Mine tailings remediation via sulfate-reducing bacteria and iron-reducing bacteria: heavy metals immobilization and biological sealing

ABSTRACT

Recent years have witnessed a steep rise in the use of SRB and IRB for the remediation of heavy metal contamination. This study investigated the effects of SRB and IRB on the physical and chemical properties of copper tailings. Besides, altered microbial community structure during the remediation process and the remediation mechanism were also explored. The results showed that bioremediation using SRB and IRB increased the pH of copper tailing and permeation time, and reduced ORP and the concentration of heavy metals, resulting in a friendly environment. The biological sealing was created from insoluble precipitates secreted by microbes in blocked seepage channels. This biological sealing prevented the infiltration of rain and oxygen and prevented the leaching of heavy metals. These findings have never been reported previously. In the exudates, the bioremediation resulted in the change of the dominant microorganisms from oxidised bacteria to SRB and IRB. In the copper mine tailings, the effect of bioremediation on microbial community varied with the depths of tailings. In addition, the species of microorganisms were also significantly different at different depths of tailings, and the key SRB, including Desulfosporosinus, Desulfotomaculum and Desulfovibrio, mainly existed in the middle and low part of mine tailings.

GRAPHICAL ABSTRACT

KEYWORDS:

• Sulfate-reducing bacteria
• iron-reducing bacteria
• copper tailings
• microbial remediation
• biological sealing

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the National Natural Science Foundation of China [grant numbers U1402234, 41573074, and 51974279], the National Key Research and & Development Program of China [grant numbers 2018YFC18018, 2018YFC18027], KeJunPing [2018] No. 159, the Guangxi Scientific Research and Technology Development Plan [grants number GuikeAB16380287 and GuikeAB17129025].

Notes on contributors

Mingjiang Zhang

Mingjiang Zhang is a senior engineer at National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Corporation Limited. His research examines the distribution of heavy metals. His research aims to understand the distribution and migration of heavy metals in and around tailings pond.

Jianlei Wang

Jianlei Wang is an engineer at National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Corporation Limited. His research is microbial high-throughput analysis. His research aims to understand the microbial community characteristics of tailings pond.

Xingyu Liu

Xingyu Liu is a senior engineer at National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Corporation Limited. He revised English grammar and checked language errors. He aims to improve language quality.

Ying Lv

Ying Lv is PhD at National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Corporation Limited. Her research is physicochemical analysis. Her research aims to understand the distribution and migration of heavy metals in and around tailings pond.

Bingbing Yu

Bingbing Yu is an engineer at National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Corporation Limited. His research is physicochemical detection. His research aims to understand the distribution and migration of heavy metals in and around tailings pond.

Bowen Gao

Bowen Gao is an engineer at National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Corporation Limited. His research is sample collection. His research aims to understand the distribution and migration of heavy metals in and around tailings pond.

Xiao Yan

Xiao Yan is PhD at National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Corporation Limited. Her research is microbial DNA extraction and detection. Her research aims to understand the microbial community characteristics of tailings pond.