Pieter Van Aken

Comparison of Different Oxidation Methods for Recalcitrance Removal of Landfill Leachate

In this work several oxidation methods, such as conventional ozonation, O3/UV, O3/UV/ferrous iron and Fenton oxidation, for the removal of recalcitrant organic matter present in landfill leachates are evaluated. The samples of the leachate are taken after a biological treatment and membrane ultra-filtration (UF). The contribution of the UV radiation and the effect of ferrous iron ions on the ozone process efficiency is discussed. At lower ozone dosages, the partial oxidation efficiency is reduced as compared to conventional ozonation and therefore, a higher degree of mineralization of the organic matter is achieved. Finally, the best results are obtained by the Fenton oxidation, however, based on economic considerations this method is not recommended.

COD and AOX Removal and Biodegradability Assessment for Fenton and O3/UV Oxidation Processes: A Case Study from a Graphical Industry Wastewater

Due to process stability and excellent effluent quality, the use of membrane processes is rapidly expanding. However, a drawback is the production of concentrates and their proper disposal. In this study, reverse osmosis concentrate was treated by Fenton and O3/UV oxidation processes. The concentrate contains halogenated compounds, recalcitrant COD and low biodegradability. The removal of halogenated compounds and the enhancement of biodegradability were examined. Comparing the investigated processes, Fenton oxidation resulted in a better mineralization of organic matter; however, O3/UV oxidation achieved a better enhancement of the biodegradability. Furthermore, similar degradation of halogenated compounds were observed for both oxidation processes.