Effect of sludge concentration on sludge dewaterability and cake clogging analysis

슬러지의 탈수성(脫水性)에 대한 농도(濃度)의 영향(影響)과 케이크 폐색현상(閉塞現象)의 해석(解析)

  • Published : 1996.01.15


Although the specific resistance to filtration is the most frequently employed means for characterizing dewaterability of a sludge, it presently is not possible to design nor to prediet performance of dewatering facilities using traditional linearized parabolic filtration equation, that is, the specific resistance model because of theoretical and practical inadequacies of the concept. Limitations of the specific resistance model reflect the need to examine fundamental sludge properties and filtration behaviors affecting dewaterability. From this study, two major limitations of the specific resistance model were noted. First, specific resistance values are very dependent on the sludge concentration because of the variations of particle size distribution and cake clogging to occur when surface area mean diameter is less than $25{\mu}m$ for activated sludge, $18{\mu}m$ for water treatment plant sludge. Second, nonparabolic filtration behavior can result from cake clogging, caused by the migration of fine particles into the cake pores, accelated by skin effect with highly compressible sludges.