Bromate Removal Research Articles

Technical and Cost Assessment of Electrocatalytic Bromate Removal from Drinking Water

Technical and Cost Assessment of Electrocatalytic Bromate Removal from Drinking Water

Robust Activity and Stability of P-Doped Fe-Carbon Composites Derived from MOF for Bromate Reduction.

Iron-based materials are effective for the reductive removal of the disinfection byproduct bromate in water, while the construction of highly stable and active Fe-based materials with wide pH adaptability remains greatly challenging. In this study, highly dispersed iron phosphide-decorated porous carbon (Fe2P(x)@P(z)NC-y) was prepared via the thermal hydrolysis of Fe@ZIF-8, followed by phosphorus doping (P-doping) and pyrolysis. The reduction performances of Fe2P(x)@P(z)NC-y for bromate reduction were evaluated. Characterization results showed that the Fe, P, and N elements were homogeneously distributed in the carbonaceous matrix. P-doping regulated the coordination environment of Fe atoms and enhanced the conductivity, porosity, and wettability of the carbonaceous matrix. As a result, Fe2P(x)@P(1.0)NC-950 exhibited enhanced reactivity and stability with an intrinsic reduction kinetic constant (kint) 1.53-1.85 times higher than Fe(x)@NC-950 without P-doping. Furthermore, Fe2P(0.125)@P(1.0)NC-950 displayed superior reduction efficiency and prominent stability with very low Fe leaching (4.53-22.98 μg L-1) in a wide pH range of 4.0-10.0. The used Fe2P(0.125)@P(1.0)NC-950 could be regenerated by phosphating, and the regenerated Fe2P(0.125)@P(1.0)NC-950 maintained 85% of its primary reduction activity after five reuse cycles. The study clearly demonstrates that Fe2P-decorated porous carbon can be applied as a robust and stable Fe-based material in aqueous bromate reduction.

Hierarchical porous cobalt nanoparticles encapsulated in heteroatom-doped hollow carbon as an enhancing multifunctional catalyst for hydrolysis of sodium borohydride and hydrogenation of bromate in water

Multifunctional heterogeneous catalysts have been consistently explored in recent years because of their distinctive catalytic activity in different catalysis areas at once. Here, a cobalt (Co) nanoparticles encapsulated in nitrogen-doped hollow carbon (denoted as Co@NHC) is prepared by two-step modifications of acid etching and high temperature carbonization in the inert atmosphere using a peculiar polyhedral configuration Co-ZIF as an initial template. Benefiting from an intriguing polyhedral configuration hollow structure with high specific surface area and pore volume supplying plentiful active sites, Co@NHC shows exceptional catalytic activity in catalyzing hydrolysis of NaBH4 and hydrogenation of toxic bromate in water. From experimental results, Co@NHC could efficiently enhance the generation of H2 with a H2 generation rate of 1515.4 mL min−1 gcat−1 meanwhile the activation energy (Ea) calculated from Co@NHC/NaBH4 system was only 12.6 kJ mol−1. Besides, the combination of Co@NHC and NaBH4 could further reduce toxic bromate ions into bromide via catalytic hydrogenation with a maximum bromate removal capacity of 390.6 μmol g−1. More importantly, due to its strong magnetization, Co@NHC could be simply recovered after reactions, making it well-preserve the unique structure as well as catalytic activity for multiple continuous recycles in both catalytic applications. Additionally, the plausible reaction mechanisms in catalyzing hydrolysis of NaBH4 and hydrogenation of bromate were also proposed. This work has pioneered a promising approach on preparing an engrossing magnetic heterogeneous Co-based catalyst that is practically applicable in various areas of catalysis.

Mechanisms of aqueous bromate reduction activity enhancement with well-defined bimetallic palladium-based catalysts

Catalytic reduction has been shown to remove bromate (BrO3−) in drinking water without waste stream formation, though most reported catalysts rely on palladium (Pd), a financially and environmentally expensive metal. Emerging efforts show Pd can be partially replaced with less expensive metals in nanoparticle (NP) alloys, with enhanced hydrogenation reactivity. However, it is unclear if novel NP alloys will enhance bromate reduction, and if so whether they can be intelligently designed based on underlying mechanisms of enhancement. Herein, we address this knowledge gap reporting that well-defined alloyed PdCu and PdAg nanoparticles deposited on carbon nanotubes achieve a 3.9-times improvement in catalytic activity versus monometallic Pd catalysts, which further translates to catalysts prepared using straight-forward impregnation methods. Density functional theory results indicate that improved hydrogenation rates are related to optimized BrO3− and H binding on PdM surfaces achieved by electronic effects in PdCu alloys and unique surface ensembles in PdAg alloys. Overall, these catalysts delineate a pathway for improved bromate removal activity at environmentally relevant concentrations.

Magnetic Metallic Nanoparticles Coated with Carbon for the Catalytic Removal of Bromate from Water

Bromate, often detected in drinking water, is associated with a significant risk of cancer. Catalytic reduction has been recognized as an effective treatment technique to remove ions by reducing them over metal catalysts in the presence of a reducing agent, usually hydrogen. This work aims to synthesize metallic magnetic nanoparticles of iron oxide (FeO) and mixed iron oxides with manganese (MnFeO), cobalt (CoFeO), and copper (CuFeO) coated with carbon via chemical vapor deposition (C-MNP) to be applied as catalysts to the reduction of bromate in water. The use of magnetic nanoparticles coated with carbon enables catalyst recovery via magnetic separation and takes advantage of the catalytic properties of the carbon materials. The iron particles proved to be the most promising catalysts for the reduction of bromate into bromide, the highest removal being obtained with the CFeO@CVD750 sample, resulting in a 99% conversion after 120 min of reaction under the conditions tested. Due to its magnetic nature, the catalytic material was easily removed after the reaction and applied in four consecutive cycles without losing its catalytic properties. These results highlight the great potential of carbon-coated magnetic nanoparticles for reducing bromate in water.

Enhanced photocatalytic removal of bromate in drinking water by Au/TiO2 under ultraviolet light.

The photo-reduction of bromate (BrO3 -) has attracted much attention due to the carcinogenesis and genotoxicity of BrO3 - in drinking water. In this study, a heterojunction photocatalyst was developed by depositing Au nanoparticles (NPs) onto P25 TiO2 NPs through a one-pot, solvent-thermal process. Due to the unique properties of Au, the Au NPs deposited on the TiO2 surface created a Schottky barrier between the metal and the semiconductor, leading to an effective separation of photo-generated charge carriers as the Au nanoparticles served as electron sinks. The Au/TiO2 photocatalyst demonstrated efficient reduction of BrO3 - under UV light illumination without the need for sacrificial agents. The effect of different Au loading of Au/TiO2 was systematically investigated for its influence on the generation of electrons and the reduction ability of BrO3 -. The results indicate that the 1% Au/TiO2 catalyst exhibited a higher concentration of localized electrons, rendering it more effective in BrO3 - removal. The photocatalytic efficiency for BrO3 - reduction decreased upon the addition of K2S2O8 as an electron quencher, suggesting that the primary factor in this photo-reduction process was the availability of electrons. These findings hold promise for the potential application of the Au/TiO2 catalyst in the removal of BrO3 - from drinking water through photo-reduction.

Effective Removal of Bromate in Water by Iron-Modified Spent Bleaching Earth Carbon: Reaction Behavior and Mechanism

Effective Removal of Bromate in Water by Iron-Modified Spent Bleaching Earth Carbon: Reaction Behavior and Mechanism

Critical Review on Bromate Formation during Ozonation and Control Options for Its Minimization.

Ozone is a commonly applied disinfectant and oxidant in drinking water and has more recently been implemented for enhanced municipal wastewater treatment for potable reuse and ecosystem protection. One drawback is the potential formation of bromate, a possible human carcinogen with a strict drinking water standard of 10 μg/L. The formation of bromate from bromide during ozonation is complex and involves reactions with both ozone and secondary oxidants formed from ozone decomposition, i.e., hydroxyl radical. The underlying mechanism has been elucidated over the past several decades, and the extent of many parallel reactions occurring with either ozone or hydroxyl radicals depends strongly on the concentration, type of dissolved organic matter (DOM), and carbonate. On the basis of mechanistic considerations, several approaches minimizing bromate formation during ozonation can be applied. Removal of bromate after ozonation is less feasible. We recommend that bromate control strategies be prioritized in the following order: (1) control bromide discharge at the source and ensure optimal ozone mass-transfer design to minimize bromate formation, (2) minimize bromate formation during ozonation by chemical control strategies, such as ammonium with or without chlorine addition or hydrogen peroxide addition, which interfere with specific bromate formation steps and/or mask bromide, (3) implement a pretreatment strategy to reduce bromide and/or DOM prior to ozonation, and (4) assess the suitability of ozonation altogether or utilize a downstream treatment process that may already be in place, such as reverse osmosis, for post-ozone bromate abatement. A one-size-fits-all approach to bromate control does not exist, and treatment objectives, such as disinfection and micropollutant abatement, must also be considered.

Efficient Removal Of Bromate From Aqueous Solution Through Electrocoagualtion Using Aluminum Electrodes

In this study the removal efficiency of bromate from aqueous solution using the electrocoagulation process was investigated. The effects of operational parameters such as initial pH, initial bromate concentration, current density, type electrode, salt concentration, and temperature on the removal efficiency have been studied. With an initial pH of 3.7, an initial bromate concentration of 100 mg/L, (current density 22.7 mA/cm2 using Al electrodes, salt concentration of 1.5 g/L NaCl and temperature of 25° C, The results showed that the removal percentage for bromate was 97% using Al/Al electrodes at 10 min. It can be concluded that electrocoagulation process by Al electrode is very efficient and clean process for bromate removal from Aqueous solution.

Smart in-line cleanup cartridge modules and floating sorbent systems for BrO3- removal from natural water sources – An innovative approach

Functionalized montmorillonite–chitosan hybrid systems were developed as novel and cost-effective sorbent materials for the quantitative removal of carcinogenic bromate from natural water sources. The developed materials were custom fabricated via two facile and innovative approaches viz. reusable cartridge as a ‘point of use’ clean up modules and carbon cloth based “floating sorbents”, as a removal strategy at the ‘point of entry’. The packing density and flow rate of inline clean up cartridges as well as the sorbent coating and drying procedure of floating sorbent systems were sequentially optimized and validated. The application potential of the fabricated materials was subsequently explored and the studies revealed excellent removal efficiencies of > 99% for batch and flow based systems. The developed modules could successfully remove bromate levels in spiked natural water samples such as drinking, well and river water, down to 10 µgL−1 with more than 97% efficiency. The findings were substantiated through characterisation studies and detailed mechanistic investigation was carried out to understand the better adsorption characteristics of hybrid functionalized clay-chitosan composite. Consequently, the studies implied that a modular inline clean up cartridge packed with 600 g Mt-H-CTS sorbent connected to a water purification system is sufficient to quantitatively remove as high as 100 µgL−1 bromate for a middle class household on a monthly basis. Furthermore, the rapid and efficient regeneration of the material could improve the longevity and makes it an ideal candidate for post disinfection treatment applications at drinking water outlets such as taps (point of use) as well as for large reservoirs in the form of ‘floating sorbents.

Efficient removal of bromate from contaminated water using electrochemical membrane filtration with metal heteroatom interface

Efficient utilization of atomic hydrogen (H*) is of great importance for achieving efficient bromate reduction using electrochemical technologies. Herein, an electrochemical membrane with metal heteroatom interface of Ru and Ni was developed to enhance the utilization efficiency of H* via the membrane filtration process. The RuNi membrane demonstrated 91.3% of bromate removal at 5 mA cm−2 under the flow-through operation (40 L m−2 h−1). Cyclic voltammetry (CV) curves and electron spin resonance (ESR) spectra elucidated that the bromate reduction was mainly attributed to H* -mediated reduction rather than the direct electron transfer between bromate and RuNi active layer. The quenching experiments revealed a significant contribution of adsorbed H* to the bromate removal during the membrane filtration. Based on X-ray photoelectron spectrometry and X-ray diffraction analyses, we found that the resultant Ru0Ni0 structure on the electrochemical membrane could facilitate the generation of H* during the bromate reduction reaction. Besides, the higher pH might suppress the formation of H* and increase the energy barrier for breaking the Br-O bond, resulting in dramatic increase of energy consumption for removing bromate. Our work highlights the potential of utilizing H* in electrochemical membrane for removing bromate in water treatment and remediation.

Bromate Removal from Water Using Ion Exchange Resin: Batch and Fixed Bed Column Performance

ABSTRACT 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.

Efficient and reductive removal of bromate using a novel and stable nanoscale zero-valent iron embedded in N-doped carbon derived from metal-organic frameworks

Nanoscale zero-valent iron (nZVI) has drawn great interest in the remediation of contaminated waters. In this study, we prepared a novel and stable nZVI embedded in N-doped carbon matrix (nZVI@MOF-CN) using a facile direct carbonization method, in which an iron-containing metal-organic framework (MOF) served as both the iron and carbon sources, and melamine as the nitrogen source. The nZVI@MOF-CN composites were used in the removal of bromate in water, which could be effectively reduced by the surface electrons transferred from nZVI to the carbon encapsulation layer due to the Schottky-Mott effect. Doped nitrogen significantly facilitated the reduction of bromate by nZVI, because it enhanced the nZVI dispersion and bromate adsorption, and modulated the carbon matrix conductivity. The bromate reduction activity of nZVI@MOF-CN was more than 50 times higher that of its un-doped counterpart and a commercial nZVI. Moreover, owing to the protection of carbon encapsulation layer, nZVI@MOF-CN exhibited good stability and reusability. The leached concentration of iron ions of nZVI@MOF-CN was less than 5% of the commercial nZVI under the same reaction conditions. Commercial nZVI almost completely lost its bromate reduction activity after use (3% reduction efficiency in the examined time frame), while nZVI@MOF-CN maintained a reduction efficiency of 61%. The nZVI@MOF-CN could be effectively regenerated by hydrogenation reduction. After five reaction-regeneration cycles, nZVI@MOF-CN still achieved a bromate reduction efficiency of approximately 80%. These results suggest that MOF-derived nZVI materials are highly reactive and stable for the reductive removal of pollutants in water.

Catalytic bromate reduction in water by Ru/C via borohydride-based hydrogenation: A comparative study

While H2 gas is conventionally purged during hydrogenation of bromate in the presence of catalysts, the low solubility of H2 gas leads to wasteful consumption of H2 gas. Reductants in solid forms, which act as storage media of H2, would be preferable, and borohydrides, including NaBH4, and NH3BH3 are promising candidates. Although ruthenium (Ru) is an efficient catalyst for releasing H2 from these borohydrides, almost no studies have looked into usage of Ru with borohydrides for reducing bromate, and differences between NaBH4, and NH3BH3 for reducing bromate in the presence of Ru. Therefore, the goal of this study aims to compare hydrogenation of bromate using different borohydrides as well as H2 gas purge under different conditions in the presence of Ru/C as the most representative Ru catalyst. While Ru/C could slowly reduce bromate to bromide, the addition of NaBH4 or NH3BH3 would tremendously accelerate bromate removal and bromide production. Nevertheless, the H2 purge might cause interferences with the entire reaction, thereby leading to ineffective bromate reduction. Moreover, Ru/C+NaBH4 would lead to an even faster bromate reduction because adsorption of BH4– to Ru/C was much more favorable according to the DFT calculation. The Ea of bromate reduction by Ru/C+NaBH4 is also lower than that by Ru/C+NH3BH3, validating the promising advantage of NaBH4 over NH3BH3. Ru/C+NaBH4 could be also reusable for reducing bromate to bromide, demonstrating that borohydrides might be promising alternatives to H2 purge for reducing bromate to bromide in order to achieve even faster and more efficient bromate reduction.

New insights into bromate removal by UV/sulfite process: Influencing factors, mechanism, and energy efficiency

In recent years, the UV/sulfite process has shown high superiority in removing toxic halogenated organic compounds and oxyanions. Herein, the reduction of bromate (BrO3ˉ) in this process was reinvestigated. The reduction of BrO3ˉ in this process was influenced by some key coexisting species. A significant inhibition on the reduction of BrO3ˉ was observed in the presence of dissolved oxygen (DO). Nevertheless, increasing sulfite dosage could effectively mitigate the negative impact of DO on the reduction of BrO3ˉ. Humic acid (HA) could influence the reduction of BrO3ˉ through the enhancement of hydrated electron (eaqˉ) yield or the scavenging of eaqˉ. It should be noted that the presence of Cl− and HCO3− had an insignificant influence on the reduction of BrO3ˉ. In this process, besides eaqˉ, sulfite radical (SO3•−) also contributed to the reduction of BrO3ˉ, which was evidenced by scavenging experiments and fitting of a kinetic model. Moreover, the energy efficiency of this process for BrO3ˉ removal was found to be enhanced by increasing sulfite dosage, as indicated by calculation of electrical energy per order (EE/O). Meanwhile, this process was proven to be economical for BrO3ˉ removal. This study might provide a new outlook on the UV/sulfite process for real applications.

FeIIAlIII layered double hydroxide modified carbon-felt cathode for efficient electrochemical reduction of bromate

Bromate (BrO3−) is harmful to human health and may cause cancer. In this work, a novel carbon felt cathode modified by FeIIAlIII-layered double hydroxide (FeIIAlIII-LDH/CF) was synthesized in a facile manner for effective reduction of BrO3−. The effects of operational parameters such as hydrothermal time, initial solution pH, applied current, dissolved oxygen (DO), and initial BrO3− concentration were investigated. Particularly, the FeIIAlIII-LDH/CF electrochemical reduction system can remove 100% of BrO3− (1.2 μM) within 75 min and completely adsorb the reduced Br− ions at a current strength of 10 mA. As the initial BrO3− concentration increased, the treatment time for complete removal of BrO3− only needs to be prolonged accordingly, and the Br− ions exceeding the adsorption capacity would be released into the solution. The electrocatalytic reduction of BrO3− could be achieved under a wide range of DO and pH conditions, and the lower DO and moderate pH were more favorable. Mechanism studies revealed that electrocatalytic reduction of BrO3− was mainly achieved by FeIIAlIII-LDH, and electrons from the cathode allowed FeIIAlIII-LDH to be regenerated efficiently. The FeIIAlIII-LDH/CF electrode can be well preserved in air and had a stable cycling performance. It is the first time that a FeIIAlIII-LDH based electrode was used in the field of electrocatalytic reduction of bromate. To conclude, FeIIAlIII-LDH/CF cathode holds great promise in the area of water purification for bromate removal.

Ultrasound process-enhanced removal of the toxic disinfection by-product bromate from water by aluminum: A comparative study.

As bromate removal and reduction can be also achieved using metals, aluminum (Al) appears as the most promising one for reduction of bromate because Al is abundant element and exhibits a high reduction power. Reactions between bromate and Al shall be even enhanced through ultrasound (US) process because US can facilitate mass transfer on liquid/solid interfaces and clean surfaces via generating microscale turbulence to facilitate reactions. Therefore, the aim of this study is for the first time to investigate the effect of US on bromate removal by Al metal. Specifically, Al particle would be treated by HCl to afford HCl-treated Al (HCTAL), which is capable of removing bromate and even reducing it to bromide. Such a mechanism is also validated by density function theory calculation through determining adsorption energy as -152.8kJ/mole, and oxygen atoms of bromate would be extracted and reacted with Al atoms, releasing bromide ion. US not only facilitated bromate removal by further increasing removal capacity under the acidic condition but also suppressed the inhibitive effect from basicity at relatively high pH. The spent HCTAL could still remove bromate and convert it to bromide after regeneration. These features indicate that US considerably enhances bromate removal by Al. PRACTITIONER POINTS: Bromate removed by Al is elucidated by DFT calculation with Eabsorption = -152.8kJ/mole. Oxygen atoms of bromate are extracted and reacted with Al atoms, releasing bromide ion. A higher power of ultrasound would substantially enhance bromate removal efficiency. Ultrasound also suppresses the inhibitive effect from basicity at relatively high pH. With ultrasound, the interference of co-existing anions on bromate removal is lessened.

Construction of the micro-electrolysis system by Fe0 and clay-carbon derived from oil refining for the removal of ozone disinfection by-products

In this work, the construction of iron-cetyltrimethylammonium chloride modified spent bleaching earth carbon (Fe/CTAC-SBE@C) micro-electrolysis system was first proposed for bromate removal in water. The effects of system parameters including Fe to CTAC-SBE@C mass ratio, CTAC concentration, total dosage, temperature, initial pH and reaction atmosphere were studied. Bromate removal efficiency increased with the decrease of Fe/SBE@C mass ratio from 4/1–3/1, and the further decrease of the mass ratio (from 3/1–1/4) led to the decrease of bromate removal efficiency. CTAC modification could provide the active electron transport paths (SBE@C-CTAC+-BrO3-) theoretically for bromate improved removal, and the optimal CTAC concentration was 25 mmol/L. It was found that pH was a key factor of micro-electrolysis reaction, and bromate removal decreased with the increase of pH, while the removal under neutral (pH=7) and basic (pH=9) conditions still could reach more than 75%. Surprisingly, the coexisting of Cl-, SO42- and NO3- as the electrolytes could penetrate the passivated films on the surface of iron and promote bromate removal; air atmosphere was more favorable to bromate removal than nitrogen atmosphere. In addition, based on product determination and characterization data, the removal mechanism of bromate mainly included CTAC-SBE@C adsorption and electrochemical reduction.

Enhancement of photocatalytic bromate reduction by TiO2 coupled with Ti3C2MXene as efficient non-noble cocatalyst: Performance and mechanism

Although considered as a promising candidate for photocatalytic bromate reduction, TiO2 is restricted by its fast recombination of photo-induced charge carriers. In this paper, a series of efficient photocatalysts (TiO2/TC) were prepared by coupling commercial titania (P25) with titanium carbide MXene (Ti3C2) via a simple hydrothermal method, where Ti3C2 was utilized as a noble-metal-free cocatalyst. Batch experiments of photocatalytic bromate removal by TiO2/TC composites were conducted under UV irradiation. Its performance and mechanism were also investigated. The results showed that more than 95% of bromate could be removed by TiO2/TC-1 composite (Ti3C2 and P25 in a mass ratio of 1%) in 15 min, and its removal rate was 4.87 times higher than that of pure P25. The photocatalytic reduction of bromate by TiO2/TC was an interfacial reaction, and bromide was the main product. The greatly improved activity of TiO2/TC composites was attributed to the improved separation efficiency of photogenerated charge carriers and narrower band gap. TiO2/TC-1 composite exhibited a longer lifetime (6.05 ns) of electron-hole pairs than pristine P25 (4.31 ns). Moreover, due to its excellent electrical conductivity, Ti3C2 functioned as “an electron sink” to accumulate photoinduced electrons from the excited P25. And the Schottky barrier formed in the tight Ti3C2-P25 interface provided a unidirectional channel for electron transfer, facilitating the separation of electron-hole pairs. In addition, TiO2/TC-1 composite had a good stability in bromate removal. This work highlights the potential of Ti3C2 as a noble-metal-free photocatalytic cocatalyst and explores the possible expansion of the application of MXene.

Removal of Hydrogen Peroxide Residuals and By-Product Bromate from Advanced Oxidation Processes by Granular Activated Carbon

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.