Author:

Keywords:

Toxicity, Advanced oxidation, dichlorophenol

Abstract:

In order to evaluate the impact of the toxic and biorefractory compounds on activated sludge plants, a method based on the detection of the bacterial activity is necessary. Respirometry is a very sensitive measurement and interpretation of the biological oxygen consumption rate under well defined experimental conditions. In this study, a simple respirometric procedure was set up to detect effluent toxicity and to evaluate chemical pre-treatment. This method was taken because the mircroorganisms are representative for the wastewater treatment biomass. Initially, the EC50 value of 3,5- dichlorophenol and 2,4-Dichlorophenol is measured. Further, synthetic wastewater, containing the previous mentioned xenobiotic compounds, is treated with ozone to enhance the toxicity level of the wastewater. The respirometric set up is based on the OECD method 209. The respiration rate of the biomass is evaluated by the oxygen concentration profile detected in the liquid phase. Sodium acetate is utilized as a reference substrate. An EC50 value of approximately 25 mg/l can be derived from the experimental results. Compared to EC50 values reported in literature, the toxicity data obtained in this study is significant higher, however, the same order of magnitude is obtained.