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International Journal of Chemical Engineering
Volume 2010 (2010), Article ID 590169, 10 pages
http://dx.doi.org/10.1155/2010/590169
Research Article

Performance Evaluation of AOP/Biological Hybrid System for Treatment of Recalcitrant Organic Compounds

1Department of Chemical and Metallurgical Engineering, Faculty of Engineering and Built Environment, Tshwane University of Technology, Pretoria 0001, South Africa
2Water Utilization Division, Department of Chemical Engineering, University of Pretoria, Pretoria 0002, South Africa

Received 23 December 2009; Accepted 7 April 2010

Academic Editor: Josiane Nikiema

Copyright © 2010 Stanford S. Makgato and Evans M. Nkhalambayausi-Chirwa. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Process water from nuclear fuel recovery unit operations contains a variety of toxic organic compounds. The use of decontamination reagents such as C C l 4 together with phenolic tar results in wastewater with a high content of chlorophenols. In this study, the extent of dehalogenation of toxic aromatic compounds was evaluated using a photolytic advanced oxidation process (AOP) followed by biodegradation in the second stage. A hard-to-degrade toxic pollutant, 4-chlorophenol (4-CP), was used to represent a variety of recalcitrant aromatic pollutants in effluent from the nuclear industry. A UV-assisted AOP/bioreactor system demonstrated a great potential in treatment of nuclear process wastewater and this was indicated by high removal efficiency ( > 9 8 %) under various 4-CP concentrations. Adding hydrogen peroxide ( H 2 O 2 ) as a liquid catalyst further improved biodegradation rate but the effect was limited by the scavenging of O H radicals under high concentrations of H 2 O 2 .