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Freshwater represents one of the most precious resources on the planet, so it is fundamental to preserve it. In this work, an innovative sunlight‐driven device composed of bismuth oxybromide (BiOBr) grown on a material derived from natural sources, i.e., Lightweight Expanded Clay Aggregates (LECA), is developed to clean surface waters under natural solar light irradiation. For this purpose, the photodegradation of two non‐steroidal anti‐inflammatory drugs, ibuprofen, and diclofenac, is investigated under varying operative conditions. Laboratory‐ and real‐scale experiments reveal that the fabricated floating BiOBr/LECA photocatalyst fully degrades diclofenac, whereas limited abatement of ibuprofen is observed. Based on the identification of specific transformation products (TPs) during the degradation, this behavior seems to be strongly related to the different structures of the two drugs. In fact, the main TP produced during diclofenac degradation derives from dechlorination and ring condensation: this type of photocatalytic degradation pathway is generally favored over the C─C bonds's cleavage, which is a unique possibility for IBU abatement. Moreover, the potential partial adsorption of these species on the photocatalyst's active sites can cause their deactivation. Finally, reusability tests demonstrate the high stability of the floating composite. [ABSTRACT FROM AUTHOR]

The requirements for water intended for domestic and economic purposes prompt the search for new solutions in surface water treatment technologies. In this study, the enhancement of coagulation processes by connections with adsorption and/or ozonation for surface water treatment was studied. The possibility of a reduction in natural organic matter (NOM) content in modified surface water was analysed regarding changes in colour, turbidity, oxidisability (OXI), total and dissolved organic carbon (TOC, DOC) and absorbance at 254 nm (UV254). Additionally, the changes in copper and zinc ion content during the modified surface water treatments studied were analysed for initial metal concentrations of 0.5 or 1.0 mg/L. Studies of modified surface water were carried out with doses of medium-basicity PAX coagulant (C2) 5 mg/L and PAC 100 mg/L. During the coagulation process, the colour decreased by 86–90%, turbidity by 85–90%, OXI by 65–77%, TOC by 65–76% and UV254 absorbance by 73–84%. The enhancement of coagulation with adsorption and/or ozonation resulted in an increased efficiency of colour and turbidity removal by 2 and 4%, respectively. The highest increase in efficiencies of OXI, TOC, DOC and UV254 removal, by 12, 12, 11 and 11%, was observed for the connection of ozonation with coagulation and adsorption. The efficiency of metal ion removal from modified water observed for the single coagulation process was 58 and 55% for copper and 46 and 43% for zinc, respectively, for initial concentrations of 0.5 and 1.0 mg/L. The intensification of coagulation with ozonation and adsorption resulted in metal removal on the level of 66 and 62% for copper and 62 and 54% for zinc. [ABSTRACT FROM AUTHOR]

This is the first study to describe a novel, patented process for the on-site synthesis and subsequent direct utilisation of Polyferric Chloride (PFC) at low Fe concentration dosing, which aims to facilitate the potential replacement of Polyaluminium Chloride (PAC) during surface water treatment (e.g., from reservoirs) for drinking water production. For this purpose, the PFC was synthesised and subsequently used as a coagulant in simulated surface water samples under different synthesis and coagulation/flocculation conditions, namely for different pre-hydrolysed Fe concentrations, pre-hydrolysis pH, coagulation pH, and flocculation times. The effectiveness of PFC was examined mainly in terms of total organic carbon (TOC) removal and the residual Fe concentration. The obtained results showed that the pre-hydrolysed Fe concentration at 0.5 ± 0.25%, pre-hydrolysis at pH 2.5 ± 0.25, coagulation at pH 5.5–7.0 and a flocculation time of 5 min could result in the highest TOC removal (i.e., residual values < 0.60 mg/L) and the lowest residual Fe concentration (<5 μg Fe/L), which is acceptable for a water quality assessment. These values are also substantially lower when compared to the respective TOC and residual metal concentrations using PAC (usually, the relevant obtained values are around TOC > 1 mg/L and Al > 50 μg/L). [ABSTRACT FROM AUTHOR]

An upflow sand filter operated in incremental filtration rates (0.072, 0.181, 0.481 m3 m-2 h-1) was studied for turbidity, total suspended solids (TSS), ammonia (NH4), and total coliform removal rates. Each cycle lasted for 45 days. The filter bed was made of sand with 0.10 mm D10 and supported by 0.49 mm and 2.10 mm gravel with a total bed depth of 0.50 m. Turbidity removal was recorded above 80% in all cycles with a maximum concentration of 7.29 NTU. TSS removal was maintained at over 90%, with an average discharge of 4.77 mg/L in all cycles. The NH4 removal increased steadily to 91% for 0.072 m3 m-2 h-1 and 93% for 0.181 m3 m-2 h-1 filtration rate. The algal bloom occurrence at 0.481 m3 m-2 h-1 filtration rate overloaded the system with NH4, declining the removal rate to 45%. Total coliform removal recorded an average of 99% in 0.072 m3 m-2 h-1, 89% in 0.181 m3 m-2 h-1, and 66% in 0.481 m3 m-2 h-1. A high filtration rate resulted in a shorter contact time between pollutants and microorganisms within the filter bed, which reduces the removal efficiency. The Shearing effect was also experienced where the attachments of particles and bacteria were minimised.

This paper reviews the research progress of micro-nano bubbles in enhanced wastewater treatment and surface water treatment, including their enhancement of ozonation technology, photocatalysis technology, air floatation technology as well as the enhancement of microbial activity and eutrophication mitigation in water bodies.We summarize the current applications of micro and nano bubbles technology in water treatment projects and provide an outlook on the future research prospects of micro and nano bubbles technology in water treatment, in order to provide a reference for the practical application of micro and nano bubbles in water treatment. [ABSTRACT FROM AUTHOR]

No Environmental Protection Agency (EPA) chemical treatments for preharvest agricultural water are currently labeled to reduce human health pathogens. The goal of this study was to examine the efficacy of peracetic acid- (PAA) and chlorine (Cl)-based sanitizers against Salmonella in Virginia irrigation water. Water samples (100 mL) were collected at three time points during the growing season (May, July, September) and inoculated with either the 7-strain EPA/FDA-prescribed cocktail or a 5-strain Salmonella produce-borne outbreak cocktail. Experiments were conducted in triplicate for 288 unique combinations of time point, residual sanitizer concentration (low: PAA, 6 ppm; Cl, 2-4 ppm or high: PAA, 10 ppm; Cl, 10-12 ppm), water type (pond, river), water temperature (12°C, 32°C), and contact time (1, 5, 10 min). Salmonella were enumerated after each treatment combination and reductions were calculated. A log-linear model was used to characterize how treatment combinations influenced Salmonella reductions. Salmonella reductions by PAA and Cl ranged from 0.0 ± 0.1 to 5.6 ± 1.3 log10 CFU/100 mL and 2.1 ± 0.2 to 7.1 ± 0.2 log10 CFU/100 mL, respectively. Physicochemical parameters significantly varied by untreated water type; however, Salmonella reductions did not (p = 0.14), likely due to adjusting the sanitizer amounts needed to achieve the target residual concentrations regardless of source water quality. Significant differences (p PAA) and contact time (10 > 5 > 1 min) having the greatest effects. The log-linear model also revealed that outbreak strains were more treatment-resistant. Results demonstrate that certain treatment combinations with PAA- and Cl-based sanitizers were effective at reducing Salmonella populations in preharvest agricultural water. Awareness and monitoring of water quality parameters are essential for ensuring adequate dosing for the effective treatment of preharvest agricultural water.

Here, multifunctional heterogeneous ion-exchange metal nanocomposite membranes were prepared for surface water desalination and bacterial inactivation under low-pressure (0.05 MPa) filtration conditions. Ultrafiltration (UF) heterogeneous ion exchange membranes (IEMs) were modified with different concentrations of AgNO3 and CuSO4 solutions using the intermatrix synthesis (IMS) technique to produce metal nanocomposite membranes. Scanning electron microscopy (SEM) images revealed that the metal nanoparticles (MNPs) (Ag and Cu) were uniformly distributed on the surface and the interior of the nanocomposite membranes. With increasing metal precursor solution concentration (0.01 to 0.05 mol·L−1), the metal content of Ag and Cu nanocomposite membranes increased from 0.020 to 0.084 mg·cm−2 and from 0.031 to 0.218 m·cm−2 respectively. Results showed that the hydrodynamic diameter diameters of Ag and Cu nanoparticles (NPs) increased from 62.42 to 121.10 nm and from 54.2 to 125.7 nm respectively, as the metal precursor concentration loaded increased. The leaching of metals from metal nanocomposite membranes was measured in a dead-end filtration system, and the highest leaching concentration levels were 8.72 ppb and 5.32 ppb for Ag and Cu, respectively. The salt rejection studies indicated that ionic selectivity was improved with increasing metal content. Bacterial filtration showed higher antibacterial activity for metal nanocomposite membranes, reaching 3.6 log bacterial inactivation. [ABSTRACT FROM AUTHOR]

The utilization of biochar holds promise as a viable method for the preservation of water resources and the remediation of wastewater. The objective of this study is to evaluate the advancements achieved in the field of biochar research pertaining to the remediation of surface water. The review was conducted by systematically collecting data from Scopus and doing bibliometric analysis. This study utilized the Scopus database to retrieve data pertaining to countries, institutions, highly cited articles, keywords, emerging subjects, and prospective research directions. Furthermore, the VOSviewer bibliometric software was utilized to assess the scholarly citations in this research paper. The results indicate that significant advancements have been achieved in this area of study during the year 2015. A total of 48 works has been indexed by Scopus, a renowned academic database, across 28 distinct international journals. A significant proportion of researchers primarily operate within the United States, often engaging in collaborative efforts with their counterparts from China. This article attempts to study the bibliography on the biochar for surface water treatment, identify popular topics, and discern the fields of future studies in this discussion. Furthermore, it investigates future research in the field of biochar will primarily concentrate on optimizing the synthesis of biochar and exploring its potential use in the treatment of heavy metals and organic chemicals. [ABSTRACT FROM AUTHOR]

Simulation is a modus operandi often used for imitating real-world processes. It involves a system and set of assumptions used for computing a numerical model, from which the outcome is an estimate of the true characteristics of how the system behaves. The intention of this research was to investigate the efficiency of fabric in two-stage cross-flow filtration using linen, crepe-backed satin, burlap and cotton fabric filter media. The results from previous pilot-scale experiments performed showed that linen fabric was the most effective medium at retaining particles. In continuation of this research, the aim of this paper was to utilize Hydrus-1D simulation software to simulate cross-flow filtration with fabric filter medium. This was done to further confirm the efficiency of cross-flow filtration, in particular with linen fabric filter media. Simulation entailed investigating fabric water content versus pressure head; bottom pressure head versus time; fabric water storage versus time; and cumulative infiltration versus time with both single and four layers of fabric filter media. Hydrus-1D simulation was productive since it confirmed that cross-flow filtration with linen fabric filter media has the potential of becoming a pre-filtration step in surface water treatment, further adding to the results obtained from previous pilot-scale experiments. HIGHLIGHTS Pre-filtration step in surface water treatment.; Removal of suspended particles from turbid river water using fabric filter media.; The use of linen fabric as an essential filter media in the removal of particles from turbid river water.; Increased efficiency of the removal of particles is enhanced by using four layers of fabric filter media.; Successful simulations of turbid water filtration by varying fabric filter media types.;

Organic matter present in natural water is a serious problem during water treatment in terms of the possibility of creating disinfection by-products (DBP). The new materials and processes are still analyzed in order to improve the efficient removal of organic matter as well as other pollutants from water intended for human consumption. The aim of the presented study was to evaluate the efficiency of using various combined processes: (a) coagulation and adsorption, (b) oxidation with ozone and coagulation, (c) oxidation with ozone, coagulation and adsorption, and (d) oxidation with ozone, UV irradiation, coagulation and adsorption for treatment of the modified surface water. In the presented study, the changes in pH, turbidity, color, organic matter content (evaluated as oxidizability, total and dissolved organic carbon content, UV 254 and 272 absorbances), and Ni2+, Cd2+, and Pb2+ ions content were determined during modified surface water purification. Supporting the coagulation process by adsorption with additional ozonation and UV irradiation of the water sample improved the treatment processes of modified surface water. Processes associated with coagulation increased the efficiency of removing color by 4–16% and reduced the value of UV254 and UV272 absorbance by 10–20%. Using ozonation did not significantly change the content of total organic matter. Heavy metal ions were mostly removed by coagulation and adsorption processes (40–60%). Including ozone, oxidation resulted in insignificant changes in the concentration of metal ions in the purified water (less than 5%). During the treatment of the tested, modified surface water, the best efficiency was observed after the use of coagulation and adsorption processes enhanced with ozone oxidation. The additional involvement of UV irradiation did not have a significant effect on the removal of the analyzed pollutants. [ABSTRACT FROM AUTHOR]

Steam system water inventory is mainly supplied by surface sources, such as lakes or rivers. The incoming surface water is highly contaminated with organic matter and mineral salts. Inadequate treatment of such water sources results in severe and widespread deposits and water-side corrosion. This paper studied the Fenton oxidation with coagulation as pretreatment of the surface water from Nile River (Ismailia Channel) used as makeup boiler water. The incoming water has been analyzed and characterized for one year; the examined characteristics in this work are pH, total dissolved solid (TDS), total hardness (TH), chlorides, total alkalinity (TA), and organic matter (OM). Additionally, the effect of two types of coagulants and Fenton oxidation process on the reduction of the above characteristics has been studied. Moreover, the effect of the combination of Fenton/coagulation process was investigated. The influence of Fe2+ concentration and coagulant dosages was studied. The experimental work was carried out by using Jar test. The results proved that coagulation with ferric chloride is more beneficial than alum at similar doses. It is also found that treatment by Fenton oxidation with coagulation is more effective than coagulation or Fenton oxidation, under operating conditions ([Fe2+] = 10 mg/L; Fe2+:H2O2 = 1.25:1; initial pH = 2.8; followed by coagulation at initial pH 8 with 5 mg/L ferric chloride). [ABSTRACT FROM AUTHOR]

According to the World Health Organization, antibiotic resistance is one of the main threats to global health. The excessive use of several antibiotics has led to the widespread distribution of antibiotic-resistant bacteria and antibiotic resistance genes in various environment matrices, including surface water. In this study, total coliforms, Escherichia coli and enterococci, as well as total coliforms and Escherichia coli resistant to ciprofloxacin, levofloxacin, ampicillin, streptomycin, and imipenem, were monitored in several surface water sampling events. A hybrid reactor was used to test the efficiency of membrane filtration, direct photolysis (using UV-C light emitting diodes that emit light at 265 nm and UV-C low pressure mercury lamps that emit light at 254 nm), and the combination of both processes to ensure the retention and inactivation of total coliforms and Escherichia coli as well as antibiotic-resistant bacteria (total coliforms and Escherichia coli) present in river water at occurrence levels. The membranes used (unmodified silicon carbide membranes and the same membrane modified with a photocatalytic layer) effectively retained the target bacteria. Direct photolysis using low-pressure mercury lamps and light-emitting diode panels (emitting at 265 nm) achieved extremely high levels of inactivation of the target bacteria. The combined treatment (unmodified and modified photocatalytic surfaces in combination with UV-C and UV-A light sources) successfully retained the bacteria and treated the feed after 1 h of treatment. The hybrid treatment proposed is a promising approach to use as point-of-use treatment by isolated populations or when conventional systems and electricity fail due to natural disasters or war. Furthermore, the effective treatment obtained when the combined system was used with UV-A light sources indicates that the process may be a promising approach to guarantee water disinfection using natural sunlight.

Global surface waters are in a bad ecological and chemical state, which has detrimental effects on entire ecosystems. To prevent further deterioration of ecosystems and ecosystem services, it is vital to minimize environmental pollution and come up with ways to keep surface water healthy and clean. Recently, photogranules have emerged as a promising platform for wastewater treatment to remove organic matter and nutrients with reduced or eliminated mechanical aeration, while also facilitating CO 2 capture and production of various bioproducts. Photogranules are microbial aggregates of microalgae, cyanobacteria, and other non-phototrophic organisms that form dense spheroidic granules. Photogranules settle fast and can be easily retained in the treatment system, which allows increased amounts of water and wastewater to be treated. So far, photogranules have only been tested on various "high-strength" wastewaters but they might be an excellent choice for treatment of large volumes of polluted surface water as well. Here, we propose and tested for the first time photogranules on their effectiveness to remove nutrients from polluted surface water at unprecedented low concentrations (3.2 mg/L of nitrogen and 0.12 mg/L of phosphorous) and low hydraulic retention time (HRT = 1.5 h). Photogranules can successfully remove nitrogen (<0.6 mg/L, ∼80 % removal) and phosphorous (<0.01 mg/L, 90-95 % removal) to low levels in sequencing batch operation even without the need for pH control. Subjecting photogranules to surface water treatment conditions drastically changed their morphology. While, under "high-strength" conditions the photogranules were spherical, dense and defined, under polluted surface water conditions photogranules increased their surface area by forming fingers. However, this did not compromise their excellent settling properties. Finally, we discuss the future perspectives of photogranular technology for surface water treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

To investigate watershed remediation within a Total Maximum Daily Load program, this study examined the field-scale filtration performance of two specialty absorbents. The goal was to simultaneously remove nutrients and biological pollutants along Canal 23 (C-23) in the St. Lucie River Basin, Florida. The filtration system installed in the C-23 river corridor was equipped with either clay–perlite with sand sorption media (CPS) or zero-valent iron and perlite green environmental media (ZIPGEM). Both media were formulated with varying combinations of sand, clay, perlite, and/or recycled iron based on distinct recipes. In comparison with CPS, ZIPGEM exhibited higher average removal percentages for nutrients. Findings indicated that ZIPGEM could remove total nitrogen up to 49.3%, total Kjeldahl nitrogen up to 67.1%, dissolved organic nitrogen (DON) up to 72.9%, total phosphorus up to 79.6%, and orthophosphate up to 73.2%. Both ZIPGEM and CPS demonstrated similar efficiency in eliminating biological pollutants, such as E. coli (both media exhibiting an 80% removal percentage) and chlorophyll a (both media achieving approximately 95% removal). Seasonality effects were also evident in nutrient removal efficiencies, particularly in the case of ammonia nitrogen; the negative removal efficiency of ammonia nitrogen from the fifth sampling event could be attributed to processes such as photochemical ammonification, microbial transformation, and mineralization of DON in wet seasons. Overall, ZIPGEM demonstrated a more stable nutrient removal efficiency than CPS in the phase of seasonal changes. [Display omitted] • ZIPGEM perform better than CPS in removing nutrients. • Ammonification is a key process for removing nutrient. • Seasonal changes may affect the performance of filtration. [ABSTRACT FROM AUTHOR]

• Zwitterionic hydrogel nanolayer was synthesized by interfacial polymerization. • Zwitterionic monomer modulated the hydrogel layer structure and membrane characters. • Zwitterionic hydrogel hindered the adhesion of biomacromolecules and killed microbes. • The growth of biofilm on zwitterionic hydrogel nanolayer surface was inhibited. Ultralow-pressurized ultrafiltration membrane process with low energy consumption is promising in surface water purification. However, membrane fouling and low selectivity are significant barriers for the wide application of this process. Herein, an ultrathin zwitterionic hydrogel nanolayer was in-situ grown on polysulfone ultrafiltration membrane surface through interfacially-initiated free radical polymerization. The hydrogel-modified membrane possessed improved biological fouling resistance during the dynamic filtration process (bovine serum albumin, Escherichia coli and Staphylococcus aureus), comparing with commercial polysulfone membrane. The enhanced biofouling resistance ability of zwitterionic hydrogel nanolayer was derived from the foulant repulsion of hydration shell and the bactericidal effect of quaternary ammonium, according to the results of foulant-membrane interaction energy analyses and antibacterial performances. In surface water treatment, the zwitterionic hydrogel layer inhibited biofouling and resulted in the formation of a loose and thin biofilm. In addition, the hydrogel-modified membrane possessed 22% improvement in dissolved organic carbon (DOC) removal and 134% increasement in stable water flux, compared to commercial polysulfone membrane. The in-situ grown zwitterionic hydrogel nanolayer on membrane surface offers a prospectively alternative for biofouling control in ultralow-pressurized membrane process. [Display omitted] [ABSTRACT FROM AUTHOR]

This work investigates the proanthocyanidin profile of willow bark crude extracts and these materials were cationized and preliminarily tested as biocoagulants for water treatment. The characteristics of crude extracts proanthocyanidin were investigated using size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). XPS analysis indicates that the crude extracts contain significant amounts of sugars. Furthermore, SEC and liquid-state NMR spectroscopy showed that crude extract contains roughly 3–4 flavan-3-ol units with procyanidin (PC)/ prodelphinidin (PD) ratio of roughly 3–5. Thus, the modified form of tannin (proanthocyanidin-enriched) coagulants obtained the higher cationic charge density. The coagulation experiments with kaolin-river water mixture suggested that all the selected willow hybrids' tannin coagulants were effective in settling the particles down. This study indicates that the value of willow bark can be significantly improved by the usage of crude extracts for water treatment. [Display omitted] • Crude extracts from eight willow hybrids are characterized and Mannich modified. • The extract contains roughly 3-4 flavan-3-ol units with PC/PD ratio of roughly 3-5. • Modified proanthocyanidin-enriched extracts have medium cationic charge densities. • The biocoagulants were effective in settling the particles down from river water. [ABSTRACT FROM AUTHOR]

• The flocculant TRC, like proteins, has temperature-dependent hydrophobicity. • Residual TRC after flocculation hydrophilized UF membrane surface. • Inspired by protein folding, elevated cleaning temperature reduced membrane fouling. • An elevated temperature promotes the role of TRC in hydrophilization of membrane. • Structure of fouling layer containing TRC weakened at elevated temperature. Hydrophobic-modified flocculants have demonstrated considerable promise in the removal of emerging contaminants by flocculation. However, there is a lack of information about the impacts of dosing such flocculants on the performance of subsequent treatment unit(s) in the overall water treatment process. In this work, inspired by the ubiquitous protein folding phenomenon, an innovative approach using an elevated membrane cleaning temperature as the means to induce residual hydrophobic-modified chitosan flocculant (TRC), after flocculation-sedimentation, to reduce membrane fouling in a subsequent ultrafiltration was proposed; this was evaluated in a continuous flocculation-sedimentation-ultrafiltration (FSUF) process treating samples of the Yangtze River. The hydrophobic chains of TRC had similar temperature-dependent hydrophobicity to those of natural proteins. In the 40-day operation of the FSUF system with combined dosing of alum and TRC, a moderately elevated cleaning water temperature (45 °C) of both backwash with air-bubbling and soaking with sponge-scrubbing cleaning, significantly reduced reversible and irreversible fouling resistance by 49.8%∼61.3% and 73.9%∼83.3%, respectively, compared to the system using cleaning water at 25 °C. Material flow analysis, statistical analysis, instrumental characterizations, and computational simulations, showed that the enhanced fouling mitigation originated from three factors: the reduced contaminant accumulation onto membranes, the strengthened membrane-surface-modification role of TRC, and the weakened structure of the fouling material containing TRC, at the elevated cleaning temperature. Other measures of the performance, these being water purification, membrane stability and economic aspects, also confirmed the potential and feasibility of the proposed approach. This work has provided new insights into the role of hydrophobic-modified flocculants in membrane fouling control, in addition to emerging contaminant removal, in a FSUF surface water treatment process. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Asphalt and biochar-modified asphalt (BMA) absorbed Cu. • Biochar-modified asphalt enhanced the absorption. • Molecular simulations were employed to elucidate the absorption mechanisms. • More asphaltenes fractions appeared in the asphalt part of BMA. • Asphaltenes were the Cu adsorbing preference sites. Asphalt has been the primary material for pavements and other building components such as roof shingles and waterproofing systems, which can be the path for stormwater runoff pollutants such as heavy metals (HMs). In this study, the capability and mechanism of asphalt and biochar-modified asphalt (BMA) to remove Cu as the typical HM found in the road dust and surface runoff were fundamentally explored for the first time. Experiment and multiscale molecular simulations were performed. Molecular dynamics (MD) simulations showed the Cu absorption into the asphalts. Monte Carlo (MC) and density functional theory (DFT) revealed the detailed mechanism of Cu absorption. Biochar (BC) presence modified the spatial distribution of maltene and asphaltene fractions in asphalt and enhanced the absorption. Maltenes were absorbed into the porous structure of BC, leaving more asphaltenes in the asphalt part of BMA. Asphaltenes were the Cu adsorbing preference sites ascribed to the cation-π interaction between Cu and the aromatic plane. The DFT simulations also suggested favourable adsorption of other commonly found metals (e.g., Cr, Pb, Ni, Cd, and Zn) onto asphaltenes. The present study found the capability and mechanism of BMA and asphalt to remove HMs at the molecular scales, providing a path for designing asphalts with value-added functionality in minimizing environmental pollution. [ABSTRACT FROM AUTHOR]

The efficiency of persulfate-assisted advanced oxidation processes (PS-AOPs) in degrading organic pollutants is affected by the electron-donating capability of organic substances present in the water source. In this study, we systematically investigate the electron-donating capacity (EDC) difference between groundwater and surface water and demonstrate the dependence of removal efficiency on the EDC of target water by PS-AOPs with carbon nanotubes (CNTs) as a catalyst. Laboratory analyses and field experiments reveal that the CNT/PS system exhibits higher performance in organic pollutant removal in groundwater with a high concentration of phenols, compared to surface water, which is rich in quinones. We attribute this disparity to the selective electron transfer pathway induced by potential difference between PS-CNT and organic substance-CNT intermediates, which preferentially degrade organic substances with stronger electron-donating capability. This study provides valuable insights into the inherent selective removal mechanism and application scenarios of electron transfer process-dominated PS-AOPs for water treatment based on the electron-donating capacity of organic pollutants.

No Environmental Protection Agency (EPA) chemical treatments for preharvest agricultural water are currently labeled to reduce human health pathogens. The goal of this study was to examine the efficacy of peracetic acid- (PAA) and chlorine (Cl)-based sanitizers against Salmonella in Virginia irrigation water. Water samples (100 mL) were collected at three time points during the growing season (May, July, September) and inoculated with either the 7-strain EPA/FDA-prescribed cocktail or a 5-strain Salmonella produce-borne outbreak cocktail. Experiments were conducted in triplicate for 288 unique combinations of time point, residual sanitizer concentration (low: PAA, 6 ppm; Cl, 2-4 ppm or high: PAA, 10 ppm; Cl, 10-12 ppm), water type (pond, river), water temperature (12°C, 32°C), and contact time (1, 5, 10 min). Salmonella were enumerated after each treatment combination and reductions were calculated. A log-linear model was used to characterize how treatment combinations influenced Salmonella reductions. Salmonella reductions by PAA and Cl ranged from 0.0 ± 0.1 to 5.6 ± 1.3 log 10 CFU/100 mL and 2.1 ± 0.2 to 7.1 ± 0.2 log 10 CFU/100 mL, respectively. Physicochemical parameters significantly varied by untreated water type; however, Salmonella reductions did not (p = 0.14), likely due to adjusting the sanitizer amounts needed to achieve the target residual concentrations regardless of source water quality. Significant differences (p < 0.05) in Salmonella reductions were observed for treatment combinations, with sanitizer (Cl > PAA) and contact time (10 > 5 > 1 min) having the greatest effects. The log-linear model also revealed that outbreak strains were more treatment-resistant. Results demonstrate that certain treatment combinations with PAA- and Cl-based sanitizers were effective at reducing Salmonella populations in preharvest agricultural water. Awareness and monitoring of water quality parameters are essential for ensuring adequate dosing for the effective treatment of preharvest agricultural water., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

• Photoinduced NOM in natural surface water for PMS activation was realized. • Activation of PMS by irradiated NOM oxidized NOM itself. • Irradiated NOM/PMS system mitigated ultrafiltration membrane fouling. • NOM removal and membrane flux are positively correlated with light intensity. Oxidation pretreatments prior to ultrafiltration are hindered by the need for energy input and sludge disposal. Herein, a simulated sunlight-induced natural organic matter (NOM) for peroxymonosulfate (PMS) activation was used as pretreatment to alleviate ultrafiltration membrane fouling caused by NOM itself in the Songhua River water. When light intensity was over 100 mW/cm2, the pretreatment removed NOM effectively, characterized with UV 254 , dissolved organic carbon (DOC) and maximum fluorescent intensity (F max), and improved filtration flux. At 200 mW/cm2 light intensity and 0.5 mM PMS, 57.5% of UV 254 and 18.5% of DOC were removed, and humic-like fluorescent component was degraded by 84%-94% while ∼60% for protein-like substance. Membrane flux was increased by 94%, and reversible and irreversible fouling resistances were reduced by 62.4% and 51.9%, respectively. Both total fouling index (TFI) and hydraulic irreversible fouling index (HIFI) were moderately correlated with the DOC, whereas they prominently correlated with the UV 254 and the F maxs of all fluorescence components, which could be served as key indicators to predict and control membrane fouling. Mathematical modeling showed that the pretreatment alleviated the fouling in the membrane pores and cake layer. The simulated sunlight-induced NOM (3NOM* and e aq ¯) could activate PMS to form active species, which enabled to oxidize high molecular weight (MW) substances and mineralize low MW compounds in NOM as well as hinder their linking with inorganic cations, thereby reducing organic and inorganic membrane fouling simultaneously. This study may provide a new strategy for decentralized potable water treatment, especially in a single household or community. [Display omitted] [ABSTRACT FROM AUTHOR]

• Surface water containing pesticides was treated by FSUF process. • Dosing the flocculant HOC-M effectively removed pesticides. • Residual HOC-M in UF unit enhanced fouling (especially irreversible) reduction. • Hydrophobic association between HOC-M and pesticides promoted pesticide removal. • HOC-M exerted a stable hydrophilization modification effect on membrane surfaces. Pesticide concentrations in surface water occasionally exceed regulated values due to seasonal events (rainy season in high intensity agricultural areas) or intermittent discharges (leakage, spillage, or other emergency events). The need to remove pesticide compounds in these situations poses a challenge for drinking water treatment plants (DWTPs). In this work, the performance of dosing hydrophobic-modified inorganic-organic hybrid flocculants (HOC-M; lower acute toxicity than corresponding metal salt coagulants; acceptable economic costs when M=Al or Fe; prepared in large-scale quantities), for the removal of four different pesticides (each initial concentration: 0.25 μg/L) from Yangtze River water, and in mitigating membrane fouling, by an integrated flocculation-sedimentation-ultrafiltration (FSUF) process, was evaluated over a period of 40 days; the FSUF is well-established in many DWTPs. The mechanisms underlying the treatment were unveiled by employing a combination of instrumental characterizations, chemical computations, material flow analyses, and statistical analyses. Efficient pesticide removal (80.3%∼94.3%) and membrane fouling reduction (26.6%∼37.3% and 28.3%∼57.6% for reversible and irreversible membrane resistance, respectively) in the FSUF process were achieved by dosing HOC-M, whereas conventional inorganic coagulants were substantially inferior for pesticide removal (< 50%) and displayed more severe fouling development. Hydrophobic association between the pesticides and the hydrophobic organic chain of HOC-M played a predominant role in the improvement in pesticide removal; coexisting particulate/colloid inorganic minerals and natural organic matter with HOC-M adsorbed on the surface, acting as floc building materials, provided sites for the indirect combination of pesticides into flocs. The observed fouling alleviation from dosing HOC-M was ascribed to both the pre-removal of fouling-causing materials in the flocculation-sedimentation prior to UF, and a stable hydrophilization modification effect of residual HOC-M in the UF unit. The latter effect resulted from a hydrophobic association between the PVDF substrate of the membranes and the hydrophobic organic chains of the HOC-M, causing the hydrophilic ends of the HOC-M to be exposed away from the membrane surface, thereby inhibiting foulant accumulation. This work has not only demonstrated the superior performance of dosing HOC-M in the FSUF process for trace pesticide removal in DWTPs, but also clarified the underlying mechanisms. [Display omitted] [ABSTRACT FROM AUTHOR]

• The study compares the performance of outside-in and inside-out UF membrane configuration in a pilot-scale system treating surface water. • One of the tested UF modules has multi-bore inside-out type membranes (M1), and the other has reinforced hollow fiber outside-in type membranes (M2) • Although the treatment performances were quite similar, the filtration performances of the M1 and M2 were different. • This study comparatively presented the long-term operating performance, capital and operational costs for multi-bore inside-out and reinforced outside-in UF membrane configuration. The performance of ultrafiltration (UF) is heavily influenced by the specifications of membrane modules and operational modes. Pore size, configuration, and material of the UF membrane influence both treatment and filtration performances. The study compares the performance of outside-in and inside-out UF membrane configuration in a pilot-scale system treating surface water. One of the tested UF modules has multi-bore inside-out type membranes (M1), and the other has reinforced hollow fiber outside-in type membranes (M2). Although the treatment performances were quite similar, the filtration performances of the M1 and M2 were different. In long-term pilot-scale operation, the permeability of the M2 module measured 50 L/m2.h.bar, while the M1 module measured 34 L/m2.h.bar. At the same time, it was observed that the transmembrane pressure (TMP) of M1 was higher than that of M2. A cost analysis was made based on the pilot plant data; estimated capital expenses of 0.019 $/m3 and operation and maintenance (O&M) cost of 0.045 $/m3 were found for the M2 module. This study comparatively presented the long-term operating performance, capital and operational costs for multi-bore inside-out and reinforced outside-in UF membrane configuration. [ABSTRACT FROM AUTHOR]

According to the World Health Organization, antibiotic resistance is one of the main threats to global health. The excessive use of several antibiotics has led to the widespread distribution of antibiotic-resistant bacteria and antibiotic resistance genes in various environment matrices, including surface water. In this study, total coliforms, Escherichia coli and enterococci, as well as total coliforms and Escherichia coli resistant to ciprofloxacin, levofloxacin, ampicillin, streptomycin, and imipenem, were monitored in several surface water sampling events. A hybrid reactor was used to test the efficiency of membrane filtration, direct photolysis (using UV-C light emitting diodes that emit light at 265 nm and UV-C low pressure mercury lamps that emit light at 254 nm), and the combination of both processes to ensure the retention and inactivation of total coliforms and Escherichia coli as well as antibiotic-resistant bacteria (total coliforms and Escherichia coli ) present in river water at occurrence levels. The membranes used (unmodified silicon carbide membranes and the same membrane modified with a photocatalytic layer) effectively retained the target bacteria. Direct photolysis using low-pressure mercury lamps and light-emitting diode panels (emitting at 265 nm) achieved extremely high levels of inactivation of the target bacteria. The combined treatment (unmodified and modified photocatalytic surfaces in combination with UV-C and UV-A light sources) successfully retained the bacteria and treated the feed after 1 h of treatment. The hybrid treatment proposed is a promising approach to use as point-of-use treatment by isolated populations or when conventional systems and electricity fail due to natural disasters or war. Furthermore, the effective treatment obtained when the combined system was used with UV-A light sources indicates that the process may be a promising approach to guarantee water disinfection using natural sunlight.

• Layered metal oxides loaded ceramic membrane were successfully fabricated. • In-situ PMS activation could mitigate NOM membrane fouling effectively. • Surface-bound radical and 1O 2 were idenfied as the dominant ROS. • CoAl-LMO was the best activator of PMS for membrane fouling mitigation. Catalytic membrane can achieve sieving separation and advanced oxidation simultaneously, which can improve the effluent water quality while reducing membrane fouling. In this study, the catalytic membranes (M2+Al@AM) were fabricated by loading different binary layered metal oxides (M2+Al-LMO: MnAl-LMO, CuAl-LMO and CoAl-LMO) on alumina ceramic substrate membranes (AM) via vacuum filtration followed by calcination process. The performance of the catalytic membranes was investigated by filtering actual surface water. It was found that the presence of peroxymonosulfate (PMS) could mitigate membrane fouling effectively, as evidenced by the increase of normalized flux from 0.28 to 0.62 in CoAl@AM/PMS system, from 0.25 to 0.52 in CuAl@AM/PMS system, and from 0.22 to 0.31 in MnAl@AM/PMS system, respectively. Correspondingly, the CoAl@AM exhibited the highest removal for UV 254 , TOC and fluorescent components in the surface water, followed by CuAl@AM and MnAl@AM. Quenching effect of phenol and furfuryl alcohol proposed the surface-bound radicals and singlet oxygen were the major reactive oxygen species in the M2+Al@AM/PMS systems. Interface free energy calculations confirmed the in-situ PMS activation could enhance the repulsive interactions between NOM and the membranes, thus mitigating membrane fouling. This work provides an original but simple strategy for catalytic ceramic membrane preparation and new insights into the mechanism of membrane fouling mitigation in catalytic membrane system. [Display omitted] [ABSTRACT FROM AUTHOR]

• Dosing alum + hydrophobic chitosan effectively removes trace pharmaceuticals (TrP). • DOM characteristics are quantitatively correlated with removal efficiencies of TrP. • DOM surface charge and molecular weight have no correlation with TrP removal. • Strongly hydrophobic DOM with C-C & C=C groups is beneficial for TrP removal. • Hydrophilic DOM with C-OH groups is unfavored for TrP removal. Hydrophobically-modified chitosan (HC) has emerged as a promising flocculant for trace pharmaceutical removal from surface water. However, the variation in the characteristics of dissolved organic matter (DOM) in different water sources influences the efficacy of HC in removing pharmaceutical compounds. In this work, the flocculation performance of sequentially dosing alum and HC (alum+HC) for the treatment of five water types (three synthetic waters, and samples of two real waters collected from the Yangtze River and the Thames River), having different DOM and five representative pharmaceuticals (initial concentration: 100 ng/L), was assessed by bench-scale jar tests. The DOM characteristics were correlated quantitatively with the removal efficiencies (REs) of the pharmaceuticals. Density functional theory computations were performed to illuminate the interfacial interactions in the flocculation. Alum+HC exhibited a remarkably higher RE of all five pharmaceuticals (maximum RE: 73%-95%) from all waters compared to a conventional coagulant or flocculant (alum or polyacrylamide, respectively). In contrast to using HC alone, alum+HC also achieved a higher RE of pharmaceuticals with nearly half the HC dosage, thereby enhancing the cost-effectiveness of the alum+HC dosing system. Among the different key DOM characteristics, the surface charge and molecular weight of DOM had no evident correlation with RE(pharmaceutical), but the hydrophobic/hydrophilic nature and functional group composition of organic carbon of DOM were strongly correlated: Strongly hydrophobic fractions, with C-C & C=C functional groups (binding pharmaceuticals via hydrophobic association), were beneficial, while hydrophilic fractions with C-OH groups were less effective, for pharmaceutical removal. This work showed the enhanced performance of the alum+HC dosing combination in the removal of different pharmaceutical compounds from different waters, and filled the knowledge gap regarding the performance of hydrophobically-modified flocculants in the treatment of different surface water sources. [Display omitted]. [ABSTRACT FROM AUTHOR]

Enteromorpha prolifera polysaccharide (EP) was extracted under different preparation conditions and then used in conjunction with polyaluminum chloride (PAC) or ferric chloride (FeCl 3) for surface water treatment. The coagulation behavior of PAC-EP was investigated under different coagulant dosages, reaction temperatures and solution pH values. Statistical analysis was conducted to explore the main factors affecting the coagulation performance of PAC-EP. In addition, the floc structure was characterized to determine the underlying flocculation mechanism of EP in the water treatment process. The results showed that EP was a water-soluble sulfated polysaccharide with a maximum extraction rate of 15%. Compared with FeCl 3 , PAC exhibited a better cooperation effect with EP, and the coagulation efficiency could be enhanced by 20%−40% under a moderate dosage of EP 30 s after PAC addition. Moreover, the coagulation performance of the PAC-EP treatment was maintained at a high level over relatively wide pH (6.0–9.0) and temperature ranges (5–20 ℃). The statistical results indicated that the EP dosage was the main factor affecting the removal of organic substances. For water obtained from the Kui River, the optimal PAC-EP dosage was 1–4 mg/L, which adequately removed protein-like and humic acid-like organic substances. The aid mechanism of EP was attributed to the bridging effect of its long-chain molecular structure, which could connect PAC hydrolysates and colloidal particles effectively to form complex compounds, thus facilitating the formation of large flocs. [Display omitted] • EP-based composite flocculants have great application potential in water treatment. • Organics removal can be improved apparently due to bridging-sweep role of EP. • PAC-EP composites are more independent on pH variation than that of PAC. • EP application weakens the influence of temperature on coagulation efficiency. • EP plays a leading role for organics removal according to MFA analysis results. [ABSTRACT FROM AUTHOR]

[Display omitted] • FMO/GDM was investigated for treatment of surface water contaminated by Mn2+ and NH 3 -N. • FMO/GDM and GDM systems obtained similar stable permeate flux. • Mn2+ was hardly removed by GDM, but efficiently removed (∼97.7%) by FMO/GDM. • FMO/GDM system steadily removed NH 3 -N (∼77.4%) during 105 days operation. Removal of manganese (Mn2+) and ammonium (NH 3 -N) is an important issue in drinking water treatment. In this study, iron-manganese co-oxide (FMO) with high catalytic oxidation activity for Mn2+ and NH 3 -N was integrated with gravity-driven membrane (GDM) to treat surface water containing high concentration of Mn2+ (0.93 ∼ 1.07 mg/L) and NH 3 -N (0.95 ∼ 1.73 mg/L). The effect of FMO on flux stabilization, permeate quality and bio-cake layer was investigated in comparison with a single GDM system during 105 days of operation. The results indicated that flux decline rate during the initial 30 days was mitigated by FMO, and FMO/GDM system obtained similar stable permeate flux with GDM. Scanning electron microscope images suggested that FMO particles significantly increased thickness of the bio-cake layer, but resistance of the bio-cake layer in FMO/GDM was comparable with that of GDM due to porous structure. As for contaminants removal, FMO/GDM system achieved steady and efficient removal of Mn2+ (∼97.7%) and NH 3 -N (∼77.4%) throughout the whole operation period, mainly attributed to the strong catalytic oxidation activity of FMO. In contrast, Mn2+ was hardly removed by GDM during the 105 days of operation, while only 10.4% ± 8.1% of NH 3 -N was removed by GDM during the initial 30 days. Moreover, removal of dissolved organic matter was slightly improved by FMO, probably due to the increase of microbial community diversity and biodegradation in the bio-cake layer with FMO. In general, FMO enables GDM to effectively remove Mn2+ and NH 3 -N from surface water without compromising permeate flux, and therefore the integrated FMO/GDM system is promising for decentralized purification of surface water contaminated by Mn2+ and NH 3 -N. [ABSTRACT FROM AUTHOR]