Biodegradation of EDTA.

The chelating agent ethylenediaminetetraacetate (EDTA) is not degraded by conventional biological and physicochemical methods for the treatment of wastewater and the purification of drinking water. Of the measurable organic compounds it is the one present at the highest concentration in many surface and drinking waters. In recent years, however, studies have demonstrated that EDTA can be degraded by specially enriched bacterial cultures and in wastewater treatment plants receiving EDTA-containing effluents. The amounts of EDTA released into the aquatic environment could thus be reduced by establishing appropriate biological wastewater treatment plants. This article describes the degradation of EDTA and its metal chelates by different bacterial cultures, catabolic steps in EDTA degradation, and biological methods for the removal of this chelating agent from wastewaters.