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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]

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]

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]

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]

[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]

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]

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]

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]

We characterized concentrations of trihalomethanes (THMs), a measure of disinfection byproducts (DBPs), in tap water samples collected from households with utility-supplied water in two rural counties in Appalachian Virginia, and assessed associations with pH, free chlorine, and metal ions which can impact THM formation. Free chlorine concentrations in all samples (n = 27 homes) complied with EPA drinking water guidelines, though 7% (n = 2) of first draw samples and 11% (n = 3) of 5-min flushed-tap water samples exceeded the US Safe Drinking Water Act (SDWA) maximum contaminant level (MCL) for THM (80 ppb). Regression analyses showed that free chlorine and pH were positively associated with the formation of THM levels above SDWA MCLs (OR = 1.04, p = 0.97 and OR = 1.74, p = 0.79, respectively), while temperature was negatively associated (OR = 0.78, p = 0.38). Of the eight utilities serving study households, samples from water served by three different utilities exceeded the EPA MCL for THM. Overall, these findings do not indicate substantial exposures to DBPs for rural households with utility- supplied water in this region of southwest Virginia. However, given the observed variability in THM concentrations between and across utilities, and established adverse health impacts associated with chronic and acute DBP exposure, more research on DBPs in rural Central Appalachia is warranted. [ABSTRACT FROM AUTHOR]

Carpet cleaning guidelines currently do not include the use of an antimicrobial, except after a bodily fluid event. To address this gap, we compared the efficacy of three antimicrobials--two hydrogen peroxide-based (H2O2) products (A and B) and one chlorine-based product (C)--and a steam treatment against two norovirus surrogates, specifically feline calicivirus (FCV) and Tulane virus (TuV). These tests were performed on nylon carpets with either water-permeable or waterproof backing types. The effect of repeated antimicrobial use on carpet properties was also evaluated. For a carpet with water-permeable backing, products A, B, and C achieved a 0.8, 3.1, and 0.9 log10 PFU/coupon reduction of FCV and 0.3, 2.5, and 0.4 log10 TCID50/coupon reduction of TuV, respectively, following a 30 min contact time. For carpet with waterproof backing, only product B achieved a 5.0 log10 PFU/coupon reduction of FCV and >3.0 log10 TCID50/coupon reduction of TuV, whereas products A and C achieved a 2.4 and 1.6 log10 PFU/coupon reduction of FCV and a 1.2 and 1.2 log10 TCID50/coupon reduction of TuV, respectively. Steam treatment achieved a = 5.2 log10 PFU/coupon reduction of FCV and a > 3.2 log10 TCID50/coupon reduction of TuV in 15 seconds on the carpet with both backing types. The repeated use of products A and B decreased the tensile strength of the carpet backing, while use of product B resulted in cracks on carpet fibers. Overall, steam treatment for 15 seconds was efficacious on both carpet types, but only product B achieved efficacy after a 30-minute exposure on the carpet with waterproof backing. [ABSTRACT FROM AUTHOR]

It is well-known that the equilibrium isotope fractionation of mercury (Hg) includes classical mass-dependent fractionations (MDFs) and nuclear volume effect (NVE) induced mass-independent fractionations (MIFs). However, the effect of the NVE on these kinetic processes is not known. The total fractionations (MDFs + NVE-induced MIFs) of several representative Hg-incorporated substances were selected and calculated with ab initio calculations in this work for both equilibrium and kinetic processes. NVE-induced MIFs were calculated with scaled contact electron densities at the nucleus through systematic evaluations of their accuracy and errors using the Gaussian09 and DIRAC19 packages (named the electron density scaling method). Additionally, the NVE-induced kinetic isotope effect (KIE) of Hg isotopes are also calculated with this method for several representative Hg oxidation reactions by chlorine species. Total KIEs for 202Hg/198Hg ranging from − 2.27‰ to 0.96‰ are obtained. Three anomalous 202Hg-enriched KIEs (δ202Hg/198Hg = 0.83‰, 0.94‰, and 0.96‰,) caused by the NVE are observed, which are quite different from the classical view (i.e., light isotopes react faster than the heavy ones). The electron density scaling method we developed in this study can provide an easier way to calculate the NVE-induced KIEs for heavy isotopes and serve to better understand the fractionation mechanisms of mercury isotope systems. [ABSTRACT FROM AUTHOR]

Numerous tons of hazardous wastes containing persistent organic pollutants (POPs) are stored in an unsafe manner in the petrochemical industries. The planetary ball mill causes the formation of mineral Cl compounds during the degradation of polychlorinated compounds in the presence of various reagents. In addition, the planetary ball mill has been applied for the synthesis of diverse organic-inorganic hybrid nanomaterials. In the present study, Fe-metal organic framework was prepared using a planetary ball mill, and then Fe@C nanocomposite with core/shell structure was synthesised by carbonisation. X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) were utilised to study the synthesised materials. The nanocomposite was used as a reagent to degrade persistent organic pollutants in the sludge of a petrochemical wastewater treatment plant by a planetary ball mill. CaO was also used to compare the effect of nanocomposites on system performance. Ion chromatography (IC) analysis was carried out to determine chlorine mineralisation. Furthermore, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy were applied to determine chemical bonds. The results illustrated a zero-valent iron nanoparticle in the core protected by carbon shell in a synthesised nanocomposite with a core/shell structure. Hence, nanocomposite was the most efficient additive, with 97% dechlorination efficiency in the first hour while the efficiency of the planetary ball mill in the presence of CaO was only 76% after 12 hours of milling. Furthermore, major changes occurred in the organic phases, carbon and chlorine bonds. Simultaneously, graphite and amorphous carbon were produced in the final products after milling. This indicates that aromatic structures and C-Cl bonds were broken down into inorganic compounds. Thus, this study presented a practical method of producing materials while degrading hazardous pollutants in petrochemical wastewater sludge through a planetary ball mill. [ABSTRACT FROM AUTHOR]

Designing materials capable of disinfecting water without releasing harmful by-products is an ongoing challenge. Here, we report a novel polycationic sponge material synthesized from chitosan derivatives and cellulose fibers, exhibiting antibacterial properties. The design of such material is based on three key principles. First, the formation of a highly porous structure through cryogelation for an extensive surface area. Second, the incorporation of cationic quaternary ammonium moieties onto chitosan to enhance bacterial adsorption and antibacterial activity. Lastly, the reinforcement of mechanical properties through integration of cellulose fibers. The presented sponge materials exhibit up to a 4-log (99.99%) reduction within 6 h against both gram-positive B. subtilis and gram-negative E. coli. Notably, QCHI90/Cell, with the highest surface charge, exhibits a 2–4.5 log reduction within 1 h of incubation time. The eco-friendly synthesis from water and readily available biomaterials, along with cost-effectiveness and simplicity, underscores its versatility and feasibility of upscaling. Together with its outstanding antibacterial activity, this macroporous biomaterial emerges as a promising candidate for water disinfection applications. [ABSTRACT FROM AUTHOR]

Bromhexine and ambroxol are among the mucolytic drugs most widely used to treat acute and chronic respiratory diseases. Entering the municipal wastewater and undergoing transformations during disinfection with active chlorine, these compounds can produce nitrogen- and bromine-containing disinfection by-products (DBPs) that are dangerous for aquatic ecosystems. In the present study, primary and deep degradation products of ambroxol and bromhexine obtained in model aquatic chlorination experiments were studied via the combination of high-performance liquid and gas chromatography with high-resolution mass spectrometry. It was shown that at the initial stages, the reactions of cyclization, hydroxylation, chlorination, electrophilic ipso-substitution of bromine atoms with chlorine, and oxidative N-dealkylation occur. Along with known metabolites, a number of novel primary DBPs were tentatively identified based on their elemental compositions and tandem mass spectra. Deep degradation of bromhexine and ambroxol gives twenty-four identified volatile and semi-volatile compounds of six classes, among which trihalomethanes account for more than 50%. The specific class of bromhexine- and ambroxol-related DBPs are bromine-containing haloanilines. Seven of them, including methoxy derivatives, were first discovered in the present study. One more novel class of DBPs associated with bromhexine and ambroxol is represented by halogenated indazoles formed through dealkylation of the primary transformation products containing pyrazoline or tetrahydropyrimidine cycle in their structure. [ABSTRACT FROM AUTHOR]

In this article, the methods of cleaning and disinfection of drinking water in livestock farms are discussed. In order to choose the appropriate cleaning method, first an analysis is made of the water that will be used for irrigation and then the necessary processing is selected - filters, water softening, reverse osmosis, additional mineralization, disinfection by means of UV sterilizers. On the basis of the cost rate for irrigation of dairy cows, the necessary cleaning agents with the most effective capacity are indicated. By observing certain water parameters, the health and quality of life of animals in small and large farms is guaranteed. [ABSTRACT FROM AUTHOR]

Chloraminated drinking water systems commonly use free chlorine conversions (FCCs) to prevent or control nitrification, but unintended water quality changes may occur, including increased disinfection by‐product and metal concentrations. This study evaluated water quality in a chloraminated drinking water system and residential locations before, during, and after their annual, planned FCC. Water quality alternated between relatively consistent and variable periods when switching disinfectants. During the FCC, regulated four trihalomethane and five haloacetic acid concentrations increased by four and seven times, respectively, and exceeded corresponding maximum contaminant levels. Implications of disinfection by‐product sampling during an FCC were assessed, and an approach to account for increased FCC disinfection by‐product concentrations was proposed. For metals, the FCC had minor impacts on distribution system concentrations and did not appear to impact residential concentrations. Overall, observed variable water quality appeared primarily associated with switching disinfectants and depended on distribution system hydraulics. [ABSTRACT FROM AUTHOR]

• UV/chlorine needed half the time of in-situ chlorination to reach 90% CBZ removal. • LP UV/chlorine was the most energy efficient among the tested processes. • RCS were the dominant reactive species contributing to more than 70% of CBZ removal in all three processes. • Compared to •OH, RCS had lower energy barrier and higher reactivity in main CBZ degradation pathways. • UV/chlorine processes produced 15 times higher ClO 3 − than in-situ chlorination. Chlorine has been widely used in different advanced oxidation processes (AOPs) for micropollutants removal. In this study, different chlorine-based AOPs, namely medium pressure (MP) UV/chlorine, low pressure (LP) UV/chlorine, and in-situ chlorination, were compared for carbamazepine (CBZ) removal efficiency, energy consumption, and disinfection by-products (DBPs) formation. All three processes could achieve nearly 100% CBZ removal, while the reaction time needed by in-situ chlorination was double the time required by UV/chlorine processes. The energy consumed per magnitude of CBZ removed (EE/O) of MP UV/chlorine was 13 times higher than that of LP UV/chlorine, and relative to that of in-situ chlorination process. Accordingly, MP and LP UV/chlorine processes generated one to two orders of magnitude more hydroxyl radicals (•OH) and reactive chlorine species (RCS) than in-situ chlorination. Besides, RCS were the dominant reactive species, contributing to 78.3%, 75.6%, and 71.6% of CBZ removal in MP, LP UV/chlorine, and in-situ chlorination, respectively. According to the Gibbs free energy barriers between CBZ and RCS/•OH calculated based on density functional theory (DFT), RCS had more reaction routes with CBZ and showed lower energy barrier in the main CBZ degradation pathways like epoxidation and formation of iminostilbene. When applied to secondary wastewater effluent, UV/chlorine and in-situ chlorination produced overall DBPs ranging from 104.77 to 135.41 µg/L. However, the production of chlorate during UV/chlorine processes was 15 times higher than that during in-situ chlorination. [Display omitted] [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]

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]

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]

Photocatalytic sterilization technology is a strategy that is environmentally friendly for killing drug-resistant bacteria using solar energy. The role of reactive oxygen species (ROS) required for sterilization depends on the charge separation properties of the photocatalyst. Therefore, we modified the photocatalytic performance of CuIn5S8 by fabricating S-vacancies based on the work function (Φ) theory. The spin state density calculations show that S-vacancies lead to spin polarization, and it is easier to separate electrons and holes when their spin directions change. Electron paramagnetic resonance (EPR) results show that Vs-CuIn5S8-3 can produce more ROS. Under visible light irradiation, Vs-CuIn5S8-3 killed 99% of E. coli and MRSA in natural water within 30 minutes. The work adopted S-vacancies to regulate spin polarization and improve photocatalytic activity, which has great potential in natural water disinfection. [ABSTRACT FROM AUTHOR]

Human activities in daily life and industrial production generate a significant volume of substandard water with high salt content, organic compounds, and other pollutants, often exhibiting a neutral pH. Electrochemical oxidation is a widely applied technique for the purification of water sources. By integrating electrochemical oxidation reactions with electrolytic hydrogen evolution reactions, the potential arises to enhance energy utilization efficiency and reduce cost implications. This study describes the advantages and challenges of neutral aqueous chlorine solutions as electrolytes for hydrogen production from electrolyzed water. The cathodic and possibly anodic reactions in the electrolysis of neutral chlorinated electrolytes are also investigated. Finally, we present the progress of research on cathode and anode catalysts used in electrolyzing neutral chlorine-containing electrolytes. The aim is to inspire the research of industrialized low-cost and high-yield integrated hydrogen production systems. [Display omitted] • Concluded the challenges of electrolysis of neutral chlorine-containing solutions. • Low-energy anode reaction coupled with hydrogen evolution reaction can reduce lower. • Concludes the design principles of cathode and anode catalysts for water splitting. [ABSTRACT FROM AUTHOR]

In the face of ongoing water pollution challenges, the intricate interplay between dissolved organic matter and disinfectants like chlorine gives rise to potentially harmful disinfection byproducts (DBPs) during water treatment. The exploration of DBP formation originating from amino acids (AA) is a critical focus of global research. Aromatic DBPs, in particular, have garnered considerable attention due to their markedly higher toxicity compared to their aliphatic counterparts. This work seeks to advance the understanding of DBP formation by investigating chlorination disinfection and kinetics using tyrosine (Tyr), phenylalanine (Phe), and tryptophan (Trp) as precursors. Via rigorous experiments, a total of 15 distinct DBPs with accurate molecular structures were successfully identified. The chlorination of all three AAs yielded highly toxic chlorophenylacetonitriles (CPANs), and the disinfectant dosage and pH value of the reaction system potentially influence chlorination kinetics. Notably, Phe exhibited the highest degradation rate compared to Tyr and Trp, at both the CAA:CHOCl ratio of within 1:2 and a wide pH range (6.0 to 9.0). Additionally, a neutral pH environment triggered the maximal reaction rates of the three AAs, while an acidic condition may reduce their reactivity. Overall, this study aims to augment the DBP database and foster a deeper comprehension of the DBP formation and relevant kinetics underlying the chlorination of aromatic AAs. [ABSTRACT FROM AUTHOR]

Substitution reactions in carbocyanine dyes are used to determine nucleophilic compounds. The interaction of a chlorine-containing carbocyanine dye with a number of medicinal substances is studied. It is shown that, in the reaction with isoniazid in the presence of a surfactant, this dye selectively changes color from yellow-green to violet. The formation of a product of the substitution of chlorine for isoniazid is proven by chromatography–mass spectrometry. The reaction proceeds in 20 min in the presence of 1 mM cetyltrimethylammonium bromide. The limit of detection for isoniazid in water by the photometric method is 10 μg/mL and in diluted artificial urine using fluorimetry, 0.3 μg/mL. The procedure does not use full-spectrum equipment, which simplifies the determination. [ABSTRACT FROM AUTHOR]

The photocatalytic technology for indoor air disinfection has been broadly studied in the last decade. Selecting proper photocatalysts with high disinfection efficiency remains to be a challenge. By doping with the incorporation of metals, the bandgap can be narrowed while avoiding the recombination of photogenerated charge. Three photocatalysts (Ag-TiO2, MnO2-TiO2, and MnS2-TiO2) were tested in photocatalytic sterilization process. The results revealed that Ag-TiO2 had the best antibacterial performance. Within 20 min, the concentration of Serratia marcescens (the tested bacteria) decreased log number of ln 4.04 under 640 w/m2 light intensity with 1000 µg/mL of Ag-TiO2. During the process of inactivating bacteria, the cell membranes of bacterial was destructed and thus decreasing the activity of enzymes and releasing the cell contents, due to the generation of reactive oxygen species (O2•– and •OH) and thermal effect. Spectral regulation has the greatest impact on the sterilization efficiency of MnO2-TiO2, which reduces the probability of photocatalytic materials being excited. [ABSTRACT FROM AUTHOR]

Water cleaning can be provided in batch mode or in continuous flow. For the latter, some kind of framework must withhold the cleaning agents from washout. Porous structures provide an ideal ratio of surface to volume for optimal access of the water to active sites and are able to facilitate rapid and efficient fluid transport to maintain a constant flow. When functionalized with suitable photoactive agents, they could be used in solar photocatalytic disinfection. In this study, we have used the sugar cube method to fabricate PDMS-based materials that contain three different classes of photosensitizers that differ in absorption wavelength and intensity, charge as well as in ability to generate singlet oxygen. The obtained sponges are characterized by scanning electron microscopy and digital microscopy. Archimede's method was used to measure porosity and density. We show that the materials can absorb visible light and generate Reactive Oxygen Species (ROS) that are required to kill bacteria. The disinfection ability was tested by examining how irradiation time and operation mode (batch vs. flow) contribute to the performance of the material. The current strategy is highly adaptable to other (medium) pressure-driven flow systems and holds promising potential for various applications, including continuous flow photoreactions. [ABSTRACT FROM AUTHOR]

Cadmium sulfide (CdS)-based photocatalysts are prepared following a hydrothermal procedure (with CdCl2 and thiourea as precursors). The HydroThermal material annealed (CdS-HTa) is crystalline with a band gap of 2.31 eV. Photoelectrochemical investigation indicates a very reducing photo-potential of −0.9 V, which is very similar to that of commercial CdS. CdS-HTa, albeit having similar reducing properties, is more active than commercial CdS in the reductive dehalogenation of 2,2-dichloropropionic acid (dalapon) to propionic acid. Spectroscopic, electro-, and photoelectrochemical investigation show that photocatalytic properties of CdS are correlated to its electronic structure. The reductive dehalogenation of dalapon has a double significance: on one hand, it represents a demanding reductive process for a photocatalyst, and on the other hand, it has a peculiar interest in water treatment because dalapon can be considered a representative molecule of persistent organic pollutants and is one of the most important disinfection by products, whose removal from the water is the final obstacle to its complete reuse. HPLC-MS investigation points out that complete disappearance of dalapon passes through 2-monochloropropionic acid and leads to propionic acid as the final product. CdS-HTa requires very mild working conditions (room temperature, atmospheric pressure, natural pH), and it is stable and recyclable without significant loss of activity. [ABSTRACT FROM AUTHOR]

As a regulator of alveolo-capillary barrier integrity, Transient Receptor Potential Vanilloid 4 (TRPV4) antagonism represents a promising strategy for reducing pulmonary edema secondary to chemical inhalation. In an experimental model of acute lung injury induced by exposure of anesthetized swine to chlorine gas by mechanical ventilation, the dose-dependent effects of TRPV4 inhibitor GSK2798745 were evaluated. Pulmonary function and oxygenation were measured hourly; airway responsiveness, wet-to-dry lung weight ratios, airway inflammation, and histopathology were assessed 24 h post-exposure. Exposure to 240 parts per million (ppm) chlorine gas for ≥50 min resulted in acute lung injury characterized by sustained changes in the ratio of partial pressure of oxygen in arterial blood to the fraction of inspiratory oxygen concentration (PaO2/FiO2), oxygenation index, peak inspiratory pressure, dynamic lung compliance, and respiratory system resistance over 24 h. Chlorine exposure also heightened airway response to methacholine and increased wet-to-dry lung weight ratios at 24 h. Following 55-min chlorine gas exposure, GSK2798745 marginally improved PaO2/FiO2, but did not impact lung function, airway responsiveness, wet-to-dry lung weight ratios, airway inflammation, or histopathology. In summary, in this swine model of chlorine gas-induced acute lung injury, GSK2798745 did not demonstrate a clinically relevant improvement of key disease endpoints. [ABSTRACT FROM AUTHOR]

Swimming is a widely practiced exercise in modern society, where there is a heightened interest in health. The exceptional benefits of swimming are well-known, yet the issue of water quality management inevitably arises due to its nature as an aquatic exercise. Several studies reported that chlorine disinfectants commonly used in swimming pool water disinfection could degrade into toxic disinfection by-products (DBPs) and suggested that the DBPs might induce respiratory disorders, including asthma. Conversely, there were also reports that the DBPs had no significant effects on respiratory conditions. In this study, we investigated the influence of swimming exercise and DBPs on asthma. The decomposition products had little effect on the number of T cells in various immune organs. However, swimming exercise was found to increase the cell count in proportion to the exercise duration. Nevertheless, there were no significant changes in other immune cells and the secretion of asthma-related cytokines. These findings indicate that the effects of swimming pool DBPs on respiratory conditions during swimming exercise are either negligible or absent, and instead, the immunological benefits gained through consistent swimming exercise outweigh any potential drawbacks. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 pandemic illustrates the importance of understanding the behavior and control of human pathogenic viruses in the environment. Exposure via water (drinking, bathing, and recreation) is a known route of transmission of viruses to humans, but the literature is relatively void of studies on the persistence of many viruses, especially coronaviruses, in water and their susceptibility to chlorine disinfection. To fill that knowledge gap, we evaluated the persistence and free chlorine disinfection of human coronavirus OC43 (HCoV-OC43) and its surrogates, murine hepatitis virus (MHV) and porcine transmissible gastroenteritis virus (TGEV), in drinking water and laboratory buffer using cell culture methods. The decay rate constants of human coronavirus and its surrogates in water varied, depending on virus and water matrix. In drinking water without disinfectant addition, MHV showed the largest decay rate constant (estimate ± standard error, 2.25 ± 0.09 day-1) followed by HCoV-OC43 (0.99 ± 0.12 day-1) and TGEV (0.65 ± 0.06 day-1), while in phosphate buffer without disinfectant addition, HCoV-OC43 (0.51 ± 0.10 day-1) had a larger decay rate constant than MHV (0.28 ± 0.03 day-1) and TGEV (0.24 ± 0.02 day-1). Upon free chlorine disinfection, the inactivation rates of coronaviruses were independent of free chlorine concentration and were not affected by water matrix, though they still varied between viruses. TGEV showed the highest susceptibility to free chlorine disinfection with the inactivation rate constant of 113.50 ± 7.50 mg-1 min-1 L, followed by MHV (81.33 ± 4.90 mg-1 min-1 L) and HCoV-OC43 (59.42 ± 4.41 mg-1 min-1 L). IMPORTANCE This study addresses an important knowledge gap on enveloped virus persistence and disinfection in water. Results have immediate practical applications for shaping evidence-based water policies, particularly in the development of disinfection strategies for pathogenic virus control. [ABSTRACT FROM AUTHOR]

The object of the study is the process of purifying natural waters using coagulants of natural and industrial origin. The subject of the study is the analysis of the effectiveness of coagulants of natural and industrial origin. Today, there is great interest in finding alternative methods of water purification that would be more economical and environmentally friendly. The availability of clean and safe water is especially important during times of martial law. Coagulants of natural origin can be an affordable and effective means of water purification and disinfection. One of the important advantages is availability, which indicates the possibility of becoming an alternative to chemical coagulants. Thus, there is a need to study the possibility of using natural coagulants both on an industrial scale and in emergency conditions. This study presents a characterization of existing coagulants of natural origin, an analysis of the effectiveness of their use, comparison with chemical analogues, as well as an analysis of the effectiveness of using Moringa oleifera as a natural coagulant. During the work, two coagulants were synthesized from red mud from aluminium production. A comparative analysis of coagulants synthesized from red mud, Moringa oleifera, aquatone and aluminium sulphate was carried out. All reagents were used to remove turbidity and other impurities. The studies were carried out 3 times in different seasons of the year. All results were compared to determine the most effective coagulant and its dose. As a result, it was found that all of these coagulants can be used and reduce water treatment costs at local water treatment plants. The natural coagulant can be used in areas where there is no access to a central water supply, especially in war zones. [ABSTRACT FROM AUTHOR]

Singlet oxygen (1O2) plays a significant role in environmental and biomedical disinfection fields. Electrocatalytic processes hold great potential for 1O2 generation, but remain challenging. Herein, a facile Ni doping converted spin‐state transition approach is reported for boosting 1O2 production. Magnetic analysis and theoretical calculations reveal that Ni occupied at the octahedral site of Co3O4 can effectively induce a low‐to‐high spin‐state transition. The high‐spin Ni−Co3O4 generate appropriate binding strength and enhance electron transfer between the Co centers with oxygen intermediates, thereby improving the catalytic activity of Ni−Co3O4 for effective generating 1O2. In neutral conditions, 1×106 CFU mL−1 Gram‐negative ESBL‐producing Escherichia coli (E. coli) could be inactivated by Ni−Co3O4 system within 5 min. Further antibacterial mechanisms indicate that 1O2 can lead to cell membrane damage and DNA degradation so as to irreversible cell death. Additionally, the developed Ni−Co3O4 system can effectively inactivate bacteria from wastewater and bioaerosols. This work provides an effective strategy for designing high‐spin electrocatalysis to boost 1O2 generation for disinfection process. [ABSTRACT FROM AUTHOR]

Singlet oxygen (1O2) plays a significant role in environmental and biomedical disinfection fields. Electrocatalytic processes hold great potential for 1O2 generation, but remain challenging. Herein, a facile Ni doping converted spin‐state transition approach is reported for boosting 1O2 production. Magnetic analysis and theoretical calculations reveal that Ni occupied at the octahedral site of Co3O4 can effectively induce a low‐to‐high spin‐state transition. The high‐spin Ni−Co3O4 generate appropriate binding strength and enhance electron transfer between the Co centers with oxygen intermediates, thereby improving the catalytic activity of Ni−Co3O4 for effective generating 1O2. In neutral conditions, 1×106 CFU mL−1 Gram‐negative ESBL‐producing Escherichia coli (E. coli) could be inactivated by Ni−Co3O4 system within 5 min. Further antibacterial mechanisms indicate that 1O2 can lead to cell membrane damage and DNA degradation so as to irreversible cell death. Additionally, the developed Ni−Co3O4 system can effectively inactivate bacteria from wastewater and bioaerosols. This work provides an effective strategy for designing high‐spin electrocatalysis to boost 1O2 generation for disinfection process. [ABSTRACT FROM AUTHOR]

Water scarcity and contamination are urgent issues to be addressed. In this context, different materials, techniques, and devices are being developed to mitigate contemporary and forthcoming water constraints. Photocatalysis-based approaches are suitable strategies to address water contamination by degrading contaminants and eliminating microbes. Photoreactors are usually designed to perform photocatalysis in a scalable and standardised way. Few or none have been developed to combine these characteristics with portability, flexibility, and cost effectiveness. This study reports on designing and producing a portable (490 g), low-cost, and multifunctional photoreactor that includes adjustable radiation intensity and two types of wavelengths (UV-A and visible), including combined agitation in a compact mechanism produced through 3D printing technology. The mechanical, electrical, and optical subsystems were designed and assembled into a robust device. It is shown that it is possible to apply radiations that can reach 65 mW/cm2 and 110 mW/cm2 using the installed visible and UV LEDs and apply mechanical agitation up to 200 rpm, all under a ventilated system. Regarding functionality, the photoreactor proof of concept indicated the ability to degrade ~80% and 30% ciprofloxacin under UV and visible irradiation of TiO2 and Ag/TiO2 nanoparticles. The device also showed the ability to eliminate E. coli bacteria, recurring to radiation set-ups and nanoparticles. Therefore, the originally designed and constructed photoreactor concept was characterised and functionally validated as an exciting and flexible device for lab-scaled or outdoor experiments, assuring standardised and comparable results. [ABSTRACT FROM AUTHOR]

Designing efficient antimicrobials for the rapid disinfection of water is increasingly critical owing to the rising threat of pathogenic microorganisms. In this study, direct Z-scheme Bi 2 WO 6 /TiO 2 heterojunctions were constructed using a simple in situ hydrothermal method. The optimal Bi 2 WO 6 /TiO 2 Z-scheme heterojunction inhibited 98.80 % of Escherichia coli (5 × 108 CFU mL−1) at 0.35 mg mL−1 and 99.33 % of Staphylococcus aureus (5 × 108 CFU mL−1) at 0.5 mg mL−1 after 10 min of light-emitting diode (LED) light irradiation. Furthermore, in antibiotic degradation experiments, Bi 2 WO 6 /TiO 2 had a 92.91 % removal rate for ciprofloxacin with a pseudo-second-order degradation rate constant (k) of 0.056 min−1 after 240 min of irradiation. The antibacterial mechanism of Bi 2 WO 6 /TiO 2 was systematically investigated and confirmed to occur by LED light-driven surface activation and efficient charge transfer. The surface and interfacial structures of the Bi 2 WO 6 /TiO 2 samples were studied by high-resolution transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The antibacterial mechanism was studied by controlled experiments and electron spin resonance analyses, which revealed that the primary antibacterial mechanism of Bi 2 WO 6 /TiO 2 is oxidative sterilisation via generated reactive oxygen species. Time-resolved fluorescence spectroscopy was used to analyse the charge-transfer pathway in Bi 2 WO 6 /TiO 2 , which demonstrated that the spatial separation of the redox-active sites extended the lifetimes of the photogenerated carriers, enhancing the oxidative destruction of bacteria. This comprehensive understanding paves the way for the design of new Z-type heterojunction photocatalytic materials for antimicrobial applications. [ABSTRACT FROM AUTHOR]

Leafy vegetables contain nutritious levels of vitamin C. Good postharvest management and food safety are the focus of reducing food loss. This study aims to evaluate the effectiveness of superoxide water in stabilizing the Vitamin C level and simultaneously prolonging the storage period for bok choy (Brassica rapa var. chinensis). The bok choy samples were immersed in superoxidised water [100 ppm Active chlorine concentration, neutral pH] and sodium bicarbonate solution for three different soaking periods: 5, 10, and 15 minutes and stored at 4°C. Weight loss, vitamin C, and chlorophyll content were evaluated during the 12 days of storage. The shelf life of bok choy treated with superoxidised water was extended from 3 days at room temperature to 8 days at 4°C. The results indicated that superoxidised water with a 5-minute treatment time could maintain a better quality of bok choy, which provides a cost-effective and sustainable alternative for chemical washing agents in the food industry compared to market-available sodium bicarbonate. [ABSTRACT FROM AUTHOR]

In food safety implementation, bacterial inactivation is an imperative aspect of hygiene and sanitation. Studies on lithium magnesium silicate (LMS) hydrosol incorporated with slightly acidic electrolyzed water (SAEW) for decontamination of pathogenic bacteria are limited. This present study aimed to investigate the bactericidal efficacy of LMS hydrosol incorporated with SAEW against Escherichia coli. Optimum combination conditions of SAEW, hydrosol concentration, and available chlorine concentration (ACC) were optimized by response surface methodology under the central composite design against the growth of E. coli. The optimum combination conditions of exposure time, hydrosol concentration, and ACC were 9.5 minutes, 1.7%, and 20.5 ppm, respectively. The results showed that the increase in ACC led to inactivation in the survival of E. coli compared with the control (p<0.05). It can be concluded that the best combination percentage between SAEW and hydrosol ranged from 1.5-1.7%, in which E. coli was reduced by 4.50 log10 CFU/mL at an ACC of 9.94 ppm. When increasing the ACC to 14.84 ppm, E. coli was reduced by 4.51 log10 CFU/mL compared with the initial number of bacteria (8.20 log10 CFU/mL) in the control group. The number of bacteria was undetected after increasing ACC to 19.93, 25.15, and 29.88 ppm at 10 min. This study suggests that LMS hydrosol incorporated with SAEW could potentially be used as an effective sanitizer. [ABSTRACT FROM AUTHOR]

In this paper, IEC 61511 was used to evaluate the hazards and risks associated with the continuous operation of the hydrolysis reactor system in the copper-chlorine thermochemical hydrogen production cycle, with a specific focus on the application of automated active safety systems and safety integrated systems. The analysis presented herein was performed using a speculative but representative hydrolysis piping and instrumentation diagram (P&ID) for the hydrolysis reaction, which was based on currently published systems as well as experience with experimental hydrolysis reactors. This analysis was then used to inform the design of a set of automated safety systems that provide the redundant operation of critical devices and can bring the hydrolysis to a safe shutdown state if needed. [ABSTRACT FROM AUTHOR]

α‐Methylene‐γ‐butyrolactone is an important skeleton in many natural products and pharmaceuticals. The factors influencing the palladium‐catalyzed asymmetric synthesis of α‐chloromethylene‐γ‐butyrolactones were investigated, including ligands, additives, the chlorine source, temperature, and solvents. We found that the reaction had broad substrate scope for the synthesis of the corresponding chiral products when the ligand, chlorine source and additives were optimized. The results will improve the catalytic synthesis of chiral α‐chloromethylene‐γ‐butyrolactones. [ABSTRACT FROM AUTHOR]

We report a ligand‐to‐metal charge‐transfer (LMCT) process that used ferric (III) chloride as efficient chlorination reagent to mediate the vicinal dichlorination of alkenes. Under 420 nm LED light, the easily available and safe ferric (III) chloride could facilitate various alkenes to transform as 1,2‐dichloride compounds with good to excellent yields (19 examples). The strategy showed a more economic protocol than CuCl2, and provided a significant reference for the light‐Induced dichlorination in industrial catalysis. [ABSTRACT FROM AUTHOR]

As chloride (Cl−) is a commonly found anion in natural water, it has a significant impact on electrocatalytic oxidation processes; yet, the mechanism of radical transformation on different types of anodes remains unexplored. Therefore, this study aims to investigate the influence of chlorine-containing environments on the electrocatalytic degradation performance of levofloxacin using BDD, Ti4O7, and Ru-Ti electrodes. The comparative analysis of the electrode performance demonstrated that the presence of Cl− improved the removal and mineralization efficiency of levofloxacin on all the electrodes. The enhancement was the most pronounced on the Ti4O7 electrode and the least significant on the Ru-Ti electrode. The evaluation experiments and EPR characterization revealed that the increased generation of hydroxyl radicals and active chlorine played a major role in the degradation process, particularly on the Ti4O7 anode. The electrochemical performance tests indicated that the concentration of Cl− affected the oxygen evolution potentials of the electrode and consequently influenced the formation of hydroxyl radicals. This study elucidates the mechanism of Cl− participation in the electrocatalytic degradation of chlorine-containing organic wastewater. Therefore, the highly chlorine-resistant electrocatalytic anode materials hold great potential for the promotion of the practical application of the electrocatalytic treatment of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

Hospital wastewater is an important source of pollutants resulting from medical activities. It has a high vulnerability towards the outbreak of several diseases. The aim of the study was to investigate the disinfection efficiency of different dosages and contact times of chlorine and peracetic acid (PAA) to reduce the contaminated microbes. The consequences after treatments such as regrowth capacity, disinfection by-products, and water quality were also observed. The result showed that in all fourth-time samplings of effluent, its physical, chemical, and biological characteristics exceeded the standard requirement and needed further treatment before discharge. The disinfection experiments were run in parallel among 3 chlorine dosages (1.388, 1.588, and 1.988 mg/l) and 3 PAA dosages (5, 10, 15 mg/l) at contact times of 15 and 30 min. PAA performed faster than chlorine from the beginning, after that, they all provided similar microbial reduction around 2.38-4.47 log 10 MPN/100 ml. Chlorine provided higher efficiency in reducing total coliform while PAA was greater for E. coli. The efficiencies increased as contact time was increased. PAA exhibited higher physical and chemical treating capacities than those of chlorine. The study suggested that chlorine at 1.528 mg/l and/or PAA at 5 mg/l, at a contact time of 15 min, are suitable microbial treatments for this effluent. These suggested conditions could improve all water quality parameters to meet the standard requirement and inhibit regrowth of microbes during the three-day incubation period. The stakeholders should also continue to monitor effluent characteristic variation and treatment conditions regarding the application of these infectants. [ABSTRACT FROM AUTHOR]

Predictive models of disinfection byproducts (DBPs) formation in treated drinking water have been widely used to guide operational decisions. However, very few studies have addressed the issue of managing DBPs through watershed protection programs and proactive management of water supply systems through predictive modeling of DBP formation potential in source waters. Here, we propose a two‐component, simple statistical approach to predict the formation potentials of the sum of five haloacetic acids (HAA5fp) and total trihalomethanes (TTHMfp) in source water streams using environmental variables and ultraviolet absorbance at 254 nm wavelength (UV254) as a surrogate for DBP precursors. In the first component of the model, using three feature selection regression models and cross‐validation of subsets of the selected predictors, we identified three commonly monitored variables—streamflow, soil temperature, and total phosphorus for predicting UV254. In the second component, HAA5fp and TTHMfp are predicted from UV254. The approach is successfully demonstrated for two source water streams of the New York City water supply system (R2 was 0.8, and 0.7–0.8 for the two model components). Long‐term predictions of HAA5fp and TTHMfp showed distinct seasonal patterns that are linked to differences in land uses of the two watersheds. Moreover, sensitivity analysis showed that transport processes were important in one watershed whereas production processes were more important in the other. [ABSTRACT FROM AUTHOR]

Chlorination is a commonly used disinfection method in sewage treatment process. However, resistant bacteria may survive chlorination and enter the receiving aquatic environment upon effluent discharge. There has been limited research on the effects of chlorination on bacterial survival in seawater. To address this knowledge gap, microcosm experiments were conducted to simulate the discharge of chlorinated effluents into coastal seawater. The results revealed that bacterial communities in seawater‐based effluents survived better in seawater than those in freshwater‐based effluents. High chlorine dosages could significantly reduce the viable bacterial populations and their chance of regrowth in seawater. Additionally, faecal indicator bacteria (FIB) that entered the viable but non‐culturable (VBNC) state under chlorination tended to persist in the VBNC state without resuscitation during seawater incubation. Because of the prevalence of VBNC indicator bacteria, qPCR quantification of FIB was more effective than conventional culture‐based methods in tracing viable pathogenic chlorine‐resistant bacteria, although the correlation strength varied depending on the type of effluent. This study sheds light on how chlorine dosages and the intrinsic properties of effluents affect bacterial survival in seawater and highlights the potential and limitations of using FIB in monitoring the health risks associated with the discharge of chlorinated effluents. [ABSTRACT FROM AUTHOR]