(12a) Advanced Oxidation Processes for the Treatment of Azole-Containing Industrial Wastewater

Advanced oxidation processes (AOPs) are based on the formation of hydroxyl radicals and have been explored to overcome the inability of conventional water treatment methods for removing a wide variety of organic contaminants. Because of their high effectiveness, AOPs have been used for the treatment of industrial effluents for over a decade.

In this study, the effectiveness of three types of AOPs including Fenton reaction, photo-Fenton process and electrical discharge plasma treatment have been compared for the treatment of an industrial wastewater containing azoles, a class of five-membered heterocyclic compounds with at least one nitrogen atom, hydrogen peroxide, and organic and inorganic co-contaminants. The key design and operational variables such as iron dosing, pH and temperature for the Fenton reaction, UV flux and intensity for the photo-Fenton process, and discharge power and reactor electrode configuration for the plasma treatment, were investigated. The fundamental reaction mechanisms were studied and degradation byproducts identified.

The results of this study offer recommendations on the suitability of the three AOPs for treating the azole-containing wastewater and provide insights regarding the economics of the processes and their scaleup.