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Bisphenols, bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE) are commonly used as raw materials or additives in the production of several industrial and consumer products. However, information regarding the occurrence and distribution of these industrial chemicals in freshwater ecosystem is limited. In this study, four bisphenols, six BADGEs, and three BFDGEs were determined in abiotic and biotic samples collected from the Dongjiang River basin in southern China. Among the four bisphenols, BPA was widely present in all samples analyzed including surface water (median: 1.81 ng/L), sediment (3.1 ng/g dw), aquatic plants (3.69 ng/g dw), algae (7.57 ng/g dw), zooplankton (6.17 ng/g dw), and fish muscle (5.28 ng/g dw). Among the nine BADGEs and BFDGEs analyzed, BADGE, BADGE•H 2 O, BADGE·HCl·H 2 O and BADGE•2H 2 O was found in all sample types. Although the median concentration of BADGE•2H 2 O in surface water was below LOQ, this compound was found at median concentrations of 2.61, 3.59, 1.03, 1.69, and 49.8 ng/g dw in sediment, plants, algae, zooplankton, and fish muscle, respectively. Significant positive linear correlations were found among logarithmic transformed concentrations of BPA, BADGE, BADGE•H 2 O, BADGE•HCl•H 2 O, and BADGE•2H 2 O in sediment. The bioconcentration factor (logBCF) values of BADGE, BADGE•H 2 O, BADGE•HCl, BADGE•HCl•H 2 O, BADGE•2H 2 O, and BADGE•2HCl in fish, plants, algae, and zooplankton were > 3.3 L/kg (wet weight), indicating that these chemicals possess moderate bioaccumulation potential. The estimated daily total intake of bisphenols and BADGEs through fish consumption was 75.1 ng/kg bw/day for urban adult residents. The study provides baseline information on the occurrence of bisphenols, BADGEs, and BFDGEs in a freshwater 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 © 2024. Published by Elsevier B.V.)

Diclofenac (DCF) is the first drug on the EU Watch List of Priority Substances due to its extensive uses, incomplete removal in wastewater treatment plants (WWTPs), and toxic effects. Once in the environment, DCF undergoes processes that yield various transformation products (TPs) or metabolites, whichcan be more toxic than DCF. While these TPs or metabolites often dominate the majority of the drug load in municipal wastewater, they have been largely ignored. This review critically examines recent data on the formation, occurrence, fate, and toxicology of DCF TPs in the aquatic environment. This review reveals some important findings. First, DCF TPs may constitute >57 % of DCF in wastewater influent, ∼60 % in effluent, and ∼30 % in surface waters. Second, TPs persistently retain the core structure of DCF and may pose greater environmental risks than the parent drug. Third, some metabolites may revert back to the parent drug. Fourth, WWTPs serve as a consistent source that release DCF and its by-products into the environment. Fifth, mixtures of DCF and its metabolites, along with other contaminants, may pose elevated and synergistic environmental risks than individual compounds. These findings suggest that current risk assessment practices, which ignore the impacts of the metabolites and the chemical interactions/synergies, may seriously underestimate the overall toxicity of DCF and likely other pharmaceuticals. Further studies are needed to monitor the long-term fate and toxicity of the metabolites, as well as new analytical methods and standards to unveil the hidden metabolites and the associated environmental risks., 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 Ltd.)

Faced with worldwide mercury (Hg) contamination in groundwater, efficient in situ remediation technologies are urgently needed. Carboxymethyl cellulose (CMC) stabilized iron sulfide (CMC-FeS) nanoparticles have been found effective for immobilizing mercury in water and soil. Yet, the potential use of the nanoparticles for creating an in situ reactive zone (ISRZ) in porous geo-media has not been explored. This study assessed the transport and deliverability of CMC-FeS in sand media towards creating an ISRZ. The nanoparticles were deliverable through the saturated sand bed and the particle breakthrough/deposition profiles depended on the injection pore velocity, initial CMC-FeS concentration, and ionic strength. The transport data were well interpreted using an advection-dispersion transport model combined with the classical filtration theory. The resulting ISRZ effectively removed mercury from contaminated groundwater under typical subsurface conditions. While the operating conditions are yet to be optimized, the Hg breakthrough time can be affected by groundwater velocity, influent mercury concentration, dissolved organic matter, and co-existing metals/metalloids. The one-dimensional advection-dispersion equation well simulated the Hg breakthrough data. CMC-FeS-laden ISRZ effectively converted the more easily available Hg species to stable species. These findings reveal the potential of creating an ISRZ using CMC-FeS for in situ remediation of Hg contaminated soil and groundwater., 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.)

Microplastics and antibiotics are receiving increasing attention as two emerging pollutants in the aquatic ecosystem. The absorption of antibiotics by microplastics can potentially intensify their impact on marine organisms and human health. However, the detailed mechanisms underlying this interaction remain to be elucidated. Through molecular dynamics (MD) simulations and density functional theory (DFT) calculations, this study investigated the adsorption of cefradine (CED) onto three typical microplastics (MPs)-polyethylene (PE), polypropylene (PP), and polyamide (PA). The results of the molecular dynamics simulations showed that the interaction energy between CED and microplastics followed the order of PA-CED > PP-CED > PE-CED, indicating that PA microplastics had the highest adsorption capacity for CED antibiotics. The total energy contribution of the microplastics-cefradine (MPs-CED) systems suggested that the van der Waals and electrostatic interactions were the two primary mechanisms for the adsorption of CED by these three microplastics. In DFT calculations, the adsorption of CED on PA was found to be significantly influenced by both electrostatic and van der Waals effects, while the main driving force in the adsorption of PE and PP is van der Waals effect. In addition, IGMH analysis and AIM topological analysis confirmed that the adsorption of CED on PA relied heavily on the synergistic effect of hydrogen bonding and the van der Waals effect. The findings of this study validate the results obtained from molecular dynamics simulations, laying a foundation for a comprehensive exploration of the interaction mechanisms between microplastics and organic pollutants by integrating MD simulations and DFT calculations., Competing Interests: Declaration of competing interest All authors disclosed no relevant relationships., (Copyright © 2024. Published by Elsevier B.V.)

Tioxazafen (TXF) is the first 1,2,4-oxadiazole nematicide. In the present study, the aqueous degradation of TXF was investigated in terms of hydrolysis and photolysis. Under the irradiation of simulated sunlight, TXF degraded very fast in ultrapure water and buffers with half-lives (t 1/2 s) <8.3 min. A sole photoproduct (PP) PP228a was isolated, and identified by spectroscopic means (UV, IR, HRMS, and 1 H NMR) to be the thiophen-3-yl isomer converted from its thiophen-2-yl parent. Comparing with TXF, PP228a had quite extended t 1/2 s ranging from 6.9 to 7.9 d. The photolysis kinetics of TXF and PP228a showed no pH-dependence, and varied for each individual compound as affected by nitrate, fulvic acid, and humic acid. Besides, both compounds were hydrolytically stable. 6 PPs of PP228a were identified, with two of them being its isomers. The mechanisms involved in the process included the biradical photosensitization, photoinduced electron transfer, and ring contraction-ring expansion reactions. The 48 h-EC 50 to Daphnia magna was 0.808 mg/L for PP228a comparing to >1.12 mg/L for TXF, while the results of Vibrio fischeri assays indicated that one or more PPs of PP228a might have higher 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 © 2024 Elsevier B.V. All rights reserved.)

Antibiotics and polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants in the aquatic region encompassing the estuary of the Yellow River and Laizhou Bay. But little information is available about the trophic transfer of antibiotics and PAHs in the marine food web of this area. This study investigated the occurrence and trophic transfer of 19 antibiotics and 16 PAHs in marine organisms from a food web of Laizhou Bay of the Yellow River estuary. Sulfonamides, fluoroquinolones, and 2 to 4-ring PAHs were the dominant contaminants in organisms. There was a significant positive correlation between the log total concentration of sulfonamides and trophic level (TL). Sulfadiazine, sulfamethazine, and erythromycin had biomagnification effects, while ciprofloxacin and ofloxacin had biological dilution effects. The log total concentration of PAHs had a significant negative correlation with TL. Naphthalene, fluorene, anthracene, pyrene, and benzo[g,h,i]perylene had biological dilution effects. The distinct correlations of trophic magnification factors D ow of antibiotics and K ow of 2 to 5-ring PAHs, indicating that the potential of these two coefficients for predicting their transfer. Risk assessment indicated that the consumption of seafood containing antibiotics and PAHs in Laizhou Bay of the Yellow River estuary posed health and carcinogenic risks to human, respectively., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest to this work., (Copyright © 2024. Published by Elsevier B.V.)

Dissolved copper and iron ions are regarded as friendly and economic catalysts for peroxymonosulfate (PMS) activation, however, neither Cu(II) nor Fe(III) shows efficient catalytic performance because of the slow rates of Cu(II)/Cu(I) and Fe(III)/Fe(II) cycles. Innovatively, we observed a significant enhancement on the degradation of organic contaminants when Cu(II) and Fe(III) were coupled to activate PMS in borate (BA) buffer. The degradation efficiency of Rhodamine B (RhB, 20 µmol/L) reached up to 96.3% within 10 min, which was higher than the sum of individual Cu(II)- and Fe(III)- activated PMS process. Sulfate radical, hydroxyl radical and high-valent metal ions (i.e., Cu(III) and Fe(IV)) were identified as the working reactive species for RhB removal in Cu(II)/Fe(III)/PMS/BA system, while the last played a predominated role. The presence of BA dramatically facilitated the reduction of Cu(II) to Cu(I) via chelating with Cu(II) followed by Fe(III) reduction by Cu(I), resulting in enhanced PMS activation by Cu(I) and Fe(II) as well as accelerated generation of reactive species. Additionally, the strong buffering capacity of BA to stabilize the solution pH was satisfying for the pollutants degradation since a slightly alkaline environment favored the PMS activation by coupling Cu(II) and Fe(III). In a word, this work provides a brand-new insight into the outstanding PMS activation by homogeneous bimetals and an expanded application of iron-based advanced oxidation processes in alkaline conditions., 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.)

Neonicotinoids (NEOs) are widely used insecticides and have been detected in aquatic environments globally. However, little is known about NEOs contamination in the coastal environments under the terrestrial pressure of multiple planting types simultaneously. This study investigated the occurrence, spatial-seasonal variability, and ecological risks of NEOs along the coast of the Shandong Peninsula during the dry and wet seasons, where located many largest fruit, vegetable, and grain production bases in China. The concentrations of ∑NEOs in seawater were higher in wet seasons (surface: 195.46 ng/L; bottom: 14.56 ng/L) than in dry seasons (surface: 10.07 ng/L; bottom: 8.45 ng/L). During the wet seasons, NEOs peaked in the northern and eastern areas of the Shandong Peninsula, where the inland fruit planting area is located. While dry seasons had higher concentrations in Laizhou Bay, influenced by rivers from vegetable-growing areas. Grain crops, fruit, and cotton planting were major NEOs sources during wet seasons, while wheat and vegetables dominated in dry seasons. Moderate or above ecological risks appeared at 53.8% of the monitoring sites. Generally, NEOs caused high risks in the wet seasons mainly caused by Imidacloprid, and medium risk in the dry seasons caused by Clothianidin, which should be prevented and controlled in advance., Competing Interests: Declaration of Competing Interest All authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Two natural adsorbent materials, potassium humate (KHA) and montmorillonite (MMT), were successfully prepared by embedding them in sodium alginate (SA) gel spheres through physical cross-linking with CaCl 2 . And CaCO 3 was used as a porogenic agent to prepare the porous composites, KHA/SA/MMT. The materials were characterized by using XRD, TGA, SEM, and N 2 adsorption/desorption equipment. The results showed that MMT and KHA were successfully embedded in the SA gel; the introduction of MMT increased the thermal stability of the composites and the embedding of MMT, and the porogenic effect of CaCO 3 increased the specific surface area of the composites substantially, which provided favorable conditions for adsorption and treatment of pollutants. In addition, a one-way exploratory experiment yielded a higher removal rate of Rhodamine B (RhB) at D = 0.6 g/L, pH = 5, C 0  = 100 mg/L, and t = 360 min. The adsorption kinetics and adsorption isotherm conformed to the secondary kinetic model and Langmuir model, respectively, and the maximum adsorption of RhB by KHA/SA/MMT could reach up to 884.96 mg/g at 303 K. The adsorption mechanism for RhB was shown by FT-IR and XPS analyses to be possibly bound by non-covalent bonding forces. After seven consecutive adsorption-desorption cycles, the adsorption of RhB by KHA/SA/MMT still reached 80.75%. Therefore, the prepared gel spheres have the advantages of easy regeneration and efficient reuse and great potential for application in purifying RhB from wastewater., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The environmental pollution of water is one of the problems that have plagued human society. The bimetallic nanoscale zero-valent iron (BnZVI) technology has increased wide attention owing to its high performance for water treatment and soil remediation. In recent years, the BnZVI technology based on the development of nZVI has been further developed. The material chemistry, synthesis methods, and immobilization or surface stabilization of bimetals are discussed. Further, the data of BnZVI (Fe/Ni, Fe/Cu, Fe/Pd) articles that have been studied more frequently in the last decade are summarized in terms of the types of contaminants and the number of research literatures on the same contaminants. Five contaminants including trichloroethylene (TCE), Decabromodi-phenyl Ether (BDE209), chromium (Cr(VI)), nitrate and 2,4-dichlorophenol (2,4-DCP) were selected for in-depth discussion on their influencing factors and removal or degradation mechanisms. Herein, comprehensive views towards mechanisms of BnZVI applications including adsorption, hydrodehalogenation and reduction are provided. Particularly, some ambiguous concepts about formation of micro progenitor cell, production of hydrogen radicals (H·) and H 2 and the electron transfer are highlighted. Besides, in-depth discussion of selectivity for N 2 from nitrates and co-precipitation of chromium are emphasized. The difference of BnZVI is also discussed., 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.)

Titanium dioxide-based materials treat wastewater contaminated by organic pollutants. However, the wide band gap and the ease of agglomeration limit its photocatalytic activity. PDA/PEI@TiO 2 @P-HSM composites were synthesized using PDA/PEI as an interfacial bonding modifier via polymerization reaction. Phase and chemical bonding analysis confirmed the modifiedTiO 2 coated P-HSM, which can effectively reduce the band gap and control the agglomeration of titanium dioxide, i.e., suitable to degrade RhB. Under UV irradiation, PDA/PEI @TiO 2 @P-HSM can remove RhB up to 90 % in 100 min. The photocatalytic degradation process conforms to the Langmuir-Hinshelwood quasi-primary equation. The composite exhibited excellent stability and recycling i.e., a high removal effect, with a removal rate of up to 60 % after seven cycles of reaction., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tongling is a significant non-ferrous metal mining city in China, which produces waste that negatively impacts the area's water environment. It is essential to comprehend the hydrochemical properties and formation processes of groundwater to safeguard and utilize it efficiently. We explored major ions, strontium, and its isotopes in water and river-bottom samples from the northern (i.e., A-A' section) and southern (i.e., B-B' section) areas. The hydrochemical facies show the mining activities have a greater impact on surface water than on groundwater. Groundwater hydrochemical formation results from several factors, with water-rock interaction and ion exchange being primary. Additionally, the dissolution of calcite, dolomite, and feldspar, oxidation of pyrite, and hydrolysis of carbonate minerals also impact the formation of groundwater chemistry. Our analysis of strontium and its isotopes indicates that carbonate dissolution primarily occurred in the recharge area; the runoff from the recharge to the discharge area results in the dissolution of certain silicate rocks; calcite dissolution sources account for > 70% contribution in both surface water and groundwater water-rock interactions, whereas silicate rock dissolution sources and dolomite dissolution sources account for < 30%. Due to changed order of dissolved carbonate and silicate minerals during groundwater flow, the distribution of strontium and its isotopes in the A-A' section is opposite to that in the B-B' section. The findings provide a basis for developing, utilizing, managing, and protecting groundwater resources, especially in similar mining areas., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this study, we prepared and tested a carbon-modified, Fe-loaded bismuth oxychloride (Fe-BiOCl/CS) photocatalyst for photocatalytic degradation of perfluorooctane sulfonate (PFOS). Structural analyses revealed a (110) facet-dominated sheet-type BiOCl crystal structure with uniformly distributed Fe and confirmed carbon modification of the photocatalyst. The presence of d-glucose facilitated the growth control of BiOCl particles and enhanced the adsorption of PFOS via added hydrophobic interaction. Adsorption kinetic and equilibrium tests showed rapid uptake rates of PFOS and high adsorption capacity with a Langmuir Q max of 1.51 mg/g. When used for directly treating PFOS in solution, Fe-BiOCl/CS was able to mineralize or defluorinate 83% of PFOS (C 0  = 100 μgL -1 ) under UV (254 nm, intensity = 21 mW cm -2 ) in 4 h; and when tested in a two-step mode, i.e., batch adsorption and subsequent photodegradation, Fe-BiOCl/CS mineralized 65.34% of PFOS that was pre-concentrated in the solid phase under otherwise identical conditions; while the total degradation percentages of PFOS were 83.48% and 80.50%, respectively, for the two experimental modes. The photoactivated electrons and/or hydrated electrons and superoxide radicals primarily initiated the desulfonation of PFOS followed by decarboxylation and defluorination, through a stepwise chain-subsiding mechanism. The elevated photocatalytic activity can be attributed to the effective separation of e - /h + pairs facilitated by the (110) interlayer electrostatic field, Fe doping, and the presence of oxygen vacancies. This work reveals the potential of carbon-modified and Fe-co-catalyzed BiOCl for concentrating and degrading PFOS and possibly other persistent organic pollutants., 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.)

Owing to the poor treatment efficiency of wastewater containing fluoroquinolones (FQs), effective removal of such pollutants has become a significant issue in waste management. In this study, a ternary covalent organic polymer anchored with SO 3 H (COP-SO 3 H) was designed using the Schiff reaction and a multicomponent solvent thermal method. The synthesized COP-SO 3 H polymer possesses multiple functional binding sites, including amide groups, sulfonic groups, and aromatic frameworks, enabling it to effectively adsorb ciprofloxacin (which belongs to FQs) through mechanisms such as pore-filling effects, electrostatic interactions, hydrogen bonding, π-π electron donor-acceptor (EDA) interactions, and hydrophilic-lipophilic balance. COP-SO 3 H demonstrated outstanding adsorption performance for ciprofloxacin, exhibiting a high adsorption capacity, broad pH stability, strong resistance to ionic interference, and good regenerability. Moreover, it displayed preferential selectivity toward fluoroquinolone antibiotics. The present study not only investigates the intricate structural and functional design of COP-SO 3 H materials but also presents potential applications for the efficient adsorption of specific antibiotics.

The adsorption performance of layered double hydroxides (LDHs) is limited owing to self-aggregation. To avoid this and effectively control the eutrophication of water bodies, biochar (BC) was synthesized, herein, by pyrolyzing waste sheep manure at 500°C, and Ca-Al-LDHs were loaded on the surface via a coprecipitation method to obtain Ca-Al-LDHs-BC(CA) composites with varying LDH contents. The fitted maximum adsorption capacities of the CA-5%, CA-10%, CA-15%, and CA-20% samples (corresponding to samples with 5%, 10%, 15%, and 20% LDHs, respectively) were 10.21, 16.14, 22.40, and 28.47 mg g -1 , which were (when converted into metal proportions) 1.48, 1.23, 1.15, and 1.13 times of that of single hydrotalcite, respectively. The double-layer model was fitted using the Levenberg-Marquardt iterative algorithm, which when combined with the characterization results, confirmed that the adsorption of phosphate ions by CA-BC occurred via the double-layer adsorption mechanism. Two types of direct adsorption were observed: ion exchange, which resulted in first-layer adsorption, and ligand exchange, which resulted in second-layer adsorption, with first-layer adsorption accounting for a higher proportion. This double-layer adsorption mechanism showed that LDHs-BC could achieve higher ligand exchange performance compared to that achieved using only LDHs., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The drinking water has become contaminated with lead in many countries across the world. In this study, a novel lead-imprinted polyvinylidene fluoride (PVDF) membrane was successfully fabricated for selective decontamination of lead from water. First of all, the membrane fabrication process was explored and optimized. The physical and chemical properties were then studied for a better understanding of the features of the membrane. The performance of lead removal by the adsorptive membrane was evaluated by systematic batch adsorption experiments, including pH effect, kinetics, isotherm, selectivity, and regeneration studies. The results indicated that the adsorptive membrane showed a high adsorption capacity of 40.59 mg Pb/g at the optimal pH of 5.5, fast kinetics of 2 h, high selectivity towards lead, and outstanding regeneration performance. The Langmuir equation fitted the isotherm better than the Freundlich equation, while the pseudo-second-order model and pore diffusion model well described the kinetics. The adsorptive membrane showed high selectivity towards lead in the lead/zinc binary solution. In the continuous filtration study, a small piece of adsorptive membrane could treat 3.75 L of lead solution. The XPS studies revealed that the lead uptake was mainly due to the complex reaction between lead and carboxyl and hydroxyl in the membrane., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Recently, selective phosphorus removal from aqueous solution has been a highly desirable strategy to combat eutrophication due to the increasingly stringent phosphorous emission standards. However, conventional adsorbents pose the limitations in phosphate removal suffering from lack of selectivity and stability under complicated condition and poor separation. In this study, novel Y 2 O 3 based calcium-alginate (Y 2 O 3 /SA) beads of feasible stability and highly selectivity towards phosphate by encapsulating Y 2 O 3 nanoparticles inside calcium-alginate beads via Ca 2+ controlled gelation process was synthesized and characterized. The phosphate adsorption performance and mechanism were investigated. In general, a high selectivity among co-existing anions was found with co-existing anion concentration up to 62.5 times of the phosphate concentration. Additionally, phosphate adsorption by Y 2 O 3 /SA beads exhibited stable performance over a wide pH range between 2 and 10, while reaching the maximum adsorption capacity at pH 3 (48.54 mg-P/g). The value of point of zero charge (pH pzc ) of Y 2 O 3 /SA beads was approximately 3.45. Pseudo-second-order and Freundlich isotherm models can well accord with kinetics and isotherms data. The FTIR and XPS characterizations analyzed that inner-sphere complexes were proposed to be the major contributor of Y 2 O 3 /SA beads for phosphate removal. In conclusion, Y 2 O 3 /SA beads as the mesoporous material exhibited excellent stability and selectivity towards phosphate removal., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Adsorption of vanadium from wastewater defends the environment from toxic ions and contributes to recover the valuable metal. However, it is still challenging for the separation of vanadium (V 5+ ) and chromium (Cr 6+ ) because of their similar properties. Herein, a kind of CeO 2 nanorod containing oxygen vacancies is facilely synthesized which displays ultra-high selectivity of V 5+ against various competitive ions (i.e., Fe, Mn, Cr, Ni, Cu, Zn, Ga, Cd, Ba, Pb, Mg, Be, and Co). Moreover, a large separation factor (SF V/Cr ) of 114,169.14 for the selectivity of V 5+ is achieved at the Cr 6+ /V 5+ ratio of 80 with the trace amount of V 5+ (~ 1 mg/L). The results show that the process of V 5+ uptake is the monolayer homogeneous adsorption and is controlled by external and intraparticle diffusions. In addition, it also shows that V 5+ is reduced to V 3+ and V 4+ and then formation of V-O complexation. This work offers a novel CeO 2 nanorod material for efficient separation of V 5+ and Cr 6+ and also clarifies the mechanism of the V 5+ adsorption on the CeO 2 surface., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Grass carp (Ctenopharyngodon idella) is among the most important freshwater fish species in China. However, it remained unclear how salinity could affect grass carp. Two experiments were performed. The first experiment was a 4-day acute salt tolerance experiment with six salinities (0, 4, 8, 12, 16, and 20 ppt). The second experiment was an 8-week chronic salt stress experiment with three salinities (0, 2 and 6 ppt). To investigate the intestinal bacterial community of grass carp from three salinities (0, 2, and 6 ppt), the 16S rDNA sequencing was performed. The results showed that grass carp exhibited great adaptability to low salinity (2 ppt), with no significant difference in growth and maintained stable physiological and immune status. However, exposed to high salinity (6 ppt) caused significant deleterious effects on grass carp, including growth inhibition as well as physiological and immune-related changes. The gut microbiota in grass carp changed with salinity. With the increase of salinity, the proportion of beneficial bacteria in the gut of grass carp gradually decreased, while some harmful bacteria gradually occupied the dominant position. Changes in gut microbial composition ultimately affected the growth of grass carp. This study helps further clarify the effects of salinity on grass carp., 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.)

An understanding of the vertical variations in hydrogeochemical processes in various aquifers and quality suitability assessment is crucial for the utilization of groundwater in the Ningtiaota coalfield of Ordos Basin, Northwestern China. Based on 39 water samples collected from surface water (SW), Quaternary pore water (QW), weathered fissure water (WW), and mine water (MW), we conducted self-organizing maps (SOM) algorithm, multivariate statistical analysis (MSA), and classical graphical methods to elucidate the mechanisms controlling the vertical spatial variations in SW and groundwater chemistry and conducted a health risk assessment. The findings indicated that the hydrogeochemical type showed a transition from the HCO 3 - -Na + type in SW to the HCO 3 - -Ca 2+ type in QW, then to the SO 4 2- -Mg 2+ type in WW, and back to HCO 3 - -Na + type in MW. Water-rock interaction, silicate dissolution, and cation exchange were the main hydrogeochemical processes in the study area. Additionally, groundwater residence time and mining operations were critical external factors that affect water chemistry. Contrary to phreatic aquifers, confined aquifers featured greater circulation depth, water-rock interactions, and external interventions leading to worse quality and higher health risks. Water quality surrounding the coalfield was poor, causing it to be undrinkable, with excessive SO 4 2- , arsenic (As), and F - , etc. Approximately 61.54% of SW, all of QW, 75% of WW, and 35.71% of MW can be used for irrigation., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Microplastics have been proven to be one of the critical environmental pollution issues. Moreover, microfibers, the most prominent form of microplastics in the environment, have likewise attracted the attention of various countries. With the increase in global population and industrialization, the production and use of fibers continue to increase yearly. As a result, a large number of microfibers are formed. If fiber products are not used or handled correctly, it will cause direct/indirect severe microfiber environmental pollution. Microfibers will be further broken into smaller fiber fragments when they enter the natural environment. Presently, researchers have conducted extensive research in the identification of microfibers, laying the foundation for further resourcefulness research. This work used bibliometric analysis to review the microfiber contamination researches systematically. First, the primary sources of microfibers and the influencing factors are analyzed. We aim to summarize the influence of the clothing fiber preparation and care processes on microfiber formation. Then, this work elaborated on the migration in/between water, atmosphere, and terrestrial environments. We also discussed the effects of microfiber on ecosystems. Finally, microfibers' current and foreseeable effective treatment, disposal, and resource utilization methods were explained. This paper will provide a structured reference for future microfiber research., 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 B.V.)

Landfills have served as the final repository for > 50 % municipal solid wastes in the United States. Because of their widespread uses and persistence in the environment, per- and polyfluoroalkyl substances (PFAS) (>4000 on the global market) are ubiquitously present in everyday consumer, commercial and industrial products, and have been widely detected in both closed (tens ng/L) and active (thousands to ten thousands ng/L) landfills due to disposal of PFAS-containing materials. Along with the decomposition of wastes in-place, PFAS can be transformed and released from the wastes into leachate and landfill gas. Consequently, it is critical to understand the occurrence and transformation of PFAS in landfills and the effectiveness of landfills, as a disposal alternative, for long-term containment of PFAS. This article presents a state-of-the-art review on the occurrence and transformation of PFAS in landfills, and possible effect of PFAS on the integrity of modern liner systems. Based on the data published from 10 countries (250 + landfills), C4-C7 perfluoroalkyl carboxylic acids were found predominant in the untreated landfill leachate and neutral PFAS, primarily fluorotelomer alcohols, in landfill air. The effectiveness and limitations of the conventional leachate treatment technologies and emerging technologies were also evaluated to address PFAS released into the leachate. Among conventional technologies, reverse osmosis (RO) may achieve a high removal efficiency of 90-100 % based on full-scale data, which, however, is vulnerable to the organic fouling and requires additional disposal of the concentrate. Implications of these knowledge on PFAS management at landfills are discussed and major knowledge gaps are identified., 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.)

Wastewater treatment plant (WWTP) effluent is discharged into rivers as supplemental water, which may result in ecological risk. This study compares the element composition and microbial community of WWTP effluent and natural surface water (NSW) and reveals the potential ecological risk of WWTP effluent discharge. Twenty recently upgraded WWTPs and three relatively large reservoirs in Zhengzhou city, China, were selected. The contents of N, P, S, K, Ca, Mg, B, Si, Na, Fe, Mn, Co, Ni and Sn were significantly higher in WWTP effluent than in NSW, while those of Mo, V, Pb and Cd were significantly lower. There was no significant difference between WWTP effluent and NSW in terms of the element imbalance index (IMI) (representing the extent of imbalance of element proportions) relative to the class IV surface water quality standard (the control standard for most Chinese rivers). The macronutrient IMI relative to the Hoagland formula was significantly lower in WWTP effluent than in NSW, and WWTP effluent discharge could significantly lower this index in NSW; this may be an important cause of primary productivity explosion. The microbial diversity was significantly higher in WWTP effluent than in NSW. The predicted relative abundances of mobile genetic elements and oxidative-stress-tolerant phenotypes were significantly higher in WWTP effluent than in NSW, whereas the abundance of gram-negative phenotypes was significantly lower, and that of potential pathogenic phenotypes was slightly lower. The effluent from upgraded WWTPs exhibited a low risk of pathogen diffusion but a high risk of antibiotic resistance gene diffusion. The element composition and microbial community should be considered when evaluating the ecological risk of WWTP effluent discharge., 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.)

Polycyclic aromatic hydrocarbon (PAH) pollution caused by marine oil spills and antibiotic pollution caused by aquaculture industries were common environmental problems in the Yellow River Estuary, China. But few data are reported on the bioaccumulation and influencing factors of these two types of contaminants in aquaculture simultaneously. This study investigated the occurrence and bioaccumulation of PAHs and antibiotics in aquaculture areas of the Yellow River Estuary, and explored the factors affecting the bioaccumulation. 3-ring PAHs and fluoroquinolones were dominant contaminants in the study area. The concentrations of PAHs and antibiotics in lipid-rich tissues (fish viscus, shrimp head, and crab ovary) was higher than that in muscle. It indicated that the lipid content was an important factor affecting the bioaccumulation capacity. Physicochemical parameters (K ow and D lipw ) and the concentrations of PAHs or antibiotics also affected the bioaccumulation capacity of them. Meanwhile, biotransformation was a factor affecting the bioaccumulation of PAHs and antibiotics. The biotransformation (pyrene to 1-hydroxypyrene and enrofloxacin to ciprofloxacin) might explain the poor correlation between log bioaccumulation factor and log K ow /log D lipw in fish. Risk assessment indicated that PAHs in mature aquatic products posed carcinogenic risks to human and enoxacin in sea cucumbers posed health risks to human., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Huangshui (HS), a typical by-product of traditional Chinese Baijiu, has attracted more and more attention since its rich resources of polysaccharides. However, there's little information on hydrogels preparation by Huangshui polysaccharides (HSPs). A series of novel HSP-loaded hydrogels were synthesized using crude HSP (cHSP), polyvinyl alcohol (PVA), sodium carboxyl methyl cellulose (CMC), and in situ incorporation of Fe 3 O 4 for methylene blue (MB) adsorption for the first time. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and texture tests indicated the paramagnetic hydrogels with porous structure were formed via physical crosslinking, and cHSP had no effect on hydrogel texture. Notably, cHSP enhanced the swelling capacity and MB adsorption ability of the hydrogels, and the corresponding maximum value was 38.67 g/g and 71.07 mg/g, respectively, when the additive amount of cHSP to the hydrogels was 2 % at 25°С. In addition, the swelling kinetics of hydrogels followed the Schott's second-order kinetics model, while MB adsorption fitted well with the Freundlich isotherm and pseudo-second-order model. Furthermore, intraparticle and film diffusion-controlled MB adsorption process. Significantly, cHSP amount could counteract the negative influence of high temperature on MB adsorption, and the prepared hydrogels could be reusable, demonstrating cHSP effectively promoted the properties of hydrogels and had potential application in MB removal. The adsorption mechanism of MB onto the hydrogels involved ion-exchange, hydrogen bonding, electrostatic interaction, and chemical reaction according to the above results together with the analysis by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) characterizations, thermodynamic, etc., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Efficient removal of cumene from gaseous streams and recovery of its derivatives was accomplished using a MCM-41-supported sulfuric acid (SSA/MCM-41) adsorbent. The results indicated that the removal performance of the SSA/MCM-41 for cumene was significantly influenced by the process conditions such as bed temperature, inlet concentration, bed height, and flow rate. The dose-response model could perfectly describe the collected breakthrough adsorption data. The SSA/MCM-41 adsorbent exhibited a reactive temperature region of 120-170 °C, in which the cumene removal ratios ( X c ) were greater than 97%. Rising the bed height or reducing the flow rate enhanced the theoretical adsorption performance metrics, such as theoretical breakthrough time ( t B,th ) and theoretical breakthrough adsorption capacity ( Q B,th ), whereas increasing the inlet concentration resulted in t B,th shortening and Q B,th rising. As demonstrated in this paper, the highest t B,th and Q B,th were 69.60 min and 324.50 mg g -1 , respectively. Meanwhile, the spent SSA/MCM-41 could be desorbed and regenerated for cyclic reuse. Moreover, two recoverable adsorbed products, 4-isopropylbenzenesulfonic acid and 4, 4'-sulfonyl bis(isopropyl-benzene), were successfully separated and identified using FTIR and 1 H/ 13 C NMR characterization. Accordingly, the relevance of a reactive adsorption mechanism was confirmed. This study suggests that the SSA/MCM-41 has remarkable potential for application as an adsorbent for the resource treatment of cumene pollutants.

Benzotriazole ultraviolet stabilizers (BUVSs) have received increasing attention as emerging contaminants. However, most of the existing relevant studies focused on the adverse ecological effect of BUVSs under their single exposure, information about the bioconcentration potential of BUVSs and their joint exposure with heavy metals remains scarce. In this study, we investigated the bioconcentration kinetics of 6 frequently reported BUVSs in four main tissues of common carp under different Cu concentration. The bioconcentration factors (BCFs) and half-lives (t 1/2 ) in the fish tissues ranged from 5.73 (UV-PS in kidney) to 1076 (UV-327 in liver), and 2.19 (UV-PS in kidney) to 31.5 (UV-320 in liver) days, respectively. Under the effect of Cu, an increase in BCF values was observed, which is mainly due to the decreased depuration rate (k 2 ). These results indicated that BUVSs accumulated in fish and that Cu can affect the bioconcentration of BUVSs. This study provides important insight into the co-exposure of heavy metal and BUVSs, contributing to the perfection of BUVSs risk assessment., (Copyright © 2022 Elsevier Inc. All rights reserved.)

In the study, Fe-MIL-100 was modified by adding Co 2+ in the synthesis process; Co/Fe-MIL-100 was successfully synthesized and used to adsorb tetracycline. The addition of Co 2+ increased the thermal stability of Fe-MIL-100 without changing the crystal structure. It was found that Co/Fe-MIL-100 exhibited satisfactory performance in tetracycline removal, the tetracycline removal efficiency reached almost 100% in the initial concentration range of 10-40 mg/L, and it still reached 82.38% under the condition of 60 mg/L tetracycline. Besides, the factors of tetracycline concentration, pH and inorganic anion on removal efficiency were explored. The coexistence of inorganic anion decreased the adsorption capacity of tetracycline due to the competitive adsorption. CO 3 2- had a more obvious inhibition effect on the adsorption efficiency of tetracycline than Cl - . The fitting correlation coefficient of Langmuir model was higher and the kinetics better fitted by pseudo-second-order, respectively. As a result of its high removal efficiency and excellent recycling performance, it has great potential in application fields such as removing tetracycline from wastewater., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The effluent of wastewater treatment plants (WWTPs) is an important water resource for some rivers in regions with relatively low precipitation, which may pose ecological risks. Various pollutants and microorganisms are discharged into rivers, along with the WWTP effluent, but this process has not been thoroughly studied. The objective of this study was to evaluate the effect of WWTP effluent on the bacterial community in the sediment and water column of an urban river and to identify the relationship between the total and active bacterial communities. Five sites were sampled in the river, including the most upstream site of the river (Up-most), 200 m upstream of the WWTP (Up-200), at the point of effluent discharge of the WWTP (Eff-pl) and 50 m (Down-50) and 1000 m (Down-1000) downstream of the WWTP. Compared with the two upstream sites (Up-most and Up-200), the bacterial species composition of Eff-pl was significantly different (p < 0.05) in both the sediment and water columns, while the bacterial species composition at Down-1000 was significantly different (p < 0.05) in the sediment but not in the water. The relative abundance of Proteobacteria, Actinobacteriota and Verrucomicrobiota was significantly different (p < 0.05) at Eff-pl in both the sediment and water columns compared with that at the upstream sites. The shared bacterial species between the DNA and RNA 16 S rRNA analyses were only 45.5-62.2% and 43.2-52.3% for the sediment and water, respectively. Accordingly, WWTP effluent drainage significantly alters (p < 0.05) the bacterial composition in the receiving river but can be recovered in water within a short distance. However, in sediment, a longer recovery space is probably needed. Analyses of the combination of total and active bacterial compositions are recommended to evaluate the ecological consequences of WWTP effluent drainage on the bacterial composition., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Hexabromocyclododecane (HBCD), an emerging persistent organic pollutant, has been widely detected in aquatic ecosystems with various hydrodynamic conditions, however, the effects of hydrodynamic changes on microbial degradation of HBCD in aquatic sediment remains unclear. Here, we conducted an annular flume experiment to characterize variation in HBCD removal from contaminated sediment under three hydrodynamic conditions with different flow velocities, as well as clarify the underlying microbial mechanisms. We detected significant HBCD removal and bromine ion generation in all contaminated sediments, and microbial reduction debromination was an important process for HBCD removal. At the end of the 49-day experiment, both HBCD removal percentage and the bromine ion concentration were significantly lower under dynamic water condition with higher sediment redox potential, compared with static water conditions. The dynamic water conditions resulted a relatively high sediment redox potential and decreased the iron reduction rate and the abundance of organohalide-respiring bacteria (OHRB) in the genera Geobatcer, Dehalogenimonas, Dehalobacter, and Dehalococcoide, which reduced the microbial degradation of HBCD in contaminated sediments. The community composition of both total bacteria and OHRB also differed significantly among hydrodynamic conditions. Some bacterial groups with HBCD degradation abilities such as Pseudomonas and Sulfuricurvum were less abundant under dynamic water conditions, and the HBCD degradation efficiencies were lower. These findings enhance our understanding of the bioremediation potential of HBCD-contaminated sediments in different hydrodynamic 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 © 2022 Elsevier B.V. All rights reserved.)

In order to improve the phosphate adsorption capacity of Ca-loaded biochar at a wide range of pH values, Ca (oyster shell) was loaded as Ca(OH) 2 on the tobacco stalk biochar (Ca-BC), which was prepared by high-temperature calcination, ultrasonic treatment, and stirring impregnation method. The phosphorus removal performance of Ca-BC adsorption was studied by batch adsorption experiments, and the mechanism of Ca-BC adsorption and phosphorus removal was investigated by SEM-EDS, FTIR, and XRD. The results showed that after high-temperature calcination, oyster shells became CaO, then converted into Ca(OH) 2 in the process of stirring impregnation and had activated the pore expansion effect of biochar. According to the Langmuir model, the adsorption capacity of Ca-BC for phosphate was 88.64 mg P/g, and the adsorption process followed pseudo-second-order kinetics. The Ca(OH) 2 on the surface of biochar under the initial pH acidic condition preferentially neutralizes with H + acid-base in solution, so that Ca-BC chemically precipitates with phosphate under alkaline conditions, which increases the adsorption capacity by 3-15 times compared with other Ca-loaded biochar. Ca-BC phosphate removal rate of livestock wastewater (pig and cattle farms) is 91~95%, whereas pond and domestic wastewater can be quantitatively removed. This study provides an experimental basis for efficient phosphorus removal by Ca-modified biochar and suggesting possible applications in real wastewater.

Zero valent iron-loaded biochar (Fe 0 -BC) has shown promise for the removal of various organic pollutants, but is restricted by reduced specific surface area, low utilization efficiency and limited production of reactive oxygen species (ROS). In this study, iron carbide-loaded activated biochar (Fe 3 C-AB) with a high surface area was synthesized through the pyrolysis of H 3 PO 4 activated biochar with Fe(NO 3 ) 3 , tested for removing bisphenol A (BPA) and elucidated the adsorption and degradation mechanisms. As a result, H 3 PO 4 activated biochar was beneficial for the transformation of Fe 0 to Fe 3 C. Fe 3 C-AB exhibited a significantly higher removal rate and removal capacity for BPA than that of Fe 0 -BC within a wide pH range of 5.0-11.0, and its performance was maintained even under extremely high salinity and different water sources. Moreover, X-ray photoelectron spectra and density functional theory calculations confirmed that hydrogen bonds were formed between the COOH groups and BPA. 1 O 2 was the major reactive species, constituting 37.0% of the removal efficiency in the degradation of BPA by Fe 3 C-AB. Density functional reactivity theory showed that degradation pathway 2 of BPA was preferentially attacked by ROS. Thus, Fe 3 C-AB with low cost and excellent recycling performance could be an alternative candidate for the efficient removal of contaminants., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The loss of soil organic phosphorus can easily cause water eutrophication. In order to effectively reduce the loss of soil organic phosphorus, this manuscript investigated the adsorption of soil organic phosphorus by lanthanum modified biochar (BC), traditional adsorbent gypsum (GY) and zeolite (ZE) by taking phytic acid as the representative. The adsorption isotherm model and kinetic models were used to fit the phosphorus absorption characteristics of the adsorbents. The effects of initial pH and temperature on the adsorption capacity were discussed, and the adsorption mechanism of each adsorbent was explained by means of FTIR and XRD. The results showed that the adsorption capacity of phytate phosphorus followed the trend of BCTS > GYTS > ZETS > TS (soil), and the maximum phosphorus adsorption capacity obtained from Langmuir isotherm for treatment with BCTS was 2.836 mg g -1 , and the treatment had the strongest affinity for phytate phosphorus and also the ability to store phosphorus. The adsorption process fits well with Langmuir isotherm equation and pseudo-second-order kinetic equation, and the adsorption behavior of phytate phosphorus was mainly controlled by the chemisorption of monolayer. When the concentration of phytate phosphorus was 100 mg L -1 , percentage of modified biochar added to the soil was 3% and the pH was 6, the adsorption capacity reached the maximum, and the maximum adsorption capacity was 2.000 mg g -1 . The results of FTIR and XRD characterization showed that complexation was the main adsorption mechanism. In this study, the combination of modified biochar and soil phytate phosphorus can provide a good theoretical basis for reducing the loss of soil organic phosphorus., (Copyright © 2021 Elsevier Inc. All rights reserved.)

As eco-friendly adsorption material, hydroxyapatite (Ca 5 (PO 4 ) 3 OH, HA) has been extensively applied to the removal of heavy metal ions. However, separating and recovering of HA powder after the adsorption process limits their application. Alginate-based composite beads (HCA) encapsulated with HA and cellulose were designed to remove Cu(II) from aqueous solution. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used for characteristic analysis. An extensive discussion in terms of HCA adsorption capacity, effect of various Cu(II) concentration, and analysis of the involved mechanisms of Cu(II) removal on the biosorption. HCA beads showed that the maximum adsorption capacity for Cu(II) of 64.14 mg/g at pH = 5 with 8 h contact time. The Langmuir adsorption isotherm and second-order kinetic model gave the closest fit. HCA beads display good regeneration ability after four cycles and offer potentiality for practical application., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

An in-depth understanding of the rainfall-runoff process is essential for effective stormwater management. However, the understanding of the hierarchy of rainfall characteristics in terms of their importance in influencing runoff generation is limited. This paper investigates the influence of rainfall characteristics and catchment characteristics on runoff generation in urban catchments. The outcomes showed that there are 4 dominant factors affecting runoff generation: total precipitation TP and maximum 60-min rainfall intensity MAX60 are the two top-ranked factors while average rainfall intensity RI and maximum 5-min rainfall intensity MAX5 are ranked second. Additionally, compared to the moderate rainfall regime (MR), the heavy rainfall regime (HR) tends to produce higher peak flow rates, higher total inflow per unit area, and lower runoff control effect. Note that the antecedent precipitation has a more significant effect on runoff generation and is even the dominant factor when rainstorm events with daily rainfall larger than 50 mm are not considered. The results of analyzing the influence of catchment characteristics suggest that only under HR regime conditions do the catchment characteristics have an impact on runoff generation and behave as smaller catchment areas, and higher proportions of green landscapes always lead lower peak flow rates, lower total inflows per unit area, and higher runoff control effects., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The anion exchange properties of layered composite metal hydroxide (LDHs) make it a significant anion purification material in aquatic environment. Ca-Al-LDHs as a calcium-based adsorbent can significantly improve the removal rate of phosphate. In this manuscript, waste oyster shell was used as the source of calcium and waste cans as the source of aluminum, and compared with the LDHs prepared by chemical reagents. The optimal molar ratio of for both the types of materials prepared from waste material as well as reagents was found to be 4:1 for best adsorption performance, with the waste group and reagent group materials showing similar adsorption capacities of 127.50 mg g -1 and 126.67 mg g -1 , respectively. The effects of adsorbent dosage, initial solution pH and presence of coexisting ions on the adsorption capacity were investigated. Langmuir adsorption isotherm, quasi-second-order kinetic equation and mass transfer kinetics was found to describe the phosphorus adsorption process of CAs-4 and CA-4 in better way. The maximum adsorption capacities of Langmuir equation for CAs-4 and CA-4 adsorption process were 126.41 mg g -1 and 127.43 mg g -1 , respectively, for CAs-4 and CA-4. The characterization results of FTIR, XRD and ICP showed that the main adsorption mechanisms were intercalation anion exchange, electrostatic attraction and dissolution precipitation. This work not only provides a method to prepare Ca-Al-LDHs for efficient utilization of solid waste, but also provides theoretical significance for controlling water eutrophication and realize waste recycling., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Dissolved organic matter (DOM) has been found to attenuate the ecotoxicity of various environmental pollutants, but research on its own toxic effects in aquatic ecosystems has been very limited. Herein, the toxic effects of humic acid (HA), a represent DOM typically found in natural waters, on the freshwater alga Scenedesmus capricornus were investigated. As result, HA exerted a double-dose effect on the growth of Scenedesmus capricornus. At HA concentrations below 2.0 mgC/L, the growth of Scenedesmus capricornus was slightly promoted, as was the synthesis of chlorophyll and macromolecules in the algae. Moreover, S. capricornus can maintain its growth by secreting fulvic acid as a nutrient carbon source. However, the growth of Scenedesmus capricornus was significantly inhibited when HA was beyond 2.0 mgC/L. The main mechanisms of humic acid's toxicity were membrane damage and oxidative stress. Particularly, when the oxidative stress exceeds the algae's carrying capacity, the synthesis of EPS is greatly inhibited and HA damage results. Taken together, DOM may have both positive and negative effects on 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 © 2021 Elsevier B.V. All rights reserved.)

Nanoplastics (NPs) pollution of aquatic systems is becoming an emerging environmental issue due to their stable structure, high mobility, and easy interactions with ambient contaminants. Effective removal technologies are urgently needed to mitigate their toxic effects. In this study, we systematically investigated the removal effectiveness and mechanisms of a commonly detected nanoplastics, carboxyl-modified polystyrene (PS-COOH) via coagulation and sedimentation processes using aluminum chloride (AlCl 3 ) as a coagulant. PS-COOH appeared as clearly defined and discrete spherical nanoparticles in water with a hydrodynamic diameter of 50 nm. The addition of 10 mg/L AlCl 3 compressed and even destroyed the negatively charged PS-COOH surface layer, decreased the energy barrier, and efficiently removed 96.6% of 50 mg/L PS-COOH. The dominant removal mechanisms included electrostatic adsorption and intermolecular interactions. Increasing the pH from 3.5 to 8.5 sharply enhanced the PS-COOH removal, whereas significant loss was observed at pH 10.0. High temperature (23 °C) favored the removal of PS-COOH compared to lower temperature (4 °C). High PS-COOH removal efficiency was observed over the salinity range of 0 - 35‰. The presence of positively charged Al 2 O 3 did not affect the PS-COOH removal, while negatively charged SiO 2 reduced the PS-COOH removal from 96.6% to 93.2%. Moreover, the coagulation and sedimentation process efficiently removed 90.2% of 50 mg/L PS-COOH in real surface water even though it was rich in inorganic ions and total organic carbon. The fast and efficient capture of PS-COOH by AlCl 3 via a simple coagulation and sedimentation process provides a new insight for the treatment of NPs from aqueous environment., (Copyright © 2021. Published by Elsevier Ltd.)

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in landfill leachate due to their widespread applications in various industrial and consumer products. Yet, there has been no cost-effective technology available for treating PFAS in leachate because of the intrinsic persistency of PFAS and the high matrix strength of landfill leachate. We tested a two-step 'Concentrate-&-Destroy' technology for treating over 14 PFAS from a model landfill leachate through bench- and pilot-scale experiments. The technology was based on an adsorptive photocatalyst (Fe/TNTs@AC), which was able to selectively adsorb PFAS despite the strong matrix effect of the leachate. Moreover, the pre-concentrated PFAS on Fe/TNTs@AC were effectively degraded under UV, which also regenerates the material. The presence of 0.5 M H 2 O 2 during the photocatalytic degradation enhanced the solid-phase destruction of the PFAS. Fresh Fe/TNTs@AC at a dosage of 10 g/L removed >95% of 13 PFAS from the leachate, 86% after first regeneration, and 74% when reused three times. Fe/TNTs@AC was less effective for PFBA and PFPeA partially due to the transformation of precursors and/or longer-chain homologues into these short-chain PFAS. Pilot-scale tests preliminarily confirmed the bench-scale results. Despite the strong interference from additional suspended solids, Fe/TNTs@AC removed >92% of 18 PFAS in 8 h under the field conditions, and when the PFAS-laden solids were subjected to the UV-H 2 O 2 system, ~84% of 16 PFAS in the solid phase were degraded. The 'Concentrate-&-Destroy' strategy appears promising for more cost-effective removal and degradation of PFAS in landfill leachate or PFAS-laden high-strength wastewaters., 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 © 2021 Elsevier B.V. All rights reserved.)

For the decontamination of both pathogenic microorganism and toxic dye from wastewater, new type of materials should be exploited to fabricate more cost-effective, eco-friendly biosorbent. Herein, a promising hydrogel beads based on the incorporation of nano‑silver/diatomite into calcium alginate (named as Ag-DE@CAH) was designed to disinfect water and remove methylene blue (MB). Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM), etc. were utilized for characterization analysis. Compared with nano‑silver/diatomite (Ag-DE), the novel Ag-DE@CAH beads displayed a better sustained release profile for Ag + , and it noteworthy that the concentration of Ag + in aqueous media is below the limit of the World Health Organization (WHO) standard (100 ppb) for a 30-days release experiment. It was found that Ag-DE@CAH beads exhibited better disinfection ability towards Escherichia coli (E. coli) than Staphylococcus aureus (S. aureus), and the maximum adsorption capacities of Ag-DE@CAH for MB was 128.21 mg/g. In addition, the as-prepared Ag-DE@CAH beads showed superior and reusable performance in the process of adsorption experiments for MB. Overall, the study indicates that the materials with both excellent disinfection and adsorption properties have potential application prospects for water purification., (Copyright © 2021. Published by Elsevier B.V.)

A wide variety of organic micropollutants in drinking water pose a serious threat to human health. This study was aimed to reveal the characteristics of organic micropollution profiles in water from a drinking water treatment plant (DWTP) in the Yangtze River Delta, China and investigate the mutagenicity, health risk and disease burden through mixed exposure to micropollutants in water. The presence of organic micropollutants in seven categories in organic extracts (OEs) of water from the DWTP was determined, and Ames test was conducted to test the mutagenic effect of OEs. Meanwhile, health risk of exposure to organic micropollutants in finished water through three exposure routes (ingestion, dermal absorption and inhalation) was assessed with the method proposed by U.S. EPA, and disability-adjusted life years (DALYs) were combined to estimate the disease burden of cancer based on the carcinogenic risk (CR) assessment. The results showed that 28 organic micropollutants were detected in the raw and finished water at total concentrations of 967.28 ng/L and 1073.45 ng/L, respectively, of which phthalate esters (PAEs) were the dominant category (95.79% in the raw water and 96.61% in the finished water). Although the results of the Ames test for OEs were negative and the non-carcinogenic hazard index of the organic micropollutants in the finished water was less than 1 in all age groups, the total CR was 2.17 × 10 -5 , higher than the negligible risk level (1.00 × 10 -6 ). The total DALYs caused by the organic micropollutants in the finished water was 2945.59 person-years, and the average individual DALYs was 2.21 × 10 -6 per person-year (ppy), which was 2.21 times the reference risk level (1.00 × 10 -6 ppy) defined by the WHO. Exposure to nitrosamines (NAms) was the major contributor to the total CR (92.06%) and average individual DALYs (94.58%). This study demonstrated that despite the negative result of the mutagenicity test with TA98 and TA100 strains, the health risk of exposure to organic micropollutants in drinking water should not be neglected., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Hexabromocyclododecane (HBCD) is one of the priority persistent organic pollutants (POPs), yet a cost-effective technology has been lacking for the removal and degradation of HBCD. Zero-valent aluminum (ZVAl) is an excellent electron donor. However, the inert and hydrophilic surface oxide layer impedes the release of the electrons from the core metallic Al, resulting in poor reactivity towards HBCD. In this research, a new type of modified mZVAl particles (AC@mZVAl bm/NaCl ) were prepared through ball milling mZVAl in the presence of activated carbon (AC) and NaCl, and tested for adsorption and reductive degradation of HBCD in water. AC@mZVAl bm/NaCl was characterized with a metallic Al core with newly created reactive surface coated with a thin layer of crushed carbon nanoparticles. AC@mZVAl bm/NaCl was able to rapidly (within 1 h) adsorb HBCD (C 0  = 2 mg L -1 ) and thus effectively enriched HBCD on the carbon surface of AC@mZVAl bm/NaCl . The pre-enriched HBCD was subsequently degraded by the electrons from the core Al, and ∼63.44% of the pre-sorbed HBCD was completely debrominated after 62 h of the contact. A notable time lag (∼12 h) from the onset of the adsorption to the debromination was observed, signifying the importance of the solid-phase mass transfer from the initially adsorbed AC particles to the reactive Al-AC interface. Overall, AC@mZVAl bm/NaCl synergizes the adsorptive properties of AC and the high reactivity of metallic Al, and enables a novel two-step adsorption and reductive degradation process for treating HBCD or likely other POPs., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A novel porous carbon adsorbent for the removal of deoxynivalenol was prepared from soybean dreg (SD). The new material was characterized by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) analysis, N 2 adsorption/desorption measurement techniques, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The specific surface area of the SDB-6-KOH was found to be 3655.95 m 2 g -1 , the pore volume was 1.936 cm 3 g -1 and the average pore size was 2.125 nm. The high specific surface area and effective functional groups of the carbon material promoted the adsorption of deoxynivalenol. By comparing the adsorption effect of SDB-6-X prepared with different activators (X: KOH, K 2 CO 3 , KHCO 3 ), SDB-6-KOH had the highest adsorption capacity. The maximum adsorption capacity of SDB-6-KOH to deoxynivalenol was 52.9877 µg mg -1 , and the removal efficiency reached 88.31% at 318 K. The adsorption kinetic and isotherm data were suitable for pseudo-second-order and Langmuir equations, and the results of this study show that the novel carbon material has excellent adsorptive ability and, thus, offers effective practical application potential for the removal of deoxynivalenol.

Microscale zero-valent aluminum (mZVAl) is prone to surface passivation due to formation of the surface Al-(hydr)oxide layer, resulting in short reactive life. To overcome this critical drawback, we developed a mechanochemical ball milling approach to modify and activate commercially available mZVAl assisted by the fragile FeSO 4 ·7H 2 O crystals. SEM-EDS and XPS analyses indicated that the particle surface of the mechanochemically modified mZVAl (Fe-mZVAl bm ) was not only fractured with newly formed fresh reactive surfaces, but also attached with a rough layer of Fe-oxides that were uniformly distributed on mZVAl. While pristine mZVAl failed to degrade any phenol, Fe-mZVAl bm was able to rapidly degrade 88.8% within 90 min (initial phenol = 20 mg/L, pH = 2.50, dosage = 3 g/L) under normal oxic conditions, with a pseudo first-order rate constant of 0.040 min -1 and about 70.0% of phenol mineralized in 8 h. Moreover, Fe-mZVAl bm also showed prolonged reactive life, and no significant reactivity drop was evident after six cycles of consecutive runs for phenol degradation. The much enhanced reactivity and reactive longevity of Fe-mZVAl bm are attributed to the critical roles of the surface Fe-oxides, including 1) protecting the newly exposed reactive Al 0 from being oxidized by side reactions, 2) serving as an electron mediator facilitating the electron transfer from the core Al 0 reservoir to the exterior surface, and 3) acting as an Fe 2+ source and a heterogeneous catalyst to enable the Fenton (-like) reactions. This study provides a novel and practical approach for preparing Fe-oxides modified mZVAl with enhanced and long-lasting reactivity., 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 © 2021 Elsevier Ltd. All rights reserved.)

Zinc (Zn 2+ ) and cadmium (Cd 2+ ) in water pose serious threats to human health and the environment. In search for a more effective treatment technology, we prepared a type of carboxymethyl cellulose (CMC) bridged chlorapatite (CMC-CAP) nanoparticles and tested the material for removal of Zn 2+ and Cd 2+ from water. CMC macromolecules were attached to CAP by bidentate bridging and hydrogen bonding, preserving the high adsorption capacity of CAP nanoparticles while allowing for easy gravity-separation of the nanoparticles. CMC-CAP showed rapid adsorption kinetics and 22.8% and 11.2% higher equilibrium uptake for Zn 2+ and Cd 2+ , respectively, than pristine CAP. An extended dual-mode isotherm model, which takes into account both sorption and chemical precipitation, provided the best fits to the sorption isotherms, giving a maximum Langmuir sorption capacity of 141.1 mg g -1 for Zn 2+ and 150.2 mg g -1 for Cd 2+ by CMC-CAP. Na + at up to 5 mM showed modest effects on the uptake of the heavy metals, while 2-5 mM of Ca 2+ exerted notable inhibitive effects. Dissolved organic matter (up to 5 mg L -1 as TOC) inhibited the Zn 2+ uptake by 16.5% but enhanced the Cd 2+ removal by 8.6%. Material characterizations and surface binding analyses revealed that ion exchange, surface precipitation, and surface complexation were the removal mechanisms for the heavy metals. This study demonstrates stabilizer bridging may serve as a convenient strategy to facilitate water treatment uses of nanoparticles., 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 © 2020 Elsevier Ltd. All rights reserved.)

The role of Tubifex tubifex in organic matter (OM) decomposition in aquatic ecosystems has been widely studied, but considerable uncertainties exist in terms of the effect mechanism. The effect of T. tubifex on sediment OM decomposition in laboratory-scale microcosms was quantified, and possible pathways were identified. In the first 7 days of the decomposition of OM mixed in sediment, no significant effect of T. tubifex on organic matter loss (OML) was observed for both low- and high-OM treatments; meanwhile, from day 7-60, T. tubifex addition significantly improved OML from 55.0%-57.5% to 71.8%-77.7% in the low-OM treatments and from 55.5%-56.6% to 64.1%-68.7% in the high-OM treatments. The enhanced OML observed with T. tubifex was mainly due to the promoted decomposition of refractory organic components, e.g., cellulose, hemicellulose and lignin. The proportion of refractory components in the gut of T. tubifex was significantly lower than that in the sediments (p < 0.01), indicating a pathway corresponding to the ingestion and digestion of refractory components by T. tubifex. Although T. tubifex reduced the water dissolved oxygen (DO) by increasing the water chemical oxygen demand (COD), the oxygen supply was improved by T. tubifex, and this could be affected by the increase in the relative abundance of aerobic to anaerobic bacteria in the sediments. T. tubifex significantly increased the diversity of the bacterial and fungal communities in the sediments. Moreover, the community structure of bacteria and fungi was substantially different between gut and sediment. Therefore, multiple pathways of the effect of T. tubifex on OM decomposition were established, and the results have great significance for the artificial manipulation of OM circulation using T. tubifex and the restoration of damaged aquatic ecosystems., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Per- and polyfluoroalkyl substances (PFAS) have emerged as a major concern in aquatic systems worldwide due to their widespread applications and health concerns. Perfluorooctanoic acid (PFOA) is one of the most-detected PFAS. Yet, a cost-effective technology has been lacking for the degradation of PFAS due to their resistance to conventional treatment processes. To address this challenge, we prepared a novel adsorptive photocatalyst, referred to Fe/TNTs@AC, based on low-cost commercial activated carbon (AC) and TiO 2 . The composite material exhibited synergistic adsorption and photocatalytic activity and enabled a novel "concentrate-&-destroy" strategy for rapid and complete degradation of PFOA in water. Fe/TNTs@AC was able to adsorb PFOA within a few minutes, thereby effectively concentrating the target contaminant on the photoactive sites. Subsequently, Fe/TNTs@AC was able to degrade >90% of PFOA that was preconcentrated on the solid in 4 h under UV irradiation (254 nm, 21 mW cm ‒2 ), of which 62% was completely mineralized to F - . The efficient photodegradation also regenerated Fe/TNTs@AC, eliminating the need for expensive chemical regenerants, and after six cycles of adsorption/photodegradation, the material showed no significant drop in adsorption capacity or photocatalytic activity. Simulations based on the density functional theory (DFT) revealed that Fe/TNTs@AC adsorbs PFOA in the side-on parallel mode, facilitating the subsequent photocatalytic degradation of PFOA. According to the DFT analysis, scavenger tests, and analysis of degradation intermediates, PFOA decomposition is initiated by direct hole oxidation, which activates the molecule and leads to a series of decarboxylation, C-F bond cleavage, and chain shortening reactions. The innovative "concentrate-&-destroy" strategy may significantly advance conventional adsorption or photochemical treatment of PFAS-contaminated water and holds the potential to degrade PFOA, and potentially other PFAS, more cost-effectively., 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 © 2020. Published by Elsevier Ltd.)

Dry microalgae Spirulina platensis shows a high capacity for heavy metal uptake, but there is a concern about dissolved organic carbon (DOC) residue, which is the precursor of disinfection by-products (DBPs). Vsp, a kind of Spirulina platensis powder prepared by vacuum freeze-drying, and Osp, a kind of Spirulina platensis powder prepared by the conventional oven drying-pulverization method, were subjected to assessments of their adsorption potential for Pb 2+ and DOC residue. The adsorption mechanism of Pb 2+ by the two adsorbents was studied by SEM, FT-IR, EDX and N 2 -BET. The effects of pH, adsorbent dosage, initial Pb 2+ concentration and contact time on the biosorption process were investigated. The results showed that Pb 2+ biosorption by Vsp and Osp were fit well by a pseudo-second-order kinetic model and the Langmuir model. The maximum amount of Pb 2+ biosorption by Vsp was 253 mg/g, which was 33 mg/g greater than that of Osp. In comparison with Osp, Vsp reached adsorption saturation 8 h earlier and had a remarkable effect on the control of DOC residue in water. When both adsorption capacity and environmental risks were considered, it was determined that the dosage of 0.5 g/L Vsp for 2 h of contact time was the best method, with 85.89 mg/g of Pb 2+ removal and 3.45 mg/L of DOC residue. In summary, Vsp is a highly efficient and environmentally friendly biosorbent that can be used for heavy metal removal from water., Competing Interests: Declaration of competing interest We declared that we have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Marine oil spill often causes contamination of drinking water sources in coastal areas. As the use of oil dispersants has become one of the main practices in remediation of oil spill, the effect of oil dispersants on the treatment effectiveness remains unexplored. Specifically, little is known on the removal of dispersed oil from contaminated water using conventional adsorbents. This study investigated sorption behavior of three prototype activated charcoals (ACs) of different particle sizes (4-12, 12-20 and 100 mesh) for removal of dispersed oil hydrocarbons, and effects of two model oil dispersants (Corexit EC9500A and Corexit EC9527A). The oil content was measured as n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and total petroleum hydrocarbons (TPHs). Characterization results showed that the smallest AC (PAC100) offered the highest BET surface area of 889 m 2 /g and pore volume of 0.95 cm 3 /g (pH PZC  = 6.1). Sorption kinetic data revealed that all three ACs can efficiently adsorb Corexit EC9500A and oil dispersed by the two dispersants (DWAO-I and DWAO-II), and the adsorption capacity followed the trend: PAC100 > GAC12 × 20 > GAC4 × 12. Sorption isotherms confirmed PAC100 showed the highest adsorption capacity for dispersed oil in DWAO-I with a Freundlich K F value of 10.90 mg/g∙(L/mg) 1/n (n = 1.38). Furthermore, the presence of Corexit EC9500A showed two contrasting effects on the oil sorption, i.e., adsolubilization and solubilization depending on the dispersant concentration. Increasing solution pH from 6.0 to 9.0 and salinity from 2 to 8 wt% showed only modest effect on the sorption. The results are useful for effective treatment of dispersed oil in contaminated water and for understanding roles of oil dispersants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this study, reactive pyrite (FeS 2 ) particles were prepared through a modified hydrothermal method and tested for immobilization of Cr(VI) in contaminated soil and synthetic groundwater. The addition of a NaAc buffer in the synthetic process resulted in pyrite particles of greater specific surface area, more uniform size, and more crystalline structure. The particles can effectively immobilize Cr(VI) in both water and a model Chinese loess soil. Over 99.9% of Cr(VI) was rapidly removed from water at pH 6.0 (Initial Cr(VI) = 25 mg/L, FeS 2 dosage = 0.48 g/L), and the removal remained high (>82%) even at pH 9.5. Both adsorption and reductive precipitation were found operative in the Cr(VI) immobilization, with ∼66% of Cr immobilized due to reduction. Fe(II) ions associated on the FeS 2 surface played a key role in the reduction of Cr(VI) to Cr(III), and S 2 2- also facilitated the reductive removal of Cr(VI). The presence of humic acid enhanced Cr(VI) removal at pH 4.0, but the effect was negligible at pH 6.0. Batch kinetic tests showed that treating a Cr(VI)-laden soil with 0.48 g/L (as Fe) of FeS 2 decreased the equilibrium water-leachable Cr(VI) by >99.0% at pH 6.0 and by >70.0% at pH 9.0. The distribution coefficient (K d ) value of the pyrite-amended soil was 1477.8 at pH 6.0, which is 306 times higher than that for the untreated soil. Column elution tests showed that installation of a 3-cm reactive layer of FeS 2 in a soil column was able to capture the leachable Cr(VI) from the soil, and the retardation factor (R d ) for the 3-cm FeS 2 layer sample was 381 times higher than that for the plain soil. The synthetic pyrite particles may serve as a reactive material for effective removal or immobilization of Cr(VI) in contaminated water or soil., (Copyright © 2019 Elsevier Ltd. All rights reserved.)