Biodegradability and Toxicological Studies

Besides biodegradability, the toxicity of a wastewater is a crucial parameter for the evaluation of the effectiveness of an AOP treatment. It is of utmost importance with respect to the complex reaction schemes of AOPs producing a large variety of intermediary oxidation products (e.g. Figs. 7-4 to 7-10, Tab. 7-1). In most cases, the toxic potential of these intermediary products is not known and it should be evaluated by appropriate methods (cf. Chapter 5.1.2). 

Sometimes an increase in toxicity is observed during the first few minutes of AOP treatment. Ince et al. (1997) demonstrated this effect by H2O2-UV treatment of a textile azo dye (Remazol Black-B) in aqueous solution (Fig. 7-20). After a sig- 

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