Application of Photocatalysis Methods to Enhance Sludge Disintegration

Abstract

This paper investigated the disintegration of waste sludge with different photocatalytic processes. For this objective, the effects of initial pH, reaction time, TiO2 amount with Fe2+, Fe0 and H2O2 doses on the disintegration degree (DD) were determined. Soluble chemical oxygen demand (SCOD) was used as the main parameter in the study. Process optimizations, kinetic study and Disintegration degree calculation were performed based on the SCOD parameter. In order to observe the effect of UV light, UV-A, UV-B, UV-C lights were used, and the best DD was determined. In addition, SEM analyzes were performed to determine Particle Size Distribution, toxicity and sludge characterization in raw sludge and disintegrated sludge. As a result of optimization studies, optimum pH 3, reaction time 60 min, 6 g/kg TS Fe2+, 4 g/kg TS Fe0, 40 g/kg TS/20 g/ kg TS H2O2 and 0.8 g/l TiO2 doses were obtained. The highest DD was obtained in the TiO2/ Fe0/H2O2/UVB process with 69.49%, while the lowest DD value was obtained in the TiO2/ Fe2+/UVC and TiO2/ Fe0/UVC processes with 15.25%. Results suggest that the amount of sludge was reduced between 19.2% and 34.6% by photocatalytic disintegration. As a result, it was concluded that the Photocatalysis process is a feasible and efficient process for disintegration of sludge.