THE BIOTOXICITY AND COLOR FORMATION RESULTS FROM OZONATION OF WASTEWATERS CONTAINING PHENOL AND ANILINE

Abstract

This study was undertaken to investigate the color forming phenomena and biotoxicity related problems during the initial stage of ozonation in the wastewater containing phenol or aniline. Experimental results indicate that the phenol under alkaline condition and aniline in all pH conditions cause a serious color problem during the period of early initial ozonation. In addition, the ozonated aniline exhibited more severe color formation than the ozonated phenol did. Both of these compounds revealed that either a high compound concentration or low ozone dosage applied incurred a strong color forming phenomena. Moreover, according to the Microtox test, both ozonated byproducts increased the toxicity during early ozonation when the color formation occurred. The EC₅₀-value as COD decreased from 0.72 (for phenol, pH = 7) to 1.38 (for aniline, pH = 4) orders-of-magnitude. This observation implies that the ozonated color formation would generate new toxicity problems if these colored matters were not further oxidized.

Keywords:

• Microtox
• Biotoxicity
• Ozonation
• Color formation
• Phenol
• Aniline

ACKNOWLEDGMENTS

The authors would like to thank the National Science Council of the Republic of China, Taiwan for financially supporting this research under Contract No. NSC 89-2211-E-002-025.