2003 Volume 46 Pages 47-53
The purification performance of an improved porous ceramics was investigated to confirm the lower maintenance and cost of a swine wastewater treatment system using a biofilm process. Three types of biofilm were examined: 1) a marketed ceramics carrier (reference), 2) a low price ceramics carrier (ceramics carrier I) and 3) an improved ceramics carrier with rough porous (ceramics carrier II) . In this study, we used the aeration tank with the capacity of 6 liters, and the tank was filled with biofilm at volume ratios of 40% and 50%. The wastewater volume treated in the aeration tank was 1 liter per day. During the first 40 days, treatment was carried out at the rate of 0.1-0.2 kg/m3⋅per day of biochemical oxygen demand (BOD) volume loading, and thereafter treatment was at 0.1-0.8 kg/m3⋅per day. The porosity of ceramics carriers I and II was similar to that of the reference. A unit cost of the ceramics carrier II was estimated less than that of the ceramics carrier I, because of its rougher and lighter structure than the ceramics carrier I. Three types of biofilm were similar in the removal of BOD and SS, and a high removal of total nitrogen was achieved by ceramics carrier II at a volume ratio of 50%, as compared to others. All biofilm groups were similar in the removal of BOD, chemical oxygen demand and ammonium nitrogen, but a higher removal rate was obtained in the summer than in the winter. All biofilm groups were also similar in the concentration of excess sludge except for the reference and the ceramics carrier II at volume ratios of 50%. These findings indicated that the ceramics carrier II were much similar to the marketed ceramics carrier and the ceramics carrier I in the durability and purification.
