Dewatering sewage sludge by a combination of hydrogen peroxide, jute fiber wastes and cationic polyacrylamide

Abstract

This study reported an effective method of using hydrogen peroxide (H2O2), jute fiber (JF) wastes and cationic polyacrylamide (CPAM) to precondition sewage sludge to improve its dewatering performance. The sludge preconditioned with H2O2, JF and CPAM showed better dewatering performance than the sludge that preconditioned with JF and CPAM and the sludge that preconditioned with CPAM alone. The sludge preconditioned with JF and CPAM showed better dewatering performance but worse settling performance than the sludge that preconditioned with CPAM alone. The filter cake moisture and SRF decreased with JF and CPAM dosages at 2 kg t−1 and 300 kg t−1 respectively and a rising H2O2 dosage below 100 kg t−1 but increased when H2O2 dosage was above 100 kg t−1. The dewatering performance of sewage sludge was significantly improved by three factors: 1) the release of the bound water and intracellular water of sludge cells caused by H2O2; 2) the porous and low compressible structure of the sludge filter cake formed by CPAM, the sludge particle and JF; and 3) the strong, long and hollow structure of JF. The combination of H2O2, JF and CPAM was ideal for sludge dewatering, which contributed to filter cake incineration and JF wastes reutilization.