Enhanced cadmium immobilization by sulfate-mediated microbial zero-valent iron corrosion

Mingjia Yan; Weiquan Li; Jinxin Zhao; Weizhao Yin; Ping Li; Zhanqiang Fang; Li Liu; Jinhua Wu

doi:10.1016/j.jenvman.2021.113894

Enhanced cadmium immobilization by sulfate-mediated microbial zero-valent iron corrosion

J Environ Manage. 2022 Jan 1:301:113894. doi: 10.1016/j.jenvman.2021.113894. Epub 2021 Oct 9.

Authors

Mingjia Yan¹, Weiquan Li¹, Jinxin Zhao², Weizhao Yin², Ping Li¹, Zhanqiang Fang³, Li Liu⁴, Jinhua Wu¹

Affiliations

¹ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
² School of Environment, Jinan University, Guangzhou, 510632, China.
³ School of Environment, South China Normal University, Guangzhou, 510006, China.
⁴ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China; The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions, Guangzhou, 510006, China. Electronic address: liuli@scut.edu.cn.

PMID: 34638045
DOI: 10.1016/j.jenvman.2021.113894

Abstract

A biotic iron (Fe⁰) treatment system combined with mixed microorganisms was applied to remediate cadmium (Cd)-contaminated groundwater under the intervention of sulfate. Due to hydrogenotrophic desulfuration effect, severe iron corrosion was observed in this microbe-collaborative Fe⁰ system according to surface morphology analysis as lots of secondary minerals (e.g. magnetite, green rust and lepidocrocite) were generated, which was essential for Cd(II) adsorption and immobilization. The sulfate-mediated biotic Fe⁰ system thereafter achieved a significantly enhanced Cd(II) removal efficiency of 86.1%, over 3.3 times than that in the abiotic Fe⁰ system. Increasing initial sulfate concentration could improve the removal of cadmium, which further proved that hydrogenotrophic desulfuration played a key role for enhanced Cd removal. According to the experimental results and current reports, the mechanism of Cd(II) removal was revealed into three pathways including adsorption to secondary iron minerals, co-precipitation with iron (hydr)oxides and formation of cadmium sulfide precipitation. Increasing Fe⁰ dosages showed positive correlation to Cd(II) removal and neutral pH was preferred to sulfate-mediated biotic Fe⁰ corrosion. These results indicated that sulfate-mediated biotic Fe⁰ corrosion could greatly relieve the limitation of Fe⁰ in Cd(II) immobilization, which could be a promising method to eliminate Cd(II) pollution from groundwater.

Keywords: Cadmium; Desulfuration; Green rust; Secondary mineral; Zero-valent iron.

MeSH terms

Cadmium* / analysis
Corrosion
Groundwater*
Iron
Sulfates

Substances

Sulfates
Cadmium
Iron