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Urban road dust (URD) is essential for transporting heavy metals (HMs), which can be a major danger to both the environment and human health. Moreover, URD has the potential to be carried into bodies of water, leading to contamination of the aquatic ecosystem. A study was conducted in Xi'an, a city in northwestern China known for high air pollution levels, during January 2024 - a period characterized by peak pollution due to frequent low wind speeds and temperature inversions. The research investigated the presence of 10 types of HMs (Cu, Zn, Cd, Cr, Pb, As, Ni, Hg, Co, and Mn) in URD. Findings revealed elevated levels of Cu, Zn, Cd, Cr, Pb, As, and Hg in URD compared to background levels. Hg showed the most significant contamination (moderate to heavy), followed by moderate contamination of Cd, and lower levels of As, Zn, and Cu. The main sources of HMs were traffic (58.2%), mixed natural and industrial (30.3%), and industrial (11.5%). The ecological risk in the area was deemed to be very high, primarily because of Hg and Cd. Based on probabilistic health risk assessments, it was determined that non-carcinogenic risks were deemed acceptable for all groups. Nevertheless, the possibility of carcinogenic risks should not be disregarded. Strategies for controlling ecological-health risks prioritize mixed natural and industrial sources, with a focus on Hg, Cd, and As in URD. The results offer a foundation for policymakers to create specific control strategies., 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.)

As a byproduct of water treatment, drinking water treatment aluminum sludge (DWTAS) has challenges related to imperfect treatment and disposal, which has caused potential harm to human health and the environment. In this paper, heat treatment DWTAS as a supplement cementitious material was used to prepare a green cementing material. The results show that the 800°C is considered as the optimum heat treatment temperature for DWTAS. DWTAS-800°C is fully activated after thermal decomposition to form incompletely crystallized highly active γ-Al 2 O 3 and active SiO 2 . The addition of DWTAS promoted the formation of ettringite and C-(A)-S-H gel, which could make up for the low early compressive strength of cementing materials to a certain extent. When cured for 90 days, the compressive strength of the mortar with 30% DWTAS-800°C reached 44.86 MPa. The dynamic process was well simulated by Krstulović-Dabić hydration kinetics model. This study provided a methodology for the fabrication of environmentally friendly and cost-effective compound cementitious materials and proposed a "waste-to-resource" strategy for the sustainable management of typical solid wastes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Nanofiltration (NF) is being increasingly applied to produce high-quality drinking water; however, its cost-effective operation remains challenging due to the perennial membrane fouling. On account of the low tolerance of common NF membranes to chemical oxidants, this study proposed high-dose UV irradiation as a pretreatment strategy for organic fouling mitigation. Results showed that the permeate flux decline of the membrane with UV-treated feedwater (with a dose of 750 mJ cm -2 ) was less drastic than that with raw feedwater, but slightly faster as compared to that with UV/Cl 2 pretreatment. The final normalized fluxes were 0.69, 0.79, and 0.82, respectively, after 10 h of operation with raw, UV- and UV/Cl 2 -treated feedwaters. With the characterization of feedwaters and membranes, the fouling was found to be initiated by the adsorption of hydrophilic biopolymers onto the membrane, followed by the deposition of hydrophobic humic substances. Reduction of the "glue" biopolymers was crucial to membrane fouling mitigation. The applicability of UV pretreatment in practice was testified with a pilot-scale UV-NF system where permeate flux of the NF module decreased by 37% after six-week continuous operation. Moreover, UV pretreatment could remove most of the identified pesticides in the feedwater with a removal efficiency over 80% for metolachlor and imidacloprid, but had no or even a negative effect on perfluorinated compounds. This work discloses the efficacy and mechanism of high-dose UV irradiation for NF membrane fouling control, which facilitates future research and application of NF technology., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Peroxymonosulfate (PMS) is an eco-friendly disinfectant gaining attention. This study examined the influence of metal ions (Co(II), Cu(II), Fe(II)) on PMS disinfection with chloride ions (Cl - ) against waterborne microorganisms, encompassing both bacteria and fungal spores. The findings elucidated that metal ions augment the inactivation of bacteria in the PMS/Cl - system while concurrently impeding the inactivation of fungal spores. Specifically, the PMS/Co(II)/Cl - process increased E. coli inactivation rates by 2.25 and 2.75 times compared to PMS/Co(II) and PMS/Cl - , respectively. Conversely, PMS/Me(II)/Cl - generally exhibited a diminished inactivation capacity against the three fungal spores compared to PMS/Cl - , albeit surpassing the efficacy of PMS/Me(II). For instance, the inactivation levels of A. niger by PMS/Cl - , PMS/Cu(II)/Cl - , and PMS/Cu(II) are 4.47-log, 1.92-log, and 0.11-log, respectively. Notably, fungal spores demonstrated a substantially higher resistance to disinfectants compared to bacteria. Differences in microbial susceptibility were linked to cell wall structure, composition, antioxidant defenses, and reactive species generation, such as hydroxyl radicals (•OH), sulfate radicals (SO 4 •- ), and reactive chlorine species (RCS). This study demonstrated the novel and unique phenomenon of metal ions' dual role in modulating the PMS/Cl - disinfection process, which has not been reported before and has important implications for the field of 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 Elsevier B.V. All rights reserved.)

In recent years, large quantities of pharmaceuticals and personal care products (PPCPs) have been discharged into sewers, while the mechanisms of PPCPs enrichment in sewer sediments have rarely been revealed. In this study, three PPCPs (tetracycline, sulfamethoxazole, and triclocarban) were added consecutively over a 90-day experimental period to reveal the mechanisms of PPCPs enrichment and the transmission of resistance genes in sewer sediments. The results showed that tetracycline (TC) and triclocarban (TCC) have higher adsorption concentration in sediments compared to sulfamethoxazole (SMX). The absolute abundance of Tets and suls genes increased in sediments under PPCPs pressure. The increase in secretion of extracellular polymeric substances (EPS) and the loosening of the structure exposed a large number of hydrophobic functional groups, which promoted the adsorption of PPCPs. The absolute abundance of antibiotic resistance genes (ARGs), EPS and the content of PPCPs in sediments exhibited significant correlations. The enrichment of PPCPs in sediments was attributed to the accumulation of EPS, which led to the proliferation of ARGs. These findings contributed to further understanding of the fate of PPCPs in sewer sediments and opened a new perspective for consideration of controlling the proliferation of resistance genes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Sediment siltation has been regarded as the serious challenge in sewer system, which dominantly root in the gelatinous extracellular polymeric substance (EPS) structure and cohesive ability. Considering the crucial roles of divalent cation bridging and macromolecular biopolymer winding in sediment EPS formation and adhesive behavior, an innovative combination strategy of sodium pyrophosphate (SP)-mediated divalent cation chelation and alkaline biopolymer hydrolysis was developed to degenerate sediment adhesion. At the SP dosage of 0.25 g/g TS and the alkaline pH 12, the SP + pH 12 treatment triggered structural transformation of aromatic proteins (α-helix to β-turn) and functional group shifts of macromolecular biopolymers. In this case, the deconstruction and outward dissolution of gelatinous biopolymers were achievable, including proteins (tyrosine-like proteins, tryptophan-like proteins), humic acids, fulvic acids, polysaccharides and various soluble microbial products. These were identified as the major driving forces for sediment EPS matrix disintegration and bio-aggregation deflocculation. The extraction EPS content was obviously increased by 18.88 mg COD/g TS. The sediment adhesion was sensitive to EPS matrix damage and gelatinous biopolymer deconstruction, leading to considerable average adhesion degeneration to 0.98 nN with reduction rate of 78.32%. As such, the sediments could be disrupted into dispersive fragments with increased surface electronegativity and electric repulsion (up to -45.6 mV), thereby the sediment resistance to hydraulic erosion was impaired, providing feasibility for in-situ sediment floating and removal by gravity sewage flow in sewer., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Heliang Pang reports financial support was provided by National Natural Science Foundation of China. If there are other authors, they 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.)

This study aimed to explore the chemical looping gasification (CLG) reaction characteristics of the metal-supported composite phosphogypsum (PG) oxygen carriers (OCs) and the thermodynamic mechanism. The FactSage 7.1 thermodynamic simulation was used to explore the oxygen release and H 2 S removal mechanisms. The experimental results showed that the syngas yield of CLG with PG-CuFe 2 O 4 was more than that with PG-Fe 2 O 3 20/CuO40 or PG-Fe 2 O 3 30/CuO30 OC at 1023 K when the water vapor content was 0.3. Furthermore, the maximum syngas yield of the CO selectivity was 70.3% and of the CO 2 selectivity was 23.8%. The H 2 /CO value was 0.78, and the highest carbon conversion efficiency was 91.9% in PG-CuFe 2 O 4 at the gasification temperature of 1073 K. The metal-supported PG composite oxygen carrier was proved not only as an oxygen carrier to participate in the preparation of syngas but also as a catalyst to catalyze coal gasification reactions. Furthermore, both the experimental results and FactSage 7.1 thermodynamic analysis revealed that the trapping mechanism of H 2 S by composite OCs was as follows: CuO first lost lattice oxygen as an oxygen carrier to generate Cu 2 O, which, in turn, reacted with H 2 S to generate Cu 2 S. This study provided efficient guidance and reference for OC design in CLG., 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 study., (Copyright © 2023. Published by Elsevier B.V.)

Variations in water chemistry may lead to the release of harmful heavy metals in drinking water distribution systems (DWDSs). In this study, the effects of chloride on the release of heavy metals such as Fe, Mn, As, Cr, Mo, V, Sr, and Co were examined using steel and cast iron pipe loops. After chloride was added, the relative contents of goethite (α-FeOOH), lepidocrocite (γ-FeOOH), and siderite (FeCO 3 ) in pipe scales increased, but the contents of magnetite (Fe 3 O 4 ) decreased. The most prevalent compounds were α-FeOOH and γ-FeOOH. When the chloride levels were increased, the effluent concentrations of Fe, Mn, As, Cr, Mo, V, Sr, and Co significantly increased. These heavy metals were released presumably because of the destabilization and dissolution of corrosion scales induced by chloride and adsorption site competition. Strong positive correlations were also observed between Fe&Mn, Fe/Mn&As, Fe/Mn&Cr, Fe/Mn&Mo, Fe/Mn&V, Fe/Mn&Sr, and Fe/Mn&Co, indicating the co-release of Fe, Mn, and other metals. This study may be helpful for the potential strategies on avoidance of heavy metal release and improvement of water supply security., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The MNBs-coagulation process as a novel and cleaning enhanced coagulation process has been demonstrated to enhance the removal efficiency of hydrophilic organics. In this study, while continuing the concept of cleaning production, the MNBs-coagulation process was first applied to the ultrafiltration process and was expected to alleviate the ultrafiltration membrane fouling. This study investigated the effect of the involvement of MNBs in coagulation-ultrafiltration process (the MC-UF process) on the fouling behaviour of ultrafiltration membrane based on the calculation of membrane resistance distribution and the fitting of membrane fouling model. In addition, the NOM removal efficiency, floc characteristics analysis and membrane hydrophilicity analysis were used to illustrate the mechanism of mitigating ultrafiltration mebrane fouling by the MC-UF process. The experimental results showed that the involvement of MNBs in the coagulation-ultrafiltration process was able to reduce the irreversible fouling and TMP by 43.1 % and 41.6 % respectively. This phenomenon could be attributed to the involvement of MNBs in the coagulation process to improve the removal efficiency of hydrophilic organics and to enhance the characteristics of flocs, thus reducing the possibility of hydrophilic organics and broken flocs entering and blocking the membrane pores. In addition, the FT-IR spectral changes before and after the floc breakage were analyzed by 2D-COS technique in this study, and it was found for the first time that the participation of MNBs in the coagulation process could change the sequence of functional group transformation within the floc, and promote the generation of hydrogen bonds between flocs by hindering the generation of hydroxyl groups (-OH), and improve the shear resistance and regrowth capacity of flocs while reducing the possibility of broken flocs entering and blocking membrane pores. In summary, the MC-UF process proposed in this study can significantly mitigate ultrafiltration membrane fouling while meeting cleaning production, providing theoretical support for the application of the process to practical engineering., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

The gelatinous structure and adhesion of sediments induced strong hydraulic erosion resistance and bottom siltation, which brought about serious challenges in sewer management. The in-situ sediment self-cleaning technology with low energy and labor consumption has become urgent demand. This study proposed an innovative plant ash-triggered molecule hydrolysis strategy for driving sewer sediment self-cleaning. Plant ash treatment at the optimal dosage of 0.10 g/g SS promoted molecular deconstruction and dissolution of aromatic proteins (tryptophan-like and tyrosine-like proteins), humic acids (fulvic acid-like and humic acid-like substances) and carbohydrates with secondary structure deflocculation (α-helix to β-turn), meanwhile numerous microbial cells were lysed, contributing to linkage breakage in extracellular polymeric substance (EPS). The gelatinous EPS disruption and outward migration with cohesion reduction were achievable. Sediment adhesion was vulnerable to EPS structural damage, which was degenerated by 91.14 %. Correspondingly, the sediment matrix structure was observably disintegrated into dispersive and small fragments, with increased surface electronegativity and eliminated adhesive bio-agglomeration. Thereby, the sensitivity of sediments to hydraulic erosion was greatly improved. In this case, substantial organic and inorganic sediment particles were solubilized and downstream transported by gravity sewage flow. Such plant ash-triggered hydrolysis provided a sustainable strategy for sediment self-cleaning in "waste control by waste" pattern, which improved sediment floating by 7.25-9.57 times. Considerable economic benefits of 35.56-123.46 CNY/(sewer meter length) were obtained compared with traditional mechanical flushing approaches. The findings might provide theoretical and engineering inspirations for solving sewer sediment issues., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Heliang Pang reports financial support was provided by National Natural Science Foundation of China., (Copyright © 2023. Published by Elsevier B.V.)

Scale not only affects the taste and color of water, but also increases the risks of osteoporosis and cardiovascular diseases associated with drinking it. As a popular beverage, tea is rich many substances that have considerable potential for scale inhibition, including protein, tea polyphenols and organic acids. In this study, the effect of tea brewing on scale formation was explored. It was found that the proteins, catechins and organic acids in tea leaves could be released when the green tea was brewed in water with sufficient hardness and alkalinity. The tea-released protein was able to provide carboxyl groups to chelate with calcium ions (Ca 2+ ), preventing the Ca 2+ from reacting with the carbonate ions (CO 3 2- ). The B rings of catechins were another important structure in the complexation of Ca 2+ and magnesium ions (Mg 2+ ). The carboxyl and hydroxyl groups on the organic acids was able to form five-membered chelating rings with Ca 2+ and Mg 2+ , resulting in a significant decrease in Ca 2+ from 100.0 to 60.0 mg/L. Additionally, the hydrogen ions (H + ) provided by the organic acids consumed and decreased the alkalinity of the water from 250.0 to 131.4 mg/L, leading to a remarkable reduction in pH from 8.93 to 7.73. It further prevented the bicarbonate (HCO 3 - ) from producing CO 3 2- when the water was heated. The reaction of the tea constituents with the hardness and alkalinity inhibited the formation of scale, leading to a significant decrease in turbidity from 10.6 to 1.4 NTU. Overall, this study provides information to help build towards an understanding of the scale inhibition properties of tea and the prospects of tea for anti-scaling in industrial applications., (Copyright © 2022. Published by Elsevier B.V.)

In this study, immobilization technique was employed to improve simultaneous algicidal and denitrification of immobilized Acinetobacter sp. J25 with magnetic Fe 3 O 4 in eutrophic landscape water. After 7 days of operation, the maximum superoxide dismutase (SOD) activity (54.43 U mg -1 ), nitrate removal efficiency (100% (0.2127 mg L -1  h -1 )), and chlorophyll-a removal efficiency (89.71%) were obtained from the immobilized J25 with magnetic Fe 3 O 4 . The results suggest that immobilized J25 with magnetic Fe 3 O 4 had better nitrogen removal efficiency and algicidal activity in eutrophic landscape water. High-throughput sequencing data profiled the strain J25 that was immobilized with magnetic Fe 3 O 4 which changed the composition of the microbial community. The results indicated a novel concept of enhancing the algicidal and denitrification property of immobilized bacteria with magnetic Fe 3 O 4 in eutrophic landscape water.