Anaerobic biodegradability and toxicity of hydrogen peroxide oxidation products of phenols

The anaerobic biodegradability and toxicity of oxidation products of two phenolic compounds (o-cresol and 2,4-dinitrophenol) reacted with hydrogen peroxide were evaluated in batch methanogenic cultures. The reaction products of o-cresol under high doses of hydrogen peroxide were biodegradable to methane and the biodegradable fraction increased with increasing dose of hydrogen peroxide. The reaction products of o-cresol under low doses of hydrogen peroxide were inhibitory and were not degraded to methane. However, the inhibition was reduced and conversion of biodegradable products to methane was noted after applying powdered activated carbon. Sufficient oxidation also reduced the toxicity of 2,4-dinitrophenol to a phenol-enriched methanogenic culture.