KWRRI Research Reports


Ozone pretreatment studies of four model phenolic compounds were conducted to evaluate the effects of ozonation on the anaerobic biodegradability and toxicity of these compounds. Two types of batch studies, the Biochemical Methane Potential (BMP) and the Anaerobic Toxicity Assay (ATA), were performed on samples ozonated upon phenol, o-cresol, 2,5-dichlorophenol, and 2,4-dinitrophenol.

Experimental results showed that toxic and refractory phenolic compounds were converted to methane gas by means of preozonation. In general, the biodegradable fraction of the oxidation products increased as the ozone dose was increased. However, ozonation to achieve at least 60% COD reduction was necessary to faciliate methane production. Ozonation reduced the toxicity of 2,5-DCP and 2,4-DNP on both acetate utilization and phenol degradation. The early ozonation products of o-cresol and phenol, however, were more toxic than the initial compounds. The rates of COD and DOC reduction through ozonation were faster and products formed were less inhibitory in the basic pH range than in the acid pH range.

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Funding Information

The work upon which this report is based was supported in part by funds provided by the United States Department of the Interior, Washington, D.C., as authorized by the Water Resources Research Act of 1984. Public Law 98-242.