Effect of Jarosite on the Removal of Arsenic ions in Sulfuric Acid Solution

Abstract

Jarosite (KFe₃(SO₄)₂(OH)₆) is a secondary mineral in acidic polluted environments such as mine tailing dump, but few investigations have evaluated arsenic removal by jarosite.
This study investigated the role of jarosite in arsenic removal using flask shaking experiments in diluted sulfuric acid solutions (pH1-3). Jarosite was synthesized and the chemical composition of the jarosite was K_0.54(H₃O)_0.46Fe_2.38(SO₄)₂(OH)₆. The shaking experiments found that As(V) was removed by the jarosite but As(III) was not removed. The mechanisms of As(V) removal were adsorption on the jarosite and co-precipitation with Fe(III) extracted from jarosite. The removal of As(V) from the liquid phase were increased with increasing pH, indicating that the adsorption of As(V) and SO₄^2- is competitive or that ionic As species (H₂AsO₄^-) is selectively adsorbed. The results suggest that jarosite is a sink for As(V) in acidic polluted environments.