Efficient inhibition of heavy metal release from mine tailings against acid rain exposure by triethylenetetramine intercalated montmorillonite (TETA-Mt)

Beini Gong; Pingxiao Wu; Zhujian Huang; Yuanyuan Li; Shanshan Yang; Zhi Dang; Bo Ruan; Chunxi Kang

doi:10.1016/j.jhazmat.2016.07.011

Efficient inhibition of heavy metal release from mine tailings against acid rain exposure by triethylenetetramine intercalated montmorillonite (TETA-Mt)

J Hazard Mater. 2016 Nov 15:318:396-406. doi: 10.1016/j.jhazmat.2016.07.011. Epub 2016 Jul 6.

Authors

Beini Gong¹, Pingxiao Wu², Zhujian Huang³, Yuanyuan Li³, Shanshan Yang³, Zhi Dang⁴, Bo Ruan³, Chunxi Kang³

Affiliations

¹ School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China; Guangdong Key Laboratory of Agro-Environmental Integrated Control, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou 510006, PR China.
² School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Engineering and Technology Research Centre for Environment Risk Prevention and Emergency Disposal, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China; Guangdong Environmental Protection Key Lab of Solid Waste Treatment and Recycling, Guangzhou 510006, PR China. Electronic address: pppxwu@scut.edu.cn.
³ School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China.
⁴ School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, PR China.

PMID: 27450331
DOI: 10.1016/j.jhazmat.2016.07.011

Abstract

The potential application of triethylenetetramine intercalated montmorillonite (TETA-Mt) in mine tailings treatment and AMD (acid mine drainage) remediation was investigated with batch experiments. The structural and morphological characteristics of TETA-Mt were analyzed with XRD, FTIR, DTG-TG and SEM. The inhibition efficiencies of TETA-Mt against heavy metal release from mine tailings when exposed to acid rain leaching was examined and compared with that of triethylenetetramine (TETA) and Mt. Results showed that the overall inhibition by TETA-Mt surpassed that by TETA or Mt for various heavy metal ions over an acid rain pH range of 3-5.6 and a temperature range of 25-40°C. When mine tailings were exposed to acid rain of pH 4.8 (the average rain pH of the mining site where the mine tailings were from), TETA-Mt achieved an inhibition efficiency of over 90% for Cu(2+), Zn(2+), Cd(2+) and Mn(2+) release, and 70% for Pb(2+) at 25°C. It was shown that TETA-Mt has a strong buffering capacity. Moreover, TETA-Mt was able to adsorb heavy metal ions and the adsorption process was fast, suggesting that coordination was mainly responsible. These results showed the potential of TETA-Mt in AMD mitigation, especially in acid rain affected mining area.

Keywords: Acid rain; Adsorption; Buffering; Mine tailings; Montmorillonite.