Ozone-enhanced biological Treatment of Wastewater with high COD content

Wastewaters generated by many economically relevant activities contain non biodegradable pollutants which pass unaltered through biological stage of the treatment plant making it difficult to meet the discharge limits currently in force. Therefore, an additional treatment is usually required to remove these compounds. The combination of biological treatment with ozonation is one of the most effective approaches. The synergistic effect between biological and ozonation stage is, however, a crucial key factor for giving a considerable cost advantage. The synergistic effect in existing plants and in an innovative system (SBBGR - Sequencing Batch Biofilter Granular Reactor) is compared in the present study for treating landfill leachates. The results obtained have shown that in the innovative system the synergistic effect measured as (g ozone/g reduced COD) is up to 2 times stronger than in existing plants.