Arsenic removal in aqueous solutions using FeS2

Dun Fu; Tonni Agustiono Kurniawan; Lan Lin; Yaqiong Li; Ram Avtar; Mohd Hafiz Dzarfan Othman; Feng Li

doi:10.1016/j.jenvman.2021.112246

Arsenic removal in aqueous solutions using FeS₂

J Environ Manage. 2021 May 15:286:112246. doi: 10.1016/j.jenvman.2021.112246. Epub 2021 Mar 3.

Authors

Dun Fu¹, Tonni Agustiono Kurniawan², Lan Lin³, Yaqiong Li⁴, Ram Avtar⁵, Mohd Hafiz Dzarfan Othman⁶, Feng Li⁷

Affiliations

¹ National Engineering Research Center of Coal Mine Water Hazard Controlling, School of Resources and Civil Engineering, Suzhou University, Suzhou 234000, Anhui, PR China; College of the Environment & Ecology, Xiamen University, Xiamen, 361102, Fujian, PR China.
² College of the Environment & Ecology, Xiamen University, Xiamen, 361102, Fujian, PR China. Electronic address: tonni@xmu.edu.cn.
³ Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
⁴ School of Environment, Harbin Institute of Technology, Harbin, 150090, Heilongjiang, PR China.
⁵ Faculty of Environment Earth Sciences, Hokkaido University, Sapporo, 0600810, Japan.
⁶ Advanced Membrane Technology Research Centre (AMTEC), School of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia.
⁷ National Engineering Research Center of Coal Mine Water Hazard Controlling, School of Resources and Civil Engineering, Suzhou University, Suzhou 234000, Anhui, PR China.

PMID: 33667817
DOI: 10.1016/j.jenvman.2021.112246

Abstract

This study tested the technical feasibility of pyrite and/or persulfate oxidation system for arsenic (As) removal from aqueous solutions. The effects of persulfate on As removal by the pyrite in the integrated treatment were also investigated. Prior to the persulfate addition into the reaction system, the physico-chemical interactions between As and the pyrite alone in aqueous solutions were explored in batch studies. The adsorption mechanisms of As by the adsorbent were also presented. At the same As concentration of 5 mg/L, it was found that As(III) attained a longer equilibrium time (8 h) than As(V) (2 h), while the pyrite worked effectively at pH ranging from 6 to 11. At optimum conditions (0.25 g/L of pyrite, pH 8.0 and 5 mg/L of As(III) concentration), the addition of persulfate (0.5 mM) into the reaction promoted a complete removal of arsenic from the solutions. Consequently, this enabled the treated effluents to meet the arsenic maximum contaminant limit (MCL) of <10 μg/L according to the World Health Organization (WHO)'s requirements. The redox mechanisms, which involved electron transfer from the S₂^2- of the pyrite to Fe³⁺, supply Fe²⁺ for persulfate decomposition, oxidizing As(III) to As(V). The sulfur species played roles in the redox cycle of the Fe³⁺/Fe²⁺ of the pyrite by giving its electrons, while the As(III) oxidation to As(V) was attributed to the pyrite. Overall, this work reveals the applicability of the pyrite as an adsorbent for water treatment and the importance of persulfate addition to promote a complete As removal from aqueous solutions.

Keywords: Arsenic contamination; Low-cost adsorbents; Natural minerals; Persulfate; Pyrite.

MeSH terms

Adsorption
Arsenic* / analysis
Hydrogen-Ion Concentration
Oxidation-Reduction
Water
Water Pollutants, Chemical* / analysis
Water Purification*

Substances

Water Pollutants, Chemical
Water
Arsenic