Biodegradability Improvement of Aqueous 2,4-Dichlorophenol And Nitrobenzene Solutions By Means of Single Ozonation

Abstract

The possibility of the integration of ozonation and biological processes as an economical way to treat biorecalcitrant organic compounds such as nitrobenzene and 2,4-dichlorophenol was investigated. In the pre-treatment step, stoichiometric coefficients and pseudo first-order kinetic constants were obtained. Biodegradability was monitored throughout the ozonation step, in order to evaluate the optimum ozone doses. The low TOC reduction after these ozone doses allowed much of the organic carbon to be removed in the biological stage. In the case of 2,4-dichlorophenol, the biodegradability improvement was checked in an aerobic bioreactor. By means of the combined ozonation-biological oxidation, up to 80% of the initial organic content was removed. Results presented in this study show the feasibility of using the combination of ozone and conventional biological treatments to treat wastewaters containing these pollutants.

Keywords:

• Ozonation
• Biodegradability Enhancement
• Nitrobenzene 2
• 4-Dichlorophenol
• BOD
• Industrial Wastewater

ACKNOWLEDGMENTS

The authors wish to express their gratitude for the economic support given by the Ministry of Education of Spain (project PPQ2002-00565), Generalitat de Catalunya (Spain) and the agreement ULA-CONICIT (Venezuela).