At high alkaline pH, the surface hydroxyl groups get deprotonated and negatively charged, thus causing desorption of negatively charged arsenic species very efficiently. Subsequent rinsing with dilute acid allows formation of protonated surface functional groups with high arsenic sorption affinity. The regeneration step allows reuse of the adsorbent media and reduces the volume of arsenic-laden sludge by over an order of magnitude. In contrast, nonregenerable adsorbent media are used universally for arsenic removal in the developed western world.