(115o) Use of a Hybrid Technology for the Removal of Perchlorate from Contaminated Groundwater

According to the Environmental Protection Agency (EPA) perchlorate is present in groundwater in 25 states. Highly soluble in water, perchlorate is an endocrine disrupting chemical preventing proper functioning of the thyroid gland which regulates metabolism by releasing hormones. In adults, exposure to perchlorate causes irregular metabolism. In children who are still growing, perchlorate exposure is much more serious because it interferes with their proper development. Perchlorate has been mostly identified in the groundwater of areas with explosives and munitions industries. It is also found in some herbicides.

This project is focused on testing a hybrid method that is sustainable and cost-effective for removing perchlorate contaminant from water. It combines the use of polymeric ligand exchangers (PLE) and bioremediation for fast removal of perchlorate to below regulated limits from water, followed by its reduction in highly contaminated regenerant solutions of spent to manageable products.

Results with low concentrations of perchlorate, 15ppm, show successful removal of the contaminant using both, fresh and spent PLE. Regeneration of the spent PLE was effectively carried out by a mixture of 5%ethanol and 2% sodium chloride solution. The effluent from this process with a concentration of 9.38ppm was then reduced by perchlorate respiring bacteria (Azospira sp. KJ), destroying perchlorate. This presentation will report on the results obtained with recommendations to improve this hybrid process.