Preozonation of Chlorophenolic Wastewater for Subsequent Biological Treatment

Abstract

Preozonation was investigated for its effects on the biodegradability of five chlorophenolic compounds in activated-sludge systems. The biodegradability was expressed in terms of the oxidation of each compound itself and of the total organic contents of the whole sample.

Results indicate that preozonation could either promote or retard the biodegradability, depending primarily on whether or not the sludge used in the subsequent biological system had been acclimated beforehand. For unacclimated sludge, preozonation was found to be helpful in promoting the biodegradability of all the compounds, especially the chlorophenols with a meta-position chlorine attachment. For acclimated sludge, a reverse effect generally, was observed.

Key Words:

• Ozone
• Preozonation
• Wastewater Treatment
• Biological Treatment
• Chlorophenols
• 2-Chlorophenol
• 3-Chlorophenol
• 4-Chlorophenol
• 2,4-Dichlorophenol
• 2,4,5-Trichlorophenol