A novel arsenic immobilization strategy via a two-step process: Arsenic concentration from dilute solution using schwertmannite and immobilization in Ca-Fe-AsO4 compounds

Ilhwan Park; Takashino Ryota; Takeuchi Yuto; Carlito Baltazar Tabelin; Theerayut Phengsaart; Sanghee Jeon; Mayumi Ito; Naoki Hiroyoshi

doi:10.1016/j.jenvman.2021.113052

A novel arsenic immobilization strategy via a two-step process: Arsenic concentration from dilute solution using schwertmannite and immobilization in Ca-Fe-AsO₄ compounds

J Environ Manage. 2021 Oct 1:295:113052. doi: 10.1016/j.jenvman.2021.113052. Epub 2021 Jun 17.

Authors

Ilhwan Park¹, Takashino Ryota², Takeuchi Yuto², Carlito Baltazar Tabelin³, Theerayut Phengsaart⁴, Sanghee Jeon⁵, Mayumi Ito⁵, Naoki Hiroyoshi⁵

Affiliations

¹ Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, 060-8628, Japan. Electronic address: i-park@eng.hokudai.ac.jp.
² Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, 060-8628, Japan.
³ School of Minerals and Energy Resources Engineering, University of New South Wales, Sydney, 2052, NSW, Australia.
⁴ Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand.
⁵ Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, 060-8628, Japan.

PMID: 34147990
DOI: 10.1016/j.jenvman.2021.113052

Abstract

Acid mine drainage (AMD) with toxic arsenic (As) is commonly generated from the tailings storage facilities (TSFs) of sulfide mines due to the presence of As-bearing sulfide minerals (e.g., arsenopyrite, realgar, orpiment, etc.). To suppress As contamination to the nearby environments, As immobilization by Ca-Fe-AsO₄ compounds is considered one of the most promising techniques; however, this technique is only applicable when As concentration is high enough (>1 g/L). To immobilize As from wastewater with low As concentration (~10 mg/L), this study investigated a two-step process consisting of concentration of dilute As solution by sorption/desorption using schwertmannite (Fe₈O₈(OH)_8-2x(SO₄)_x; where (1 ≤ x ≤ 1.75)) and formation of Ca-Fe-AsO₄ compounds. Arsenic sorption tests indicated that As(V) was well adsorbed onto schwertmannite at pH 3 (Q_max = 116.3 mg/g), but its sorption was limited at pH 13 (Q_max = 16.1 mg/g). A dilute As solution (~11.2 mg/L As) could be concentrated by sorption with large volume of dilute As solution at pH 3 followed by desorption with small volume of eluent of which pH was 13. The formation of Ca-Fe-AsO₄ compounds from As concentrate solution (2 g/L As(V)) was strongly affected by temperature and pH. At low temperature (25-50 °C), amorphous ferric arsenate was formed, while at high temperature (95 °C), yukonite (Ca₂Fe_3-5(AsO₄)₃(OH)_4-10·xH₂O; where x = 2-11) and johnbaumite (Ca₅(AsO₄)₃OH) were formed at pH 8 and 12, respectively. Among the synthesized products, johnbaumite showed strongest As retention ability even under acidic (pH < 2) and alkaline (pH > 9) conditions.

Keywords: Arsenic immobilization; Ferric arsenate; Johnbaumite; Schwertmannite; Sorption/desorption; Yukonite.

MeSH terms

Arsenic* / analysis
Ferric Compounds
Hydrogen-Ion Concentration
Iron
Iron Compounds
Mining

Substances

Ferric Compounds
Iron Compounds
schwertmannite
Iron
Arsenic