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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.

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]

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).

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.

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]

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.

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]

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.

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]

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]

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.;

The supercapacitive properties of synthesized nickel phthalocyanine multiwalled carbon nanotubes nanocomposite on a glassy carbon electrode (NiPcMWCNTs-GCE) in four different electrolytes were investigated. The successful synthesis of the NiPcMWCNTs nanocomposite was confirmed by UV/vis electrode spectroscopy, SEM, TEM, EDX, and XRD techniques. The supercapacitive behaviors of the modified electrodes were examined in PBS, H2SO4, Na2SO4, and SAB electrolytes via CV and EIS techniques. The highest specific capacitance of 6.80 F g−1 was achieved for the GCE-NiPcMWCNTs electrode in 5 mM [Fe(CN)6]4−/3− prepared in 0.1 M PBS (pH 7). Charge transfer resistance Rct values of 0.06, 0.36, 0.61, and 1.98 kΩ were obtained for the GCE-NiPcMWCNTs in H2SO4, SAB, Na2SO4, and PBS electrolytes, respectively. Power density values, otherwise known as the "knee" frequency f°, of 21.2, 6.87, 2.22, and 1.68 Hz were also obtained for GCE-NiPcMWCNTs in H2SO4, Na2SO4, PBS, and SAB electrolytes, respectively. GCE-NiPcMWCNTs demonstrated the fastest electron transport capability and the highest power density in H2SO4 compared to the other electrolytes. Hence, GCE-NiPcMWCNTs-modified electrodes had high stability, high energy and power densities, and a large specific capacitance. [ABSTRACT FROM AUTHOR]

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.;

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.

In persulfate-based advanced oxidation processes (PS-AOPs), sulfate radicals (SO 4 •-) have been recognized to play more important roles in inducing bromate (BrO 3 −) formation rather than hydroxyl radicals (HO•) because of the stronger oxidation capacity of the former. However, this study reported an opposite result that HO• indeed dominated the formation of bromate instead of SO 4 •-. Quenching experiments were coupled with electron paramagnetic resonance (EPR) detection and chemical probe identification to elucidate the contributions of each radical species. The comparison of different thermal activated persulfates (PDS and PMS) demonstrated that the significant higher bromate formation in HEAT/PMS ([BrO 3 −]/[Br−] 0 = 0.8), as compared to HEAT/PDS ([BrO 3 −]/[Br−] 0 = 0.2), was attributable to the higher concentration of HO• radicals in HEAT/PMS. Similarly, the bromate formation in UV/PDS ([BrO 3 −]/[Br−] 0 = 1.0), with a high concentration of HO•, further underscored the dominant role of HO•. As a result, we quantified that HO• and SO 4 •- radicals accounted 66.7% and 33.3% for bromate formation. This controversial result can be reconciled by considering the critical intermediate, hypobromic acid/hypobromate (HOBr/BrO−), involved in the transformation of Br− to BrO 3 −. HO• radicals have the chemical preference to induce the formation of HOBr/BrO− intermediates (contributing ∼ 60%) relative to SO 4 •- radicals (contributing ∼ 40%). This study highlighted the dominant role of HO• in the formation of bromate rather than SO 4 •- in PS-AOPs and potentially offered novel insights for reducing disinfection byproduct formation by controlling the radical species in AOPs. [Display omitted] • Bromate formation was related to the distribution ratio of SO 4 •- and HO•. • HO• dominated bromate formation in persulfate-based advanced oxidation Processes. • The oxidation of bromide to bromate proceeds in two steps with HOBr/BrO- as intermediates. [ABSTRACT FROM AUTHOR]

[Display omitted] • The prevalence of bromate in drinking water was observed globally. • UV-based advanced reduction process (ARP) is a potent strategy in removing bromate. • UV/sulfite ARPs are complex that yield reactive reductive and oxidative species. • Without oxygen, hydrated electrons and sulfite radicals play an important role. • Oxygen, inorganic and organic anions have competitive effects on bromate reduction. Bromate, a potential carcinogen, is a major disinfection byproduct formed during the ozonation of bromide-containing water; hence, the suppression of bromate in ozonated drinking water is imperative for protecting human health. Owing to the elevated levels of bromide ions transported to the source water through seawater intrusion and anthropogenic inputs, bromate concentration in drinking water is increasing in some regions of the world. Moreover, the excessive application of ozone for treating this water has resulted in an elevated risk of bromate in drinking water. Therefore, this review presents the current status of the occurrence of bromate in drinking water, followed by presenting the development of recent technologies for bromate reduction—specifically focusing on the effectiveness of ultraviolet (UV)/sulfite advanced reduction processes (ARPs). The application of UV/sulfite ARPs as a post-ozonation treatment is of increasing interest to researchers because these have shown superior bromate removal efficiencies as compared to previous methods. The highly reactive free radicals (e.g., hydrated electrons and sulfite radicals) obtained from UV/sulfite ARPs substantially enhanced bromate reduction efficiency to 60 %–100 %, with a reduction rate of 3.0 × 10−2–2.5 × 10−1 min−1. An increase in the sulfite dosage and pH showed positive effects on the performance of UV/sulfite ARPs for bromate reduction. However, other factors including dissolved oxygen, inorganic anions, and organic anions potentially impaired the performance of UV/sulfite ARPs due to their competition with bromate for reactive radicals. Finally, this review also discusses the limitations of UV/sulfite ARPs. [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.

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. [ABSTRACT FROM AUTHOR]

A direct ion chromatographic method for determination of chlorite, chlorate and bromate in the presence of fluoride, chloride, nitrate, nitrite and bromide in treated drinking waters was described. Separation of target analytes was achieved using an AS19-HC analytical column (250 mm x 4 mm), AG 19-HC guard column (50 mm x 4 mm) and KOH 25 mmol/L as mobile phase. Inorganic analytes were eluted using a flow rate of 1 mL/min. Column temperature was set up and maintained at 300C. The analyte ions were quantified using a suppressed conductivity detector.

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.

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.

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.

The manuscript deals with the fundamental problem of platinum hydrogen oxidation catalyst poisoning of the hybrid chemical power source based on bromate electroreduction and hydrogen electro-oxidation reactions. The poisoning is caused by the crossover of bromine-containing species through the proton exchange membrane separating compartments of the flow cell. Poisoning results in a drastic decrease in the flow cell performance. This paper describes the results of the direct measurement of bromine-containing species’ crossover through perfluorosulfonic acid membranes of popular vendors in a hydrogen−bromate flow cell and proposes corresponding scenarios for the flow battery charge−discharge operation based on the electrolyte’s control of the pH value. The rate of the crossover of the bromine-containing species through the membrane is found to be inversely proportional to the membrane thickness.

[Display omitted] • Preparation and characterization of Pd and PdCu catalysts on ZrO 2 -CeO 2 support. • Elimination of NO 3 −, NO 2 − and BrO 3 − from distilled and groundwater. • The ZrO 2 -CeO 2 support has oxygen vacancies that favors the elimination reaction. • High selectivities to the products of interest were obtained. In the present work, the elimination of NO 3 -, NO 2 - and BrO 3 - in distilled and groundwater samples using H 2 as reducing agent is studied. For this purpose, PdCu-based catalysts were prepared on CeO 2 pure and modified with 10 % of ZrO 2 supports. The prepared catalysts were characterized by N 2 physisorption, SEM-EDS, XRD, TPR, RAMAN, FTIR and XPS. The results showed that the materials obtained were mesoporous, exposing the cubic CeO 2 crystalline phase. Raman and FTIR analysis allow corroborating that both supports have oxygen vacancies, being higher in the ZrCe support, due to the presence of Zr4+ ions in the CeO 2 lattice. All the prepared catalysts were active in the elimination of the selected oxyanions, showing high selectivities (>99 %) towards the product of interest (N 2 and Br−), especially the catalyst PdCu/10ZrCe. This catalyst presented the highest oxyanion removal rate, which is higher for NO 3 − elimination (V 0,NO3- : 5.6; V 0,BrO3- :.0.93). In the reduction stage, Ce4+ is reduced to Ce3+, generating oxygen vacancies at the metal-support interface. It is postulated that the reduction of the anions occurs by interaction of the oxygen atoms of the NO 3 −, NO 2 − or BrO 3 − species with the oxygen-vacant sites generated. The addition of Zr on ceria support increases its ability to activate anions and reduce them. PdCu/10ZrCe catalyst was also tested using groundwater. The conversion results obtained were promising, 60 % for NO 2 −, 70 % for NO 3 − and 27 % for BrO 3 −. [ABSTRACT FROM AUTHOR]

Cockayne syndrome (CS) is a human DNA repair-deficient disease that involves transcription coupled repair (TCR), in which three gene products, Cockayne syndrome A (CSA), Cockayne syndrome B (CSB), and ultraviolet stimulated scaffold protein A (UVSSA) cooperate in relieving RNA polymerase II arrest at damaged sites to permit repair of the template strand. Mutation of any of these three genes results in cells with increased sensitivity to UV light and defective TCR. Mutations in CSA or CSB are associated with severe neurological disease but mutations in UVSSA are for the most part only associated with increased photosensitivity. This difference raises questions about the relevance of TCR to neurological disease in CS. We find that CSB-mutated cells, but not UVSSA-deficient cells, have increased levels of intramitochondrial reactive oxygen species (ROS), especially when mitochondrial complex I is inhibited by rotenone. Increased ROS would result in oxidative damage to mitochondrial proteins, lipids, and DNA. CSB appears to behave as an electron scavenger in the mitochondria whose absence leads to increased oxidative stress. Mitochondrial ROS, however, did not cause detectable nuclear DNA damage even when base excision repair was blocked by an inhibitor of polyADP ribose polymerase. Neurodegeneration in Cockayne syndrome may therefore be associated with ROS-induced damage in the mitochondria, independent of nuclear TCR. An implication of our present results is that mitochondrial dysfunction involving ROS has a major impact on CS-B pathology, whereas nuclear TCR may have a minimal role.

Cockayne syndrome (CS) is a human DNA repair-deficient disease that involves transcription coupled repair (TCR), in which three gene products, Cockayne syndrome A (CSA), Cockayne syndrome B (CSB), and ultraviolet stimulated scaffold protein A (UVSSA) cooperate in relieving RNA polymerase II arrest at damaged sites to permit repair of the template strand. Mutation of any of these three genes results in cells with increased sensitivity to UV light and defective TCR. Mutations in CSA or CSB are associated with severe neurological disease but mutations in UVSSA are for the most part only associated with increased photosensitivity. This difference raises questions about the relevance of TCR to neurological disease in CS. We find that CSB-mutated cells, but not UVSSA-deficient cells, have increased levels of intramitochondrial reactive oxygen species (ROS), especially when mitochondrial complex I is inhibited by rotenone. Increased ROS would result in oxidative damage to mitochondrial proteins, lipids, and DNA. CSB appears to behave as an electron scavenger in the mitochondria whose absence leads to increased oxidative stress. Mitochondrial ROS, however, did not cause detectable nuclear DNA damage even when base excision repair was blocked by an inhibitor of polyADP ribose polymerase. Neurodegeneration in Cockayne syndrome may therefore be associated with ROS-induced damage in the mitochondria, independent of nuclear TCR. An implication of our present results is that mitochondrial dysfunction involving ROS has a major impact on CS-B pathology, whereas nuclear TCR may have a minimal role.

Bromate is toxic compound which represent the carcinogenic effect for human health, a serial research’s has been developed by the scientists for the efficient bromate removal methods from the water with low cost in order to obtain water to Bromate a maximum concentration level (10ppb). Bromate ions are formed as a result of the reaction between bromide ions and ozone used as a water disinfectant in membrane demineralization plants .Different technologies have been used for Bromate elimination from water such as ion exchange, adsorption, biofiltration, electrolysis and membrane technology. The aim of this work is to study the rejection of bromate ions by nanofiltration membranes (N30F from Nadir and DL from Osmonics) made from different polymers using bromate solution at different conditions (feed bromate concentration, transmembrane pressure, pH and ionic strength).The bromate rejection is related to the feed solution, pH and ionic strength and the nature of the membrane. At pH=8, bromate ions were removed by the DL membrane made from polyamide around with higher than those by the N30F made from polyethersulfone

The supercapacitive properties of synthesized nickel phthalocyanine multiwalled carbon nanotubes nanocomposite on a glassy carbon electrode (NiPcMWCNTs-GCE) in four different electrolytes were investigated. The successful synthesis of the NiPcMWCNTs nanocomposite was confirmed by UV/vis electrode spectroscopy, SEM, TEM, EDX, and XRD techniques. The supercapacitive behaviors of the modified electrodes were examined in PBS, H2SO4, Na2SO4, and SAB electrolytes via CV and EIS techniques. The highest specific capacitance of 6.80 F g−1 was achieved for the GCE-NiPcMWCNTs electrode in 5 mM [Fe(CN)6]4−/3− prepared in 0.1 M PBS (pH 7). Charge transfer resistance Rct values of 0.06, 0.36, 0.61, and 1.98 kΩ were obtained for the GCE-NiPcMWCNTs in H2SO4, SAB, Na2SO4, and PBS electrolytes, respectively. Power density values, otherwise known as the “knee” frequency f°, of 21.2, 6.87, 2.22, and 1.68 Hz were also obtained for GCE-NiPcMWCNTs in H2SO4, Na2SO4, PBS, and SAB electrolytes, respectively. GCE-NiPcMWCNTs demonstrated the fastest electron transport capability and the highest power density in H2SO4 compared to the other electrolytes. Hence, GCE-NiPcMWCNTs-modified electrodes had high stability, high energy and power densities, and a large specific capacitance.

The baking industries and disinfection of tap water released a considerable amount of bromate into surface water, which has been reported as a carcinogenic compound to mammals. Rotifers play an important role in freshwater ecosystems and are model organisms to assess environmental contamination. In the present study, the effects of different concentrations (0.001, 0.01, 0.1, 1, 10, 100 and 200 mg/L) of bromate on the life-table and population growth parameters were investigated in the rotifer Brachionus calyciflorus. The results showed that the 24-h LC50 of bromate to B. calyciflorus was 365.29 mg/L (95%Cl: 290.37–480.24). Treatments with 0.01, 10 and 200 mg/L bromate shorten the reproductive period. High levels of bromate (100 and 200 mg/L) significantly decreased net reproductive rate, intrinsic rate of population increase, life span, mictic rate of B. calyciflorus. To investigate the underlying mechanisms, swimming speed and antioxidative biomarkers were compared between bromate treatments and the control. The results showed that glutathione (GSH) and malondialdehyde (MDA) contents, total superoxide dismutase (T-SOD) and peroxidase (POD) activities decreased significantly in response to bromate exposure and the reasons required further investigation. Treatments with 0.001–200 mg/L bromate all significantly reduced swimming linear speed to rotifer larvae and treatments with 100–200 mg/L bromate significantly suppressed the swimming linear speed of adult rotifer. These changes would reduce filtration of algal food and could explain the decreased survival and reproduction. Overall, bromate may not show acute toxicity to rotifers, but still have potential adverse effects on rotifer behavior, which may then influence the community structure in aquatic ecosystems.

In this study, we compared the decontamination kinetics of various target compounds and the oxidation by-products (bromate and chlorate) of PMS, PDS, and H2O2 under UV irradiation (UV/PMS, UV/PDS, UV/H2O2). Probes of different reactivity with hydroxyl and sulfate radicals, such as benzoic acid (BA), nitrobenzene (NB), and trichloromethane (TCM), were selected to compare the decontamination efficiency of the three oxidation systems. Experiments were performed under acidic, neutral, and alkaline pH conditions to obtain a full-scale comparison of UV/peroxides. Furthermore, the decontamination efficiency was also compared in the presence of common radical scavengers in water bodies [bicarbonate, carbonate, and natural organic matter (NOM)]. Finally, the formation of oxidation by-products, bromate, and chlorate, was also monitored in comparison in pure water and tap water. Results showed that UV/H2O2 showed higher decontamination efficiency than UV/PDS and UV/PMS for BA degradation while UV/H2O2 and UV/PMS showed better decontamination performance than UV/PDS for NB degradation under acidic and neutral conditions. UV/PMS was the most efficient among the three processes for BA and NB degradation under alkaline conditions, while UV/PDS was the most efficient for TCM degradation under all pH conditions. In pure water, both bromate and chlorate were formed in UV/PDS, small amounts of bromate and rare chlorate were observed in UV/PMS, and no detectable bromate and chlorate were formed in UV/H2O2. In tap water, no bromate and chlorate were detectable for all three systems.

During drinking water treatment, advanced oxidation process (AOP) with O3 and H2O2 may result in by-products, residual H2O2 and BrO3−. The water containing H2O2 and BrO3− often flows into subsequent granular activated carbon (GAC) filters. A concentrated H2O2 solution can be used as GAC modification reagent at 60 °C to improve its adsorption ability. However, whether low concentrations of H2O2 residuals from AOP can modify GAC, and the impact of H2O2 residuals on BrO3− removal by the subsequent GAC filter at ambient temperature, is unknown. This study evaluated the modification of GAC surface functional groups by residual H2O2 and its effect on BrO3− removal by GAC. Results showed that both H2O2 and BrO3− were effectively removed by virgin GAC, while pre-loaded and regenerated GACs removed H2O2 but not BrO3− anymore. At the ambient temperature 150 µmol/L H2O2 residuals consumed large amounts of functional groups, which resulted in the decrease of BrO3− removal by virgin GAC in the presence of H2O2 residuals. Redox reactions between BrO3− and surface functional groups played a dominant role in BrO3− removal by GAC, and only a small amount of BrO3− was removed by GAC adsorption. The higher the pH, the less BrO3− removal and the more H2O2 removal was observed.

The application of potassium bromate in the baking industry is used in most parts of the world to avert the human health compromise that characterizes bromates carcinogenic effect. Herein, various methods of its analysis, especially the electrochemical methods of bromate detection, were extensively discussed. Amperometry (AP), cyclic voltammetry (CV), square wave voltammetry (SWV), electrochemiluminescence (ECL), differential pulse voltammetry and electrochemical impedance spectroscopy (EIS) are the techniques that have been deployed for bromate detection in the last two decades, with 50%, 23%, 7.7%, 7.7%, 7.7% and 3.9% application, respectively. Despite the unique electrocatalytic activity of metal phthalocyanine (MP) and carbon quantum dots (CQDs), only few sensors based on MP and CQDs are available compared to the conducting polymers, carbon nanotubes (CNTs), metal (oxide) and graphene-based sensors. This review emboldens the underutilization of CQDs and metal phthalocyanines as sensing materials and briefly discusses the future perspective on MP and CQDs application in bromate detection via EIS.

The presence of bromate in water sources generates environmental concern due to its toxicity for humans. Diverse technologies, like membranes, ion exchange, chemical reduction, etc., can be employed to treat bromate-polluted water but they produce waste that must be treated. An alternative to these technologies can be the catalytic reduction of bromate to bromide using hydrogen as a reducing agent. In this review, we analyze the research published about this catalytic technology. Specifically, we summarize and discuss about the state of knowledge related to (1) the different metals used as catalysts for the reaction; (2) the influence of the support on the catalytic activity; (3) the characterization of the catalysts; (4) the reaction mechanisms; and (5) the influence of the water composition in the catalytic activity and in the catalyst stability. Based on published papers, we analyze the strength and weaknesses of this technique and the possibilities of using this reaction for the treatment of bromate-polluted water as a sustainable process.

Effective bromate removal by supramolecule BDTD photocatalyst. To guarantee drinking water security, removal of bromate (BrO 3 −) has garnered plenty of attention in water treatment. In current study, we have developed a novel conjugated donor-acceptor (D-A) photocatalyst (4,4′'-bis(diphenylamino)-[1,1′:4′,1′'-terphenyl]-2′,5′-dicarbaldehyde, BDTD) with supramolecule architecture assembling via intermolecular C H···O hydrogen bonds and C H···π interactions. Both diffuse reflectance spectrum (DRS) and density functional theoretical (DFT) calculations gave the bandgap of E g = 2.21 eV, clearly indicating the visible-light response of BDTD supramolecule. The calculations showed that BDTD supramolecule could induce nearly 100% removal of BrO 3 − stably at pH-neutral condition driven by visible light, accounting for a first-order kinetic constant being one order of magnitude higher than most of the photocatalysts previous reported. As demonstrated by our electron scavenger experiment and DFT calculations, the BDTD supramolecule should undergo the photocatalytic reduction of BrO 3 − through direct reduced by the lowest unoccupied molecular orbital of conduction band (potential of −1.705 V versus standard hydrogen electrode) electron. The BDTD supramolecule may serve as an attractive photocatalyst by virtue of response to visible light, efficient charge transfer and separation as well as high photocatalytic activity, which will make the removal of BrO 3 − in water much easier, more economical and more sustainable. [ABSTRACT FROM AUTHOR]

This study investigated the oxidative debromination of 2,2-bis(bromomethyl)-1,3-propanediol (BBMP), a widely used brominated flame retardant, and the corresponding formation of brominated by-products by the UV/persulfate process. The debromination of BBMP by the UV/persulfate process was primarily driven by sulfate radicals (SO 4 −) at pHs 4.0–6.0 and hydroxyl radicals (HO) at pHs 9.0–12.0. The debromination rate increased with increasing pH from 4.0 to 9.0 and remained the same at pHs 9.0 and 12.0. Bromate was formed through the oxidation of bromide released from BBMP mainly by SO 4 −, with free bromine as a key intermediate. Bromate formation increased with increasing pH from 4.0 to 6.0, while it remarkably decreased with increasing pH from 6.0 to 12.0. This was mainly due to the transformation of SO 4 − to HO and also the quenching of bromine atoms that were the key intermediate for the formation of free bromine, by hydroxyl ions at the alkaline pH. In addition, the oxidative debromination of BBMP resulted in a significant decrease in the concentrations of total organic bromine, but the formation of brominated acetic acids and unknown brominated organic by-products. The concentrations of brominated organic by-products firstly increased and then decreased with prolonged reaction time. Also, the formation of brominated organic by-products and genotoxicity at pH 9.0 were much lower than that at pH 6.0. In this study, we propose that the UV/persulfate process under mildly alkaline conditions not only debrominates BBMP efficiently but also eliminates the formation of bromate and brominated organic by-products and genotoxicity. Image 1 • BBMP debromination and brominated by-product formation by UV/persulfate were investigated. • BBMP debromination was mainly driven by SO 4.•− and HO• to form bromide. • Bromate formation involved stepwise oxidation of bromide and then free bromine mainly by SO 4.•−. • Brominated acetic acids and unknown brominated organic by-products were generated. • Alkaline pH increased BBMP debromination and minimized brominated by-product formation and genotoxicity. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Improved TiO 2 film photocatalytic activity by thermally pre-treating the static mixer. • More efficient TiO 2 films by vertically mounting the static mixer during dip coating. • High increase of bromate photocatalytic reduction rate for acidic aqueous solutions. • Null dissolved oxygen effect for acidic pH values and negative effect for pH > 5.5. • Reaction rate decay by adding formic acid due to its adsorption onto TiO 2 surface. Abstract This study focuses on bromate (BrO 3 −) removal from pure aqueous solutions by heterogeneous photocatalysis using a stainless steel Kenics® static mixer (SM) as support for the stabilization of TiO 2 -P25 thin films. The SM was assembled in a tubular photoreactor coupled to a compound parabolic collector (CPC) for light capture. The effect of the following parameters on the BrO 3 − photocatalytic reduction rate was assessed: SM treatment before TiO 2 -P25 deposition, number of TiO 2 -P25 layers deposited by dip coating, position of the SM during the coating procedure, solution pH, solution temperature, dissolved oxygen (DO) content, and addition of formic acid (HCOOH) as organic sacrificial agent. Furthermore, the TiO 2 -P25 films were characterized and their stability was evaluated. Higher BrO 3 − photocatalytic reduction rates were attained for: the thermally pre-treated SM, 6 TiO 2 -P25 layers, the vertically positioned SM during coating, acidic pH, and higher temperatures. The DO had a negligible effect for pH values below 5.5 and a negative effect for higher pH values. The HCOOH declined the BrO 3 − photocatalytic reduction rates when an initial [HCOOH]:[BrO 3 −] molar ratio of 3:1 was applied and had a null influence when used in lower amounts. The generated TiO 2 -P25 films proved to be stable. [ABSTRACT FROM AUTHOR]