Effect of chemical pretreatment on anaerobic biodegradation of refractory organic compounds

The potential for using chemical oxidation to enhance anaerobic biodegradability and reduce toxicity of two model phenolic compounds (o‐cresol and 2,4‐DNP) was evaluated. Batch bioassays were performed on the model compounds and their oxidation samples to determine biodegradability and toxicity in batch methanogenic cultures. Ozone, hydrogen peroxide, and potassium permanganate were the three oxidants examined in this study. A dose of approximately 5 moles hydrogen peroxide, in the presence of a ferrous iron catalyst (Fenton's reagent), 7 moles permanganate, or 25 moles of ozone per mole of o‐cresol was needed to significantly enhance anaerobic biodegradability of oxidation samples. Approximately 2.5‐4.5 moles of hydrogen peroxide or 7 moles of ozone per mole of 2,4‐DNP reduced methanogenic toxicity by 50%.