Revealing the role of calcium alginate-biochar composite for simultaneous removing SO42- and Fe3+ in AMD: Adsorption mechanisms and application effects

Rui Li; Bing Wang; Pan Wu; Jian Zhang; Xueyang Zhang; Miao Chen; Xingxing Cao; Qianwei Feng

doi:10.1016/j.envpol.2023.121702

Revealing the role of calcium alginate-biochar composite for simultaneous removing SO₄^2- and Fe³⁺ in AMD: Adsorption mechanisms and application effects

Environ Pollut. 2023 Jul 15:329:121702. doi: 10.1016/j.envpol.2023.121702. Epub 2023 Apr 22.

Authors

Rui Li¹, Bing Wang², Pan Wu³, Jian Zhang⁴, Xueyang Zhang⁵, Miao Chen¹, Xingxing Cao¹, Qianwei Feng¹

Affiliations

¹ College of Resource and Environmental Engineering, Guizhou University, Guiyang, Guizhou, 550025, China.
² College of Resource and Environmental Engineering, Guizhou University, Guiyang, Guizhou, 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou, 550025, China. Electronic address: bwang6@gzu.edu.cn.
³ College of Resource and Environmental Engineering, Guizhou University, Guiyang, Guizhou, 550025, China; Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, Guizhou, 550025, China.
⁴ Key Laboratory of Karst Georesources and Environment, Ministry of Education, Guiyang, Guizhou, 550025, China.
⁵ School of Environmental Engineering, Xuzhou University of Technology, Xuzhou, Jiangsu, 221018, China.

PMID: 37094733
DOI: 10.1016/j.envpol.2023.121702

Abstract

The remediation of acid mine drainage (AMD) is particularly challenging because it contains a large amount of Fe³⁺ and a high concentration of SO₄^2-. To reduce the pollution caused by SO₄^2- and Fe³⁺ in AMD and realize the recycling of solid waste, this study used distillers grains as raw materials to prepare biochar at different pyrolysis temperatures. Calcium alginate-biochar composite (CA-MB) was further synthesized via the entrapment method and used to simultaneously remove SO₄^2- and Fe³⁺ from AMD. The effects of different influencing factors on the sorption process of SO₄^2- and Fe³⁺ were studied through batch adsorption experiments. The adsorption behaviors and mechanisms of SO₄^2- and Fe³⁺ were investigated with different adsorption models and characterizations. The results showed that the adsorption process of CA-MDB600 on SO₄^2- and Fe³⁺ could be well described by Elovich and Langmuir-Freundlich models. It was further proved by the site energy analysis that the adsorption mechanisms of SO₄^2- onto CA-MDB600 were mainly surface precipitation and electrostatic attraction, while that of Fe³⁺ removal was attributed to ion exchange, precipitation, and complexation. The applications of CA-MDB600 in actual AMD proved its good application potential. This study indicates that CA-MDB600 could be applied as a promising eco-friendly adsorbent for the remediation of AMD.

Keywords: Acid mine drainage; Adsorption; Alginate-biochar composite; Biochar.

MeSH terms

Adsorption
Alginates*
Charcoal
Kinetics
Water Pollutants, Chemical* / analysis

Substances

biochar
Alginates
Water Pollutants, Chemical
Charcoal