In-situ immobilization of arsenic and antimony containing acid mine drainage through chemically forming layered double hydroxides

Hongping Chen; Jing Li; Zhengbo Dai; Yulu Ai; Yufei Jia; Lu Han; Wenying Zhang; Mengfang Chen

doi:10.1016/j.scitotenv.2023.166601

In-situ immobilization of arsenic and antimony containing acid mine drainage through chemically forming layered double hydroxides

Sci Total Environ. 2023 Dec 10:903:166601. doi: 10.1016/j.scitotenv.2023.166601. Epub 2023 Aug 25.

Authors

Hongping Chen¹, Jing Li¹, Zhengbo Dai², Yulu Ai³, Yufei Jia³, Lu Han¹, Wenying Zhang¹, Mengfang Chen⁴

Affiliations

¹ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Jiangsu Engineering Laboratory for Soil and Groundwater Remediation of Contaminated Sites, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
² Zhejiang Environmental Monitoring Engineering Co Ltd, Hangzhou 310012, China.
³ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Jiangsu Engineering Laboratory for Soil and Groundwater Remediation of Contaminated Sites, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Jiangsu Engineering Laboratory for Soil and Groundwater Remediation of Contaminated Sites, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: mfchen@issas.ac.cn.

PMID: 37634714
DOI: 10.1016/j.scitotenv.2023.166601

Abstract

Acid mine drainage (AMD) rich in arsenic (As) and antimony (Sb) is considered as a significant environmental challenge internationally. However, simultaneous removal of As and Sb from AMD is still inadequately studied. In this study, a highly effective and simple approach was proposed for mitigating As and Sb-rich AMD, which involves in-situ formation of layered double hydroxides (LDHs). Following the treatment, the residual concentrations of iron (Fe), magnesium (Mg), sulfate, As and Sb in field AMD were decreased from their initial concentrations of 1690, 1524, 2055, 7.8 and 10.6 mg L^-1, respectively, to 1.3, 12.4, 623, 0.006 and 0.004 mg L^-1, respectively. Chemical formula of the resulting As and Sb-loaded LDHs can be identified as Mg_4.226Fe_2.024OH₂SO₄AsSb_0.006∙mH₂O. The dissolution rates of metal(loid)s in As and Sb-loaded LDH were lower than 1% under strongly acidic and alkaline environments. In presence of the mixed adsorbates, the As immobilization capacity by LDHs was significantly decreased, with an apparent intervention from Sb. However, As did not have a significant effect on the immobilization of Sb by LDH. As was immobilized by LDHs through anion exchange and complexation with -OH groups, while Sb was captured by anion exchange and complexation with [Formula: see text] . Density functional theory (DFT) calculations further proved the above conclusions. This novel approach is effective and can be applied for in-situ AMD treatment from abandoned mines.

Keywords: Acid mine drainage; Antimony; Arsenic; In-situ immobilization; Layered double hydroxides.