Bioleaching for detoxification of waste flotation tailings: Relationship between EPS substances and bioleaching behavior

Maoyou Ye; Jialin Liang; Xiaojian Liao; Lili Li; Xidan Feng; Wei Qian; Siyu Zhou; Shuiyu Sun

doi:10.1016/j.jenvman.2020.111795

Bioleaching for detoxification of waste flotation tailings: Relationship between EPS substances and bioleaching behavior

J Environ Manage. 2021 Feb 1:279:111795. doi: 10.1016/j.jenvman.2020.111795. Epub 2020 Dec 15.

Authors

Maoyou Ye¹, Jialin Liang², Xiaojian Liao³, Lili Li⁴, Xidan Feng⁴, Wei Qian⁴, Siyu Zhou³, Shuiyu Sun⁵

Affiliations

¹ Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control of Guangdong Higher Education Institutes, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China; Guangdong Provincial Key Laboratory of Development and Comprehensive Utilization of Mineral Resources, Guangdong Institute of Resource Comprehensive Utilization, Guangzhou, 510650, China. Electronic address: zhkmyye@zhku.edu.cn.
² Institute of Bioresource and Agriculture, Department of Biology, Hong Kong Baptist University, Hong Kong, China.
³ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
⁴ Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control of Guangdong Higher Education Institutes, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
⁵ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China; Guangdong Engineering and Technology Research Center of Solid Waste Resource Recovery and Heavy Metal Pollution Control, Guangdong Polytechnic of Environmental Protection Engineering, Foshan 528216, China. Electronic address: sysun@gdut.edu.cn.

PMID: 33338773
DOI: 10.1016/j.jenvman.2020.111795

Abstract

The production of large volumes of waste flotation tailings results in environmental pollution and presents a major ecological and environmental risk. This study investigates bioleaching of waste flotation tailings using Acidithiobacillus ferrooxidans. The experiments were performed with 5.00% solid concentration, pH 2.0 with 100 mL medium for 25 d in the lab. The pH, OPR, metal concentration, dissolved organic matter (DOM) in leachate and extracellular polymeric substances (EPS) were recorded. Bioleaching tailing materials were finally characterized. Results showed that microorganisms, acclimating with mine tailings, effectively accelerated the bioleaching process, achieving maximum Zn and Fe extraction efficiencies of 95.45% and 83.98%, respectively, after 25 days. Compared with raw mine tailings, bioleaching could reduce 96.36% and 95.84% leachable Zn and Pb, and Pb presented a low risk (4.13%), while Zn, Cu, and Cr posed no risk (0.34%, 0.64%, and 0%). Toxicity and environmental risk analysis revealed bioleaching process significantly reduced the environmental risk associated with mine tailings. EPS analysis indicated that the loosely-bound EPS (LB-EPS) and tightly-bound EPS (TB-EPS) fractions contained different organic substances, which played different roles in the bioleaching process. Pearson correlation analysis revealed that EPS was highly correlated with bioleaching behavior (p < 0.05), and EPS was the main factor affecting the bioleaching process, promoting bioleaching in the LB-EPS and TB-EPS fractions.

Keywords: Bioleaching; Environmental risk; Extracellular polymeric substances; Pearson correlation analysis; Waste flotation tailings.

MeSH terms

Acidithiobacillus*
Extracellular Polymeric Substance Matrix*
Metals

Substances

Metals

Supplementary concepts

Acidithiobacillus ferrooxidans