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

Photocatalysis and its combination with biological oxidation have increasingly attracted researcher's attention. A novel TiO sub(2)/PP composite media was produced by loading TiO sub(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 sub(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.