Scaling filtration time initial dependencies of wastewater sludges

Abstract

The filtration time, tf, during constant pressure dead-end filtration testing of wastewater sludge is dependant on the initial height, h0, and the initial solids concentration, φ0. The theoretical dependencies of these initial conditions are explored: tf varies with h02 and c φ02, where c is a material dependant parameter that is also dependant on φ0 and the applied pressure. Empirical values for c relative to a given φ0 are determined from phenomenological filtration theory to give a qualitative scaling method to compare the filtration behaviour of highly compressible materials under differing initial conditions. The method is validated using filtration testing of municipal wastewater sludg..