An integrated active biochar filter and capacitive deionization system for high-performance removal of arsenic from groundwater

Dinh Viet Cuong; Po-Chang Wu; Sofia Ya Hsuan Liou; Chia-Hung Hou

doi:10.1016/j.jhazmat.2021.127084

An integrated active biochar filter and capacitive deionization system for high-performance removal of arsenic from groundwater

J Hazard Mater. 2022 Feb 5;423(Pt A):127084. doi: 10.1016/j.jhazmat.2021.127084. Epub 2021 Aug 30.

Authors

Dinh Viet Cuong¹, Po-Chang Wu², Sofia Ya Hsuan Liou³, Chia-Hung Hou⁴

Affiliations

¹ Faculty of Environmental Engineering, Hanoi University of Civil Engineering, 55 Giai Phong, Hai Ba Trung, Hanoi 100000, Vietnam.
² Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan.
³ Department of Geosciences, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan; Research Center for Future Earth, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan.
⁴ Graduate Institute of Environmental Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan; Research Center for Future Earth, National Taiwan University, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan. Electronic address: chiahunghou@ntu.edu.tw.

PMID: 34488095
DOI: 10.1016/j.jhazmat.2021.127084

Abstract

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^-1 h^-1 and high maximum removal capacities of 40.76 and 48.15 mg g^-1 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^-1, 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^-1 with a low energy consumption of 0.0066 kW h m^-3. Furthermore, the integrated system can remove As from real groundwater to achieve the World Health Organization guideline value for drinking water quality.

Keywords: arsenic removal; capacitive deionization; engineered biochar; fixed bed filter; groundwater remediation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Arsenic* / analysis
Charcoal
Groundwater*
Water Pollutants, Chemical* / analysis
Water Purification*

Substances

Water Pollutants, Chemical
biochar
Charcoal
Arsenic