2007 Volume 44 Issue 4 Pages 248-258
Although the up-flow filtration system with fibrous filtration media has some advantages in filtration rate and purity of filtrate, the particle trapping mechanism has not been fully understood. The filtration performances of PMMA particles, KANTO loam particles, and Kaolin floc with the up-flow filtration system were investigated using filtration beds with the height of 0.1-0.6m. For the filtration of PMMA particles the effects of flow rate, feed concentration, and particle size were studied with the 0.1m long filtration bed and we found that the filtration performances is well described by the deep filtration model, in which the particle are trapped on the surface of fibers in the initial stage of filtration followed the surface filtration with the layer of collected particles. The filtration performance of 0.4m long filtration bed was predicted from the filtration performance of 0.1m long filtration bed with the model. The filtration performances of KANTO loam particles in the 0.1m long filtration bed could be elucidated by the deep bed filtration model with a constant filtration coefficient but the model could not predict the filtration performance in the 0.6m long filtration bed. The filtration performance of Kaolin floc could be elucidated by the bed filtration model with a limitation of the amount of trapped particles. The particle trapping capacity and the particle trapping efficiency of those particles could be compared using the fitting parameter obtained from the model analysis.
