Arsenic Removal System for Residential and Point-of-Use Applications

Arsenic contamination in drinking water is a severe health risk to populations throughout the world, including the United States. In recognition of this threat, the U.S. Environmental Protection Agency (EPA) recently lowered its water standard for arsenic from 50 ppb to 10 ppb. This change is expected to impact 10 percent of U.S. community drinking water systems. The operators of small water systems and individual well water users will face the greatest challenge in meeting this new standard. All water systems serving 25 or more users must meet the new standard for arsenic. However, systems supplying between 25 and 500 users are typically not large enough to make centralized treatment systems cost effective. Consequently, such systems often will use distributed point-of-use and point-of-entry (POU/POE) treatment units. A historic difficulty with such arrangements, particularly for home use, is determining when the device requires service¿a feature required by law. The goal of this multiphased research project is to demonstrate a compact, simple system for arsenic removal in POU/POE drinking water systems. The unit will combine a highly effective arsenic sorbent with an arsenic-monitoring sensor and alarm to alert the user that the bed requires replacement. The system features ADA Technologies, Inc.¿s new amended silicate sorbent¿a material that exhibits long life and the ability to remove both forms of arsenic that commonly are found in well water. During the Phase I research project, the project team will develop and test a novel sensor for arsenate, one that detects arsenate ions by their molecular ¿footprint.¿ Concurrently, the team will integrate the amended silicate sorbent and flow-sensing electronics into a compact water-treatment package. Local and remote alert functions will be included. Phase I will conclude with tests using arsenic-contaminated water from southwest Colorado. Phase II will incorporate the novel sensor into the overall design and expand its functionality to include arsenite detection. The goal is to provide an affordable unit with an operation that is as understandable as a home smoke alarm¿a device that alerts when danger exists, and provides peace of mind when all is well.