Functionalised polymeric materials for the removal of arsenate from contaminated water

Abstract

Inorganic arsenic is a carcinogen and, in some regions, one of the biggest contaminants in drinking water. The World Health Organisation (WHO) has indicated that over 140 million people worldwide are drinking water with levels of arsenic above the recommended guideline value of 10 μg L⁻¹. Therefore, there is a pressing need to find low-cost technologies for the removal of inorganic arsenic from water. As part of our efforts to tackle this problem, we previously developed an efficient sorbent material (ImpAs) based on a polymeric support (HypoGel) functionalised with a selective chemical receptor for arsenate (i.e. arsenic(V)). With the aim to lower the production cost of this material and improve its arsenate removal capacity, we have studied other polymeric materials as solid supports. Herein, we report the synthesis of new inexpensive sorbent materials by covalently attaching our previously reported arsenate receptor onto Merrifield and Purolite C106 polymer beads. We carried out batch and flow-through experiments with the new polymeric materials demonstrating that they have up to 60% higher arsenate removal capacities than the original functionalised HypoGel material. Furthermore, the new polymeric materials operate very well under flow-through conditions, removing over 99% of arsenate present in solutions containing low (15 μg L⁻¹) and high (300 μg L⁻¹) levels of arsenate. We also report on the lower production cost of the new Purolite-based material as compared to the original functionalised HypoGel polymer beads.