Bromate Ion Removal by Electrochemical Reduction Using an Activated Carbon Felt Electrode
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- 作者：Naoyuki Kishimoto* ; Nobuaki Matsuda
- 刊名：Environmental Science & Technology
- 出版年：2009
- 出版时间：March 15, 2009
- 年：2009
- 卷：43
- 期：6
- 页码：2054-2059
- 全文大小：195K
- 年卷期：v.43,no.6(March 15, 2009)
- ISSN：1520-5851
文摘
The electrochemical removal of bromate ion (BrO3−) was investigated using a two-compartment electrolytic flow cell with activated carbon felt electrodes. Bromate ion removal and corresponding Br− increase was observed during electrochemical treatment, whereas the activated carbon felt used possessed no catalytic effect on BrO3− reduction. The BrO3− reduction rate was accelerated at lower pH, which also improved current efficiency. Transition of chemical equilibrium of the BrO3− reductive reaction was theorized as the reason for pH dependency of the BrO3− reduction. The electrochemical treatment of BrO3−-contaminated tap water resulted in a rapid decrease in BrO3− concentration from 100 to 48 μg/L with a contact time of 9.2 s. Thus, electrochemical treatment allowed the rapid removal of BrO3−. However, competitive hydrogen evolution at the cathodes reduced current efficiency of BrO3− reduction. Standard potentials of corresponding anodic and cathodic reactions suggested that electrolysis at a terminal voltage less than 1.229 V would promote BrO3− reduction without hydrogen evolution. However, the activated carbon felt electrode did not function well at a terminal voltage of 1.0 V. Accordingly, the development of an electrode material with high catalytic activity will be required to improve current efficiency.