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Discharge from Wastewater Treatment Plants (WWTPs) can result in the emission of organic micropollutants (OMPs) and microplastics (MPs) into the aquatic environment. To prevent this harmful release, a pilot plant consisting of an ozonation followed by a granular activated carbon (GAC) filter was operated at a WWTP in Germany, and its side-effects on the concentrations of nitrogen (N) and phosphorous (P) compounds were measured. Over 80% of OMPs and transformation products were removed during the operating time (around 6000 bed volumes) no matter the ozone dose (from around 0.1 to 0.5 mgO3/mgDOC), except for Diatrizoic acid, whose breakthrough appeared at 3500 BV. Formation of the oxidation by-product, NDMA, increased with higher ozone doses, but the concentration remained below 100 ng/L. Bromate was formed at a higher ozone dose (>0.4 mgO3/mgDOC) but at a low concentration—below 10 µg/L. The MP particles detected in the inflow (PE, SBR, PP, and PS) were effectively eliminated to a high degree, with a removal rate of at least 92%. Carbon parameters (COD, DOC, and SAC254) were removed further by the pilot plant, but to different extents. As expected, nitrate was formed during ozonation, while nitrite's concentration decreased. Further, nitrite decreased and nitrate increased within the GAC filter, while ammonium was eliminated by at least 90%. Total P concentration decreased after the pilot, but the concentration of PO4-P increased. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Here, we analyzed the performance of a hydrogen/bromate fuel cell (HBFC) operating in batch recirculation mode. We adjusted the catholyte composition and operating conditions to ensure stable cell discharging and prevent the formation of liquid bromine. To achieve this, we analyzed the evolution of bromate catholytes with different acid content using thermodynamic calculations, which considered equilibria between bromine compounds and material balance for protons. We used the results of these calculations and data on catholyte chemical stability to select compositions appropriate for HBFC testing. To obtain data on catholyte evolution, we employed novel spectrophotometric and electrochemical in situ/operando techniques. Our study revealed that the composition of the catholyte and its average oxidation state, as well as the interplay between chemical and electrochemical reactions, significantly impact the power output of the HBFC. The main practical finding of our study is that under optimized conditions, the HBFC demonstrated both high energy density and reasonable performance. For instance, with a catholyte composition of 1 M LiBrO 3 and 0.3 M H 2 SO 4 , energy density is 116 Wh L−1 (theoretical 1270 Wh L−1 for 5.5 M LiBrO 3) the cell operated with 98.7% capacity utilization and power of 194 mW cm−2 at 250 mA cm−2. • Operation of H 2 /BrO 3 fuel cell in batch recirculation mode is studied. • Catholyte composition during device discharge measured by in-situ methods. • Main components of acidic bromate catholyte are BrO 3 −, Br 2 , Br−, and Br 3 − • Interplay between chemical and electrochemical reactions determines power output. • CU of H 2 /BrO 3 fuel cell reaches up to 98.7 % at 250 mA cm−2 [ABSTRACT FROM AUTHOR]

Bromate–thiourea coordinated leaching of gold sulfide ore for gold sulfide ore as leaching object. The effects of leaching reagent, stirring speed, and leaching time on gold leaching were investigated in this article. The results showed that the optimum leaching conditions were potassium bromate 0.1 M, thiourea 0.6 g·L−1, hydrochloric acid 0.2 M, agitation speed 250 rpm, ratio of liquid to solid 4, and leaching time 10 min. Under these conditions, high efficiency and rapid leaching of gold can be achieved, and reagent consumption is reduced. The research results have theoretical and practical significance for expanding new green gold extraction technology.

Adding CrIII or AlIII salts into the water suspension of platinum group metal (PGM) catalysts accelerated oxyanion pollutant reduction by up to 600%. Our initial attempts of adding K2CrVIO4, K2CrVI2O7, or KCrIII(SO4)2 into Pd/C enhanced BrO3- reduction with 1 atm H2 by 6-fold. Instrument characterizations and kinetic explorations collectively confirmed the immobilization of reduced CrVI as CrIII(OH)3 on the catalyst surface. This process altered the ζ-potentials from negative to positive, thus substantially enhancing the Langmuir-Hinshelwood adsorption equilibrium constant for BrO3- onto Pd/C by 37-fold. Adding AlIII(OH)3 from alum at pH 7 achieved similar enhancements. The Cr-Pd/C and Al-Pd/C showed top-tier efficiency of catalytic performance (normalized with Pd dosage) among all the reported Pd catalysts on conventional and nanostructured support materials. The strategy of adding inert metal hydroxides works for diverse PGMs (palladium and rhodium), substrates (BrO3- and ClO3-), and support materials (carbon, alumina, and silica). This work shows a simple, inexpensive, and effective example of enhancing catalyst activity and saving PGMs for environmental applications.

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bromate is receiving increased attention as a typical disinfection by-product in aquatic environments, but bromate toxicity tests on invertebrate such as Brachionus calyciflorus rotifer are inadequate. In the present study, the long-term toxicity tests on B. calyciflorus were performed during 21 days under the exposure of different bromate concentrations and two algal density conditions. Furthermore, we evaluated the feeding behaviors of the rotifers under the impact of bromate. The maximum population density of rotifers was significantly reduced at 100 and 200 mg/L bromate exposure at the two algal density conditions. However, we observed that the maximum population density and population growth rate of rotifers were higher at 3.0 × 106 cells/mL algal density than those at 1.0 × 106 cells/mL under the same conditions of bromate exposure. These results suggest that higher food density may have alleviated the negative effects of bromate on rotifers. Meanwhile, the ingestion rate at an algal density of 3.0 × 106 cells/mL was higher than that at 1.0 × 106 cells/mL. The present study provides a basic reference to comprehensively evaluate the toxic effects of bromate on aquatic organisms. [ABSTRACT FROM AUTHOR]

Abstract This work presents a collaboration between the so-called Gasset Service Association (responsible for providing drinking water to 100,000 inhabitants from a surface water reservoir) and researchers from the University of Castilla-La Mancha (Spain). The main aim of this work was providing a comprehensive characterization of the formation and removal of disinfection by-products in a real drinking water treatment plant (DWTP) and water distribution network. According to the results obtained, it can be stated that bromate is formed on the pre-oxidation stage and it is not eliminated throughout the DWTP; meanwhile, total organic carbon is partially removed on the clarification process. Moreover, it demonstrates the key role of the residence time and the type of water storage throughout the distribution network (either in pipes or in tanks) due to the combined effect of, at least, four overlapped mechanisms: THMs chemical generation, air stripping, hydrolysis and biological removal. This comprehensive view of the drinking water production and distribution network represents an excellent framework for allowing the improvement in the drinking water quality for a very common water production case study: a medium-size city fed by a surface water source.

Abstract A sensitive bromate sensor was developed using nickel phthalocyanine multi-walled carbon nanotubes nanocomposite modified on a glassy carbon electrode. The NiPcMWCNTs nanocomposite was prepared from nickel nanoparticles, phthalocyanine, and functionalized MWCNTs via ultrasonication. UV–visible spectroscopy, SEM, XRD, TEM, and EDX techniques were used to verify the successful fabrication of the nanomaterials. The results of the EIS and CV experiments conducted in 5 mM K3(Fe(CN)6/K4(Fe(CN)6 made in 0.1 M of PBS (pH 7) revealed that the NiPcMWCNTs/GCE exhibited higher current response, faster electron transfer, and high specific capacitance compared to other electrodes. The electrochemical reduction of bromate was actualized in 0.1 M H2SO4 (pH 1) using EIS and SWV techniques. Using the EIS technique, an LoD of 6.72 μM was obtained with a sensitivity of 483.7 μA μM−1 over a linear dynamic range (LDR) of 24–100 μM. Whereas, with the SWV technique, a lower LoD (1.47 μM) was obtained with a higher sensitivity (1293 μA μM−1) over an LDR of 12–56 μM. The developed sensor was characterized by good selectivity, high stability (95.5%), and good reproducibility (% RSD; 3.5%). The fabricated sensor was effectively used to detect bromate in bread samples with a good recovery rate, demonstrating the practical application of the sensor to detect bromate in real samples (bread).

As disinfection is employed extensively, disinfection by-product bromate has become an emerging environmental issue due to its carcinogenic toxicity. For developing an effective alternative approach for reducing bromate, cobalt and nickel-based Prussian Blue (PB) analogues are proposed here for incorporating a convenient reducing agent, NaBH4 (i.e., a H2-rich reagent) for reducing bromate to bromide as cobalt and nickel are recognized as effective metals for catalyzing hydrolysis of NaBH4, and PB exhibits versatile catalytic activity. While CoPB and NiPB are comprised of the same crystalline structure, CoPB exhibits slightly higher specific surface area, more reductive surface, and more superior electron transfer than NiPB, enabling CoPB to accelerate bromate reduction. CoPB also exhibits a higher affinity towards NaBH4 than NiPB based on density functional theory calculations. Moreover, CoPB also exhibits a relatively low activation energy (i.e., 59.5 kJ/mol) of bromate reduction than NiPB (i.e., 63.2 kJ/mol). Furthermore, bromate reduction by CoPB and NiPB could be also considerably enhanced under acidic conditions, and CoPB and NiPB could still effectively remove bromate even in the presence of nitrate, sulfate and phosphate. CoPB and NiPB are also validated to be recyclable for reducing bromate, indicating that CoPB and NiPB are promising heterogeneous catalysts for reducing bromate. [ABSTRACT FROM AUTHOR]

The occurrence of manganese (Mn) oxides on Mars is believed to be an indicator of an O 2 -rich paleoenvironment of Mars because Mn oxides often form through the oxidation of Mn(II) by O 2 on the surface of Earth. An alternative formation pathway was recently proposed, in which Mn(II) is oxidized by bromate (BrO 3 −), a common oxidant in contemporary Martian regolith. However, the oxidation of Mn(II) by bromate in solution is kinetically controlled and slow unless using very high concentrations (100 mM) of reactants that may be irrelevant to the conditions of Mars. We conducted laboratory simulations to determine whether iron (Fe) oxides (hematite and goethite) and a phyllosilicate (montmorillonite), abundant minerals on the surface of Mars, could catalyze the oxidation of Mn(II) by bromate. Hematite and goethite, but not montmorillonite, dramatically accelerated the oxidation with a low concentration (1 mM) of Mn(II) and bromate under various solution conditions. The reaction system was autocatalytic with Fe oxides initiating the oxidation of Mn(II) at the early stage and the subsequent catalysis mainly provided by the Mn oxide products. In contrast to producing Mn(IV)O 2 only during the homogeneous oxidation of Mn(II) by bromate in solutions, the heterogeneous mineral-surface catalyzed oxidation resulted in a mixture of Mn(III)OOH and Mn(IV)O 2 phases. Mn(III)OOH was an intermediate product and can be further oxidized by bromate to Mn(IV)O 2. The occurrence and accumulation of the intermediate product MnOOH can be attributed to its rapid formation due to surface-enhanced nucleation and growth on Fe oxide surfaces and to its higher resistance to oxidation by bromate than Mn(III) ions or clusters. Overall, mineral-surface catalyzed oxidation of Mn(II) by bromate is favorable from both thermodynamic and kinetic perspectives, and can be a major pathway for the occurrence of Mn oxides on Mars where microorganisms are lacking to catalyze the reaction. Our study further improves our understanding of the thermodynamic and kinetic controls on Mn(II) oxidation. [ABSTRACT FROM AUTHOR]

Bromate is a potentially carcinogenic disinfection by-product of potential concern in desalinated waters, where bromide derived from seawater can be converted to bromate by the oxidising species used for disinfection. Historically, it has been difficult to maintain complete adherence to national standards of no more than 10 ppb for bromate at all locations served with desalinated seawater by the Saline Water Conversion Corporation (SWCC) in the Kingdom of Saudi Arabia. In this full-scale study, the addition of 100–200 ppb of ammonia to the produced water of a Multi-Stage Flash Desalination plant effectively controlled the formation of bromate in the transmission system supplying inland centres in the Makkah Province of the Kingdom of Saudi Arabia (Arafa, Taif) on a time scale sufficient for the distribution of water to the consumer, even when the bromide content of the produced water was artificially enhanced (up to 132 ppb) via the addition of seawater. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As an increasing number of potable water reuse projects consider feasibility of implementing ozonation for achieving disinfection goals and removal of trace organic compounds, bromate formation presents a practical barrier. In this study, data received from five potable water reuse facilities showed that ozone dissolution method such as fine bubble diffusion resulted in lower concentrations of bromate compared to side-stream addition. When using multipoint ozone dissolution some reduction in bromate formation was also observed. Data from these facilities displayed a positive correlation between ozone (as a function of O3:TOC ratio) and bromate formation (as molar ratio of bromide converted to bromate) with lower formation as monochloramine or hydrogen peroxide concentrations increase. This study provides an empirical model with four equations which can be used to estimate the bromate formation and the required monochloramine or hydrogen peroxide dose to achieve adequate bromate control, i.e. below MCL of 10 µg/L, if a desired O3:TOC ratio and initial bromide concentration are known. The empirical model estimates for monochloramine and hydrogen peroxide were found to be in good agreement with experimental data (R2 = 0.96 and R2 = 0.87, respectively) while within a set of boundary conditions expressed by range of concentrations of typical water quality parameters. [ABSTRACT FROM AUTHOR]

In this study, the spent bleaching earth carbon (SBE@C) was modified with iron to obtain the iron-modified spent bleaching earth carbon (defined as FexOy-SBE@C) to remove bromate. The pseudo-second-order kinetic model and Langmuir model could well fit the bromate removal process. When the temperature was increased from 25 to 45 °C, bromate removal efficiency increased, and FexOy-SBE@C exhibited the highest bromate removal capacity of 521.82 mg/g at 45 °C. The effect of coexisting anions was investigated, and their adverse effects decreased in the order of PO43->NO3->SO42-. The higher the concentration of coexisting ions, the greater their inhibitory effect on bromate removal. By studying the effect of pH, it was found that the bromate removal was the highest at pH = 3. Characterization analysis confirmed that the iron was successfully loaded on the surface of SBE@C. The main mechanism for bromate removal by FexOy-SBE@C was the reduction of zero-valent iron and divalent iron with bromate to form the bromide ion. Overall, FexOy-SBE@C is a high-performance material for bromate removal. [ABSTRACT FROM AUTHOR]

This work presents a collaboration between the so-called Gasset Service Association (responsible for providing drinking water to 100,000 inhabitants from a surface water reservoir) and researchers from the University of Castilla-La Mancha (Spain). The main aim of this work was providing a comprehensive characterization of the formation and removal of disinfection by-products in a real drinking water treatment plant (DWTP) and water distribution network. According to the results obtained, it can be stated that bromate is formed on the pre-oxidation stage and it is not eliminated throughout the DWTP; meanwhile, total organic carbon is partially removed on the clarification process. Moreover, it demonstrates the key role of the residence time and the type of water storage throughout the distribution network (either in pipes or in tanks) due to the combined effect of, at least, four overlapped mechanisms: THMs chemical generation, air stripping, hydrolysis and biological removal. This comprehensive view of the drinking water production and distribution network represents an excellent framework for allowing the improvement in the drinking water quality for a very common water production case study: a medium-size city fed by a surface water source. [ABSTRACT FROM AUTHOR]

A sensitive bromate sensor was developed using nickel phthalocyanine multi-walled carbon nanotubes nanocomposite modified on a glassy carbon electrode. The NiPcMWCNTs nanocomposite was prepared from nickel nanoparticles, phthalocyanine, and functionalized MWCNTs via ultrasonication. UV–visible spectroscopy, SEM, XRD, TEM, and EDX techniques were used to verify the successful fabrication of the nanomaterials. The results of the EIS and CV experiments conducted in 5 mM K3(Fe(CN)6/K4(Fe(CN)6 made in 0.1 M of PBS (pH 7) revealed that the NiPcMWCNTs/GCE exhibited higher current response, faster electron transfer, and high specific capacitance compared to other electrodes. The electrochemical reduction of bromate was actualized in 0.1 M H2SO4 (pH 1) using EIS and SWV techniques. Using the EIS technique, an LoD of 6.72 μM was obtained with a sensitivity of 483.7 μA μM−1 over a linear dynamic range (LDR) of 24–100 μM. Whereas, with the SWV technique, a lower LoD (1.47 μM) was obtained with a higher sensitivity (1293 μA μM−1) over an LDR of 12–56 μM. The developed sensor was characterized by good selectivity, high stability (95.5%), and good reproducibility (% RSD; 3.5%). The fabricated sensor was effectively used to detect bromate in bread samples with a good recovery rate, demonstrating the practical application of the sensor to detect bromate in real samples (bread). [ABSTRACT FROM AUTHOR]

In this study, one type of layered double hydroxide (LDH), the meta-aluminate intercalated mafic-modified hydrotalcite (LDH-2), was engineered through an unprecedentedly facile, affordable one-step procedure. In the interest of meticulous perception regarding our superior strategy, the conventional two-step synthesis method—the fabrication of optimal mafic-modified hydrotalcite through the coprecipitation and roasting process followed by a second aging step (LDH-1)—was also synthesized. After scrutinization of as-derived nanostructures, the adsorption capacity of both structures for bromate remediation was elaborated. When the effect of experimental variation was optimized and the impact of various ions was investigated, the more astounding performance of LDH-2 (0.97 mg/g) was detected when compared with conventional LDH-1 (0.90 mg/g). Therefore, the novel approach for the engineering of meta-aluminate intercalated mafic hydrotalcite not only introduces facile and practical procedures, but also furnishes a much more efficient adsorption system. In the matter of structure durability, the as-synthesized LDH-2 presented exceptional resistance, maintaining activity after five consecutive cycling runs. This investigation sheds light on the facile and affordable synthesis of the LDH construction. [ABSTRACT FROM AUTHOR]

Objectives The purpose of this study is to suggest operating conditions that can minimize the disinfection by-products of sodium hypochlorite produced in on-site sodium hypochlorite generators. Methods The characteristics of disinfection by-products were investigated by operating conditions (dissolved water type, brine concentration, temperature of electrolytic cell inflow water, pH of electrolytic cell inflow water and electrolyzer current density) using a on-site sodium hypochlorite generator(5 kg/day). Results and Discussion The concentration of disinfection by-products (chlorate, bromate) according to the type of dissolved water was found to be high in the order of softened water > tap water > RO treated water. As the brine concentration increased, chlorate decreased and bromate increased. The optimal saline concentration was found to be 3% or more. As temperature of electrolytic cell inflow water increases,, chlorate decreases and bromate increases. The difference in the concentration of disinfection by-products(chlorate, bromate) according to the pH of electrolytic cell inflow water is not large, and the appropriate pH is determined to be about 7 when the free available chlorine and disinfection by-products are taken into account. Also, as the current density increases, the chlorate increases and bromate showed a decreasing trend. Conclusion It has been shown that the concentration of disinfection by-products can be minimized when operating within the operating range suggested by the on-site sodium hypochlorite generator manufacturer, and some operating conditions are thought to have been suggested by the manufacturer to protect the electrolyzer cells. As the market for on-site sodium hypochorite generator gradually expands, it is expected that improved facilities will be continuously released in consideration of the stricter standards for disinfection by-products.

Objectives This study was conducted to suggest field operating conditions that can minimize disinfection by-products for three types of sodium hypochlorite. Methods In this study, changes in free available chlorine, chlorate and bromate were analyzed according to storage temperature, storage time and presence or absence of sunlight for three types of sodium hypochlorite(two types of bleach and one type of sodium hypochlorite made on-site hypochlorite generator). Results and Discussion In the case of bleach with 12% free available chlorine, when operating with a target of 10% of more of free available chlorine, the storage time for each storage temperature was 3 days at 40℃, 13 days at 30℃, 27 days at 20℃, 85 days at 10℃, and 200 days at 5℃. In the case of bleach with 5% free available chlorine, when operating with a target of 4% of more of free available chlorine, the storage time for each storage temperature was 37 days at 35℃, 255 days at 20℃, 1,343 days at 10℃, and 4,821 days at 4℃. In the case of sodium hypochlorite with 0.8% free available chlorine made on-site hypochlorite generator, when operating with a target of 0.7% of more of free available chlorine, the storage time for each storage temperature was 10 days at 3 5℃, 42 days at 20℃, 470 days at 10℃, and 1,770 days at 4°C. As a result of evaluating the quality change according to the presence or absence of UV protection, the free available chlorine decreased rapidly when exposed to sunlight, whereas the free available chlorine decreased slowly in the case of indoor storage. Conclusion Bleach with 12% free available chlorine can be stored for about 60 days at 15℃, and bleach with 5% free available chlorine can be used within about 6 months at 15℃. And sodium hypochlorite with 0.8% free available chlorine can be used within 10 days at room temperature. In addition, when storing sodium hypochlorite, it is suggested that it be stored indoors protected from sunlight.

In this study, the removal of bromate, a regulated ozone by-product, was evaluated using a strong-base anion (SBA) exchange resin in batch and column experiments. The kinetics studies in batch mode showed that film diffusion-controlled bromate exchange in SBA and the isotherm studies showed that the Langmuir model fitted the experimental results with a maximum exchange capacity of 296.66 mg BrO3−/g (~1.3 meq/mL resin). In the fixed-bed column studies, breakthrough curves were obtained under different operating conditions to examine the effects of feed flow rate, inlet bromate concentration, and bed height on column performance. A modified n-order Bohart and Adams model (n-BAM-c), which considered the asymmetry of the breakthrough curve and flow channeling, was applied for the first time to describe the experimental data obtained from the column and to predict the breakthrough curves. It was found that n-BAM-c fitted the experimental data well (R2 > 0.99) and the effects of the key operating conditions on the model parameters were determined. Overall, the results show that SBA exchange is suitable for bromate removal from water and n-BAM-c could be a powerful tool for the design and upscaling of bromate ion exchange columns. [ABSTRACT FROM AUTHOR]

This article presents solid-phase spectrophotometric method of bromate determination using methyl red immobilised into transparent polymethacrylate matrix. The method is based on oxygenation of the indicator immobilised into the matrix by a bromate. We discovered the optimal conditions for bromate determination, studied the effect of interference of the foreign ions, and evaluated the analytical performance of the suggested method. The method we developed makes it possible to quantify the content of a bromate in the concentration range of 0.1–1.0 mg·L−1 with the limit of detection 0.01 mg·L−1. The mean relative standard deviation of the results was ≤1.2%, which confirmed reproducibility of this assay technique. We demonstrated usability of the suggested method for detection of bromates in drinking water using solid-phase spectrophotometry without any preliminary sample preparation. Polymethacrylate matrix with methyl red immobilised into it can be used as a ready-made analytical form for the rapid visual bromate determination test. [ABSTRACT FROM AUTHOR]

Bromate formation is a complex process that depends on the properties of water and the ozone used. Due to fluctuations in quality, surface waters require major adjustments to the treatment process. In this work, we investigated how the time of year, ozone dose and duration, and ammonium affect bromides, bromates, absorbance at 254 nm (UV254), near-infrared (NIR) spectra, and fluorescent components (humic-like and tyrosine-like) during surface water ozonation. Linear and non-linear models were used to determine and predict the relationships between input and output variables. Season, ozonation dose and time were correlated with the output variables, while ammonium affected only bromates. All coefficients of determination (R2) for the multiple linear regression models were >0.64, while R2 for the piecewise linear regression models was >0.89. The season had no effect on bromate formation in either model, while ammonium only affected bromides and bromates. Three input variables influenced UV254 in both models. The artificial neural network (ANN) model with the season, ozonation dose and time, ammonium, and NIR spectra was an effective way to describe water ozonation results. The multilayer perception neural network 14-14-5 had the lowest errors and was the best ANN model with R2 values for training, testing, and validation of 0.9916, 0.9826, and 0.9732, respectively. [ABSTRACT FROM AUTHOR]

Swimming is a physical activity that is accessible to people of all ages in all seasons. However, continuous organic and inorganic precursor load and disinfectant dosing make pool water chemistry much more complex than other disinfected waters. Carcinogenic bromate compound is one of the hundreds of disinfection by-products in pool water. The occurrence of bromate in pool waters depends on the precursor content of filling water, the disinfection process, operating parameters, and the purity of disinfectants. While the average filling water bromide concentrations of University Campus indoor swimming pool in Gülbahçe -Urla (SP1) and Buca public indoor swimming pool (SP2) were determined to be 182 µg/L and 11.0 µg/L, respectively, the average bromate concentrations of SP1 and SP2 were 59.4 µg/L and 68.3 µg/L. Estimated chronic-toxic health risks of accidental ingestion of pool water during swimming (between 10-3 and 10-1) were lower than the threshold level ('1'). Although the carcinogenic risks in central tendency scenario (<10-6) indicate negligible risks for swimmers, worst case scenario indicates carcinogenic risks (medians were ranged from 1.61×10-6 to 9.42×10-6) for highly exposed specific swimmer groups. Bromate accumulation in swimming pools needs attention for mitigating the health risks for swimmers. [ABSTRACT FROM AUTHOR]

The Hanshin Water Supply Authority is the first bulk water supplier in Japan that currently operates two drinking water treatment plants. Both plants employ an ozonation process for the reduction of musty odor compounds, 2-methylisoborneol and geosmin, and trihalomethanes. In this study, we aim to estimate hydroxyl radical (HO∙) exposure in a three-stage countercurrent ozone contactor applied at the Inagawa drinking water treatment plant. We estimated the HO∙ exposure as the product of the ozone exposure multiplied by the RCt value, that is, the ratio of the HO∙ exposure to the ozone exposure. The ozone exposure was estimated by a methodology we developed earlier, and the RCt values were experimentally evaluated in this study. The estimated HO∙ exposure ranged from 0.4 × 10−10 to 6.7 × 10−10 M·s across the contactor during our research period. The highest HO∙ exposure of 6.7 × 10−10 M·s indicated that the reduction ratio of musty odor compounds exceeded 95%. At these exposures, the detected concentration of bromate was 6 µg/L, which is equal to the 60% concentration level of Japan's water quality standard for drinking water. Further, we attempt to balance the reduction in musty odor compounds with control of bromate formation. [ABSTRACT FROM AUTHOR]

Bromate (BrO3−) and ammonia nitrogen (NH4+) are both typical environmental pollutants: BrO3− has been categorized as one of the Group 2B carcinogen by IARC; an excess of NH4+ might result in the eutrophication of water. The existence of NH4+ could inhibit the transformation of bromide (Br−) to bromate (BrO3−). However, the interaction of NH4+ and BrO3− during the removal process is not clear. This study intends to disclose the mutual relationships of ammonia nitrogen and bromate ions under UV irradiation or UV/TiO2 conditions. Without UV irradiation, BrO3− and NH4+ were both stable even under the presentation of each other. Under UV irradiation or UV/TiO2 conditions, BrO3− and NH4+ promoted the degradation of each other, showing the synergistic degradation mechanism. In the neutral environment, both of BrO3− and NH4+ could be transformed effectively. Furthermore, NH4+ accelerated the transformation of BrO3− to Br− at the reaction beginning and the existence of BrO3− is beneficial for the transformation of NH4+ to N2. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the previous advances, current challenges, and future opportunities for the research of catalytic reduction of water pollutants. We present five case studies on the development of palladium-based catalysts for nitrate, chlorate, and perchlorate reduction with hydrogen gas under ambient conditions. We emphasize the realization of new functionalities through the screening and design of catalytic metal sites, including (i) platinum group metal (PGM) nanoparticles, (ii) the secondary metals for improving the reaction rate and product selectivity of nitrate reduction, (iii) oxygen-atom-transfer metal oxides for chlorate and perchlorate reduction, and (iv) ligand-enhanced coordination complexes for substantial activity enhancement. We also highlight the facile catalyst preparation approach that brought significant convenience to catalyst optimization. Based on our own studies, we then discuss directions of the catalyst research effort that are not immediately necessary or desirable, including (1) systematic study on the downstream aspects of under-developed catalysts, (2) random integration with hot concepts without a clear rationale, and (3) excessive and decorative experiments. We further address some general concerns regarding using H2 and PGMs in the catalytic system. Finally, we recommend future catalyst development in both “fundamental” and “applied” aspects. The purpose of this perspective is to remove major misconceptions about reductive catalysis research and bring back significant innovations for both scientific advancements and engineering applications to benefit environmental protection. [ABSTRACT FROM AUTHOR]

Bromide in treated natural waters is oxidized to toxic bromate with ozone. For the novelty of pulsed corona discharge (PCD) in water treatment, it's potential in bromide transformation needs clarification. Experimental research into bromide-bromate conversion dependent on control parameters, including pulse repetition frequency, pH, Br− concentration, and presence of organics, was undertaken. Bromide transformed to bromate in acidic and circum-neutral media; transformation of bromate to bromide was also observed. Bromide was poorly oxidized in alkaline media. Oxidation of bromide was obstructed with oxalate. Formation of nitrate was noticeably decelerated by bromate. [Display omitted] • Pulsed corona discharge (PCD) reversibly oxidize bromide in acidic and neutral media. • Bromate and hypobromous forms are bromide oxidation products. • Oxalate reduces bromide PCD oxidation ruling out hypobromite in neutral media. • In acidic media, bromate formation was reduced two-fold with oxalic acid. • Aqueous bromate strongly inhibit nitrate formation in air PCD. [ABSTRACT FROM AUTHOR]

A streamlined, precise, and dependable method for the concurrent quantification of bromate has been established, employing ion chromatography in conjunction with electrospray ionization tandem mass spectrometry (IC-ESI-MS/MS). In an effort to expedite sample analysis duration, the AG18 short column was utilized for rapid separation of the specified analytes. Utilizing a blend of water and acetonitrile as the mobile phase within an optimized gradient elution setting, it was possible to achieve satisfactory resolution in under 3 minutes. Specifically, the mixing of acetonitrile in water samples improves the sensitivity and immunity of the method. This phenomenon may be attributed to the similar proportions of acetonitrile in the sample and the mobile phase, which effectively reduces the viscosity and surface tension of the droplets during the ESI process. Detection limits and quantification thresholds were 0.14 µg/L and 0.41 µg/L, respectively. Analyte recoveries, when spiked into tap water between 2.5 µg/L to 50 µg/L, ranged from 69.5 % to 116.7 %; precision metrics, measured as intra- and inter-day relative standard deviations, spanned 5.1–7.9 %. The devised approach encountered minimal interference from prevalent water matrix constituents, including chloride (50–200 mg/L), sulfate (25–200 mg/L), bicarbonate/carbonate (1–6 mM), and natural organic matter (1–8 mg/L). In environmental contexts, this methodology effectively tracked the production of bromate in controlled ozonation experiments conducted in the laboratory. Segmented ozone dosing reduced bromate production when the solution contained low concentrations of DOC, which provides an alternative strategy for controlling bromate production. [Display omitted] • A short-column IC-ESI-MS/MS method was developed for bromate analyse. • Adding ACN to samples improves the sensitivity and anti-interference ability. • The analysis method obviates the inclusion of additives in the mobile phase. • Bromate can be separated from interfering matrix ions. • Multi-stage ozone dosing reduced bromate production. [ABSTRACT FROM AUTHOR]

The purification of bromate (BrO 3 −)-contaminated water has become a challenge because of its persistence and adverse effects. Furthermore, there has been concern over the release of byproducts, such as diphenyl phosphate (DPHP), from flame retardants in wastewater treatment plant (WWTP). In this study, we designed the water treatment system for the oxidation of DPHP accompanied by bromate (BrO 3 −) reduction via freezing the solution. A sample containing 10 μM DPHP, 100 μM Br−, and 50 μM BrO 3 −, with a pH of 3 was frozen at −20oC, approximately 25 μM BrO 3 − was reduced, and DPHP was fully eliminated after a 0.5 h reaction time. Conversely, these reactions did not advance in water at 20oC. This increase in the rate of chemical reaction in ice is the consequence of the freeze concentration effect, which refers to the extraction of dissolved chemical species into the liquid-like regions of the polycrystalline ice micro-structure during the freezing of the solution. The redox reactions among DPHP, Br−, and BrO 3 − become thermodynamically favorable due to the distinctive environment in the liquid brine in ice. The efficiency of the DPHP oxidation significantly increased with an increase in BrO 3 − concentration, and vice versa. The Br−/BrO 3 −-induced HOBr production is proposed as a primary oxidant for DPHP degradation. The proton activity (pH) has a significant influence on the reaction efficiency. The low freezing temperature accelerated the reaction kinetics of DPHP degradation and BrO 3 − reduction. The results of this study indicate the possibility of utilizing ice chemistry for the BrO 3 − reduction that concomitantly removes DPHP for water treatment. This environmentally friendly water treatment method can be considered to implement in regions with a cold climate. • A freezing-induced bromate reduction was accompanied with organophosphate diester degradation. • During freezing process, bromate reduction was initiated by bromide oxidation and hypobromous acid was produced. • The freeze concentration effect resulted in an increased chemical reaction during the freezing process. • Hypobromous acid generated by bromate reduction degraded DPHP in frozen solution. • Ice chemistry offers efficient process for natural arctic river water treatment. [ABSTRACT FROM AUTHOR]

Unlike halides, where the kosmotropicity decreases from fluoride to iodide, the kosmotropic nature of halates apparently increases from chlorate to iodate, in spite of the lowering in the static ionic polarizability. In this paper, we present an experimental study that confirms the results of previous simulations. The lyotropic nature of aqueous solutions of sodium halates, i.e., NaClO3, NaBrO3, and NaIO3, is investigated through density, conductivity, viscosity, and refractive index measurements as a function of temperature and salt concentration. From the experimental data, we evaluate the activity coefficients and the salt polarizability and assess the anions' nature in terms of kosmotropicity/chaotropicity. The results clearly indicate that iodate behaves as a kosmotrope, while chlorate is a chaotrope, and bromate shows an intermediate nature. This experimental study confirms that, in the case of halates XO3−, the kosmotropic–chaotropic ranking reverses with respect to halides. We also discuss and revisit the role of the anion's polarizability in the interpretation of Hofmeister phenomena. [ABSTRACT FROM AUTHOR]

The ever-increasing characteristics of microcomputers, sensors, actuators, and communication systems require more powerful and more compact autonomous power sources. Al/bromate and Al/iodate flow batteries are proposed as new power supply units for use in oxygen-deficient environments. The batteries employ a mechanically rechargeable aluminum anode flooded with aqueous salt electrolytes or seawater, a cation-exchange membrane, and a carbonaceous porous cathode, where acidified alkali metal bromate, or iodate, is reduced in a six-electron process. The theoretical energy density of an Al/bromate flow cell per reactants is 0.65 kWh kg−1. Seawater is assumed as an electrolyte for the anode compartment. Using a H2/iodate flow cell, it is shown that iodate–iodine–iodide electrochemical transformations can be realized in both directions in acidic media at carbonaceous electrodes. At 30 °C, the area-specific power of the single cells of the Al/bromate and Al/iodate flow batteries reaches 0.26 W cm−2 and 0.075 W cm−2, respectively. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Iron and titanium doped γ-Al2O3 (γ-Fe-Ti-Al2O3) mesoporous catalysts were synthesized by evaporation-induced self-assembly using glucose as template, and applied to ozonation of ibuprofen in bromide-containing water. X-ray diffraction (XRD), nitrogen adsorption–desorption (BET), X-ray photoelectron spectroscopy (XPS) results showed that iron and titanium successfully doped into the skeleton of γ-Al2O3, uniform distribution, maintain the ordered mesoporous structure of γ-Al2O3, with larger specific surface area. The valence of titanium coexists with Ti4+ and Ti3+, and the valence of iron was Fe3+. Infrared spectra of chemisorbed pyridine (Py-FTIR) results showed that the doped titanium and iron into the framework position of γ-Al2O3 altered the surface acidity of the alumina surface, especially increasing the medium Lewis acid sites, which was conducive to the effective decomposition of ozone into active oxygen species. The γ-Fe-Ti-Al2O3 catalyst (Al/Fe = 25, Al/Ti = 75) enhanced the removal rate of ibuprofen in ozonation of bromide-containing water, and effectively blocked the formation of bromate. After the reaction of 60 min, the removal rate of TOC was increased from 54% of γ-Al2O3/O3 to 86% with γ-Fe-Ti-Al2O3/O3, while the ozonation alone was only 13%. Electron Paramagnetic Resonance (EPR) spectra showed that hydroxyl and superoxide radicals were reactive oxygen species, which was beneficial to the mineralization of organic matter. The capture experiment of Fe2+ ion confirmed that the electronic cycle of Fe2+ ion and Fe3+ ion was beneficial to block the formation of bromated. The addition of ibuprofen and humic acid can enhance the reduction of Fe3+ in the catalytic ozonation of γ-Fe-Ti-Al2O3, which further strengthened the blocking of bromate formation. [ABSTRACT FROM AUTHOR]

Kinetic investigation of Ru(III) catalyzed oxidation of menthol in an acidified solution of potassium bromate in the presence of Hg(OAc)2 as a scavenger of bromine intermediate has been studied. The reaction exhibits zero order kinetics with respect to KBrO3. While first order kinetics with respect to menthol and Ru(III) respectively. Hydrogen ion does not affect the rate but rate is enhanced by ionic strength. The influence of Hg(OAc)2 on the rate was found to be insignificant. Menthone as the oxidation product of menthol has been confirmed spectrally. The proposed mechanism involves slow and rate-controlling disproportionate of a transient complex formed between reactive species of Ru(III) and menthol. The various activation parameter such as energy of activation (∆E)#, Arrhenius factor (A), and entropy of activation (∆S)# were calculated. The rate law derived on the basis of experimental data corresponds well with the proposed mechanism. [ABSTRACT FROM AUTHOR]

Due to the wide applications of the Reactive Black B (RB−B) in textile industries, it is largely present within the aqueous environment which is a serious environmental threat. Previous studies were unsuccessful to completely remove the color of RB−B from the contaminated environment. In this work, the decolorization of aqueous solutions with RB−B was performed by Potassium bromate. It was found to be a promising oxidizing agent for chemical degradation of organic pollutant. The decolorization and degradation of Reactive Black B by potassium bromate in an aqueous acidic medium was carried out at 591 nm spectrophotometrically at laboratory scale. The reaction was studied under pseudo order conditions having concentration of BrO3− in excess than dye. Under constant conditions, the reaction was found to be first order with respect to both oxidant and reductant. The kinetic salt effect of added salt for the determination of reactive species in the rate‐determining step showed that the rate of reaction is directly related to the increasing concentration of salt, suggesting that two same charged species are involved in the rate‐determining step. Activation parameters were also calculated for the reaction. The highest decolorization percentage of RB−B (99 %) was obtained showing almost complete removal of color of dye from aqueous medium. The proposed degradation of RB−B with bromate was confirmed by qualitative and analytical tests (TDS, EC, UV‐Visible and FTIR spectroscopy). [ABSTRACT FROM AUTHOR]

Bread is a staple food across the world, especially in Nigeria. Potassium bromate is widely used by bakers to enhance bread elasticity, functionality, and quality. Due to its toxicity, the use of potassium bromate in bread production in Nigeria was banned by the National Agency for Food and Drug Administration and Control (NAFDAC); the regulatory agency for food and pharmaceutical products in 2003. This review aims to assess the compliance levels of potassium bromate used in the production of low and high-cost bread consumed across Nigeria. 17 selected articles across the six geopolitical zones were evaluated. This review identified that most of the bread sold and consumed in Nigeria contained potassium bromate in quantities above the permissible limit. Surprisingly, even bread labeled as “bromate-free”, “with NAFDAC registration number” and sold at high-costs also contained potassium bromate in excess concentration. This implies that many bread sold in Nigeria are unsafe for human consumption. Due to the deleterious effects of potassium bromate, its continual usage and consumption above the safe limit is a threat to the total well-being of the consumers. Its use in the bread-making industry also poses a serious health occupational hazard to bakers. Bread makers should opt for other alternative dough conditioners such as ascorbic acid, glucose oxidase, and potassium iodate for bread production. NAFDAC should put in more proactive measures to ensure constant monitoring of food products pre-and post-production to guarantee adherence to its regulatory standards and the safety of human life.

Sulfate radical (•SO4−)-based advanced oxidation processes are widely used for wastewater treatment. This study explored the potential use of UV/persulfate (UV/PS) system for the degradation of 17β-estradiol (E2). The pH of the reaction system can affect the degradation rate of E2 by UV/PS and the optimum pH was 7.0; Br− and Cl− in water can promote the degradation rate, HCO3− has an inhibitory effect on the reaction, SO42− and cations (Na+, Mg2+, K+) have no effect on the degradation rate. The degradation of E2 by UV/PS was a mineralization process, with the mineralization rate reaching 90.97% at 8 h. E2 in the UV/PS system was mainly degraded by hydroxylation, deoxygenation, and hydrogenation. E2 reaction sites were mainly located on benzene rings, mainly carbonylation on quinary rings, and bond breakage between C10 and C5 resulted in the removal of benzene rings and carboxyl at C2 and C3 sites. In the presence of halogen ions, halogenated disinfection by-products were not formed in the degradation process of E2 by UV/PS. E2 in the UV/PS system could inhibit the formation of bromate. The results of this study suggest that UV/PS is a safe and reliable method to degrade E2. HIGHLIGHTS The reaction kinetics, mechanisms and degradation pathways of the UV/PS process in degrading E2 in marine aquaculture water were elucidated.; The fates of E2 in marine aquaculture water were analyzed in the presence of potential interfering factors such as anions (Br−, Cl−, HCO3−, SO42−), cation (Na+, Mg2+, K+) and pH value.; The inorganic disinfection by-products namely bromate of E2 treated by UV/PS was also explored.;

Background: Trace elements and potassium bromate represent health risks in food substances owing to their potential toxicity. Methods: Bread samples were obtained from different stores in Ile-Ife, Osun State, Nigeria. The levels of potentially toxic elements (PTEs) (cadmium, chromium, cobalt, copper, lead, manganese, nickel, and zinc) and potassium bromate were determined in the bread samples using Atomic Absorption Spectrophotometer and Ultraviolet Spectrophotometer respectively. Results: The results of the study showed that copper had the highest mean concentration (39.20 ± 1.12 mg/kg) while lead had the lowest mean concentration (0.42 ± 0.02 mg/kg). The levels of the PTEs followed the order: Cu > Zn > Cr > Mn > Ni > Co > Cd > Pb. The concentrations of all the investigated elements exceeded the FAO/WHO legislations. Potassium bromate was undetected in the samples. The target hazard quotients of Cr, Cu, and Cd were greater than 1, as opposed to the other elements which were less than 1. The children were the more vulnerable population given that their total target hazard quotient (35.09) was higher than the adults (9.35) equivalent. Carcinogenic health risks (CR > 10−5) were associated with bread consumption. Conclusion: Due to possible contamination sources emanating from used equipments and processing methods, compliance with regulatory agencies towards ensuring a healthy production environment should be enforced.

This paper summarizes studies undertaken at a water treatment plant in Skawina (WTP Skawina) where the disinfection process was modified by introducing a mobile ozonation system. The application of a small-size, fully-automated ozonation installation only slightly complicates the water treatment process, without the need to redesign the water treatment line, and with relatively low investment costs. The aim of this study was to analyze whether the change of the disinfection method affects the final water quality. The investigated water samples were treated in the mobile ozonation system using a disinfection process with only sodium hypochlorite. Treated water was of excellent quality, and seasonal variations in raw water parameters (variable organic matter contents) did not result in elevated trihalomethanes (THM) and bromate concentrations. Despite the trace amounts of bromides in the water prior to treatment, the water in the municipal drinking water system did not contain determinable amounts of bromates. The bromine concentrations in the treated water supplied to the water distribution system were higher than in raw water, which could be attributable to the presence of bromine as a contaminant in sodium hypochlorite (the disinfection agent). Water quality tests carried out by the water treatment plant (WTP) and by the State Sanitary Inspectorate after the modification of the process line confirmed the high quality of water in the distribution network after the change of disinfection method. [ABSTRACT FROM AUTHOR]

Copyright of Taiwanese Journal of Agricultural Chemistry & Food Science is the property of Agricultural Chemical Society of Taiwan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microbial bromate reduction plays an important role in remediating bromatecontaminated waters as well as biogeochemical cycling of bromine. However, little is known about the molecular mechanism of microbial bromate reduction so far. Since the model strain Shewanella oneidensis MR-1 is capable of reducing a variety of oxyanions such as iodate, which has a high similarity to bromate, we hypothesize that S. oneidensis MR-1 can reduce bromate. Here, we conducted an experiment to investigate whether S. oneidensis MR-1 can reduce bromate, and report bromate reduction mediated by a dimethylsulfoxide reductase encoded with dmsA. S. oneidensis MR-1 is not a bromate-respiring bacterium but can reduce bromate to bromide under microaerobic conditions. When exposed to 0.15, 0.2, 0.25, 0.5, and 1 mM bromate, S. oneidensis MR-1 reduced bromate by around 100, 75, 64, 48, and 23%, respectively, within 12 h. In vivo evidence from gene deletion mutants and complemented strains of S. oneidensis MR-1 indicates that MtrB, MtrC, CymA, GspD, and DmsA are involved in bromate reduction, but not NapA, FccA, or SYE4. Based on our results as well as previous findings, a proposed molecular mechanism for bromate reduction is presented in this study. Moreover, a genomic survey indicates that 9 of the other 56 reported Shewanella species encode proteins highly homologous to CymA, GspD, and DmsA of S. oneidensis MR-1 by sequence alignment. The results of this study contribute to understanding a pathway for microbial bromate reduction. [ABSTRACT FROM AUTHOR]

Bromide in water can form undesirable by-products such as bromate when treated by ozonation during drinking water production. The maximum contaminant level (MCL) for bromate is 10 µg/L in most countries because it is suspected of being carcinogenic. In this paper, the geographical distribution of bromide concentration in Croatian groundwater is presented covering the Pannonian basin and the Dinarides (Adriatic Sea). Groundwater in Croatian wellfields predominantly has a bromide content of less than 50 µg/L and thus belongs to the group with low potential for bromate formation. Waters with higher bromide concentrations were found mainly in the coastal regions of Croatia, probably due to seawater intrusion. In addition, bromide concentration showed a positive correlation of 0.6 with conductivity, chloride, and sodium. In addition, the potential of 123 groundwaters analyzed in this study to form bromate when treated with ozone was evaluated using models available in the literature. Analysis of water from Croatian wellfields indicated that the potential for bromate formation above the MCL during ozonation was relatively low. The models used from the literature predicted quite different values of bromate concentration when applied to the same water, with some values exceeding those theoretically possible. Selected models may be useful as a general warning of possible bromate formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel mechanism involving the excited states in the UV/sulfite system was proposed. • The rate constants of the excited states of propranolol with sulfite were determined. • Sulfate radical plays a vital role in the aerated UV/sulfite system. • The aerated UV/sulfite has a great advantage over UV/persulfate on bromate control. In recent years, the UV/sulfite (S(IV)) has been proposed as a promising advanced oxidation process for water treatment in the presence of oxygen. However, the mechanism of S(IV) activation is not fully understood, as the interaction between S(IV) and photo-excited pollutants has been underexplored. In this work, an aerated UV/S(IV) system was established, and propranolol (PRO) was selected as a target pollutant. Under the irradiation at 254 nm, this system could degrade 95.6 % of PRO with 2 mM S(IV) in 60 min. The removal of PRO was positively related to the S(IV) dose, while an increasing pH exhibited a negative effect. Direct photolysis, SO 4 •−, and HO• collaboratively contributed to PRO removal, with SO 4 •− playing a primary role. Laser flash photolysis reveals that both radical cation of PRO (product of biphotonic process) and the triplet state (T1PRO) can react with HSO 3 − at rate constants of 5.2 × 108 M−1 s−1 and 2.1 × 107 M−1 s−1, accordingly. These reactions may offset the deficient photoactivation of S(IV) under acidic conditions. Apart from PRO, other organic pollutants could also be effectively degraded. Furthermore, this system has a great advantage over UV/persulfate due to the absence of transformation of background bromide ions to hazardous bromate. Our study significantly updates the decontaminating mechanism of organic pollutants in the aerated UV/sulfite system. [ABSTRACT FROM AUTHOR]

Perchlorate, chlorate and bromate are ubiquitously present in the environment. Perchlorate and chlorate could affect thyroid functions, while bromate is carcinogenic and has been listed as a possible human carcinogen in group 2B by the International Agency for Research on Cancer (IARC). This study aimed to determine the occurrence of perchlorate, chlorate and bromate in three types of drinking water (n=226) in Shenzhen, and assess potential human exposure risks. The detection rates of chlorate and perchlorate were both greater than 60%, and they were positively correlated in both bottled water and tap water, indicating similar sources. Bromate and chlorate were negatively correlated in tap water, indicating that the production of them in tap water disinfection might restrict each other. The hazard quotient (HQ) and hazard index (HI) values of perchlorate, chlorate and bromate in drinking water were less than 1 regardless of age groups. However, for bromate some individual excess cancer risk (ICER) values in drinking water exceeded the maximum acceptable level, indicating potential cancer risk to Shenzhen residents.

Background: The continued use of bromate due to its oxidizing property poses health hazards since it is an established nephrotoxic agent. Objectives: This study evaluated the capacity of the ethanol extract of Aframomum angustifolium seeds to ameliorate the nephrotoxicity of potassium bromate in Wistar rats. Methods: In stage I of this study, the main phytochemical groups in the seeds were quantified using spectrophotometric procedures. The acute and sub-chronic toxicities of the extract were studied by monitoring physical and biochemical parameters in stage II. In stage III, the reno-protective effect of the extract were determined by administering 350 and 750 mg/kg bw of the extract with 30 mg/kg bw potassium bromate orally. The reno-protective study lasted for 56 days and the effect of treatment on biomarkers was determined on days 28 and 56. Results: The phytochemical groups (i.e., alkaloids, flavonoids, saponins, tannins, ascorbic acid, and alpha-tocopherol) were detected in the seeds. The acute and sub-chronic oral administration of the extract did not induce any significant toxic reactions across the studied concentrations. The sub-chronic administration of the extract reduced average weight gain in the treated groups. The obtained results in the reno-protective and histological studies indicated that the seed extract offers protection against the induced oxidative assault by bromate. Conclusion: In general, the co-administration of the ethanol extract of A. angustifolium seeds with bromate can reduce its nephrotoxicity in a dose-dependent manner.

It is known that the excess of oxyanions such as and in drinking water affects its quality. In this work, three adsorbents (montmorillonite (Mt), silica (Si), and diatomaceous earth) loaded with hexadecyl- (H) and octadecyl-trimethylammonium (O) were used to remove these oxyanions from aqueous solutions by adsorption. In batch systems, the highest removal was obtained with Mt modified with H and O (Mt-H and Mt-O), attaining 33% and 50%, respectively, while for removal Si modified with H and O, Si-H and Si-O samples, reached 38% and 42%, respectively. A direct relationship between the adsorption capacity of and and the mass of the adsorbent was found in column filtration tests with Mt-O and Mt-H samples in standard solution and real groundwater samples. The adsorption capacity of the column, in the groundwater sample, remained constant after two reuses.The results obtained are promising for the development of a continuous oxyanion removal system containing the low-cost clay Mt modified with either H or O. HIGHLIGHTS Three adsorbents were evaluated for oxyanion removal.; Montmorillonite modified with surfactants was efficient in nitrate removal.; Silica modified with surfactants was efficient in bromate removal.; Adsorption column experiments were performed for oxyanion removal.; The column was successfully reused twice.;

• Synthetic water matrices as a surrogate for dissolved organic matter during ozonation. • Micropollutant abatement and product formation match for real and synthetic waters. • Bromate formation in real waters is well represented by synthetic matrices. • Synthetic matrices can be tailored for ozonation of natural water and wastewater. Ozonation is used worldwide for drinking water disinfection and increasingly also for micropollutant abatement from wastewater. Identification of transformation products formed during the ozonation of micropollutants is challenging due to several factors including (i) the reactions of both oxidants, ozone and hydroxyl radicals with the micropollutants, as well as with intermediate transformation products, (ii) effects of the water matrix on the ozone and hydroxyl radical chemistry and (iii) the generation of oxidation by-products. In this study, a simple approach to achieve realistic ozonation conditions in the absence of dissolved organic matter has been developed. It is based on composing synthetic water matrices with low-molecular-weight scavenger compounds (phenol, methanol, acetate, and carbonate) that mimic the chemical interactions of ozone and hydroxyl radicals with real water matrices. Synthetic waters composed of only four low-molecular-weight compounds successfully replicated two lake waters and two secondary wastewater effluents, matching instantaneous ozone demand, ozone and hydroxyl radical exposures in the initial phase, as well as the ozone evolution in the second phase of the ozonation process. The synthetic water matrices also reproduced the effects of temperature and pH changes observed in real waters. The abatement of two micropollutants, bezafibrate and atrazine, and the formation of the corresponding transformation products during ozonation were in agreement for synthetic and real waters. Furthermore, the kinetics and extent of bromate formation during ozonation in synthetic water were comparable to real lake water and wastewater. This supports the robustness of the proposed approach because bromate formation is very sensitive to the interplay of ozone and hydroxyl radicals. Furthermore, with the novel reaction system, a significant effect of hydroxyl radicals scavenging by carbonate on bromate formation was demonstrated. Overall, the herein-developed approach based on synthetic water matrices allows to perform realistic ozonation studies including both oxidants, ozone and hydroxyl radicals, without the constraints of using dissolved organic matter. [Display omitted] [ABSTRACT FROM AUTHOR]