Methanogenic toxicity reduction of 2,4-dinitrophenol by ozone

Two types of batch studies, the Biochemical Methane Potential (BMP) and the Anaerobic Toxicity Assay (ATA), were performed on ozonated and unozonated 2,4-dinitrophenol to evaluate the anaerobic biodegradability and toxicity of this refractory priority pollutant induced by ozone. Both acetic acid and phenol supplemented cultures were used to allow an independent evaluation of toxicity toward the specific bacterial groups in a mixed methanogenic culture. The ozonation products were well biodegradable to methane after about 80% COD reduction was achieved by ozonation. However, the toxicity of ozonation products to the methanogenic culture was reduced as ozone doses were increased. The toxicity of ozonation products formed with 40-60% COD reduction decreased rapidly independent of both the pH during the ozonation reaction and the substrate used in the ATA tests.