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Efficient removal of toxic metals using low-pressure membrane processes from contaminated waters is an important but challenging task. In the present work, a conducting microfiltration membrane prepared by embedding a stainless steel mesh in the active layer of a polyvinylidene fluoride membrane is developed to remove Cu(II) ions from contaminated waters. Results showed that the conducting membrane had favorable electrochemical properties and stability as cathode. Batch tests showed that Cu(II) removal efficiency increased with the increase of voltages and leveled off with the further enhancement of electric field. The optimal voltages were determined to be 1.0 V and 2.0 V for the influent Cu(II) concentrations of 5 mg/L and 30 mg/L, respectively. X-ray photoelectron spectroscopy and X-ray diffraction results demonstrated the presence of Cu(0) and Cu(OH) 2 on the membrane surface. The removal mechanisms involved the intrinsic adsorption of membrane, electrosorption of membrane, adsorption of deposited layer, chemical precipitation of Cu(OH) 2 and deposition of Cu(0) which were aided by electrophoresis and electrochemical oxidation-reduction. Long-term tests showed that the major contributors for Cu(II) removal were the deposition of Cu(0) by electrochemical reduction-oxidation (47.3% ± 8.5%) and chemical precipitation (41.1% ± 0.2%), followed by electrosorption, adsorption by the fouling layer and membrane intrinsic sorption. [ABSTRACT FROM AUTHOR]

Lead (Pb) discharged from rural industries poses a significant threat to the environment and human health. Algal-bacterial aerobic granular sludge (A-B AGS) is a promising alternative for sewage treatment with high efficiency and good settleability. In this study, Pb(II) biosorption using fresh A-B AGS was investigated for the first time. The important role of extracellular polymeric substances (EPS) was revealed with the involved mechanisms being clarified. The desorbents for Pb recovery from Pb-loaded A-B AGS were also screened. Results showed that A-B AGS has an excellent maximum Pb adsorption capacity of 72.4 mg·g−1 at pH 6.0. EPS plays an important role in keeping microbial activity, Pb bonding, and providing metal ions (Ca, Na and Mg) for Pb ion exchanges. Electrostatic interaction, ion exchange, and bonding to functional groups may occur orderly in the Pb biosorption process and the formation of pyromorphite (Pb 5 (PO 4) 3 Cl) contributes to Pb biosorption. About 66 % of the adsorbed Pb was accumulated in the A-B AGS microbial cells. Na 2 EDTA (0.05 M) can recover 60.3 % of the loaded Pb with the highest microbial activity of granules being remained. All the findings will provide the theoretical basis for the large-scale application of A-B AGS to bioremediate Pb(II)-containing wastewater. [Display omitted] • Fresh algal-bacterial aerobic granular sludge (A-B AGS) as a novel adsorbent for Pb(II) removal. • A-B AGS shows an excellent Pb(II) biosorption capacity of 72.4 mg·g−1. • EPS functions in keeping microbial activity, Pb bonding, and governing ions exchange. • Both physicochemical and biological effects are involved in Pb biosorption. • Na 2 EDTA desorbs 60.3 % of Pb with the highest microbial activity remaining in A-B AGS. [ABSTRACT FROM AUTHOR]

Abstract: Two membrane bioreactors (MBRs) with different operation conditions were employed to investigate the role of dissolved organic matter (DOM) in membrane fouling. DOM characteristics and their correlations with membrane fouling in the MBR systems were studied by using three-dimensional excitation-emission matrix (EEM) fluorescence technology, gel filtration chromatography (GFC) analysis, and column chromatographic method for DOM fractionation, etc. The three-dimensional EEM fluorescence spectroscopy analysis indicated that the fluorescence intensity of protein-like peaks in DOM samples collected from the MBR zones showed positive correlations with membrane fouling. The fluorescence spectra of membrane foulants also exhibited two protein-like peaks, confirming that proteins played an important role in membrane fouling. The DOM samples collected from MBR zones were fractionated into four components, i.e., hydrophobic (HPO), transphilic (TPI), charged hydrophilic (HPI-C) and neutral hydrophilic fractions (HPI-N). It was found that HPI-N was the most abundant fraction in all the samples, accounting for 42.0–48.9% of the total DOM. Test results also showed that HPI-N had the highest fouling potential, which could be attributed to the high molecular weight (MW) distribution and the high membrane rejection rate of macromolecules. [Copyright &y& Elsevier]

Mn-based catalysts are expected to be applied for removing NO x due to its excellent low-temperature activity. However, the practical use of these catalysts is extremely restricted with the co-poisoning of alkali metal and SO 2 in the flue gas. Here the MnO 2 /TiO 2 catalyst was employed to elucidate the co-poisoning mechanisms of K and SO 2 for the low temperature selective catalytic reduction (SCR) of NO. The physicochemical properties of catalysts under different toxicity conditions were studied by experiments. The adsorption of NH 3 , SO 2 , NO, and K on active component (MnO 2) and support (TiO 2) was studied by density functional theory. This work unravels a promotion effect of support on the alkali and sulfur resistance. The SO 2 &K co-poisoning catalyst had higher SCR activity than the SO 2 -poisoned and K-poisoned catalyst alone. For a single toxic condition: (1) SO 2 was preferentially bonded with the terminated O site of MnO 2 inhibiting the dehydrogenation of NH 3 and redox cycle. (2) The presence of Lewis base (K atom) on the catalyst decreased the binding energy of a Lewis base (NH 3) and hindered the adsorption of NH 3. For the synergistic effect of K and SO 2 , the majority of K adsorbed on the support (TiO 2) lead to increase alkalinity, which could promote the adsorption of SO 2 on the TiO 2 and reduce the toxicity of the active component (MnO 2). [Display omitted] • The SO 2 &K co-poisoning MnO 2/ TiO 2 catalyst has higher SCR activity. • The synergistic poisoning mechanism of SO 2 and K+ over MnO 2/ TiO 2 is revealed. • The support promotion effect on the resistance to the co-poisoning is illustrated. [ABSTRACT FROM AUTHOR]

Abstract: The feasibility of using flat-sheet membrane for waste activated sludge (WAS) thickening and digestion was studied in this paper. The characteristics of the processes including the thickening efficiency, effluent water quality and filtration properties of the membrane for sludge thickening process (MST), digestion efficiency, effluent water quality and membrane permeability of the membrane for sludge simultaneous thickening and digestion process (MSTD) were investigated. Test results showed that good sludge thickening efficiency and superior effluent water quality were obtained in the MST process under hydraulic retention time (HRT) 0.26 and 2d operation of each cycle, and the membrane fouling was mainly due to the increase of apparent viscosity of mixed liquors and the decrease of the cross-flow velocity (CFV) along membrane surfaces during one thickening cycle. Membranes were also selected for the processes and M1 membrane of polyvinylidene fluoride (PVDF) material with pore size 0.2μm demonstrated better permeability compared with other three membranes. About 80% MLSS destruction rate and 73% MLVSS destruction rate were achieved under HRT 1d, dissolved oxygen (DO) concentration 0.5–1.5mg/L, temperature 20–28°C and 15d operation for one cycle in MSTD process, and membrane fouling of MSTD process was attributed to not only the reason of MST process mentioned above, but also the change of sludge properties such as the increase of soluble COD and microbial polymeric substances including EPS, carbohydrate and nucleic acids, etc. of the mixed liquors. [Copyright &y& Elsevier]

Graphitic carbon nitride has gained considerable attention as a visible-light photocatalyst. However, its photocatalytic efficiency is restricted by its limited capacity for absorbing visible light and swift recombination of charge carriers. To overcome this bottleneck, we fabricated an atomic Fe-dispersed ultrathin carbon nitride (Fe-UTCN) photocatalyst via one-step thermal polymerization. Fe-UTCN showed high efficiency in the photodegradation of acetaminophen (APAP), achieving > 90 % elimination within 60-min visible light irradiation. The anchoring of Fe atoms improved the photocatalytic activity of UTCN by narrowing the bandgap from 2.50 eV to 2.33 eV and suppressing radiative recombination. Calculations by density functional theory revealed that the Fe–N 4 sites (adsorption energy of − 3.10 eV) were preferred over the UTCN sites (adsorption energy of − 0.18 eV) for the adsorption of oxygen and the subsequent formation of O 2 •−, the dominant reactive species in the degradation of APAP. Notably, the Fe-UTCN catalyst exhibited good stability after five successive runs and was applicable to complex water matrices. Therefore, Fe-UTCN, a noble-metal-free photocatalyst, is a promising candidate for visible light-driven water decontamination. [Display omitted] • Fe single atoms anchored on UTCN were synthesized via simple thermal polymerization. • Doping of UTCN with Fe atoms narrowed the bandgap and improved charge separation. • The Fe–N 4 sites favored the adsorption of O 2 and subsequent generation of O 2 •−. • > 90 % APAP can be degraded over Fe-UTCN under visible light irradiation. • Fe-UTCN showed good stability and functioned efficiently in natural water samples. [ABSTRACT FROM AUTHOR]

• Supported Pt nano-/single-atom-catalyst is prepared using the molten salt method. • Supported 0.2 wt% Pt catalyst show high catalytic activity for toluene removal. • H 2 O, CO 2 , and SO 2 addition slightly decreases the catalytic activity and stability. • H 2 O, CO 2 , and SO 2 addition does not change toluene oxidation pathway. • The present Pt catalyst might be suitable for VOCs removal. Commercial TiO 2 supported 0.20 wt% Pt catalyst is obtained via the molten salt method, and both Pt nanoparticles and single atom Pt sites are observed. It exhibits high catalytic performance for toluene oxidation, with T 50 and T 90 being 173 and 183 °C, respectively. Reaction intermediates including benzene, p-xylene, o-xylene, benzaldehyde, phthalic acid, maleic anhydride, itaconic anhydride, acetone, and acetic acid, are detected during toluene oxidation. On this basis, likely toluene combustion reaction pathway is provided. Benzaldehyde is the most stable surface intermediate, and its oxidation can be rate-limiting for the entire toluene oxidation reaction. 2–10.0 vol% H 2 O slightly inhibits the reaction by competing surface sites with the reactant, while it does not poison the catalyst. 2.5–10.0 vol% CO 2 slightly poisons the catalyst by surface carbonate formation, whereas 50 ppm SO 2 severely poisons the catalyst by sulfite/sulfate formation. [ABSTRACT FROM AUTHOR]

• We report a novel magnetic polymer adsorbent which can be facilely fabricated. • The nanoscale adsorbent has high saturation magnetization of up to 130.9 emu g−1. • The maximum adsorption capacity towards Cr (VI) is up to 229.0 mg g−1. • The Cr (VI) removal rate is considerably fast. • Favorable reduction and effective adsorption contributed to the Cr (VI) removal. The rational design of novel adsorption materials is imperative to remove toxic metal species from the polluted water. Herein, a core@shell structural Fe-Fe 2 O 3 @poly (hexachlorocyclotriphosphazene-co-polyethylenimine) (Fe-Fe 2 O 3 @PHCP) magnetic nanochain with high saturation magnetization was fabricated and used for effective adsorption and reduction of hexavalent chromium. The morphology and microstructure of Fe-Fe 2 O 3 @PHCP were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The effects of concentration, pH, contact time, temperature and coexisting ions on Cr (VI) removal were studied. Four kinetic models (pseudo-first-order, pseudo-second-order, Bangham and intraparticle diffusion models) and two isotherm models (Freundlich and Langmuir) were used to fit experimental data. Results show the adsorption capacity of Fe-Fe 2 O 3 @PHCP for Cr (VI) is up to 229.0 mg g−1. The excellent performance was ascribed to the favorable reduction of Cr (VI) to Cr (III), followed by the chelation of Cr (III) with imino groups. Meanwhile, the residual Cr (VI) were adsorbed on protonated amino and imino groups. The adsorption process is exothermic and spontaneous and nicely follows pseudo-second-order kinetics, intraparticle diffusion model and Langmuir isotherm model. These results indicated that easily separable Fe-Fe 2 O 3 @PHCP magnetic nanochains could be a promising adsorbent to remediate chromate wastewater. [ABSTRACT FROM AUTHOR]

The elimination of volatile organic compounds (VOCs) emitted from the process of industry production is of great significance to improve the atmospheric environment. Herein the catalytic oxidation of the toluene and iso -hexane mixture, as the typical components from furniture paint industry, and the enhancement in the catalytic stability for toluene oxidation were investigated in detail. The formation rate of active oxygen species was very important for the development of the catalyst with high catalytic stability. Compared with the Pt/M catalyst, the Pt-Cu/M catalyst owned stronger ability of VOCs adsorption and gaseous oxygen activation by introducing additional sites for activating O 2. The Langmuir–Hinshelwood (adsorbed oxygen) and Mars–van Krevelen (lattice oxygen) mechanism existed in toluene oxidation over the present Pt/M and Pt-Cu/M catalysts, respectively. The change in the involved active oxygen species during toluene oxidation was resulted from the Pt-Cu alloy structure. In addition to the adsorption of O 2 , a part of active lattice oxygen species can also be replenished by the migration of bulk lattice oxygen over Pt-Cu/M. With a rise in the reaction temperature, weakly adsorbed iso -hexane could be timely reacted with the more active lattice oxygen species to keep the catalytic stability over the Pt/M and Pt-Cu/M catalysts. Generally, we not only prepared a promising material for the catalytic removal of VOCs from the furniture paint industry, but also provided a new strategy for the generation of active oxygen species, making the catalyst exhibit high catalytic oxidation stability. [Display omitted] • Formation rate of active oxygen species is very important for catalytic stability. • Pt-Cu/M catalyst owns stronger ability of gaseous oxygen activation. • Toluene oxidation over Pt/M or Pt-Cu/M follows L-H or MvK mechanism. • Pt-Cu alloy structure makes active lattice oxygen involved in toluene oxidation. [ABSTRACT FROM AUTHOR]

Reactive chlorine species (RCS) are inevitably generated in electrochemical oxidation process for treating high-salinity industrial wastewater, thereby resulting in the competition with coexisting hydroxyl radicals (•OH) for oxidizing recalcitrant organic compounds. Due to the low redox potentials compared to •OH, the role of RCS has been often overlooked. In this work, we developed an electroactive membrane filtration (EMF) system that had a high removal efficiency (99.1 ± 0.5 %) for tetrabromobisphenol S (TBBPS) at low energy consumption (1.45 kWh m−3). Electron spin resonance spectroscopy and molecular probing tests indicated the predominance of Cl 2 •–, of which steady-state concentration (2.2 ×10−10 M) was extremely higher than those of ClO• (6.7 ×10−13 M), •OH (0.95 ×10−13 M), and Cl• (2.39 ×10–15 M). The density functional theory (DFT) and intermediate product analysis highlighted that Cl 2 •– radicals had a higher electrophilic attack efficacy than •OH radicals for inducing changes in the electron density of the carbon atoms around phenolic hydroxyl groups, thus leading to the generation of transition state intermediates and accelerating the degradation of TBBPS. Our work demonstrates the vital role of Cl 2 •– radicals for pollutant degradation, highlighting the potential of this technology for cost-effective removal of recalcitrant organic compounds from water and wastewater. [Display omitted] • Steady-state concentration of Cl 2 •– was extremely higher than other radicals. • One electron oxidation of TBBPS was driven by Cl 2 •– radicals. • Cl 2 •–induced the formation of phenoxy radical cationic intermediate of TBBPS. • Cl 2 •–-mediated reaction could be a cost-effective electro-oxidation process. [ABSTRACT FROM AUTHOR]

Nanofiltration (NF) is a promising technology in the treatment of microelectronic wastewater. However, the treatment of concentrate derived from NF system remains a substantial technical challenge, impeding the achievement of the zero liquid discharge (ZLD) goal in microelectronic wastewater industries. Herein, a ZLD system, coupling a two-stage NF technology with anaerobic biotechnology was proposed for the treatment of tetramethylammonium hydroxide (TMAH)-contained microelectronic wastewater. The two-stage NF system exhibited favorable efficacy in the removal of conductivity (96 %), total organic carbon (TOC, 90 %), and TMAH (96 %) from microelectronic wastewater. The membrane fouling of this system was dominated by organic fouling, with the second stage NF membrane experiencing a more serious fouling compared to the first stage membrane. The anaerobic biotechnology achieved a near-complete removal of TMAH and an 80 % reduction in TOC for the first stage NF concentrate. Methyloversatilis was the key genus involved in the anaerobic treatment of the microelectronic wastewater concentrate. Specific genes, including dmd-tmd , mtbA , mttB and mttC were identified as significant players in mediating the dehydrogenase and methyl transfer pathways during the process of TMAH biodegradation. This study highlights the potential of anaerobic biodegradation to achieve ZLD in the treatment of TMAH-contained microelectronic wastewater by NF system. [Display omitted] • The TMAH removal exceeded 96 % for microelectronic wastewater by the NF process. • Membrane fouling of NF system was dominated by organic fouling. • Anaerobic biotechnology achieved near-complete removal of TMAH from NF concentrate. • Methyloversatilis played a key role in biodegradation of TMAH from the NF concentrate. • Genes of dmd-tmd , mtbA , mttB and mttC were identified in the biodegradation of TMAH. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) have attracted widespread attention because they can lead to combined toxicity by adsorbing heavy metals from the environment. Exposure to lead (Pb), a frequently adsorbed heavy metal by MPs, is common. In the current study, the coexistence of MPs and Pb was assessed in human samples. Then, mice were used as models to examine how co-exposure to MPs and Pb promotes aortic medial degeneration. The results showed that MPs and Pb co-exposure were detected in patients with aortic disease. In mice, MPs and Pb co-exposure promoted the damage of elastic fibers, loss of vascular smooth muscle cells (VSMCs), and release of inflammatory factors. In vitro cell models revealed that co-exposure to MPs and Pb induced excessive reactive oxygen species generation, impaired mitochondrial function, and triggered PANoptosome assembly in VSMCs. These events led to PANoptosis and inflammation through the cAMP/PKA-ROS signaling pathway. However, the use of the PKA activator 8-Br-cAMP or mitochondrial ROS scavenger Mito-TEMPO improved, mitochondrial function in VSMCs, reduced cell death, and inhibited inflammatory factor release. Taken together, the present study provided novel insights into the combined toxicity of MPs and Pb co-exposure on the aorta. [Display omitted] • MPs and high levels of Pb exposure were detected in patients with aortic disease. • Co-exposure to MPs and Pb promotes aortic medial degeneration in mice. • Co-exposure to MPs and Pb induces PANoptosis and inflammation in VSMCs. • The cAMP/PKA-ROS signaling pathway is involved in co-exposure to MPs and Pb. [ABSTRACT FROM AUTHOR]

Oil fouling is the crucial issue for the separation of oil-in-water emulsion by membrane technology. The latest research found that the membrane fouling rate was opposite to the widely used theoretical prediction by Derjaguin-Landau-Verwey-Overbeek (DLVO) or extended DLVO (XDLVO) theory. To interpret the contradiction, the molecular dynamics was adopted to explore the molecular behavior of oil and emulsifier (Tween 80) at membrane interface with the assistance of DLVO/XDLVO theory and membrane fouling models. The decreased flux attenuation and fitting of fouling models proved that the existence of Tween 80 effectively alleviated membrane fouling. Conversely, DLVO/XDLVO theory predicted that the membrane fouling should be exacerbated with the increase of Tween 80 concentration in O/W emulsion. This contradiction originated from the different interaction energy between oil/Tween 80 molecules and polyether sulfone (PES) membrane. The favorable free energy of Tween 80 was resulted from the sulfuryl groups in PES and hydrogen bonds (O-H...O) formation further strengthened the interaction. Therefore, Tween 80 could preferentially adsorb on membrane surface and form an isolation layer by demulsification and steric hindrance and resist the aggregation of oil, which effectively alleviated membrane fouling. This study provided a new insight in the interpretation of interaction in O/W emulsion. [Display omitted] • Tween 80 enhanced the stability, homogeneity, stable flux of O/W emulsions. • Interaction energy of Tween-PES was at least 2 times higher than that of oil-PES. • Tween 80 shows favorable free energy and forms O-H...O bonds with sulfuryl groups. • MD interprets the contradiction between DLVO/XDLVO theory and fouling propensity. [ABSTRACT FROM AUTHOR]

Scale-up treatment of real wastewater holds the key to promoting the practical application of electrochemical filtration technology. This work used a pilot-scale Ti/Pd reactive electrochemical membrane (REM) system (12 REM modules with a total REM area of 0.144 m2) to treat high-salinity reverse osmosis concentrate (ROC) from a chemical industry park. The pilot-scale Ti/Pd REM system demonstrated effective electrochemical degradation of ROC wastewater, achieving removal efficiencies of 82.3 ± 1.9% for COD and 46.7 ± 5.6% for TN at a membrane flux of 90 L/(m2·h) and a cell voltage of 5 V, with an energy consumption of 0.045 kWh/g-COD. Singlet oxygen (1O 2) and reactive chlorine species were identified as the two primary reactive oxygen species generated in the Ti/Pd REM system. Fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) analysis indicated that the pilot-scale Ti/Pd REM treatment effectively oxidized humic acid-like substance and unsaturated aromatic compounds. Overall, the Ti/Pd REM technology shows a promising application potential for the treatment of high-salinity ROC from the chemical industry. [Display omitted] • The pilot-scale Ti/Pd REM system effectively removed COD and TN from RO concentrate. • 1O 2 and reactive chlorine species were the primary oxidants for pollutant removal. • Humic-like substances and unsaturated aromatic compounds were efficiently oxidized. • The energy consumption for RO concentrate treatment was about 0.045 kWh/g-COD. [ABSTRACT FROM AUTHOR]

The influences of mixed liquor properties on critical flux were investigated in the membrane for simultaneous thickening and digestion of activated sludge (MSTD) process, and the sustainable operation of the MSTD process was examined by employing sub-critical operation. The critical flux significantly decreased with the increase of operation time due to the variations of sludge properties in the MSTD process. Test results showed that mixed liquor suspended solids (MLSS), capillary suction time (CST), soluble microbial products (SMP) and chemical oxygen demand concentrations of colloids (CODc) were found to have significant influences on critical flux while the extracellular polymeric substances (EPS) had mild impacts. MLSS was then chosen as an indicated parameter, and an empirical relationship was established to predict the variation of critical flux in the MSTD process. The variable sub-critical flux operation was proposed to realize the sustainable operation according to the changing law of the critical flux during the MSTD process. The result showed that the membrane fouling potential in the MSTD process could be controlled at an operationally accepted condition by the variable sub-critical flux operation. [Copyright &y& Elsevier]

Abstract: Utilizing preferential ion exchange of zeolite to ammonium, the conventional contact stabilization activated sludge process (CS) can be upgraded to a new type nitrogen removal process, zeolite enhanced contact–adsorption regeneration–stabilization process (ZCS). For municipal wastewater, the effluent ammonium concentration of the ZCS process was around 6.83mg/L, indicating that ammonium removal efficiency was enhanced over 27% when the influent ammonium concentration was between 24.7 and 50.5mg/L in the same hydraulic retention time (HRT) and sludge retention time (SRT) conditions as those of the CS process. The results of PCR-DGGE technology showed that the microbial diversity, uniformity and abundance of the ZCS process were all higher than that of the CS process. In addition, anoxic/oxic (A/O) process with the volumetric ratio of oxic tank to anoxic tank being 2:1 was preferred for the regeneration process. The pilot scale ZCS process with the capacity to treat up to 72m3/d of municipal wastewater was also monitored. The test results revealed that ammonium saturated zeolite could be biologically regenerated effectively and in time. The daily zeolite powder addition was limited to the amount that made up the loss due to the sludge excluding. Furthermore, the orthogonal experiments results showed that the most significant effects on nitrogen and ammonium removal were zeolite powder dose and external recycle ratio, respectively. [Copyright &y& Elsevier]

• A systemic study of enantioselectivity of ICP in rice cultivation system. • The first study to evaluate the enantioselective bioactivity of ICP enantiomers. • Bioactivity and toxicity of S-(+)-ICP was significantly greater than R-(-)-ICP. • The enantiomers toxic interaction was different for target or non-target organism. • Using rac-ICP may be more safe and reasonable in rice cultivation. The enantioselective bioactivity and acute toxicity to target and non-target model species, and environmental fate of isocarbophos (ICP) in rice cultivation were investigated systematically. Bioactivity and toxicity of S-(+)-ICP was significantly greater than R-(-)-ICP, and the difference was 2.9–101 times. Based on the toxic unit analysis, the toxic interaction of ICP enantiomers for target pests was synergistic effect, while for non-target fish was concentration addition or antagonistic effect. Rac-ICP displayed equivalent bioactivity to S-(+)-ICP under the equal dosage, but the toxicity of rac-ICP to the tested fishes reduced at least 2 times. Rac-ICP is more suitable than optically pure S-(+)-ICP for rice cultivation based on the toxicity and bioactivity results. In environmental behavior experiments, the main metabolite of ICP, isocarbophos oxon (ICPO) was detected in rice plants, water, rice and rice hull samples. S-(+)-ICP and S-(+)-ICPO were more persistent than the R-form in these matrices. The comprehensive data of ICP enantiomers in rice cultivation will improve environmental and ecological risk assessment, and using racemate may be more safe and reasonable in rice cultivation system. [ABSTRACT FROM AUTHOR]

The treatment of tetramethylammonium hydroxide (TMAH)-bearing wastewater, generated in the electronic and semiconductor industries, raises significant concerns due to the neurotoxic, recalcitrant, and bio-inhibiting effects of TMAH. In this study, we proposed the use of an anaerobic hydrolysis bioreactor (AHBR) for TMAH removal, achieving a high removal efficiency of approximately 85%, which greatly surpassed the performance of widely-used advanced oxidation processes (AOPs). Density functional theory calculations indicated that the unexpectedly poor efficiency (5.8–8.0%) of selected AOPs can be attributed to the electrostatic repulsion between oxidants and the tightly bound electrons of TMAH. Metagenomic analyses of the AHBR revealed that Proteobacteria and Euryarchaeota played a dominant role in the transformation of TMAH through processes such as methyl transfer, methanogenesis, and acetyl-coenzyme A synthesis, utilizing methyl-tetrahydromethanopterin as a substrate. Moreover, several potential functional genes (e.g., mprF , basS , bcrB , sugE) related to TMAH resistance have been identified. Molecular docking studies between five selected proteins and tetramethylammonium further provided evidence supporting the roles of these potential functional genes. This study demonstrates the superiority of AHBR as a pretreatment technology compared to several widely-researched AOPs, paving the way for the proper design of treatment processes to abate TMAH in semiconductor wastewater. [Display omitted] • AOP was limited for TMAH removal due to electrostatic repulsion and tightly-held electrons. • Anaerobic hydrolysis bioreactor (AHBR) achieved TMAH removal efficiency of 85%. • Proteobacteria and Euryarchaeota were dominant microorganisms in AHBR. • Methyl transfer, methanogenesis and acetyl-CoA synthesis were pivotal in TMAH metabolism. • Molecular docking revealed the role of choline lyase and trimethylamine methyltransferase. [ABSTRACT FROM AUTHOR]

Heavy metals (HMs), like vanadium (V), chromium (Cr), cadmium (Cd), and nickel (Ni) toxicity due to anthropogenic, impair plant growth and yield, which is a challenging issue for agricultural production. Melatonin (ME) is a stress mitigating molecule, which alleviates HM-induced phytotoxicity, but the possible underlying mechanism of ME functions under HMs' phytotoxicity is still unclear. Current study uncovered key mechanisms for ME-mediated HMs-stress tolerance in pepper. HMs toxicity greatly reduced growth by impeding leaf photosynthesis, root architecture system, and nutrient uptake. Conversely, ME supplementation markedly enhanced growth attributes, mineral nutrient uptake, photosynthetic efficiency, as measured by chlorophyll content, gas exchange elements, chlorophyll photosynthesis genes' upregulation, and reduced HMs accumulation. ME treatment showed a significant decline in the leaf/root V, Cr, Ni, and Cd concentration which was about 38.1/33.2%, 38.5/25.9%, 34.8/24.9%, and 26.6/25.1%, respectively, when compared with respective HM treatment. Furthermore, ME remarkably reduced the ROS (reactive oxygen species) accumulation, and reinstated the integrity of cellular membrane via activating antioxidant enzymes (SOD, superoxide dismutase; CAT, catalase; APX, ascorbate peroxidase; GR, glutathione reductase; POD, peroxidase; GST, glutathione S-transferase; DHAR, dehydroascorbate reductase; MDHAR, monodehydroascorbate reductase) and as well as regulating ascorbate-glutathione (AsA-GSH) cycle. Importantly, oxidative damage showed efficient alleviations through upregulating the genes related to key defense such as SOD , CAT , POD , GR , GST , APX , GPX , DHAR , and MDHAR ; along with the genes related to ME biosynthesis. ME supplementation also enhanced the level of proline and secondary metabolites, and their encoding genes expression, which may control excessive H 2 O 2 (hydrogen peroxide) production. Finally, ME supplementation enhanced the HM stress tolerance of pepper seedlings. [Display omitted] • Melatonin enhanced leaf photosynthesis and increased seedling growth. • Melatonin inhibits heavy metal translocation from root to shoot. • Melatonin modified root architecture and enhanced mineral uptake in pepper seedlings. • Melatonin reduced oxidative damage by regulating the antioxidant enzymes under heavy metal toxicity. [ABSTRACT FROM AUTHOR]

Efficient utilization of atomic hydrogen (H*) is of great importance for achieving efficient bromate reduction using electrochemical technologies. Herein, an electrochemical membrane with metal heteroatom interface of Ru and Ni was developed to enhance the utilization efficiency of H* via the membrane filtration process. The RuNi membrane demonstrated 91.3% of bromate removal at 5 mA cm−2 under the flow-through operation (40 L m−2 h−1). Cyclic voltammetry (CV) curves and electron spin resonance (ESR) spectra elucidated that the bromate reduction was mainly attributed to H* -mediated reduction rather than the direct electron transfer between bromate and RuNi active layer. The quenching experiments revealed a significant contribution of adsorbed H* to the bromate removal during the membrane filtration. Based on X-ray photoelectron spectrometry and X-ray diffraction analyses, we found that the resultant Ru0Ni0 structure on the electrochemical membrane could facilitate the generation of H* during the bromate reduction reaction. Besides, the higher pH might suppress the formation of H* and increase the energy barrier for breaking the Br-O bond, resulting in dramatic increase of energy consumption for removing bromate. Our work highlights the potential of utilizing H* in electrochemical membrane for removing bromate in water treatment and remediation. [Display omitted] • The RuNi membrane with metal heteroatom interface was constructed. • Efficient bromate removal (91.3%) was achieved in flow-through operation. • The membrane has a superior bromate removal to other reported cathodes. • Flow-through operation facilitates the utilization of H* during bromate reduction. • Higher pH value will apparently increase energy consumption of bromate removal. [ABSTRACT FROM AUTHOR]

Removal of neonicotinoids (NEOs) from contaminated water is of great importance for both ecological environment and human health. However, conventional Fenton process might be insufficient for NEOs removal due to short lifetime for generated HO• and limited Fe3+/Fe2+ redox cycle. Advancing Fenton process to produce singlet oxygen can be an effective route to improve its efficacy for NEOs removal. Herein, we developed a molybdenum sulfide modified ceramic membrane-integrated Fenton-like system to achieve efficient catalytic removal of NEOs. The reduced Mo0 and Mo4+ could promote the reduction process of Fe3+ to Fe2+, improving the activation efficiency of hydrogen peroxide (H 2 O 2) and the generation of superoxide radical (O 2 •−). Consequently, the coexisting Mo6+ reacted with O 2 •− to generate 1O 2. The membrane enabled the pollutants to adequately contact oxidants due to the enhanced convective mass transfer. The functionalized membrane exhibited stable catalytic performance for clothianidin (CLO, a kind of NEOs, 10 mg/L) removal (degradation efficiency > 85%). The presence of 1O 2 enabled the dechlorination and hydroxylation of CLO and thus reduced the toxicity of wastewater. Our work sheds light on the use of functionalized ceramic membrane integrated catalytic Fenton system for effective environmental remediation. [Display omitted] • A functionalized ceramic membrane-integrated Fenton-like system was developed. • The reduced Mo0 and Mo4+ carried by membranes promoted the reduction of Fe3+ to Fe2+. • The membrane system had a degradation efficiency > 85% for neonicotinoids removal. • The coexisting Mo6+ in this system reacted with O 2 •− to generate 1O 2. • The presence of 1O 2 enabled the dechlorination and hydroxylation of CLO. [ABSTRACT FROM AUTHOR]

Sulfonamides, such as sulfadiazine (SDZ), are frequently detected in water and wastewater with their toxic and persistent nature arousing much concern. In this work, a novel electrochemical membrane biofilm reactor (EMBfR) was constructed for the removal of SDZ whilst suppressing the development of antibiotic resistance genes (ARGs). Results showed that the EMBfR achieved 94.9% removal of SDZ, significantly higher than that of a control membrane biofilm reactor (MBfR) without electric field applied (44.3%) or an electrolytic reactor without biofilm (77.3%). Moreover, the relative abundance of ARGs in the EMBfR was only 32.0% of that in MBfR, suggesting that the production of ARGs was significantly suppressed in the EMBfR. The underlying mechanisms relate to (i) the change of the microbial community structure in the presence of the electric field, leading to the enrichment of potential aromatic-degrading microorganisms (e.g. , Rhodococcus accounting for 51.0% of the total in the EMBfR compared to 10.0% in the MBfR) and (ii) the unique degradation pathway of SDZ in the EMBfR attributed to the synergistic effect between the electrochemical and biological processes. Our study highlights the benefits of EMBfR in removing pharmaceuticals from contaminated waters and suppressing the development (and transfer) of ARGs in the environment. ga1 • A novel EMBfR was used for removal of SDZ and suppressing of ARG development. • The EMBfR achieved 94.9% SDZ removal, significantly higher than that in control. • The relative abundance of ARGs in the EMBfR was significantly reduced. • Synergistic effect of electrochemical/biological process enhanced the performance. • Enrichment of potential aromatic-degrading microbes (e.g., Rhodococcus) occurred. [ABSTRACT FROM AUTHOR]

• A ClO-mediated photoelectrochemical filtration system was proposed for ammonia conversion. • Highly efficient and complete ammonia conversion to N 2 was achieved. • Convection-enhanced mass transport results in 5-fold increase in ammonia oxidation kinetics. • A synergistic effect between photochemical and electrochemical processes was observed. The ability to convert excess ammonia in water into harmless N 2 is highly desirable for environmental remediation. We present a chlorine-oxygen radical (ClO)-mediated photoelectrochemical filtration system for highly efficient and complete ammonia removal from water. The customized photochemical device comprised a Ag-functionalized TiO 2 nanotube array mesh photoanode and a Pd-Cu co-modified nickel foam (Pd-Cu/NF) cathode. Under illumination, holes generated at the anode catalyzed the conversion of H 2 O and Cl− to HOand Cl, respectively. In turn, these radicals then reacted further, yielding ClO, which selectively decomposed ammonia. The cathode enabled further reduction of anodic byproducts such as NO 3 − to N 2. The complete oxidation of all dissolved ammonia was achieved within 15 min reaction under neutral conditions, where N 2 was the dominant product. The impact of key parameters was assessed, which enabled the discovery of optimal reaction conditions and the proposal of the underlying working mechanism. The flow-through configuration demonstrated a 5-fold increase of ammonia oxidation rate compared to the conventional batch reactor. The role of ClO in the oxidation of ammonia was verified with electron paramagnetic resonance and scavenger studies. This study provided greater mechanistic insights into photoelectrochemical filtration technology and demonstrated the potential of future nanotechnology for removing ammonia. [ABSTRACT FROM AUTHOR]

• Recent advances in Cu-Fenton processes for industrial wastewater are summarized. • Cu complexes and Cu composites facilitate the enhancement of catalytic performance. • Roles of ligands/components are examined with focus on the mechanisms involved. • Perspectives and future efforts needed for Cu-based Fenton systems are presented. Cu-based Fenton systems have been recognized as a promising suite of technologies for the treatment of industrial wastewaters due to their high catalytic oxidation capacity. Rapid progress regarding Cu Fenton systems has been made not only in fundamental mechanistic aspects of these systems but also with regard to applications over the past decade. Based on available literature, this review synthesizes the recent advances regarding both the understanding and applications of Cu-based Fenton processes for industrial wastewater treatment. Cu-based catalysts that are essential to the effectiveness of use of Cu Fenton reactions for oxidation of target species are mainly classified into two types: (i) Cu complexes with organic or inorganic ligands, and (ii) Cu composites with inorganic materials. Performance of the Cu-based catalysts for the removal of organic pollutants in industrial wastewaters are reviewed, with the key operating parameters illustrated. Furthermore, the roles of Cu complexes and composites in both homogeneous and heterogeneous Cu-Fenton systems are critically examined with particular focus on the mechanisms involved. Perspectives and future efforts needed for Cu-based Fenton systems using Cu complexes and composites for industrial wastewater treatment are presented. [ABSTRACT FROM AUTHOR]

• Key principle problems for hindering anaerobic digestion efficiency are analyzed. • Two perspectives on enhancing anaerobic digestion efficiency are proposed. • The available strategies for enhancing anaerobic sludge digestion are reviewed. • Main knowledge gaps in enhancing anaerobic sludge digestion are identified. • Sludge's structure and property responsible for poor biodegradability is emphasized. Anaerobic digestion (AD) of waste activated sludge (WAS) is an important bio-energy strategy that has been hindered by low conversion efficiency. This paper presents a comprehensive review of research on the sludge's property and enhancing AD of WAS, and proposes two perspectives of material structure and microbial activity on improving AD efficiency. In the first part of this review, the key principle problems for hindering AD efficiency are identified based on the concept of AD. Then, the possibility that the complex microstructure and composition of WAS are responsible for poor biodegradability is considered and main methods for enhancing AD are summarized. In the third part, according to the published works, the main knowledge gaps in research are recognized as the identification and specific activity adjustment of functional microbes, the understanding of key constituents of WAS and their interactions, the deciphering of complex structure of sludge organic substance, and the revealing of relationships between complex nature of WAS and biodegradability. Further discussions reveal that to enhance AD more studies should be centered on the sludge's structure and properties in future. However, this review is expected to provide the clear and accurate research directions for enhancing AD efficiency of WAS. [ABSTRACT FROM AUTHOR]

• A bifunctional photoelectron-active filter was constructed for Sb(III) decontamination. • Simultaneous Sb(III) detoxification and Sb(V) adsorption were achieved. • A synergistic effect between photocatalytic and electrochemical oxidation of Sb(III) were observed. • The mechanism of photoelectrochemical-enhanced "one-step" Sb(III) removal was proposed. Developing advanced technologies to achieve decontamination of emerging contaminants such as antimony (Sb) is highly demanded. Herein, we successfully designed a dual-functional photoelectrochemical filter system for "one-step" detoxification and sequestration of highly toxic Sb(III). The key to this technology is a photoelectrical-responsive CNT filter functionalized with nanoscale MIL-88B(Fe) photocatalysts. At 2.5 V and under illumination, a 97.7 ± 1.5 % Sb(III) transformation and a 92.9 ± 2.3 % Sb total removal efficiency can be obtained using an optimal hybrid filter (e. g. CM(50:3)) over 2 h continuous filtration. This can be explained by the synergistic effects of the filter's flow-through design, photoelectrochemical reactivity, fine pore size, and plentiful exposed sorption sites. Various advanced characterization techniques validated the system efficacy. Improved Sb(III) removal kinetics were observed when compared with conventional batch system (97.5 % vs 75.8 %). A synergistic effect between photocatalytic (PC) and electrochemical (EC) process were identified (k PEC =0.99 h–1 > k PC =0.21 h–1 + k EC =0.30 h–1). EPR and photochemical characterizations suggested that hydroxyl radicals dominated the Sb(III) conversion. The proposed technology works effectively across a wide range of pH values and water matrixes. The outcomes of this study can facilitate mechanistic insights into photoelectrocatalysis and provide a promising nanotechnology for efficient Sb(III) decontamination. [ABSTRACT FROM AUTHOR]

• Anaerobic side-stream reactor (ASSR) coupled MBR was proposed for sludge reduction. • Effect of filling fractions of carriers in ASSR on membrane fouling (MF) was studied. • 25 % carriers alleviated MF by promoting hydrolysis and reducing sludge viscoelastic. • 50 % carriers improved MF little due to the increase of shear forces to biofilm. • MiSeq revealed biomarkers related to severe MF easily attached on membrane surface. An anoxic/oxic membrane bioreactors (AO-MBR) and three identical anaerobic side-stream reactor coupled with anoxic/oxic membrane bioreactors (ASSR-MBR) were constructed and operated in parallel to investigate the appropriate filling fraction of carriers packed in ASSR, influences on pollutants removal, sludge reduction, membrane fouling and microbial community of ASSR-MBR. Inserting ASSR achieved efficient COD removal and nitrification, and packing carriers in ASSR obtained the highest sludge reduction efficiency of 50.5 % at filling fraction of 25 %. Compared to AO-MBR, inserting ASSR without carriers induced the release of viscous components in extracellular polymeric substances (EPS) and the formation of calcium carbonate-related bacteria on membrane surface, and thus deteriorated membrane fouling. Packing carriers with 25 % filling fraction promoted the hydrolysis of soluble microbial products and EPS, whilst reduced the viscoelasticity of sludge flocs. Higher filling fraction of 50 % increased the shear forces to the biofilm and biomarkers related to membrane fouling, and thus showed little improvement to alleviate membrane fouling. MiSeq sequencing revealed that although it enriched in the bulk sludge of conventional ASSR-MBR and the coupled reactor with filling fraction of 50 %, the floc-forming, hydrolytic and fermentative bacteria were more inclined to attach on the membrane surface and alleviate fouling process. [ABSTRACT FROM AUTHOR]