Perchlorate (ClO4-) is an emerging drinking water contaminant of concern that may impact water treatment plants in the near future. The United States Environmental Protection Agency (EPA) has announced its intention to regulate perchlorate in drinking water and California and Massachusetts have already established maximum contaminant levels for perchlorate. Biological treatment is an effective way to remove perchlorate from drinking water and groundwater. MicroC® serves as a supplemental carbon source and electron donor in such processes.
Perchlorate is primarily used in the manufacture of rocket fuel, munitions, explosives and fireworks. Perchlorate is very soluble and mobile in water. Despite being a strong oxidant, it has limited reactivity and persists in the environment.
Perchlorate is known to affect thyroid function in humans. It reduces the thyroid’s ability to take up iodine, which reduces thyroid hormone production and results in hypothyroidism. Thyroid hormones regulate metabolism, growth and development. Infants and children are especially susceptible to hypothyroidism because a lack of thyroid hormones early in life can severely impact their long-term growth and development.
An EPA study from 2001-2005 found perchlorate contamination in 26 states and in just over 4 percent of public water systems in the United States. In 2011, USEPA announced its intention to regulate perchlorate in drinking water, but the agency has not yet proposed a maximum contaminant level (MCL). California and Massachusetts have already established perchlorate MCLs of 6 and 2 μg/L, respectively. However, California is reviewing its perchlorate MCL in light of a 1 μg/L public health goal established in 2015 by the California EPA's Office of Environmental Health Hazard Assessment.
How EOSi can help
Perchlorate can be removed from drinking water or groundwater by physical-chemical processes such as ion exchange or reverse osmosis, but these processes produce waste brine that can be challenging to manage. Biological processes break down the perchlorate into harmless chloride ions (Cl-) and oxygen gas (O2).
Biological treatment of perchlorate is very similar to denitrification, and denitrifying bacteria have been found to be capable of degrading perchlorate. The process occurs under anoxic conditions, and requires an electron donor and a supplemental carbon source such as MicroC® to support bacterial growth.
In addition to our traditional MicroC® Carbon Sources, EOSi has developed MicroC® 4000, an NSF60 certified product that can be used to remove nitrate and perchlorate in potable water systems.