Comparing the arsenic sorption capacity of Bauxsol™ and its derivatives with other sorbents

In view of the frequency of occurrence of groundwaters with high arsenic contents in many countries, including several of the poorest developing countries, the development of an inexpensive and efficient system for arsenate removal from drinking water is essential. Treatment of water and effluents with solid industrial residues for adsorptive removal of arsenic offers a potentially cost-effective and sustainable approach. Herein, promising sorbents have been developed by the authors from seawater-neutralised bauxite refinery residues (Bauxsol (TM)) including acid treated Bauxsol (ATB), acid and heat treated Bauxsol (AB), Bauxsol coated sand (BCS), and AB coated sand (ABCS). A comparison of the affinity of commonly used adsorbents towards arsenic with that of the sorbents developed by the authors shows that the sorptive capacity of the new materials is comparable to, or better than, that of alternative materials. Because the raw material for the developed sorbents (red mud) is originally an industrial residue, the developed sorbents should be readily available and inexpensive compared to alternative materials and their use will enhance resource use efficiency.