Enhancement of Odor Removal and Dewaterability of Anaerobically Digested Sludge by Protease Addition

摘要

Breaking the gel-like structure of sludge by disrupting the extracellular polymeric substances (EPS) with specific enzyme-protease- application was investigated. After 8 hours of incubation, the final cake solid content of sludge increased more than 20% with protease pretreatment.FESEM images taken from protease treated-un- conditioned samples revealed the significance of prote?ns in sludge structure. Protease pre-treatment improved the removal of major sulfur odors. Decrease in total amount of MT, DMS, DMDS, CS2 and H2S production in the headspace was found 32%, 41%, 36%, 34% (5 mg/l protease) and 58% (15 mg/l protease) respectively in the unconditioned samples. Addition of protease led to an increased rate of hydrolysis of the matrix by breaking the peptide bonds maintaining the integrity of sludge floc, resulting to an improvement in both odor removal and dewaterability.