Arsenic removal from drinking water is a priority for local water authorities, given that long-term exposure has been linked to a host of serious health problems, including cancer, nervous system damage and atherosclerosis (inflammation) in the arteries leading to the brain. That's why Water Technology Group, Inc., in Harvard, Mass., last week licensed arsenic-trapping technology from the U.S. Department of Energy's Idaho National Laboratory (INL).
Water Technology Group–an affiliate of Northeast Water Solutions, Inc. in Warwick, R.I.–wants to use INL's Nano-Composite Arsenic Sorbent (N-CAS), a beadlike resin containing high concentrations of microscopic metal oxides, to improve its ability to catch arsenic in contaminated water. The company plans to make the beads available to Northeast Water as well as other water treatment companies doing arsenic remediation.
Demand for N-CAS has been high since the U.S. Environmental Protection Agency (EPA) in 2006 reduced the maximum concentration of arsenic it permits in drinking water from 50 parts per billion (ppb) to 10 ppb. The decision affected 4,000 U.S. municipalities and nearly 14 million U.S. homeowners whose water resources now exceed the new limits. (INL says 70 million people worldwide are exposed to dangerous arsenic concentrations.)
INL began developing N-CAS in 2005 in anticipation of the stiffer regs, says INL research engineer and project leader Troy Tranter. INL Researchers, experts in the separation and removal of fissionable material used as nuclear fuel, engineered a nanoparticle that would react specifically with arsenic. The resin's chemistry would need to be altered for it to detect and trap other elements.
N-CAS is only one of many technologies being tested for its ability to treat drinking water. New Mexico's Sandia National Laboratories, which also serves the Energy Department, since 2000 has offered local utilities, including the Public Water Service Utilities Board in El Paso, Texas, its Specific Anion Nanoengineered Sorbents (SANS) treatment for arsenic-heavy water.
Images courtesy of Idaho National Laboratory