Faculty of Environmental Engineering, Hanoi University of Civil Engineering, 55 Giai Phong, Hai Ba Trung, Hanoi 100000, Vietnam.
Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan.
J Hazard Mater. 2022 Feb 5;423(Pt A):127084. doi: 10.1016/j.jhazmat.2021.127084. Epub 2021 Aug 30.
An integrated process of filtration and electrosorption was first applied to enable high-performance arsenic removal for groundwater remediation. An active manganese dioxide-rice husk biochar composite (active BC) filter was utilized for oxidization of As(III) to As(V) and initial removal of As(III, V). Subsequently, electrosorption by capacitive deionization (CDI) was applied as a posttreatment to improve arsenic removal. The active BC approach exhibited fast removal rates of 0.75 and 0.63 g mg h and high maximum removal capacities of 40.76 and 48.15 mg g for As(III) and As(V), respectively. Importantly, column experiments demonstrated that the arsenic removal capacity in the active BC filter was 2.88 mg g, which was 72 times higher than that of BC. The results were due to the high efficiency (94%) of redox transformation of As(III) to As(V). The electrosorptive removal of arsenic was further controlled by changing the voltage in CDI. With a charging step of 1.2 V, the total arsenic concentration can be reduced to 0.001 mg L with a low energy consumption of 0.0066 kW h m. Furthermore, the integrated system can remove As from real groundwater to achieve the World Health Organization guideline value for drinking water quality.
首次应用过滤与电吸附一体化工艺，实现地下水修复中砷的高效去除。采用活性二氧化锰-稻壳生物炭复合材料（活性 BC）过滤器将 As(III)氧化为 As(V)并初步去除 As(III、V)。随后，采用电容去离子（CDI）进行电吸附作为后处理，以提高砷的去除率。活性 BC 法对 As(III)和 As(V)的去除率分别达到 0.75 和 0.63 g mg h，最大去除容量分别达到 40.76 和 48.15 mg g。重要的是，柱实验表明，活性 BC 过滤器中的砷去除容量为 2.88 mg g，是 BC 的 72 倍。这是由于 As(III)向 As(V)的氧化还原转化效率很高（94%）。通过改变 CDI 中的电压，进一步控制了砷的电吸附去除。在 1.2 V 的充电步骤下，总砷浓度可降低至 0.001 mg L，能耗低至 0.0066 kW h m。此外，该集成系统可从实际地下水中去除砷，达到世界卫生组织饮用水质量标准。
