Effects of phosphate, silicate, sulphate, and bicarbonate on arsenate removal using activated seawater neutralised red mud (bauxsol)

Arsenic in drinking water is of major concern because, it is a well-documented carcinogen. Arsenate (As (V)) and arsenite (As (III)) are the most common soluble inorganic arsenic species in water, and under oxidising conditions arsenate oxyanions are dominant. The aim of this work is to study the effects of phosphate, silicate, sulphate, and bicarbonate anions on the removal of arsenate using activated seawater neutralised red mud (bauxsol). The effects are investigated for different initial anion and arsenate concentrations using batch experiments. The order of anion suppression on arsenate removal is found to be phosphate > silicate > sulphate > bicarbonate on a molar basis. This is important since of an understanding of the anion competition during arsenate adsorption using bauxsol is useful in designing effective arsenic removal systems.