Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Sec. 4. Roosevelt Rd., Taipei 10617, Taiwan.
Department of Geosciences, National Taiwan University, No. 1, Sec. 4. Roosevelt Rd., Taipei 10617, Taiwan.
Chemosphere. 2017 Oct;184:924-931. doi: 10.1016/j.chemosphere.2017.06.068. Epub 2017 Jun 16.
A single-pass-mode capacitive deionization (CDI) reactor was used to remove arsenic from groundwater in the presence of multiple ions. The CDI reactor involved an applied voltage of 1.2 V and six cell pairs of activated carbon electrodes, each of which was 20 × 30 cm. The results indicate that this method achieved an effluent arsenic concentration of 0.03 mg L, which is lower than the arsenic concentration standard for drinking water and irrigation sources in Taiwan, during the charging stage. Additionally, the ability of the CDI to remove other coexisting ions was studied. The presence of other ions has a significant influence on the removal of arsenic from groundwater. From the analysis of the electrosorption selectivity, the preference for anion removal could be ordered as follows: NO > SO > F > Cl >As. The electrosorption selectivity for cations could be ordered as follows: Ca > Mg > Na ∼ K. Moreover, monovalent cations can be replaced by divalent cations at the electrode surface in the later period of the electrosorption stage. Consequently, activated carbon-based capacitive deionization is demonstrated to be a high-potential technology for remediation of arsenic-contaminated groundwater.
采用单通道模式电容去离子（CDI）反应器，在多种离子共存的情况下，从地下水中去除砷。CDI 反应器的工作电压为 1.2 V，使用了六对活性炭电极，每个电极的尺寸为 20×30 cm。结果表明，在充电阶段，该方法可以将出水砷浓度降低至 0.03 mg/L，低于台湾饮用水和灌溉水源的砷浓度标准。此外，还研究了 CDI 去除其他共存离子的能力。其他离子的存在对地下水除砷有很大影响。从电吸附选择性分析可知，阴离子的去除顺序为：NO3->SO42->F->Cl->As。阳离子的电吸附选择性顺序为：Ca2+>Mg2+>Na+∼K+。此外，在电吸附阶段后期，一价阳离子可以被二价阳离子在电极表面取代。因此，基于活性炭的电容去离子被证明是一种具有高潜力的修复砷污染地下水的技术。
