Assessment of enhancement in biodegradation of dichlorodiethyl ether (DCDE) by pre-oxidation.

The objective of this study is to assess the enhancement in biodegradation of dichlorodiethyl ether (DCDE) by ozonation and Fenton treatment. Acclimated and non-acclimated sludge cultures were used to test the biodegradability of the preoxidized DCDE solutions by three different tests: Short-term and long-term respirometry through continuous monitoring of oxygen consumption, and the mid-term test in which the amount of remaining organic matter was measured by TOC and COD tests. These tests were applied to solutions of DCDE preoxidized at the levels of 25%, 50%, 75%, and 100%. The results indicated that the biodegradability of oxidized DCDE solutions improved substantially compared to non-oxidized solutions. Fenton-treated DCDE exhibited toxicity to microorganisms under long-term exposure. Higher levels of preoxidation of DCDE led to mineralization of larger amounts of organic matter during subsequent biodegradation. There was no significant difference in the rate of biodegradation of oxidized products by either acclimated or non-acclimated bacteria.