Geographical distribution and risk assessment of heavy metals: a case study of mine tailings pond

ABSTRACT

In China, a large number of tailings deposited on natural surfaces, the potential risk of tailings attracts people’s attention. In this study, heavy metals distribution, geo-accumulation index, ecological risk index, microbial diversity and community were examined to evaluate the risks of a tailings pond. Results indicated the tailings pH is about 8.17, and the redox potential was lower than zero. Heavy metals could be leached and migrate from the tailings. The tailings pond had more influence on the distribution of Pb, Zn, As, Cu, and S. The influence distance of Pb, Zn, and Cu was less than 10 m, and the influence distance of As and S was less than 50 m. S and As had stronger migration capability than other elements in the soil. The biggest potential ecological risk resulted from Pb, and the distances more than 100 m had low ecological risk. The tailings decreased microbial richness and diversity of the surrounding environment. Oxidising bacteria and reducing bacteria existed in both the tailings and the surrounding soils; however, there were more oxidising and reducing microbes in the tailings than in the surrounding soils. The tailings pond currently has little impact on the environment, but the potential risk still exists.

KEYWORDS:

• Mine tailings
• heavy metals pollution
• risk assessment

Disclosure statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

Notes on contributors

Mingjiang Zhang is a senior engineer at National Engineering Laboratory of Biohydrometallurgy, GRINM Resources and Environment Tech. Co., Ltd. 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.

Minjie Sun is a senior engineer at China Certification & Accreditation Research Center, State Administration for Market Regulation. She revised English grammar and checked language errors. She aims to improve language quality.

Jianlei Wang is an engineer at National Engineering Laboratory of Biohydrometallurgy, GRINM Resources and Environment Tech. Co., Ltd. His research is microbial high-throughput analysis. His research aims to understand the microbial community characteristics of tailings pond.

Xiao Yan is PhD at National Engineering Laboratory of Biohydrometallurgy, GRINM Resources and Environment Tech. Co., Ltd. Her research is microbial DNA extraction and detection. Her research aims to understand the microbial community characteristics of tailings pond.

Xuewu Hu is PhD at National Engineering Laboratory of Biohydrometallurgy, GRINM Resources and Environment Tech. Co., Ltd. His research is physicochemical analysis. His research aims to understand the distribution and migration of heavy metals in and around tailings pond.

Juan Zhong is master at National Engineering Laboratory of Biohydrometallurgy, GRINM Resources and Environment Tech. Co., Ltd. Her research is physicochemical detection. Her research aims to understand the distribution and migration of heavy metals in and around tailings pond.

Xuezhe Zhu is master at National Engineering Laboratory of Biohydrometallurgy, GRINM Resources and Environment Tech. Co., Ltd. His research is sample collection. His research aims to understand the distribution and migration of heavy metals in and around tailings pond.

Xingyu Liu is Professor at General Research Institute for Non Ferrous Metals in National Engineering Lab of Biohydrometallurgy. His research evaluates the risks of a tailings pond located in China. His research aims to understand the heavy metal leaching behaviour and microbial community succession in the tailing pond.

ORCID

Mingjiang Zhang http://orcid.org/0000-0001-5225-0042

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 and 2018YFC18027], the Guangxi Scientific Research and Technology Development Plan [grants number GuikeAB16380287 and GuikeAB17129025].