Removal of perchlorate from water

Numerous reports on perchlorate contamination in water have given rise to substantial concern among regulatory agencies and the general public. The United States Environmental Protection Agency (USEPA) has established an oral reference dose of a drinking water level of 24.5 μg/L (NRC, 2005), although the Massachusetts Department of Environmental Protection has promulgated a drinking water standard of 2.0 μg/L (USEPA, 2005). With the emergence of perchlorate contamination as an important issue for drinking water quality, several advanced removal technologies including activated carbon adsorption, membrane filtration, ion exchange, and biological reduction have been briefly considered as means of perchlorate removal, since conventional processes including coagulation, flocculation, sedimentation, filtration, and disinfection are not effective perchlorate removal techniques. Since perchlorate is present at extremely low concentrations (in the range of micrograms per liter) and does not respond to conventional treatment technologies, perchlorate removal has become one of the biggest challenges for the drinking water industry. Although some technologies such as ion exchange and biological reduction have become more established than others, the experience gained thus far in the development of perchlorate removal technologies suggests that such technologies can be integrated into existing water treatment plants or incorporated into new facilities to promise high levels of perchlorate removal.