Effect of Microwave-coupled Fe0/H2O2 on Excess Sludge Dewaterability

Abstract

The effects of initial pH, microwave power, reaction time, H2O2 dosage, and Fe0 dosage in microwave-coupled Fe0/H2O2 (MW-Fe0/H2O2) Fenton-like process on sludge dewaterability were systematically investigated by the specific resistance to filtration (SRF), water content of sludge cake, and capillary suction time (CST). And the mechanism of MW-Fe0/H2O2 improving sludge dewaterability was analyzed by analogy experiment. Results show that the reduction of SRF, water content of sludge cake, and CST were 90.5%, 15.5%, and 63.3%, respectively, at initial pH of 3, microwave power of 400 W, reaction time of 150 s, H2O2 dosage of 90 mg/g, and Fe0 dosage of 60 mg/g. The analysis of extracellular polymeric substances (EPS) components indicates that the reduction of protein and polysaccharide in TB-EPS was positively related to the improvement of sludge dewaterability. Three-dimensional fluorescence spectrometry (3D-EEM) analysis demonstrates that soluble microbial byproduct and tryptophan protein in TB-EPS were oxidatively degraded, thus improving the sludge dewaterability.

Keywords

• sludge dewaterability
• microwave
• zero valent iron
• eps