Deep insight on mechanism and contribution of arsenic removal and heavy metals remediation by mechanical activation phosphogypsum

Mengyu Ma; Xiangqun Xu; Zhihao Ha; Qingmuke Su; Chenyang Lv; Jia Li; Dongyun Du; Ruan Chi

doi:10.1016/j.envpol.2023.122258

Deep insight on mechanism and contribution of arsenic removal and heavy metals remediation by mechanical activation phosphogypsum

Environ Pollut. 2023 Nov 1:336:122258. doi: 10.1016/j.envpol.2023.122258. Epub 2023 Aug 1.

Authors

Mengyu Ma¹, Xiangqun Xu², Zhihao Ha², Qingmuke Su², Chenyang Lv², Jia Li², Dongyun Du³, Ruan Chi⁴

Affiliations

¹ Hubei Province Engineering Research Center for Control and Treatment of Heavy Metal Pollution, College of Resources and Environmental Science, South-Central Minzu University, Wuhan, 430074, PR China; Hubei Novel Reactor & Green Chemical Technology Key Laboratory, Key Laboratory for Green Chemical Process of Ministry of Education, School of Xingfa Mining Engineering, Wuhan Institute of Technology, Wuhan 430074, PR China.
² Hubei Province Engineering Research Center for Control and Treatment of Heavy Metal Pollution, College of Resources and Environmental Science, South-Central Minzu University, Wuhan, 430074, PR China.
³ Hubei Province Engineering Research Center for Control and Treatment of Heavy Metal Pollution, College of Resources and Environmental Science, South-Central Minzu University, Wuhan, 430074, PR China. Electronic address: dydu666@mail.scuec.edu.cn.
⁴ Hubei Novel Reactor & Green Chemical Technology Key Laboratory, Key Laboratory for Green Chemical Process of Ministry of Education, School of Xingfa Mining Engineering, Wuhan Institute of Technology, Wuhan 430074, PR China.

PMID: 37536479
DOI: 10.1016/j.envpol.2023.122258

Abstract

Arsenic-containing wastewater and arsenic-contaminated soil can cause serious environmental pollution. In this study, phosphogypsum with partial mechanical activation of calcium oxide was used to prepare a new phosphogypsum-based passivate (Ca-mPG), and its remediation performance on arsenic-contaminated soil was evaluated in terms of both effectiveness and microbial response. The results showed that the optimum conditions for the preparation of the passivate were optimized in terms of single factor and response surface with a ball milling speed of 200 r/min, a material ratio of 6:4 and a ball milling time of 4 h. Under these conditions, the adsorption capacity was 37.75 mg/g. The leaching concentration of arsenic (As) in the contaminated soil after Ca-mPG modification decreased from 25.75 μg/L to 5.88 μg/L, which was lower than the Chinese national standard (GB/T 5085.3-2007); Ca-mPG also showed excellent passivation effect on other heavy Metals (copper, nickel, cadmium, zinc). In addition, As-resistant bacteria and passivators work together to promote the stabilization effect of contaminants during the remediation of As-contaminated soil. The mechanisms of Cu, As(III)/As(V), Zn, Cd, and Ni removal were related to ion exchange, electrostatic adsorption of substances on heavy metals, calcium binding to other substances to produce precipitation; and microbially induced stabilization of HMs, oxidized. Overall, this study demonstrates an eco-friendly "waste-soil remediation" strategy to solve problems associated with solid waste reuse and remediation of HM-contaminated soils.

Keywords: Arsenic (As); Heavy metals; Phosphogypsum; Soil remediation.