Detoxification of water and wastewater by advanced oxidation processes

Nowadays there is a continuously increasing attention for the treatment of recalcitrant compounds present in water and wastewater due to their toxicity on both human health and the environment. Advanced oxidation processes (AOPs) are found to be effective for the degradation of recalcitrant compounds by increasing biodegradability and reducing toxicity. The present review focuses on the detoxification aspects of AOPs with special emphasis on arsenic toxicity. Different bioassays employing bacteria, invertebrates, algae, plants, and fish have been critically reviewed in this article as a valuable tool for assessing the toxicity as well as biodegradability of the industrial wastewater post AOP treatment. Various toxicity tests employed during AOP treatment of wastewater with high toxicity revealed that AOPs are effective for reducing their toxicity significantly. These processes are also effective to reduce arsenic toxicity by oxidizing arsenite to arsenate. By-products formed during AOP treatment of wastewater are also found more toxic than its parent compound. Thus, toxicity tests are essential for AOP treated wastewater before its disposal.