ifi30) could be associated with the increased pathogens in intestinal microbiota. This study is useful for understanding the toxicity effect of antibiotics and NPs on aquatic organisms in coastal ecosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Soil contamination with micropollutants is an important global problem and the impact of these pollutants on living organisms cannot be underestimated. The effects of diclofenac (DCF) and sulfamethoxazole (SMX), their mixture (MIX), and wastewater containing these drugs on the mortality and reproduction of Eisenia fetida were investigated. The impact on the activities of antioxidant enzymes in earthworm cells was also assessed. Furthermore, the influence of the following parameters of the vertical flow constructed wetlands on wastewater toxicity was investigated: the dosing system, the presence of pharmaceuticals and the plants Miscanthus giganteus. The compounds and their mixture significantly affected the reproduction and mortality of earthworms. The calculated values of LC 50,28 days values were 3.4 ± 0.3 mg kg -1 for DCF, 1.6 ± 0.3 mg kg -1 for SMX, and 0.9 ± 0.1 mg kg -1 for MIX. The EC 50 (reproduction assay) for DCF was 1.2 ± 0.2 mg kg -1 , whereas for SMX, it was 0.4 ± 0.1 mg kg -1 , and for MIX, it was 0.3 ± 0.1 mg kg -1 , respectively. The mixture toxicity index (MTI) was calculated to determine drug interactions. For both E. fetida mortality (MTI = 3.29) and reproduction (MTI = 3.41), the index was greater than 1, suggesting a synergistic effect of the mixture. We also observed a negative effect of wastewater (raw and treated) on mortality (32% for raw and 8% for treated wastewater) and fertility (66% and 39%, respectively) of E. fetida. It is extremely important to analyze the harmfulness of microcontaminants to organisms inhabiting natural environments, especially in the case of wastewater for irrigation of agricultural fields., (© 2023. The Author(s).)

The coexistence of nanoplastics and antibiotics in the aquatic environment has raised a complicated risk for ecosystems and human health. How the environmental factors e.g., light, regulate the interaction between nanoplastics and antibiotics and the resulting combined toxicity is poorly understood. Here, we investigated the individual and combined toxicity of polystyrene nanoplastics (nPS, 100 mg L 1 ) and sulfamethoxazole (SMX, 2.5 and 10 mg L -1 ) toward the microalgae Chlamydomonas reinhardtii under low (LL, 16 μmol m -2 ·s -1 ), normal (NL, 40 μmol m -2 ·s -1 ), and high light (HL, 150 μmol m -2 ·s -1 ) in terms of cellular responses. Results indicated that the joint toxicity of nPS and SMX commonly exhibited a strong antagonistic/mitigative effect under LL/NL at 24 h, and under NL at 72 h. nPS could adsorb more SMX under LL/NL at 24 h (1.90/1.33 mg g -1 ) and under NL at 72 h (1.01 mg g -1 ), thereby alleviating SMX toxicity to C. reinhardtii. However, the self-toxicity of nPS had a negative influence on the degree of antagonism between nPS and SMX. The experimental results coupled with computational chemistry further revealed that the adsorption capacity of SMX on nPS was stimulated by low pH under LL/NL at 24 h (∼7.5), while by less co-existing saline ions (0.83 ppt) and algae-derived dissolved organic matter (9.04 mg L -1 ) under NL at 72 h. nPS toxicity that was responsible for the toxic action modes was mainly attributed to the shading effect induced by hetero-aggregation and hindrance of light transmittance (>60%), as well as being regulated by additives leaching (0.49-1.07 mg L -1 ) and oxidative stress. Overall, these findings provided a critical basis for the risk assessment and management of multiple pollutants in the complex natural environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The present study quantitatively determined the degree and type of functional disturbance in the nitrifying microbiome caused by exposure to a single oxytetracycline (OTC) and a two-antibiotic mixture containing OTC and sulfamethoxazole (SMX). While the single antibiotic had a pulsed disturbance on nitritation that was recoverable within three weeks, the antibiotic mixture caused a more significant pulsed disturbance on nitritation and a potential press disturbance on nitratation that was not recoverable for over five months. Bioinformatic analysis revealed significant perturbations for both canonical nitrite-oxidizing (Nitrospira defluvii) and potential complete ammonium-oxidizing (Ca. Nitrospira nitrificans) populations that were strongly associated with the press perturbation on nitratation. In addition to this functional disturbance, the antibiotic mixture reduced the biosorption of OTC and altered its biotransformation pathways, resulting in different transformation products compared with those produced when OTC was treated as a single antibiotic. Collectively, this work elucidated how the antibiotic mixture can affect the degree, type, and duration of the functional disturbance on nitrifying microbiome and offer new insights into the environmental consequences of antibiotic residues (e.g., their fate, transformation, and ecotoxicity) when present as an antibiotic mixture rather than single antibiotics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Graphite-phase carbon nitride (g-C 3 N 4 ) has shown great potential for antibiotic wastewater treatment due to its unique electronic structure and corresponding to visible light. In this study, a series of Bi/Ce/g-C 3 N 4 photocatalysts with different doping amount were developed by direct calcination method for Rhodamine B and sulfamethoxazole photocatalytic degradation. The experiment result shows that the photocatalytic performance of Bi/Ce/g-C 3 N 4 catalysts were better than that of single component samples. Under the optimal experimental conditions, the degradation rates of RhB (20 min) and SMX (120 min) by 3Bi/Ce/g-C 3 N 4 reached 98.3% and 70.5%, respectively. The theoretical calculation results of DFT show that after Bi and Ce doping modification, the band-gap width of g-C 3 N 4 is reduced to 1.215 eV and carrier migration rate is greatly improved. The enhanced photocatalytic activity was mainly attributed to the capture of electrons after doping modification, which inhibition of photogenerated carriers recombination and reduced the gap width. The cyclic treatment experiment of sulfamethoxazole showed that Bi/Ce/g-C 3 N 4 catalysts had good stability. Ecosar evaluation and leaching toxicity test showed that Bi/Ce/g-C 3 N 4 can be safely used for wastewater treatment. This study provides a perfect strategy for modifying g-C 3 N 4 and a new way to improve the photocatalytic performance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Numerous studies have revealed the spread mechanism of antibiotic resistance genes (ARGs) in single antibiotic-contaminated soils. However, the comprehensive impacts of heavy metals and antibiotics on ARGs and the underlying mechanisms are still unknown. Here, high-throughput quantitative PCR and high-throughput sequencing were used to investigate changes in ARGs and bacterial communities under various sulfamethoxazole (SMX) regimes (0, 1, 10, 50 mg kg -1 ) in arsenic (As) contaminated soils. The study found that the abundances of ARGs, mobile genetic elements (MGEs), and heavy metal resistance genes (HMRGs) significantly increased in the soil fortified at 10 and 50 mg kg -1 SMX concentrations. The ARGs abundance increased with the increase in the MGEs abundance. Many significant positive correlations between various ARGs subtypes and HMRGs subtypes were found. These results indicate that the HMRGs and MGEs positively contributed to the enrichment of ARGs in As-contaminated soils under SMX stress. Meanwhile, the abundance of copiotrophic (Actinobacteriota) reduced and oligotrophic (Gemmatimonadota) increased, indicating that the life history strategy of the community changed. In addition, Gemmatimonadota was positively correlated to ARGs, HMRGs, and MGEs, suggesting that Gemmatimonadota, which can cope with As and SMX stress, was the host for resistance genes in the soil. Finally, the study found that MGEs play a determinant role in ARGs proliferation due to the direct utilization of HGT, and the indirect effect for ARGs spread under a co-selection mechanism of ARGs and HMRGs, while the bacterial community showed indirect influences by altering environmental factors to act on MGEs. Collectively, this study revealed new insights into the mechanisms of resistance gene transmission under combined SMX and As contamination in soil ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Microbial fuel cells (MFCs) are a promising and sustainable technology which can generate electricity and treat antibiotic wastewater simultaneously. However, the antibiotic resistance genes (ARGs) induced by antibiotics in MFCs increase risks to ecosystems and human health. In this study, the activities of enzymes and regulation genes related to ARGs in MFCs spiked with sulfamethoxazole (SMX) were evaluated to explore the induction mechanism of ARGs. Under lower doses of SMX (10 mg/L and 20 mg/L SMX in this study), microorganisms tend to up regulate catalase and RpoS regulon to induce sul1, sul3 and intI1. The microorganisms exposed to higher doses of SMX (30 mg/L and 40 mg/L SMX in this study) tend to up regulate superoxide dismutase and SOS response to generate sul2 and sulA. Moreover, the exposure concentrations of SMX had no significant effect on the electricity production of MFCs. This work suggested that the ARGs in MFCs might be inhibited by affecting enzymatic activities and regulatory genes according to the antibiotic concentration without affecting the electricity production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Ethinylestradiol (EE2) and sulfamethoxazole (SMX) are among pharmaceuticals and personal care products (PPCPs) and regarded as emerging contaminants in groundwater worldwide. However, the ecotoxicity and potential risk of these co-contaminants remain unknown. We investigated the effects of early-life long-term co-exposure to EE2 and SMX in groundwater on life-history traits of Caenorhabditis elegans and determined potential ecological risks in groundwater. L1 larvae of wild-type N2 C. elegans were exposed to measured concentrations of EE2 (0.001, 0.75, 5.1, 11.8 mg/L) or SMX (0.001, 1, 10, 100 mg/L) or co-exposed to EE2 (0.75 mg/L, no observed adverse effect level derived from its reproductive toxicity) and SMX (0.001, 1, 10, 100 mg/L) in groundwater. Growth and reproduction were monitored on days 0 - 6 of the exposure period. Toxicological data were analyzed using DEBtox modeling to determine the physiological modes of action (pMoAs) and the predicted no-effect concentrations (PNECs) to estimate ecological risks posed by EE2 and SMX in global groundwater. Early-life EE2 exposure significantly inhibited the growth and reproduction of C. elegans, with lowest observed adverse effect levels (LOAELs) of 11.8 and 5.1 mg/L, respectively. SMX exposure impaired the reproductive capacity of C. elegans (LOAEL = 0.001 mg/L). Co-exposure to EE2 and SMX exacerbated ecotoxicity (LOAELs of 1 mg/L SMX for growth, and 0.001 mg/L SMX for reproduction). DEBtox modeling showed that the pMoAs were increased growth and reproduction costs for EE2 and increased reproduction costs for SMX. The derived PNEC falls within the range of detected environmental levels of EE2 and SMX in groundwater worldwide. The pMoAs for EE2 and SMX combined were increased growth and reproduction costs, resulting in lower energy threshold values than single exposure. Based on global groundwater contamination data and energy threshold values, we calculated risk quotients for EE2 (0.1 - 123.0), SMX (0.2 - 91.3), and combination of EE2 and SMX (0.4 - 341.1). Our findings found that co-contamination by EE2 and SMX exacerbates toxicity and ecological risk to non-target organisms, suggesting that the ecotoxicity and ecological risk of co-contaminants of pharmaceuticals should be considered to sustainably manage groundwater and aquatic ecosystems., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

With the soar use range of pesticides and antibiotics in agricultural production, the pollution of surrounding runoff has become more severe; thus, the health and safety of non-target species such as fish are at risk. Excessive amounts of cypermethrin (CMN, 0.651 mg/l) and sulfamethoxazole (SMZ, 0.3 mg/l) are known to trigger oxidative stress and endoplasmic reticulum stress, resulting in toxic effects on cells. The damage degree of poisons on grass carp and the effect of the corresponding axis pathway PERK/eif2α/CHOP are still unknown. Therefore, our study set up two single poison groups (CMN/SMZ) and a combined poison group (CMN&SMZ) to detect this pathway and related indicators. After detection, the content of MDA both in CMN and SMZ group myocardium tissue was increased, while the SOD, CAT activity and GSH levels were decreased. Apoptosis-related genes (Bax, PUMA, P53 and Caspase-3/9), inflammation-related genes (TNF-α, iNOS and IL-1β/6/8), ER stress pathway PERK/eif2α/CHOP and related genes (ATF6, IRE1a and GRP78) were all increased; in contrast, the anti-apoptotic gene Bcl-2 was down-regulated. From the overall trend observation, the apoptosis proportion of cardiomyocytes in the combined poison group was higher than that of the single poison. In summary, this study shows that CMZ and SMZ can induce oxidative stress and subsequent ER stress in grass carp cardiomyocytes by regulating the PERK/eif2α/CHOP signaling axle, thereby inducing apoptosis, and followed by inflammatory responses. The combined effect of the CMZ and SMZ mixture was severer than that of a single poison (CMZ or SMZ), so it can be inferred that the damage degree of grass carp myocardium tissue would be aggravated with the appearance of CMZ or/and SMZ. The experimental results of this study have suggestions and warnings for the toxicological research of CMZ and SMZ and the management of industrial and ecological balance., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Prolonged exposure to antibiotics would likely favor the development of antibiotic resistance and their gene transfer among bacterial communities that are responsible for enriched antibiotic resistant microbes. Sulfamethoxazole (SFM) is a commonly used antibiotic that is released into the environment through human and animal wastes. Improper degradation of SFM poses severe threats to mankind and all life forms. The present study aims in analyzing the process and the probability of utilizing bio-electrokinetic degradation for elimination of SFM from artificially contaminated soil employing Enterobacter hormaechei HaG-7. The desired optimal conditions for SFM degradation (∼98%) were observed at SFM initial concentration (100 mg/L) with an inoculum dose (1% v/v) and applied potential voltage (1.5 V) at pH (7). The results indicated efficient and complete degradation of SFM when compared with the conventional biodegradation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Sulfamethoxazole (SMX), is a ubiquitous antibiotic in the aquatic environment and received concerns on its health hazards, especially its sub-lethal effects on non-target organisms which were remained largely unknown. In the present study, in order to investigate SMX induced tissue damages and reveal underlying mechanisms, marine mussels, Mytilus galloprovincialis were challenged to SMX series (0.5, 50 and 500 μg/L) for six-days followed by six-day-recovery. Comprehensive histopathological alteration (including qualitative, semi-quantitative and quantitative indices), together with transcriptional and (post-) translational responses of key factors (p38, NFκB and p53) in the p38-MAPK signaling pathway were analyzed in gills and digestive glands. Tissue-specific responses were clearly investigated with gills showing more prompt responses and digestive glands showing higher tolerance to SMX. The histopathology showed that SMX triggered inflammatory damages in both tissues and quantitative analysis revealed more significant responses, suggesting its potential as a valuable health indicator. SMX activated expressions of p38, NFκB and p53 at transcriptional and (post-) translational levels, especially after exposed to low level SMX, evidenced by p38 coupled with NFκB/p53 regulation on immunity defense in mussels. Less induction of targeted molecules under severe SMX exposure indicated such signaling transduction may not be efficient enough and can result in inflammatory damages. Taken together, this study expanded the understanding of aquatic SMX induced health risk in marine mussels and the underlying regulation mechanism through p38 signaling transduction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Cyanobacteria and green algae are the OECD recommended test organisms for environmental toxicity assessments of chemicals. Whether the differences in these two species' responses to the identical chemical affect the assessment outcomes is a question worth investigating. Firstly, we investigated the distinct resistance mechanisms of Synechococcus sp. (cyanobacteria) and R. subcapitata (green algae) to sulfamethoxazole (SMX). The antioxidant system analysis demonstrated that R. subcapitata mainly relies on enhancing the activity of first line defense antioxidants, including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), which is the most powerful and efficient response to get rid of ROS, whereas Synechococcus sp. depends upon increasing the activity of glutathione-S-transferase (GST) and GPx to resist oxidative stress. Besides, a total 7 transformation products (TPs) of SMX were identified in R. subcapitata culture medium. The analysis of conjectural transformation pathways and the predicted toxicity indicates that R. subcapitata could relieve SMX toxicity by degrading it to low eco-toxic TPs. Additionally, we summarized numerous exposure data and assessed the environmental risk of various antibiotics, revealing an inconsistent result for the same type of antibiotic by using cyanobacteria and green algae, which is most likely due to the different resistance mechanisms. In the future, modified indicators or comprehensive assessment methods should be considered to improve the rationality of environmental toxicity assessments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Developing highly efficient, stable, recyclable, and application value heterogeneous catalysts in advanced oxidation processes has essential application value in the degradation of refractory pollutants. In this paper, the CoNi alloy anchored onto N-doped porous carbon (CoNi-600@NC) catalyst was prepared using bimetallic doped metal-organic frameworks as precursors. The magnetic CoNi-600@NC can activate peroxymonosulfate (PMS) to degrade sulfamethoxazole (SMX). Therefore, SMX can be removed 100% within 25 min. CoNi-600@NC/PMS has a broad pH (3-9) application range, good applicability, and repeatability. Radical quenching, quantitative and electrochemical experiments proved that the degradation of SMX was dominated by free radical (Superoxide anions) and non-free radical pathways (surface-bound radicals). Mechanistic analysis showed that the interaction between Co-N x /pyridine N-sites and graphitized carbon with PMS induced the formation of surface-bound active species. Moreover, CoNi nanoparticles promoted the redox cycle of metals. The synergistic catalytic mechanisms between the CoNi alloy and the abundant functional groups gave CoNi-600@NC excellent catalytic properties and applicability. Using density functional theory predicted the reaction sites of SMX and proposed four degradation pathways. The toxicity of intermediates was comprehensively evaluated. In addition, a CoNi-600@NC continuous flow reactor was constructed with a daily treatment capacity of 45 L and 100% SMX removal. This study expands the application of persulfate advanced oxidation technology by synthesizing recyclable magnetic catalysts and provides new synergistic degradation mechanisms for removing refractory organics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Sulfamethoxazole (SMZ) is an important antibiotic used to prevent and treat infections in both clinical settings and animal husbandry. High levels of SMZ may exhibit endocrine toxicity. Environmental SMZ enters the human body via food and water; however, the toxicity of environmental doses of SMZ and its effects on reproductive health are unknown. In the present study, zebrafish were exposed to low concentrations of SMZ (1000 and 5000 ng/L) from 2 h post-fertilization to 120 d post-fertilization. Consequently, the proportion of mature oocytes in adult female zebrafish ovarian tissue increased by 98.2 %, indicating that SMZ promotes ovarian maturation. Metabolomics analysis revealed significant changes in ovarian lipid and amino acid levels after SMZ treatment. An enzyme-linked immunoassay used to detect sex hormones in the ovaries showed that SMZ exposure significantly increased the levels of estradiol, a follicle-stimulating hormone, and of luteinizing hormone. Furthermore, an association analysis showed that most of the differentially expressed metabolites in the ovary were strongly correlated with the levels of sex hormones secreted by the pituitary gland. Therefore, significantly increased transcript levels of gonadotropin-releasing hormone (GnRH) and follicle-stimulating hormone detected in brain tissue suggested that SMZ may exhibit ovarian toxicity via the hypothalamus. In vitro experiments were performed to demonstrate that SMZ targets neurons in the hypothalamus. Exposure to SMZ significantly increased the GnRH content in GnRH neurons. Finally, molecular docking simulations indicated the potential interaction of SMZ with G protein-coupled receptor 54; this molecular binding can activate, synthesize, and release GnRH in neurons. In conclusion, long-term environmental exposure to SMZ may induce ovarian toxicity by affecting the hypothalamus-pituitary-gonad axis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Inc.)

Sulfamethoxazole (SMX) is one of veterinary drugs and food additives, which has been frequently detected in surface waters in recent years and will cause damage to organisms. Therefore, SMX was selected as a target to be investigated, including the degradation kinetics, evolution of toxicity, and antibiotic resistance genes (ARGs) of SMX during chlorination in batch reactors and water distribution systems (WDS), to determine the optimal factors for removing SMX. In the range of investigated pH (6.3-9.0), the SMX degradation had the fastest rate at close to neutral pH. The chlorination of SMX was affected by the initial total free chlorine concentration, and the degradation of SMX was consistent with second-order kinetics. The rate constants in batch reactors are (2.23 ± 0.07) × 10 2  M -1  s -1 and (5.04 ± 0.30) × 10 M -1  s -1 for HClO and ClO -1 , respectively. Moreover, the rate constants in WDS are (1.76 ± 0.07) × 10 2  M -1  s -1 and (4.06 ± 0.62) × 10 M -1  s -1 , respectively. The degradation rate of SMX was also affected by pipe material, and the rate followed the following order: stainless-steel pipe (SS) > ductile iron pipe (DI) > polyethylene pipe (PE). The degradation rate of SMX in the DI increased with increasing flow rate, but the increase was limited. In addition, SMX could increase the toxicity of water initially, yet the toxicity reduced to the level of tap water after 2-h chlorination. And the relative abundance of ARGs (sul1 and sul2) of tap water samples was significantly increased under different chlorination conditions. PRACTITIONER POINTS: The degradation rate of SMX in batch reactor and WDS is different, and they could be described by first- or second-order kinetics. The degradation of SMX had the fastest rate at neutral pH. The degradation rate of SMX was also affected by pipe material and flow velocity. SMX increased the toxicity of water initially, yet the toxicity reduced after a 2-h chlorination. SMX increased the relative abundance of antibiotic resistance genes sul1 and sul2., (© 2022 Water Environment Federation.)

The degradation of three micropollutants (i.e., atrazine (ATZ), sulfamethoxazole (SMX) and metoprolol (MET)) was comprehensively investigated in flow-through UV/chlorine reactors. Results showed that the micropollutants degradation fitted well with pseudo-first-order kinetics (R 2  > 0.92) with the order of rate constants following SMX > MET > ATZ. The developed steady-state approximation (SSA) model was roughly applicable in flow-through UV/chlorine reactors with the predictions deviated within 44%. UV photolysis here stood as the major degradation pathway for ATZ while the contribution of non-radical processes (UV photolysis and chlorination) to SMX degradation increased as the reactor internal diameter enlarged. The degradation rates were reduced to varying extents with complex water matrices (chloride, bicarbonate and dissolved organic matter (DOM)) where the inhibition from the DOM was most prominent (up to 73.6%). Although reactors with a larger internal diameter resulted in reduced degradation rate constants, the energy requirements were also lowered. The E EO values of micropollutants degradation by UV/chlorine fell mostly within 1.0 kWh m -3 order -1 in deionized water and under different water matrices. The acute toxicity was observed to be higher after UV/chlorine treatment in tap water, but still stayed low in general. This study revealed the different kinetics and mechanisms of micropollutants degradation in flow-through reactors and demonstrated the potential of the UV/chlorine process in terms of low energy consumption and acute toxicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This study prepared surface-modified biochar, including acid washing biochar (HBC) and biochar supported with nanoscale zero-valent iron (nZVI-HBC). The surface-modified biochar was added to sulfamethoxazole (SMX)-contaminated soil with and without earthworms to examine the effects of surface-modified biochar and/or earthworms (Eisenia fetida) on the levels of SMX and its relevant genes (sul1, sul2, and intI1) in the soil. Additionally, the joint toxicity of these exogenous substances on earthworms was investigated. The results showed that although earthworms significantly enhanced the dissipation of SMX in the soils with and without HBC, this effect was not observed in the soil with nZVI-HBC. Among all treatments, nZVI-HBC most effectively accelerated SMX dissipation in the soil, regardless of coexisting earthworms. However, the presence of earthworms significantly increased the total relative abundances of sul1, sul2, and intI1 in the soil. A reasonable explanation for this is the shift in the bacterial community composition rather than the residual level of SMX. When earthworms coexisted, the richness of Proteobacteria evidently increased, which was the main host of the above genes. Both HBC and nZVI-HBC decreased these genes in the soil with earthworms, which was mainly due to the decrease in host genera from Proteobacteria, Actinobacteria, and Gemmatimonadetes. Although there was toxicity of single-surface-modified biochar or SMX on earthworms, the synergistic interaction of surface-modified biochar and SMX resulted in the most serious histopathological changes in earthworms and their highest superoxide dismutase activity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Sulfamethoxazole (SMX), a broad-spectrum antibiotic, has been widely used in the treatment and prevention of infection caused by bacteria in recent years. The present study was aimed to evaluate the response mechanisms to SMX stress in gills and digestive gland of Corbicula fluminea (O. F. Müller, 1774). To this end, clams were exposed to environmentally relevant concentrations of SMX (0, 1, 10 and 100 μg/L) for 7 and 28 days, and siphon behavior, tissue-specific enzymatic and transcriptional changes were assayed. Our results showed that exposure to SMX significantly suppressed filtration rate and acetylcholinesterase (AChE) activity, activated antioxidant defense system and elevated transcription of several genes related to cell apoptosis in gills and digestive gland of clams. In general, SMX at environmentally relevant concentrations exhibited a negative impact on siphon behavior and induced neurotoxicology, oxidative stress and cell apoptosis in C. fluminea. The current study will help broaden our understanding of the ecotoxicity of SMX on freshwater bivalves., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Constructed wetlands (CWs) are a promising alternative for conventional methods of wastewater treatment. However, the biggest challenge in wastewater treatment is the improvement of the technology used so that it is possible to remove micropollutants without additional costs. The impact of wastewater treatment in CWs on toxicity towards Aliivibrio fischeri , Daphnia magna and Lemna minor was investigated. The effects of feeding regime (wastewater fed in five batches per week at a batch volume of 1 L, or twice per week at a batch volume of 2.5 L) and the presence of pharmaceuticals (diclofenac and sulfamethoxazole), as well as the presence of Miscantus giganteus plants in CW columns (twelve of the 24 columns that were planted) were analyzed. A reduction in toxicity was observed in all experimental setups. The effluents from constructed wetlands were classified as moderately toxic (average TU for A. fischeri , D. magna and L. minor was 0.9, 2.5 and 5.5, respectively). The feeding regime of 5 days of feeding/2 days of resting resulted in a positive impact on the ecotoxicological and chemical parameters of wastewater (removal of TOC, N-NH 4 and pharmaceuticals). Extended exposure of Miscantus giganteus to the wastewater containing pharmaceuticals resulted in elevated activity of antioxidant enzymes (catalase and superoxide dismutase) in leaf material.

Advanced oxidation process (AOPs) is one of the most effective technologies for organic pollutants removal. In this study, diverse reactive species generation and enhanced sulfamethoxazole (SMX) degradation were investigated based on persulfate (PDS) activated by Fe 2+ &dithionite (DTN). When involving Fe 2+ &dithionite in PDS, SMX degradation efficiency reached 84 % within 30 min following a pseudo-first-order kinetic, which was higher than those in Fe 2+ /PDS (50.4 %) and Fe 2+ /O 2 /DTN (41.3 %). SO 4 •- and • OH were identified as dominant reactive species with a crucial role of FeSO 3 + based on quenching experiment and electron spin resonance (ESR). The contributions of SO 4 ·- , · OH, and other species to SMX degradation were 60.1 %, 33.9 %, and 6 %, respectively. In Fe 2+ /DTN/PDS system, SMX was effectively degraded under nearly neutral pH (5.0-9.0), with activation energy of 96.04 kJ·mol -1 . The experiments and density functional theory (DFT) calculation demonstrated that three functional groups (benzenesulfonamido, benzene ring, and oxazole ring) were attacked for SMX degradation. Moreover, acute toxicity to Vibrio fischeri has enhanced in the earlier degradation process due to the intermediates and weaken with the continuous reaction. This work not only provides a high-activity SO 4 ·- -AOP for refractory pollutant treatment with possible dual radical generation resources, but elucidated diverse reactive species formation with Fe 2+ &dithionite., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Pharmaceutical pollutants, a vital type of emerging contaminants, have attracted researchers to study their removal from water. In this research, Corn starch nanoparticles (CSNP) have been synthesized and characterized using various analytical techniques. The synthesized CSNP was used for the biosorption of two pharmaceutical drugs, ibuprofen (IBU) and sulfamethoxazole (SUL). The influence of various experimental conditions was optimized through batch study with the removal efficiency of 86.33 % (IBU) and 85.80 % (SUL) at pH 2 and 3, initial concentration of 10 mg/L, 0.01 g of CSNP dosage. The biosorption of IBU follows Temkin, and SUL follows Langmuir isotherm models. The toxicological assessment was performed using the seeds of Vigna mungo (VM) and Vigna radiata (VR) and zebrafish to evaluate the toxic effects of pollutants on these organisms. The LC 50 of IBU and SUL on zebrafish before the biosorption process was 209.50 mg/L and 338.84 mg/L. After biosorption, the LC 50 values increase to 1435.82 mg/L for IBU and 1317.04 mg/L for SUL. Thus, CSNP is an efficient biosorbent for removing the pharmaceutical pollutants to protect ecological systems., (Copyright © 2022 Elsevier B.V. All rights reserved.)