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Electrochemical synthesis of hydrogen peroxide (H2O2) via the two‐electron oxygen reduction reaction (2e−‐ORR) provides an alternative method to the energy‐intensive anthraquinone method. Metal macrocycles with precise coordination are widely used for 2e−‐ORR electrocatalysis, but they have to be commonly loaded on conductive substrates, thus exposing a large number of 2e−‐ORR‐inactive sites that result in poor H2O2 production rate and efficiency. Herein, guided by first‐principle predictions, a substrate‐free and two‐dimensional conductive metal–organic framework (Ni‐TCPP(Co)), composed of CoN4 sites in porphine(Co) centers and Ni2O8 nodes, is designed as a multi‐site catalyst for H2O2 electrosynthesis. The approperiate distance between the CoN4 and Ni2O8 sites in Ni‐TCPP(Co) weakens the electron transfer between them, thus ensuring their inherent activities and creating high‐density active sites. Meanwhile, the intrinsic electronic conductivity and porosity of Ni‐TCPP(Co) further facilitate rapid reaction kinetics. Therefore, outstanding 2e−‐ORR electrocatalytic performance has been achieved in both alkaline and neutral electrolytes (>90 %/85 % H2O2 selectivity within 0–0.8 V vs. RHE and >18.2/18.0 mol g−1 h−1 H2O2 yield under alkaline/neutral conditions), with confirmed feasibility for water purification and disinfection applications. This strategy thus provides a new avenue for designing catalysts with precise coordination and high‐density active sites, promoting high‐efficiency electrosynthesis of H2O2 and beyond. [ABSTRACT FROM AUTHOR]

Background: Although there are many uses for metal–organic framework (MOF) based nanocomposites, research shows that these materials have received a lot of interest in the field of water treatment, namely in the photodegradation of water contaminants, and disinfection of some pathogenic bacteria and fungi. This is brought on by excessive water pollution, a lack of available water, low-quality drinking water, and the emergence of persistent micro-pollutants in water bodies. Photocatalytic methods may be used to remove most water contaminants, and pathogenic microbes, and MOF is an excellent modifying and supporting material for photocatalytic degradation. Methods: This work involved the fabrication of a unique Cu-MOF based nanocomposite that was exposed to gamma radiation. The nanocomposite was subsequently employed for photocatalytic degradation and as an antimicrobial agent against certain harmful bacteria and fungi. The produced Cu-MOf nanocomposite was identified by XRD, SEM, and EDX. Growth curve analysis, UV lighting impact, and antibiofilm potential have been carried out to check antimicrobial potential. Additionally, the membrane leakage test was used to determine the mechanism of the antimicrobial action. In an experimental investigation of photocatalytic activity, a 50 mL aqueous solution including 10.0 ppm of Rhodamine B (RB) was used to solubilize 10 mg of Cu-MOF. It has been investigated how pH and starting concentration affect RB elimination by Cu-MOF. Ultimately, RB elimination mechanism and kinetic investigations have been carried out. Results: SEM images from the characterization techniques demonstrated the fact that the Cu-MOF was synthesized effectively and exhibited the Cu-MOF layers' flake-like form. Uneven clusters of rods make up each stratum. The primary peaks in the Cu-MOF's diffraction pattern were found at 2θ values of 8.75◦, 14.83◦, 17.75◦, 21.04◦, 22.17◦, 23.31◦, 25.41◦, and 26.38◦, according to the XRD data. After 135 min of UV irradiation, only 8% of RB had undergone photolytic destruction. On the other hand, the elimination resulting from adsorption during a 30-min period without light was around 16%. Conversely, after 135 min, Cu-MOF's photocatalytic breakdown of RB with UV light reached 81.3%. At pH 9.0, the greatest removal of RB at equilibrium was found, and when the amount of photocatalyst rose from 5 to 20 mg, the removal efficiency improved as well. The most sensitive organism to the synthesized Cu-MOF, according to antimicrobial data, was Candida albicans, with a documented MIC value of 62.5 µg mL−1 and antibacterial ZOI as 32.5 mm after 1000 ppm treatment. Cu-MOF also showed the same MIC (62.5 µg mL−1) values against Staphylococcus aureus and Escherichia coli, and 35.0 and 32.0 mm ZOI after 1000 ppm treatment, respectively. Ultimately, it was found that Cu-MOF (1000 µg/mL) after having undergone gamma irradiation (100.0 kGy) was more effective against S. aureus (42.5 mm ZOI) and E. coli (38.0 mm ZOI). Conclusion: From the obtained results, the synthesized MOF nanocomposites had promising catalytic degradation of RB dye and high antimicrobial potential which encouraging their use in wastewater treatment against some pathogenic microbes and polluted dyes. Due to the exceptional physicochemical characteristics of MOF nanocomposites, it is possible to create and modify photocatalytic nanocomposites in a way that improves their recovery, efficiency, and recyclability. [ABSTRACT FROM AUTHOR]

Seawater chlorination has three main industrial uses: disinfection of water and installations, control of biofouling, and preventing the transport of aquatic invasive species. Once in contact with seawater, chlorine reacts rapidly with water constituents (e.g. bromide ions, ammonia, and nitrogen-containing compounds) to form a range of oxidative species (e.g. bromine and N-haloamines), termed "chlorine-produced oxidants" (CPOs) or "total residual oxidants" (TRO). The chemical nature of CPOs and their concentration are a function of two categories of parameters related to treatment modality (e.g. chlorine dose) and water quality (e.g. temperature, pH, ammonia concentration, and organic constituents). The chlorination process may result in continuous or intermittent releases of CPOs in seawater. The reactivity and potential ecotoxicity of CPO species largely depend on their physical and chemical properties. Therefore, evaluation of the biocidal effectiveness of chlorination and its potential impacts requires not only determining the sum of CPOs (via a bulk parameter), but also their chemical speciation. The aim of this article – which is the first of a trilogy dedicated to the chemical speciation of CPOs in seawater – is to provide an overview of current knowledge about chlorine chemistry in seawater and to discuss the biocidal efficacy and the environmental fate of resulting CPOs. The 2nd and 3rd articles delineate a comprehensive and critical review of analytical methods and approaches for the determination of CPOs in seawater. [ABSTRACT FROM AUTHOR]

[Display omitted] • The catalytic mechanism and material preparation based on the piezoelectric effect. • The application of the piezoelectric effect in wastewater purification is expounded. • The development of the piezoelectric effect-assisted water purification technology. • The challenges and prospects of the piezoelectric effect in wastewater purification. The demands of human life and industrial activities result in a significant influx of toxic contaminants into aquatic ecosystems. In particular, organic pollutants such as antibiotics and dye molecules, bacteria, and heavy metal ions are represented, posing a severe risk to the health and continued existence of living organisms. The method of removing pollutants from water bodies by utilizing the principle of the piezoelectric effect in combination with chemical catalytic processes is superior to other wastewater purification technologies because it can collect water energy, mechanical energy, etc. to achieve cleanliness and high removal efficiency. Herein, we briefly introduced the piezoelectric mechanisms and then reviewed the latest advances in the design and synthesis of piezoelectric materials, followed by a summary of applications based on the principle of piezoelectric effect to degrade pollutants in water for wastewater purification. Moreover, water purification technologies incorporating the piezoelectric effect, including piezoelectric effect-assisted membrane filtration, activation of persulfate, and battery electrocatalysis are elaborated. Finally, future challenges and research directions for the piezoelectric effect are proposed. [ABSTRACT FROM AUTHOR]

Combinations of metal disinfectants (i.e., silver and copper) with chlorine in doses that meet the World Health Organization guidelines for drinking water operate synergistically to provide superior drinking water disinfection across a wide range of pathogens. Moreover, the combination of disinfectants allows for lower chlorine levels and a less objectionable taste and odor to the treated water (some people can taste or smell chlorine at concentrations as low as 300 μg/L). Towards chlorine-releasing materials for combination with silver- or copper-releasing materials in point-of-use water disinfection, N-chloramine containing polymer gels were developed and their potential for E. coli bacteria inactivation was assessed in deionized water that contained salts to simulate groundwater. Following the chlorination of gels containing chloramine precursors, these gels capably inactivated E. coli, achieving log10 reductions—depending on the gel mass—ranging from 1.1 to 4.5. While chlorine released from the gels was not spectroscopically detected, free chlorine solutions inactivated E. coli in a concentration-dependent way, with 5 and 20 μg/L Cl2 yielding log10 reductions of 0.43 and 1.69, respectively, suggesting that low levels of chlorine, below both the limit of detection of spectroscopic assays (ca. 40 μg/L Cl2) and levels known to create adverse taste and smell, are sufficient to inactivate bacteria. Unchlorinated gels or chlorinated control styrene gels (without chloramine precursor) did not inactivate bacteria, suggesting that disinfection did not come from the precursor or from chlorine trapped in the gels after chlorination. In addition, these gels were evaluated together with the MadiDrop (MD, a commercial silver-ceramic tablet) and a copper screen that release silver and copper disinfectants, respectively. Combinations of the gel and MD produced E. coli inactivation close to 2-log10 reduction, with the combination, gels alone, and MD alone achieving 1.86-, 1.10-, and 0.69-log10 reduction, respectively. When the gels were combined with the copper screen, however, neither an increase nor a decrease in bacterial reduction was observed compared to that achieved with the gels alone. The laboratory results in this study are promising and suggest the potential for chloramine-functionalized gels to serve as an alternative to existing commercial chlorine-based POU technologies and in combination with silver-based POU technologies. [ABSTRACT FROM AUTHOR]

In this study, the effect of baffle configuration on the water disinfection efficiency of a planar photoreactor equipped with ultraviolet C light-emitting diodes (UV-C LEDs) was investigated. The results indicated that the configuration of the baffles influenced the hydrodynamics inside the flow channel and thus affected the microbial trajectory, and exposure time. Accordingly, a modified serpentine configuration was developed to enhance the UV light exposure of microbes in water and improve the reactor performance for microbial inactivation. According to the simulation results, the quarter-circle baffles used in the modified serpentine configuration increased the microbial path length along the flow channel. However, because the cross-sectional area of the flow channel decreased, this configuration increased the water velocity. A modified serpentine configuration with a baffle radius of 5 mm achieved the longest microbial exposure time and highest inactivation value for Escherichia coli. At a water flow rate of 160 mL/min, this configuration achieved a UV fluence of 15.2 mJ/cm2 and an inactivation value of 3.8 log, which were approximately 22% and 0.4 log higher than those obtained with the traditional serpentine configuration, respectively. In addition, the maximum water flow rate at which the UV reactor achieved an inactivation value of 4.0 log was 154 mL/min at a baffle radius of 5 mm. This flow rate was 11.5% higher than that obtained with the traditional serpentine configuration. These close agreements between the experimental and simulation results confirmed the strong capability of the proposed modified serpentine configuration to improve reactor performance. [ABSTRACT FROM AUTHOR]

Chlorine species play a crucial role as precursors to Cl radicals, which can significantly impact the atmospheric oxidation capacity and influence the levels of trace gases related to climate and air quality. Several studies have established a chlorine emission inventory in China in recent years, but the emission remains uncertain and requires further investigation. The Anthropogenic Chlorine Emission Inventory for China (ACEIC) was the first chlorine emission inventory for China based on local data developed in our previous study, which only includes the emissions from coal combustion and waste incineration. In this study, we updated this inventory to include data for a more recent year (2019) and expanded the range of species considered (HCl, fine particulate Cl - , Cl 2 , and hypochlorous acid (HOCl)) and the number of anthropogenic sources (41 specific sources). Compared with previous studies, this updated inventory considered more anthropogenic sources, used more localized emission factors, and adopted more refined estimation methods. The total emissions of HCl, fine particulate Cl - , Cl 2 , and HOCl in mainland China for the year 2019 were estimated to be 361 (- 18 % to 27 %), 174 (- 27 % to 59 %), 18 (- 10 % to 15 %), and 79 (- 12 % to 18 %) Gg, respectively. To facilitate analysis, we aggregated the chlorine emissions from various sources into five economic sectors: power, industry, residential, agriculture, and biomass burning. HCl emissions were primarily derived from the industry (43 %), biomass burning (38 %), and residential (13 %) sectors. The biomass burning and industry sectors accounted for 74 % and 19 % of the fine particulate Cl - emissions, respectively. Residential and industry sectors contributed 61 % and 29 % of the total Cl 2 emissions. HOCl emissions were predominantly from the residential sector, constituting 90 % of the total emissions. Notably, the usage of chlorine-containing disinfectants was identified as the most significant source of Cl 2 and HOCl emissions in the residential sector. Geographically, regions with high HCl and fine particulate Cl - emissions were found in the North China Plain, northeastern China, central China, and the Yangtze River Delta, whereas the Pearl River Delta, Yangtze River Delta, and Beijing–Tianjin–Hebei regions exhibited elevated levels of Cl 2 and HOCl emissions. Regarding monthly variation, emissions of HCl and fine particulate Cl - were higher during early spring (February to April) and winter (December to January) due to intensified agricultural activities, while Cl 2 and HOCl emissions were higher in the summer months due to increased demand for water disinfection. We incorporated this emission inventory into the chemical transport model and found the simulated concentrations of chlorine species agreed reasonably well with the observations, which suggested the relatively faithful estimations of their emissions. This updated inventory contributes to a better understanding of anthropogenic sources of chlorine species and can aid in the formulation of emission control strategies to mitigate secondary pollution in China. [ABSTRACT FROM AUTHOR]

A manganese dioxide (MnO2)/bamboo carbon (BC) composite was prepared using hydrothermal and impregnation methods and used for the capacitive desalination (CDI) and disinfection of water. The results showed that these composites had fast Na+ ion exchange and charge transfer properties. During the CDI process, these composites' electrodes exhibited good cycle stability and electrosorption capacity (4.09 mg/g) and an excellent bactericidal effect. These carbon-based composite electrodes' bactericidal rate for Escherichia coli could reach 99.99% within 180 min; therefore, they had good performance and are a good choice for high-performance deionization applications. [ABSTRACT FROM AUTHOR]

• Ozonation enhanced the formation potential of regulated DBPs from Phe chlorination. • CH with highest yield of 21.31+1.05 ug/mgPhe was enhanced to 3 times after ozonation. • The DBPs formation rates in the first 6 h were much higher than subsequent time. • Br− promoted brominated DBPs generation and elevated the total cytotoxicity. • Ozonation enhanced the BIF of THMs, while reduced that of DHAAs. As a strong oxidizing agent, ozone is used in some water treatment facilities for disinfection, taste and odor control, and removal of organic micropollutants. Phenylalanine (Phe) was used as the target amino acid to comprehensively investigate variability of disinfection byproducts (DBPs) formation during chlorine disinfection and residual chlorine conditions subsequent to ozonation. The results showed that subsequent to ozonation, the typical regulated and unregulated DBPs formation potential (DBPsFP), including trichloromethane (TCM), dichloroacetonitrile (DCAN), chloral hydrate (CH), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and trichloroacetamide (TCAcAm) increased substantially, by 2.4, 3.3, 5.6, 1.2, 2.5, and 6.0 times, respectively, compared with only chlorination. Ozonation also significantly increased the DBPs yield under a 2 day simulated residual chlorine condition that mimicked the water distribution system. DBPs formations followed pseudo first order kinetics. The formation rates of DBPs in the first 6 hr were higher for TCM (0.214 hr−1), DCAN (0.244 hr−1), CH (0.105 hr−1), TCAcAm (0.234 hr−1), DCAA (0.375 hr−1) and TCAA (0.190 hr−1) than thereafter. The peak DBPsFP of TCM, DCAN, CH, TCAcAm, DCAA, and TCAA were obtained when that ozonation time was set at 5–15 min. Ozonation times > 30 min increased the mineralization of Phe and decreased the formation of DBPs upon chlorination. Increasing bromine ion (Br−) concentration increased production of bromine- DBPs and decreased chlorine-DBPs formation by 59.3%–92.2%. Higher ozone dosages and slight alkaline favored to reduce DBP formation and cytotoxicity. The ozonation conditions should be optimized for all application purposes including DBPs reduction. [Display omitted] [ABSTRACT FROM AUTHOR]

Increasing climate‐related extreme weather events and conflicts hinder safe water sanitation for vulnerable populations. In developing areas, centralized water systems are impractical due to high costs and poor infrastructure. Thus, technologies utilizing renewable energy like solar and mechanical energy for water treatment hold promise. It is critical to develop photocatalysts and piezoelectric/triboelectric catalysts that capture solar energy as well as mechanical energy to generate disinfectants to maximize energy utilization. The latest advancements in principles, materials, and processes utilizing solar and mechanical energy for water disinfection are highlighted in this review. First, we elucidate both direct and indirect mechanisms of sunlight‐mediated water disinfection, discuss the evolution of photocatalysts from simple UV absorption to visible‐light utilization, and even near‐infrared light exploitation to enhance solar spectrum utilization efficiency. Furthermore, we delve into the fundamental principles of piezoelectricity and triboelectricity relying on mechanical energy conversion as well as summarize the development of piezo/triboelectric catalysts from being driven by high‐frequency energy to utilizing low‐frequency mechanical energy from the environment. Finally, challenges and directions for efficient systems are outlined to inspire rational design strategies and accelerate the production of superior catalytic systems applicable across a broad range. [ABSTRACT FROM AUTHOR]

Inorganic arsenic (As), a known carcinogen and major contaminant in drinking water, affects over 140 million people globally, with levels exceeding the World Health Organization's (WHO) guidelines of 10 μg L−1. Developing innovative technologies for effluent handling and decontaminating polluted water is critical. This paper summarizes the fundamental characteristics of chitosan-embedded composites for As adsorption from water. The primary challenge in selectively removing As ions is the presence of phosphate, which is chemically similar to As(V). This study evaluates and summarizes innovative As adsorbents based on chitosan and its composite modifications, focusing on factors influencing their adsorption affinity. The kinetics, isotherms, column models, and thermodynamic aspects of the sorption processes were also explored. Finally, the adsorption process and implications of functionalized chitosan for wastewater treatment were analyzed. There have been minimal developments in water disinfection using metal-biopolymer composites for environmental purposes. This field of study offers numerous research opportunities to expand the use of biopolymer composites as detoxifying materials and to gain deeper insights into the foundations of biopolymer composite adsorbents, which merit further investigation to enhance adsorbent stability. [ABSTRACT FROM AUTHOR]

Consuming microbiologically‐contaminated water is the primary cause of many water‐borne diseases and deaths worldwide. Governments aim at providing drinking water for vulnerable populations, especially through low‐cost interventions. Therefore, the solar disinfection (SODIS) of such pathogens provides a simple and cost‐effective way to obtain good quality water. In this procedure, PET bottles are filled with contaminated water and exposed to sunlight for 1–2 days. To accelerate decontamination, methylene blue (MB) dye added as a photocatalyst, boosts singlet oxygen generation upon absorbing red‐band sunlight. This study explores the use of a Sunlight Simulator (SSL) device to research and standardize the SODIS method with a vital dye as MB. PET bottles were filled with artificially‐contaminated water with Streptococcus epidermidis and Deinococcus radiodurans Gram‐positive bacteria, Escherichia coli and Salmonella typhimurium Gram‐negative bacteria, or bacteriophage λ as well. In all experiments, 50 ng/mL MB ensued a synergistic lethal effect after SSL exposure. The results indicate that bacterial and bacteriophage inactivation can be achieved in shorter times with MB‐SSL treatment compared to SSL without MB. In this sense, when compared to previous sunlight‐SODIS results, the SSL source is a reliable tool to study the parameters of both SODIS and MB‐SODIS protocols, and also a feasible tool to afford assays whenever there are unfavorable climate conditions. [ABSTRACT FROM AUTHOR]

Plasma-activated water can efficiently inactivate pathogenic microorganisms and is considered to be a potent disinfectant in the medical, food, and agricultural industries. In this study, the air discharged by the gliding arc was mixed with different gases including O2, ambient air, synthetic air, and N2 at different flow rates to produce the activated gases, which were then activated gases were inducted into saline to prepare plasma-activated saline (PAS). The gaseous reactive species in the activated gases were composed of NO, NO2, and N2O5 and the aqueous reactive species in the PAS included H2O2, NO2−, NO3–, ⋅ OH , and 1O2 with different intensities, while the inactivation effects of the PAS also varied with the type and the flow rates of the mixed gases in the activated gases. The inactivation effects of the PAS treated by the discharged air mixed with O2, ambient air, and synthetic air started to become weak after 3 h placement. Scavenger analysis demonstrated that the 1O2 played a critical role in the inactivation process. This study indicated that air discharged by the gliding arc mixed with different gases could regulate the reactive species and the biological effects of PAS, providing insight into the preparation of PAS applied for disinfection. [ABSTRACT FROM AUTHOR]

[Display omitted] Exploring highly efficient ultrasound-triggered catalysts is pivotal for various areas. Herein, we presented that Ba2+ doped brookite TiO 2 nanorod (TiO 2 : Ba) with polarization-induced charge separation is a candidate. The replacement of Ba2+ for Ti4+ not only induced significant lattice distortion to induce polarization but also created oxygen vacancy defects for facilitating the charge separation, leading to high-efficiency reactive oxygen species (ROS) evolution in the piezo-catalytic processes. Furthermore, the piezocatalytic ability to degrade dye wastewater demonstrates a rate constant of 0.172 min-1 and achieves a 100 % antibacterial rate at a low dose for eliminating E. coli. This study advances that doping can induce piezoelectricity and reveals that lattice distortion-induced polarization and vacancy defects engineering can improve ROS production, which might impact applications such as water disinfection and sonodynamic therapy. [ABSTRACT FROM AUTHOR]

Trihalomethanes, the main drinking water disinfection byproducts, may be carcinogenic and are regulated to amaximum total trihalomethanes (TTHM) of 80 µg/l in the US. We aimed to determine whether total and individual trihalomethanes in drinking water across the US are associated with higher cancer mortality in 6,260 adult participants to the National Health and Nutrition Examination Surveys from 1999 to 2008 followed for mortality until 2019 (median: 14.4 years). At baseline, the geometric mean (standard error) of TTHM in drinking water was 9.61 (0.85) µg/l. During follow-up, 873 deaths occurred, including 207 from cancer. In Cox proportional hazards regression adjusted for relevant covariates, drinking water TTHM (HR: 1.45, 95% CI: 1.16–1.82), chloroform (HR: 1.35, 95% CI: 1.12–1.64), and bromodichloromethane (HR: 1.30, 95% CI: 1.05–1.59) were associated with 30% to 45% higher cancer mortality. Therefore, drinking water trihalomethanes, especially chloroform and bromodichloromethane maybe risk factors for cancer mortality. [ABSTRACT FROM AUTHOR]

Availability of safe drinking water is a major concern in many parts of the world. While many filtration units operating on various principles are available to combat this, most require electricity, which may not be consistently available in such areas. In the present study, we have designed and demonstrated a water disinfection system that can operate purely on gravity, without any electricity. For this, a potassium hydroxide modified copper‐impregnated activated carbon (KOH‐Cu‐AC) hybrid was used as a filter medium for disinfection, because it is less expensive, with performance comparable to previously reported hybrids containing silver. To maintain a constant water flow rate under gravity, during disinfection, a Mariotte bottle was used as the reservoir of the contaminated water. Using this and a constant head between the bottle and the treated water exit point, the required water‐filter contact time of 25 min (for decontamination) is maintained in the filter column, regardless of tank‐fill level. The demonstrated lab‐scale system can perform disinfection of simulated contaminated water (with an initial concentration of 104 CFU mL−1Escherichia coli), for at least 6 h, with a flow rate of 150 mL h−1. The disinfection performance from the gravity‐based filter was further validated with the conventional pump‐driven filter, used for continuous disinfection of drinking water. Equivalence of results between pump‐ and gravity‐driven operations helps us to eliminate the need for power, without any compromise in disinfection efficacy. Finally, copper concentration from treated water (106 ppb at steady state) remains very well within the safe limit (1000 ppb as per USEPA guideline). Hence, the lab‐scale design of gravity‐based packed bed filter will be useful for domestic and community‐based supply of safe drinking water in resource‐constrained areas, because it eliminated electricity requirement of conventional power‐driven systems. Practitioner Points: Cost‐effective KOH‐Cu‐AC hybrid is developed as a disinfection material.Mariotte bottle used for maintaining constant disinfected water flow rate works without any electrical power supply.This system can be used for getting on‐spot, continuous disinfected water supply.The concentration of copper in the treated water is well within the safety limit.It can be applicable in rural and remote areas (no electric power source) as well as natural calamity‐affected areas. [ABSTRACT FROM AUTHOR]

Monitoring organic pollutants in rainwater is important to understand relations between air pollutants and water safety. Non-targeted liquid chromatography–mass spectrometry (LC–MS) is a powerful tool but because of big differences of pollutants in polarity, ionization efficiency, and low concentrations, it is challenging to detect all pollutants in a single analysis. Chemical derivatization is a widely adapted strategy to fractionate complex samples with enhanced sensitivity and selectivity. Herein, we propose the usage of dansylation as a chemical derivatization method to improve both LC retention and MS ionization of organic pollutants containing amine, hydroxyl, and carboxyl for non-targeted LC–MS analysis. We first evaluated the labeling coverage of dansylation to organic pollutants in water matrix. Using dansyl chloride (DnsCl) and dansyl hydrazine (DnsHz) to label 100 amine- and hydroxyl-containing compounds and 100 carboxyl compounds, respectively, we found DnsCl and DnsHz had over 60% labeling coverage for 8 categories of compounds. Then dansylation was applied to label the rainwater, source water, disinfected rainwater, and drinking water samples. To facilitate the annotation of dansylated compounds, we also established a web-based tool termed DansylFinder. Using DansylFinder, 3889, 5813, 6077, and 4050 tentative annotations were found in rainwater, source water, disinfected rainwater, and drinking water samples by dansylation-based non-targeted LC-HRMS analysis. Four hundred fifty four were persistently detected in all water samples, suggesting significant organic overlaps of the four water samples. In addition, two degradation pathways reported in drinking water disinfection process were also detected in disinfected rainwater, suggesting rainwater is a potential path for air pollutants to infiltrate drinking water system. [ABSTRACT FROM AUTHOR]

An analysis of the physical and chemical phenomena accompanying electrical discharges is carried out, and the main factors influencing microorganisms' abatement are studied. The similarity of the cavitation processes in water systems induced by underwater electric discharges and ultrasound is experimentally demonstrated. The characteristic features of electrical discharge in the cavitation mode, providing effective water disinfection with electric discharges with a significantly reduced amount of active chlorine, are identified in order of importance. The inactivation of microorganisms is intensified, firstly, by the generation of chemically active particles from the water medium itself, due to the integral action of the electro-discharge cavitation of the whole treated volume, and by local shock waves, acoustic flows, and ultraviolet radiation in the area near the cavitating bubbles. The main advantages of electric discharge cavitation over ultrasonic range are the wider range of high-frequency acoustic radiation inherent in an electric discharge, the high intensity and power of the cavitation processes, and the possibility of a significant increase in the volume of disinfected liquid. This study allows for a better understanding and prediction of the bacterial effects that occur during a high-voltage underwater electrical discharge. [ABSTRACT FROM AUTHOR]

Proper disinfection treatment is the basic guarantee for safe utilisation of sewage. However, the commonly used disinfection methods are not suitable for nutrients containing reclaimed water. In this work, the microwave disinfection method assisted by a microwave-absorbing material in recycled water samples was investigated. Magnetic corn stalk biochar (MCSB), the microwave absorbing material, was prepared by high temperature carbonisation of corn stalk particles impregnated with ferrous sulfate. Escherichia coli and fecal coliforms were selected as target microorganisms to investigate the disinfection efficiency of MCSB assisted microwave radiation (MW/MCSB). The addition of microwave absorbing materials significantly improves the disinfection effect of water samples. Compared with the microwave radiation (MW) without MCSB, the bactericidal rate by using 107 CFU/L E. coli suspension increased from 63.5% to 100% at 480 W for 30 s after adding 4 g/L MCSB. Besides, the effects of MCSB dosage, microwave power, microwave radiation time, and initial bacterial concentration on disinfection efficiency were explored. Moreover, the bactericidal efficiency for actual sewage samples was also demonstrated by treating the effluent from septic tank sewage. The residual fecal coliforms in treated water samples met China's farmland irrigation water standard (GB 5084-2021). The result indicates that the proposed method of microwave disinfection strengthened by MCSB has a promising application prospect for reclaimed water disinfection. [ABSTRACT FROM AUTHOR]

Contaminated drinking water sources pose a significant health risk worldwide. Monitoring programs for drinking water quality aims to ensure safe water supply by informing management practices. Improved online monitoring of water systems is necessary as current lab‐based methods are slow and do not offer real‐time public health protection. Rapid detection and response to potential contamination events are crucial to mitigate health risks. Mark of‐purpose water treatment strategies offer a reasonable method for upgrading drinking water quality at the family level and forestalling waterborne illnesses. This study focuses on collecting household drinking water and utilizing various sensors to measure parameters such as pH, turbidity, water level, temperature, and humidity. A consistent water quality noticing system using the stacking outfit model, which solidifies Bayesian association and decision tree techniques, is proposed in this article. Bayesian network analyzes the input data attained from sensors collecting real‐time data and concludes whether the data represents the contamination event. DTs are utilized to demonstrate the connections between multivariate water boundaries utilized in the review. Afterward, a multiobjective, such as a biobjective optimization model and a nondominated genetic algorithm (NGA) are used in this work of optimization to minimize the volume of contaminated water. After the pollution in the water is identified, water decontamination processes are done given point of purpose medicines like ceramic channels and solar water disinfection (SODIS). The method outlined is executed through Python software. The findings indicate that the estimated values for PH, temperature, and turbidity are 7.3, 31.8, and 0.77, respectively. However, the proposed method is compared with the existing C‐NSGA‐II, while compared to this method, the proposed system produces improved cost functions. Consequently, suitable water treatment and supply should be considered to reduce the effects on people's health as well as to improve living conditions, respectively. [ABSTRACT FROM AUTHOR]

The present research aims to refine the hydrodynamic cavitation technique with traditional knowledgebase of Ayurveda for more efficient water disinfection and that has huge potential for implementation in real life, especially for substituting the existing chlorination method for drinking water treatment. The study incorporates use of newer copper reactor configuration, employing vortex flow for generating cavitation for the disinfection of water. Elimination of model contaminant, Escherichia coli, with initial concentration of ∼105 CFU/mL of bacteria was used for the disinfection study. Copper vortex diode with a capacity of 1 m3/h was employed as a cavitating device. The cavitation using copper vortex diode gave significantly higher disinfection, over 30%, compared that with conventional vortex diode, with aluminum as material of construction, under similar conditions. Remarkably, the addition of 0.1% betel leaf oil led to an extraordinary 260‐fold increase in the rate of disinfection, requiring only a single pass to achieve complete bacteria elimination. Furthermore, a notably high synergistic index of 246.96 was achieved for the process intensification approach using the Cu vortex diode. The cost was substantially reduced by approximately three times to 0.011 $/m3 using the Cu vortex diode compared to the conventional vortex diode. The developed strategy offers significantly enhanced performance, as well as a techno‐economical and sustainable solution for drinking water treatment to ensure the provision of safe drinking water. Moreover, the newer methodology can have the advantage of producing no harmful carcinogenic disinfection by‐products compared to chemical disinfection processes apart from sustainable alternative to chlorination. [ABSTRACT FROM AUTHOR]

• The effects of cast iron pipe corrosion on water quality risk and microbial ecology were investigated. • More trihalomethane and antibiotic resistance genes (ARGs) occurred in old cast iron pipe. • The extracellular polymeric substances with stronger bioflocculation ability and weaker hydrophobicity promoted chlorine reactivity. • Stronger microbial antioxidant systems respond caused higher ARGs abundance. • Corroded cast iron pipes induced a unique interaction system of biofilms, chlorine, and corrosion products. The effects of cast iron pipe corrosion on water quality risk and microbial ecology in drinking water distribution systems (DWDSs) were investigated. It was found that trihalomethane (THMs) concentration and antibiotic resistance genes (ARGs) increased sharply in the old DWDSs. Under the same residual chlorine concentration conditions, the adenosine triphosphate concentration in the effluent of old DWDSs (Eff-old) was significantly higher than that in the effluent of new DWDSs. Moreover, stronger bioflocculation ability and weaker hydrophobicity coexisted in the extracellular polymeric substances of Eff-old, meanwhile, iron particles could be well inserted into the structure of the biofilms to enhance the mechanical strength and stability of the biofilms, hence enhancing the formation of THMs. Old DWDSs significantly influenced the microbial community of bulk water and triggered stronger microbial antioxidant systems response, resulting in higher ARGs abundance. Corroded cast iron pipes induced a unique interaction system of biofilms, chlorine, and corrosion products. Therefore, as the age of cast iron pipes increases, the fluctuation of water quality and microbial ecology should be paid more attention to maintain the safety of tap water. [Display omitted] [ABSTRACT FROM AUTHOR]

Residents of remote areas in the Amazon often lack access to a water supply system and thus need to produce their potable water at home. This study examined the efficacy of household water treatments traditionally used by these communities to treat rainwater and river water, their predominant water sources. Samples of untreated, treated, and stored drinking water were collected from 18 households in three communities in Central Amazon, Amazonas State, Brazil. We describe the materials and practices involved and traditionally used in each treatment technique - cloth filtration (water straining), chlorination, and sedimentation, and their efficiency. In the samples we evaluate water quality analyses, as free chlorine, color, coliforms, and turbidity. The treatment steps for the separation of solids in river water were effective only for removing turbidity and apparent color. Straining river water after sedimentation had no relevant effect on water quality. Chlorination of rainwater was efficient in inactivating Escherichia coli; however, all samples showed some level of contamination by E. coli. We found a significant difference (p < 0.05) between untreated and treated river water turbidity, reduced by up to 22%. Untreated rain and river waters showed similar levels of microbiological contamination, close to 3.5 log CFU/100 mL of E. coli. Chlorine effectively removed microbiological contaminants in rainwater (median removal of 100, 44.5% of samples with <1 CFU/100 mL). Yet, this treatment was less effective for river water (94% median removal, with 11% of samples with <100 CFU/100 mL and only 5.5% with <1 CFU/100 mL found in treated water), showing a significant reduction in both cases when the Wilcoxon test was applied. Sodium hypochlorite treatment showed the best results among the techniques evaluated in this study. It can be used in remote areas where rainwater is available for consumption. Microorganism concentration increased after water underwent water straining and sedimentation processes. These results suggest that the improper handling of water containers and materials used during treatment processes leads to contamination of water. Thus, more robust outreach and educational efforts are recommended to improve remote communities' water collection, treatment, and storage practices. [ABSTRACT FROM AUTHOR]

It is important to find the estimation methodology with the highest accuracy in order to determine the parameters of water disinfection and to provide the most ideal disinfection. In this study, the usability of artificial neural networks in predicting response disinfection efficiency in electrochemical water disinfection processes was investigated. An artificial neural network model was developed using a total of 17 data sets and Response Disinfection Efficiency values were estimated from the model. Current density, treatment time and interelectrode spacing values are defined as input parameters in the network model, which has a multilayer perceptron architecture with 10 neurons in its hidden layer. The coefficient of determination value for the developed model was 0.98682 and the average deviation rate was −0.1%. The study findings showed that neural networks are an ideal tool that can be used to predict response disinfection efficiency in electrochemical water disinfection processes. [ABSTRACT FROM AUTHOR]

Dexamethasone (DEX) degradation was investigated using three UV-based advanced oxidation processes combined with sodium persulphate, hydrogen peroxide, and free chlorine in aqueous solutions in a bench-scale reactor. The goal was to determine which process would be the best option in terms of DEX degradation without the subsequent generation of toxic compounds. The process performance for DEX degradation followed the UV/S2O82−> UV/H2O2> UV/HOCl order under equal conditions. In the UV/S2O82− process, sulphate radicals led to a 70.4% DEX degradation. The experimental mineral inhibitory factors showed that nitrite and bicarbonate further decrease the efficiency of the UV/S2O82− process. In the optimal conditions, the UV/S2O8−2 process removed DEX by 100% and had a 74.1% mineralisation. Furthermore, the intermediates were detected using LC-MS/MS, and the cytotoxicity of the UV/S2O8−2 process effluent was evaluated using human embryonic kidney cultured cells. The treatment of DEX solution by the UV/S2O8−2 process significantly decreased the toxicity of the effluent. Therefore, it can be concluded that the UV/S2O8−2 process can be a reliable process for DEX degradation and detoxification in aqueous solutions. [ABSTRACT FROM AUTHOR]

Chlorine is widely used for sterilization and disinfection of water, but the presence of excess residual chlorine in water poses a substantial threat to human health. At present, there is no portable device which can achieve accurate, rapid, low-cost, and convenient detection of residual chlorine in water. Therefore, it is necessary to develop a device that can perform accurate, rapid, low-cost, and convenient detection of residual chlorine in water. In this study, a portable residual chlorine detection device was developed. A microfluidic chip was studied to achieve efficient mixing of two-phase flow. This microfluidic chip was used for rapid mixing of reagents in the portable residual chlorine detection device, reducing the consumption of reagents, detection time, and device volume. A deep learning algorithm was proposed for predicting residual chlorine concentration in water, achieving precise detection. Firstly, the microfluidic chip structure for detecting mixed reagents was optimized, and the microfluidic chip was fabricated by a 3D-printing method. Secondly, a deep learning (LS-BP) algorithm was constructed and proposed for predicting residual chlorine concentration in water, which can realize dual-channel signal reading. Thirdly, the corresponding portable residual chlorine detection device was developed, and the detection device was compared with residual chlorine detection devices and methods in other studies. The comparison results indicate that the portable residual chlorine detection device has high detection accuracy, fast detection speed, low cost, and good convenience. The excellent performance of the portable residual chlorine detection device makes it suitable for detecting residual chlorine in drinking water, swimming pool water, aquaculture and other fields. [ABSTRACT FROM AUTHOR]

A multifactor interaction study was performed using the combined response surface methodology and an artificial neural network on the operational parameters and their influence on residual chlorine production. The operating variables, sodium chloride concentration, electrical potential, electrolysis time, and electrode gap, were evaluated over the response, residual chlorine and energy consumption. The results indicated that the optimum value for residual chlorine was 2450 mg/L achieved at an electrical potential of 8.8 V for 25 min in the presence of 25 g/L of sodium chloride and an electrode distance of 1 cm, and the optimum corresponding energy consumption was measured at 21.76 kWh/L. The study reveals that electric potential, sodium chloride concentration, and electrolysis time positively influence residual chlorine production. ANN models showed superior prediction ability compared with RSM models. This suggests electrolysis can be used for active chlorine production from saline solutions, potentially for industrial applications and water disinfection. Highlights: The electrode gap was shown to have little effect on the formation of residual chlorine.The electrolysis time and electric potential have a direct impact on energy consumption.Artificial neural network models demonstrated superior capability for process prediction.A maximum of 21.756 kWh/L of energy can be utilized for producing residual chlorine. [ABSTRACT FROM AUTHOR]

Objectives: Compare the tensile strength and rupture elongation of room temperature vulcanizing silicone (RTV), heat temperature vulcanizing silicone (HTV) and 3% SiO2 reinforced RTV and HTV following disinfection with various agents. Materials and Methods: According to ASTM D412, 384 samples were fabricated using HTV, RTV, RTV and HTV reinforced with 3% SiO2 nanoparticles. The control group received no disinfection treatment, while the other samples were disinfected for 10 minutes using neutral soap, 4% chlorhexidine, and ozone water, three times a day for 60 days. Additionally, accelerated aging was carried out for 252,504,1008 hours. Tensile strength and rupture elongation were assessed using a universal testing machine at 500 mm/min speed, and the mean values were analyzed using two-way ANOVA and Tukey HSD test (P<0.05). Results: The mean value of tensile strength of RTV (2.96 ± 0.41), 3%SiO2 RTV (3.26 ±0.33), HTV (3.30 ±0.36),3% SiO2 HTV (4.07 ±0.85) MPa which was statistically significant for control, neutral soap and 4% chlorhexidine at 252,504, 1008 hours of aging. (P <0.05). The percentage of elongation of RTV (545 ±29.2),3%SiO2 RTV (617 ±30.5), HTV (735 ±48.7),3% SiO2 HTV (801 ±55.7) which was statically significant for control, neutral soap, 4% chlorhexidine and Ozone water for 252, 504, 1008 hours of aging. (P <0.05). Conclusion: The HTV silicone showed more tensile strength and rupture elongation compared to HTV, RTV and RTV silicones reinforced with 3% SiO2 nanoparticles. Ozone water disinfection had least effect on tensile strength and rupture elongation of maxillo-facial silicone compared to other disinfectant. [ABSTRACT FROM AUTHOR]

Recent advancements in membrane technologies and disinfection methods have enhanced drinking water quality significantly. However, microorganisms, including free-living amoebae (FLA), persist and pose potential threats to humans. FLA are linked to severe neuro-ophthalmic infections and serve as hosts of pathogenic bacteria. This study examined FLA presence in chlorinated and ultrafiltration drinking water and evaluated chlorine's disinfectant. Of 115 water samples, 21 tested positive for Acanthamoeba sp., Allovahlkampfia sp., and Vermamoeba vermiformis, originating from chlorinated sources. FLA trophozoites withstand temperatures up to 37 °C, while the cysts tolerate heat shocks of 60–70 °C. Trophozoites are susceptible to 5 mg L−1 chlorine, but cysts remain viable at concentrations up to 10 mg L−1. FLAs' survival in chlorinated waters is attributed to high cyst tolerance and lower residual chlorine concentrations. These findings highlight the need for ultrafiltration or enhanced chlorination protocols to ensure safer drinking water. [ABSTRACT FROM AUTHOR]

LaOCl belongs to one kind of promising solid electrolyte for chlorine-ion batteries due to its excellent electric insulation performance and special layered structure. However, LaOCl still suffers from poor chlorine-ion conductivity. Then, we proposed microstructure modulation of LaOCl to solve this problem based on Al doping method. Firstly, we carried out first-principles and ab-initio molecular dynamics (AIMD) calculations to investigate the internal relation among structure stability, chlorine-ion conductivity and related physicochemical properties of Al doped LaOCl(La 1- x Al x OCl). It is found that La 0.75 Al 0.25 OCl not only possesses most stable structure but also demonstrates the best ductility. Moreover, La 0.75 Al 0.25 OCl also possesses much lower chlorine-ion diffusion energy barrier than LaOCl(0.40 eV vs.0.78 eV) and its chlorine-ion conductivity goes as high as 5.4 × 10−3 S/cm at 300K. This is attributed to the optimal reconstruction of La–Cl coordination structure induced by Al dopant, which weakens the limiting effect of La–Cl bond as far as possible. Meanwhile,La 0.75 Al 0.25 OCl exhibits excellent electrical insulating property due to its wide band gap of 5.87 eV. In addition, La 0.75 Al 0.25 OCl exhibits wide electrochemical window with La and Al metal acted as anode materials, respectively (1.92–9.66 V for La and 0–7.74 V for Al). At this stage, La 0.75 Al 0.25 OCl solid electrolyte requires no chlorine-ion uptake and loss in the process of oxidation and reduction, indicating its excellent electrochemical stability. [ABSTRACT FROM AUTHOR]

This article discusses the effect of UV-C radiation on two types of cured polymer resins, epoxy and polyester, intended for use in disinfection chambers. The exposure of the samples to UV-C rays lasted 168 h. Our evaluation covered two aspects: the effect of UV-C rays on the flammability and flame retardancy of the resins, and the effect of UV-C rays on the adhesion of the resins to the steel substrate. It was found that the applied halogen and halogen-free organophosphate agents can be used for the tested resins under UV-C conditions (e.g. disinfection chambers), and no negative impact of UV-C radiation on the performance of these flame retardants was found. The use of the tested types of resins in the form of thin coatings on a steel substrate is feasible in disinfection chambers under UV-C radiation conditions, as the obtained results indicate that the radiation did not affect the adhesion of the coating. The visible effect of UV-C radiation on both the tested resins was discoloration, giving yellow and brown colors. Our results suggest that further studies, probably involving longer UV-C exposure, would be advisable. [ABSTRACT FROM AUTHOR]

Cryptosporidium and Giardia are infectious parasitic forms widely distributed in aquatic ecosystems and resistant to disinfection of drinking water. Their presence was investigated in the lower areas of the city's four rivers through a four-stage methodology. Between December 2017 and April 2018, three monitoring campaigns were conducted, with results ranging between not detected to 500 oocysts/L for Cryptosporidium, and between not detected and 300 for Giardia. Cryptosporidium was more abundant, especially in the Machángara River. In the same period, the bacteriological quality of the rivers was also reviewed using Total Streptococci and Fecal Enterococci expressed in colony-forming units (CFU)/100 mL as indicators. The results showed a progressive increase in pollution as the course of the rivers progressed. The sensitivity of bacterial indicators to changes in quality is also observed, which is why their use in specific studies is recommended. It is concluded that untreated domestic wastewater discharges may be the main source of contamination by bacteria and parasites and that there is a relationship between their concentration and the seasonal period. In dry weather, the concentration is higher for both microorganisms. This study fills a gap in knowledge in the region, due to the absence of data on parasitic indicators with great impacts on public health. [ABSTRACT FROM AUTHOR]

The disinfection of treated water is an important process to provide healthy water to the public. The chosen disinfection methods can vary depending on the water source, regulations, targeted microorganisms, operating conditions, capital costs and operation and maintenance costs. Another important factor for decision-makers is the environmental impacts caused by the disinfection process. This paper will reveal the life cycle assessment (LCA) of four different water disinfection scenarios at a municipal scale from the operational phase. A comparison is made between chlorination systems, two ultraviolet disinfection systems that use different types of lamps and an ozonation system. The results demonstrate that the UV disinfection system with low-pressure lamps had the lowest environmental impact across all categories, followed by chlorination. In contrast, the ozonation system and the UV disinfection system with LED lamps showed the highest impacts in all categories, primarily due to their high electricity consumption. Changes in the electricity mix had a substantial influence on the impact categories for all disinfection methods, but the gradation of the water disinfection methods was not that significant. Studies on the environmental impacts of the water disinfection process need to be carried out for larger flow rates to increase the information on this topic. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is a mild, environmentally friendly, and versatile oxidizer. The current main production process, the anthraquinone method, has high energy consumption and pollution. However, the photocatalytic production of H2O2 is considered to be a green and sustainable process. In this paper, the research progress of photocatalytic production of H2O2 was reviewed. Firstly, the basic principle of photocatalytic production of H2O2 and the three production pathways, namely, oxygen reduction, water oxidation, and dual-channel were introduced. Then, advanced photocatalysts for H2O2 production were introduced with emphasis. From the reactants and products, several new reaction systems and improvement strategies were introduced, including the construction of a spontaneous system without a sacrifice agent, a gas–liquid–solid three-phase system, and inhibition of H2O2 decomposition. The in-situ applications of photocatalytic H2O2 production in the environmental field, including in-situ disinfection and in-situ degradation of pollutants are discussed. Finally, the research progress and future research directions in this field are summarized and prospected. [ABSTRACT FROM AUTHOR]

Ozone generation is a water disinfection method, superior to chlorine in terms of fewer byproducts and no residual taste. However, its high production cost limits its widespread adoption. This paper designs an ozone generation sinusoidal power supply for water treatment. Ozone generation requires a high-frequency and high-voltage power supply to produce ozone from oxygen molecules. The study evaluates two power supply topologies, one with a parallel LC filter and the other with an LCL filter, assessing their feasibility, effectiveness, and reliability. Theoretically, the LCL filter achieves higher gains than the parallel LC filter. The larger inductance in the parallel LC filter reduces gain, while the larger inductance in the LCL filter increases gain. Simulation and practical results validate these findings, achieving gains of 40 for the parallel LC filter and 150 for the LCL filter. [ABSTRACT FROM AUTHOR]

The World Health Organization (WHO) estimates that microbiologically contaminated drinking water is estimated to cause 485,000 diarrheal deaths each year. Household water treatment is a low-cost method for reducing the pathogen load in drinking water to decrease instances of diarrhea and sometimes death. This study developed and evaluated a new silver and copper water treatment product that meets WHO one-star performance criteria for household water treatment without using electricity: the MadiDrop+Cu. First, we tested different configurations of a copper mesh and a copper screen with the MadiDrop to evaluate the effects of their proximity to one another on copper and silver concentrations in water. Wrapping the copper mesh around the MadiDrop decreased silver concentrations in water compared with the MadiDrop alone. Folding the copper screen into smaller dimensions decreased the copper concentrations in water compared with the copper screen unfolded. The MadiDrop and copper screen, coined MadiDrop+Cu , provided an average of 125–415 μg/L copper and 4–21 μg/L silver daily for 150 days of use. When tested individually and in combination against E. coli, MadiDrop+Cu removed the most bacteria together rather than separately after 8 h. A previous study found a prototypic chlorinated polymer gel removed more E. coli with the MadiDrop than either intervention alone after 8 h. This study tested the viral (MS2 Bacteriophage) disinfection from the chlorinated polymer and MadiDrop+Cu by themselves and in combination with one another. The MadiDrop alone removed <1 log (90%) of viruses, whereas MadiDrop+Cu removed >3 log (99.9%) after 24 h. The greatest viral disinfection occurred when the MadiDrop+Cu and chlorine-charged polymer gel were used together, removing >4 log (99.99%) after 24 h. Practical Applications: Low-cost and simple household water treatment products can be used in underresourced settings to prevent waterborne disease. This study designed and tested a novel approach to low-cost water treatment: combining a silver-embedded ceramic tablet with a high specific-surface-area copper screen and a chlorine-charged polymer gel. MadiDrop+Cu was found to consistently release sufficient levels of silver and copper over 150 days of use. The MadiDrop alone killed less than 90% of viruses, whereas the MadiDrop+Cu killed over 99.9% of viruses after 24 h. The MadiDrop, copper screen, and the chlorine-charged polymer gel killed over 99.99% of viruses after 24 h. Although a 24 h wait time is not ideal for emergency settings, the findings suggest that this novel approach to combining silver, copper, and chlorine without electricity is a promising method for a low-cost, household water treatment. [ABSTRACT FROM AUTHOR]

Aims This study aimed to assess the effects of chlorine dioxide (ClO2) in water on whiteleg shrimp Penaeus vannamei , evaluating its impact on the stomach microbiota, gill transcriptome, and pathogens. Methods and results ClO2 was added to the aquarium tanks containing the shrimp. The application of ClO2 to rearing water was lethal to shrimp at concentrations above 1.2 ppm. On the other hand, most of the shrimp survived at 1.0 ppm of ClO2. Microbiome analysis showed that ClO2 administration at 1.0 ppm significantly reduced the α-diversity of bacterial community composition in the shrimp stomach, and this condition persisted for at least 7 days. Transcriptome analysis of shrimp gill revealed that ClO2 treatment caused massive change of the gene expression profile, including stress response genes. However, after 7 days of the treatment, the gene expression profile was similar to that of shrimp in the untreated control group, suggesting a recovery to the normal state. This 1.0-ppm ClO2 significantly reduced shrimp mortality in artificial challenges with an acute hepatopancreatic necrosis disease-causing Vibrio parahaemolyticus and white spot syndrome virus, which were added to rearing water. Conclusions The use of ClO2 at appropriate concentrations effectively eliminates a significant portion of the bacteria in the shrimp stomach and pathogens in the water. The results of this study provide fundamental knowledge on the disinfection of pathogens in water using ClO2 and the creation of semi germ-free shrimp, which has significantly decreased microbiome in the stomach. [ABSTRACT FROM AUTHOR]

[Display omitted] Pathogen contamination in drinking water sources causes waterborne infectious diseases, seriously threatening human health. Nowadays, stimuli-responsive self-propelled nanomotors are appealing therapeutic agents for antibacterial therapy in vivo. However, achieving water disinfection using these nanobots is still a great challenge. Herein, we report on prebiotic galactooligosaccharide-based nanomotors for sunlight-regulated water disinfection. The nanomotors can utilize galactooligosaccharide-based N -nitrosamines as sunlight-responsive fuels for the spontaneous production of antibacterial nitric oxide. Such a solar-to-chemical energy conversion would power the nanomotors for self-diffusiophoresis, which could promote the diffusion of the nanomotors in water and their penetration in the biofilm, significantly enhancing the inhibition and elimination of the pathogens and their biofilms in aquatic environments. After water treatments, the prebiotic-based residual disinfectants can be selectively utilized by beneficial bacteria to effectively relieve safety risks to the environment and human health. The low-energy-cost, green and potent antibacterial nanobots show promising potential in water disinfection. [ABSTRACT FROM AUTHOR]

Water treatment plants (WTPs) in developing countries play an important role in providing potable water to rural and urban areas. However, they often face many challenges, making them unable to produce quality water for consumers. We surveyed the performance of two rural WTPs from the Vhembe District Municipality, South Africa for eight months using secondary water quality data from each plant. Turbidity at the WTPs and most points of use (POU) exceeded the aesthetic (5 NTU) and operational (1 NTU) risk guidelines. Fluoride, iron, and manganese were within the regulated limits of < 1 mg/L, <3 mg/L and < 4 mg/L, respectively), but with signs of post-treatment change in the concentration of iron and manganese in the distribution system. At both WTPs, the free chlorine residual was below limits (<5 mg/L,), posing a risk of proliferation of pathogens in the distribution system. The results indicated problems with water disinfection at both WTPs. The study suggested the existence of challenges with the integrity, good operation, and maintenance of the water treatment system and distribution network. It is necessary to continuously monitor the performance of WTPs and POU to ensure public health and safety. [ABSTRACT FROM AUTHOR]

Chlorinated organic compounds (COCs) are typical refractory organic compounds, having high biological toxicity. These compounds are a type of pervasive pollutants that can be present in polluted soil, air, and various types of waterways, such as groundwater, rivers, and lakes, posing a significant threat to the ecological environment and human health. Bioelectrochemical systems (BESs) are an effective strategy for the degradation of bio-refractory compounds. BESs improve the waste treatment efficiency through the application of weak electrical stimulation. This review discusses the processes of BESs configurations and degradation performances in different environmental media including wastewater, soil, waste gas and groundwater. In addition, the degradation mechanisms and performance-enhancing additives are summarized. The future challenges and perspectives on the development of BES for COCs removal are briefly discussed. [ABSTRACT FROM AUTHOR]

Key Takeaways: With elevated disinfection byproduct (DBP) levels in its distribution system, a water treatment plant in Maine worked with an engineering consultant to develop solutions and avoid possible regulatory violations. Four mitigation options were determined—two of them immediate and two long‐term, with the chosen strategy being premembrane coagulation. Recommendations from the success of the DBP mitigation project include being proactive, collaborating with team members and outside experts, and planning for resilience. [ABSTRACT FROM AUTHOR]

Purpose: In addition to agriculture, energy production, and industries, potable water plays a significant role in many fields, further increasing the demand for potable water. Purification and desalination play a major role in meeting the need for clean drinking water. Clean water is necessary in different areas, such as agriculture, industry, food industries, energy generation and in everyday chores. Design/methodology/approach: The authors have used the different search engines like Google Scholar, Web of Science, Scopus and PubMed to find the relevant articles and prepared this mini review. Findings: The various stages of water purification include coagulation and flocculation, coagulation, sedimentation and disinfection, which have been discussed in this mini review. Using nanotechnology in wastewater purification plants can minimize the cost of wastewater treatment plants by combining several conventional procedures into a single package. Social implications: In society, we need to avail clean water to meet our everyday, industrial and agricultural needs. Purification of grey water can meet the clean water scarcity and make the environment sustainable. Originality/value: This mini review will encourage the researchers to find out ways in water remediation to meet the need of pure water in our planet and maintain sustainability. [ABSTRACT FROM AUTHOR]

This research presents a point‐of‐use (POU) water treatment technology utilizing metal/metallic surfaces based on Triply Periodic Minimal Surface (TPMS) structured filtration infills. Computational Fluid Dynamics modeling using Ansys CFX software is employed to analyze the behavior of Escherichia coli bacteria within a continuous liquid phase moving through the filtration infill, assess particle collision dynamics, and evaluate the efficiency of filtration, considering pressure drop as a fundamental factor in process energy consumption. TPMS infill meshes are coded in a Schwarz P shape using Python, and the Darcy‐Forchheimer equation is employed to determine the permeability and resistance loss coefficient of the infill geometry. The results indicate that the TPMS infill efficiently captures particles while introducing a negligible pressure drop into the system. It is found that a single 40 mm infill configuration is the most efficient, exhibiting a higher collision rate compared to the smaller 20 mm infill configuration and a lower pressure drop compared to the two 20 mm infill configurations in the series. Additionally, this study provides insights into the behavior of continuous fluid flow through TPMS infill in view of scaled‐up implementation, including the presence of recirculation zones that can be exploited to further enhance the collision rate of particles. [ABSTRACT FROM AUTHOR]

This study focuses on the application of activated carbon obtained from cocoa shells for wastewater treatment. The methodology covered the preparation of activated car-bon through collection, drying, carbonization, and chemical activation, followed by the characterization of the wastewater, its treatment through filtration, adsorption, and the final evaluation of the quality of the treated water. Trihalomethanes (THM), metabi-sulfite, and residual free chlorine were determined in the treated water before and after using activated charcoal. The results indicate a 31.2% reduction in THM levels with considerable decreases in metabisulfite and residual free chlorine concentrations. These findings suggest that cocoa shell-activated carbon is effective in removing common contaminants and more specialized compounds. The study highlights the importance of using sustainable materials in wastewater treatment, promoting more efficient and environmentally responsible practices. [ABSTRACT FROM AUTHOR]

Wastewater monitoring provides essential information about water quality and the degree of contamination. Monitoring these waters helps identify and manage risks to public health, prevent the spread of disease, and protect the environment. Standardizing the appropriate and most accurate methods for the isolation and identification of viruses in wastewater is necessary. This review aims to present the major classes of viruses in wastewater, as well as the methods of concentration, isolation, and identification of viruses in wastewater to assess public health risks and implement corrective measures to prevent and control viral infections. Last but not least, we propose to evaluate the current strategies in wastewater treatment as well as new alternative methods of water disinfection. [ABSTRACT FROM AUTHOR]

Introduction: Salinity of water and soil resources is one of the most basic agricultural problems, especially in arid and semi-arid regions. Identifying and domesticating salinity-resistant plant (halophytes) species with economic value is an important strategy for these regions. Materials and methods: This research aimed to investigate the amount of elements and the quality of fodder in several Salicornia species under the influence of water salinity in a factorial experiment with a completely randomized design in pot culture conditions in Bojnourd (North Khorasan province) in 2018. Irrigation treatment was applied at two levels (brackish water and normal water), and Salicornia species treatment included four species (Salicornia persica, S. sinus persica, S. europaea, and S. bigelovii) and Salicornia var Markazi. The source of salty water was the Kal-Shoor river in Esfrain and the source of normal water was the well located in Research and Education of Agriculture and Natural Resurces Center in Bojnourd. Due to the high salinity of Kal-Shoor river, normal water was used to adjust the salinity to the treatment limit of 45 dSm-1. To produce seedlings, Salicornia seeds were planted in plastic combs for seedling production in April 2018. After 60 days, seedlings (10-15 cm) were transferred to pots. The irrigation circuit varied in different growth stages according to weather conditions, and irrigation was done by the weight method with the 80% moisture index of the pots. Results and discussion: The results showed that the amount of nitrogen, phosphorus, potassium, magnesium, sodium and chlorine increased with the increase in irrigation water salinity in all species. The highest accumulations of sodium (11%) and chlorine (23.5%) were observed in S. sinus persica and the lowest amount of sodium (8.6%) and chlorine (21%) were observed in S. persica. Among the Salicornia species, the lowest amount of elements is related to potassium and phosphorus ions, which is mostly due to the limitation of the absorption of these elements under the influence of sodium ions, and as mentioned in the sources, the process of absorption of these elements increases gradually with the growth stages. Maintaining a more negative potential of the membrane is an important factor for salinity tolerance, considering that in saline soils, chlorine and sodium are the most common solutes, the absorption of sodium and chlorine ions is important for regulating osmotic pressure and cytoplasmic concentration. In this experiment, in both irrigation treatments, the most elements in all species were related to chlorine and sodium ions. Based on the measurement of quality variables of fodder, the percentages of protein, crude fat, and ash in salty water treatment were higher than those in normal water. The highest percentage of crude fat (1.32%) in S. var. Markazi was affected by saltwater treatment, which was significantly different from the other species. The highest percentages of protein in S. bigelovii and S. europaea under the influence of saltwater treatment were 6.06% and 6.31%, respectively, which were significantly different from the other species. The highest amounts of ash belonged to S. europaea (63%) and S. bigelovii (62%) in saltwater treatment, and S. sinus persica contained the least ash (49%) in normal water treatment. Although the increase in protein increases the quality of fodder, the increase in the amount of ash and crude fat causes limitations in animal nutrition and digestibility. Therefore, the increase of water salinity has a negative effect on the quality of fodder. Conclusion: Brackish water treatment increased the amount of ash in all species to different proportions, which is a limiting factor for the pure consumption of salicornia in animal feed. Therefore, the relative reduction of water salinity and the selection of suitable species are effective in increasing the quality of fodder.On the other hand, the great ability of Salicornia species to absorb and store salts in their aerial parts provides the basis for the exploitation of their vegetative organs for the production of vegetable salt. Moreover, it is economically important along with other applications of Salicornia (production of fodder, oil, medicines, and protection). [ABSTRACT FROM AUTHOR]

N -doped carbon nanosheets were synthesized to reveal wide-spectrum photocatalytic H 2 O 2 generation. After the loading of Fe ions, they reveal the enhanced water disinfection ability via photocatalytic cascade. [Display omitted] The pervasive presence of pathogenic bacteria in water environment poses a serious threat to public health. Here, a photocatalytic cascade was developed to reveal great water disinfection. Firstly, N -doped carbon nanosheets (N -CNSs) about 30–50 nm in size were synthesized by a hydrothermal strategy. It revealed wide-spectrum photocatalysis for H 2 O 2 generation via a typical two-step single-electron process. A Fenton agent (Fe ion) was loaded, N -CNSs-Fe can in-situ convert photocatalytic H 2 O 2 into ·OH with high oxidation potential. Moreover, its Fenton active is three times greater than pure Fe2+ owing to electron enrichment from N -CNSs to Fe for Fe3+/Fe2+ cycle. Further investigation displayed that Fe loading also could decrease bad gap and promote charge separation to boost photocatalysis. In addition, N -CNSs-Fe possesses positive surface potential to exhibit strong interaction with negative bacteria, facilitating the capture. Therefore, the nanocomposite can effectively inactivate E. coli with a lethality rate of 99.7 % under stimulated sunlight irradiation. In addition, it also was employed to treat a complex lake water sample, revealing great antibacterial (95.1 %) and dye-decolored (92.3 %) efficiency at the same time. With novel biocompatibility and antibacterial ability, N -CNSs-Fe possessed great potential for water disinfection. [ABSTRACT FROM AUTHOR]

Due to the complexity of the actual polluted water components, the development of efficient and economical multifunctional materials has great significance and value in the remediation of polluted water. In this study, we have employed MoS2 nanosheets as a carrier to sequentially load magnetic Fe3O4 and ZnO nanoparticles via the electrostatic interaction, yielding a three-in-one MoS2/Fe3O4/ZnO (MFZ) composite nanosheet. The prepared MFZ could catalyze the conversion of H2O2 into hydroxyl radicals (•OH), induce intracellular oxidative stress in situ by nanosized ZnO or Zn2+, and produce photonic hyperpyrexia to promote the catalytic generation of •OH. In vitro antibacterial assays demonstrated that MFZ had high-performance multimodal elimination against Escherichia coli and Staphylococcus aureus in the presence of H2O2 and an 808 nm laser. Moreover, MFZ could also catalyze the rapid degradation of organic pollutants in water including tetracycline (TC), methylene blue (MB), Congo red (CR), methyl orange (MO), and rhodamine B (RhB), which was mainly attributed to the strong oxidization of •OH. Not surprisingly, MFZ displayed satisfactory capacity for killing pathogenic bacteria and removing organic pollutants in real polluted water samples, and importantly, the MFZ could be efficiently recovered by applying an external magnetic field. Therefore, the magnetically recoverable MFZ composite nanomaterial proposed in this work is a versatile and sustainable alternative for future water disinfection and purification. [ABSTRACT FROM AUTHOR]

Although, different plant species were utilized for the fabrication of polymorphic, hexagonal, spherical, and nanoflower ZnO NPs with various diameters, few studies succeeded in synthesizing small diameter ZnO nanorods from plant extract at ambient temperature. This work sought to pioneer the ZnO NPs fabrication from the aqueous extract of a Mediterranean salt marsh plant species Limoniastrum monopetalum (L.) Boiss. and assess the role of temperature in the fabrication process. Various techniques have been used to evaluate the quality and physicochemical characteristics of ZnO NPs. Ultraviolet–visible spectroscopy (UV–VIS) was used as the primary test for formation confirmation. TEM analysis confirmed the formation of two different shapes of ZnO NPs, nano-rods and near hexagonal NPs at varying reaction temperatures. The nano-rods were about 25.3 and 297.9 nm in diameter and in length, respectively while hexagonal NPs were about 29.3 nm. The UV–VIS absorption spectra of the two forms of ZnO NPs produced were 370 and 365 nm for nano-rods and hexagonal NPs, respectively. FT-IR analysis showed Zn–O stretching at 642 cm−1 and XRD confirmed the crystalline structure of the produced ZnO NPs. Thermogravimetric analysis; TGA was also used to confirm the thermal stability of ZnO NPs. The anti-tumor activities of the two prepared ZnO NPs forms were investigated by the MTT assay, which revealed an effective dose-dependent cytotoxic effect on A-431 cell lines. Both forms displayed considerable antioxidant potential, particularly the rod-shaped ZnO NPs, with an IC50 of 148.43 µg mL−1. The rod-shaped ZnO NPs were superior candidates for destroying skin cancer, with IC50 of 93.88 ± 1 µg mL−1 ZnO NPs. Thus, rod-shaped ZnO NPs are promising, highly biocompatible candidate for biological and biomedical applications. Furthermore, both shapes of phyto-synthesized NPs demonstrated effective antimicrobial activity against various pathogens. The outcomes highlight the potential of phyto-synthesized ZnO NPs as an eco-friendly alternative for water and wastewater disinfection. [ABSTRACT FROM AUTHOR]

Objective: Evaluate the effects of five disinfection methods on bacterial concentrations in hospital sink drains, focusing on three opportunistic pathogens (OPs): Serratia marcescens, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. Design: Over two years, three sampling campaigns were conducted in a neonatal intensive care unit (NICU). Samples from 19 sink drains were taken at three time points: before, during, and after disinfection. Bacterial concentration was measured using culture-based and flow cytometry methods. High-throughput short sequence typing was performed to identify the three OPs and assess S. marcescens persistence after disinfection at the genotypic level. Setting: This study was conducted in a pediatric hospitals NICU in Montréal, Canada, which is divided in an intensive and intermediate care side, with individual rooms equipped with a sink. Interventions: Five treatments were compared: self-disinfecting drains, chlorine disinfection, boiling water disinfection, hot tap water flushing, and steam disinfection. Results: This study highlights significant differences in the effectiveness of disinfection methods. Chlorine treatment proved ineffective in reducing bacterial concentration, including the three OPs. In contrast, all other drain interventions resulted in an immediate reduction in culturable bacteria (4–8 log) and intact cells (2–3 log). Thermal methods, particularly boiling water and steam treatments, exhibited superior effectiveness in reducing bacterial loads, including OPs. However, in drains with well-established bacterial biofilms, clonal strains of S. marcescens recolonized the drains after heat treatments. Conclusions: Our study supports thermal disinfection (>80°C) for pathogen reduction in drains but highlights the need for additional trials and the implementation of specific measures to limit biofilm formation. [ABSTRACT FROM AUTHOR]