Low Cost - Sustainable - High Capacity Potable Water Treatment Media for Arsenic Removal

According to the World Health Organization (WHO), arsenic (As) contaminated drinking water affects tens of millions of people in more than twenty countries. The WHO's Maximum Drinking Water Level (MDWL) for arsenic is 10 ppb. In some parts of the world, people are drinking highly contaminated water with arsenic levels above 250 ppb.

In this paper, we discuss our latest advances in the development of a novel arsenic removal media based on indigenous inorganic materials such as limestone which are coated with a metal oxide. Laboratory column testing of the novel media demonstrated improved capacity for As removal relative to standard media such as granular ferric hydroxide (GFH). The effects of different competing ions on the arsenic capacity were confirmed through modeling studies using the PHREEQC program.

The media, when fully loaded with arsenic, is considered a non-hazardous waste and can be easily disposed. The spent media when incorporated into concrete passes the US Environmental Protection Agency Toxicity Characteristic Leaching Procedure (TCLP) and California Wet tests.

Mechanistic models for the capture of arsenic by the media will be discussed.