THE COMBINED PROCESS OF PHOTOCATALYSIS AND BIOLOGICAL OXIDATION FOR THE TREATMENT OF MICRO-POLLUTED RAW WATER

摘要

Photocatalysis and its combination with biological oxidation have increasingly attracted researcher's attention. A novel TiO_2/PP composite media was produced by loading TiO_2 particles on suspended polypropylene plastic (PP) filter media. Biological filter media was also prepared by culturing microbe on the same PP filter media. TiO_2/PP composite media and biological filter media were used to treat the micro polluted raw water. Four processes, i.e. single photo-catalysis, single biological oxidation, photocatalysis + biological oxidation combination, and biological oxidation + photocatalysis combination, were performed to compare the treatment efficiency of micro-polluted raw water. The results showed that, the TOC removal by single photocatalysis and single biological oxidation was relatively low. The treatment efficiency of photocatalysis + biological combination process was better than that of biological + photocatalysis combination process. The removal of COD, TOC, and ammonia was 87.3%, 64.7%, 84.3% separately, by photocatalysis + biological combination process. Pho-tocatalytic oxidation degrades organic molecules into small molecules, thus improves the biodegradability of organic compounds. The subsequent biological treatment process can further remove the remains.