Effects of titanium dioxide mediated dairy waste activated sludge deflocculation on the efficiency of bacterial disintegration and cost of sludge management

摘要

This investigation explores the influence of titanium dioxide (TiO2) in deflocculating (removal of extracellular polymeric substance - EPS) the sludge and subsequent biomass disintegration by bacterial pretreatment. The EPS removed at an optimized TiO2 dosage of 0.03 g/g of SS of TiO2 and a solar radiation exposure time of 15 min to enhance the subsequent bacterial disintegration. The outcomes of the bacterial pretreatment reveal SS reduction and COD solubilization for the deflocculated (EPS removed and bacterially pretreated) sludge was observed to be 22.8% and 22.9% which was comparatively greater than flocculated (raw sludge inoculated with bacteria) and control (raw) sludge. The higher methane production potential of about 0.43 (gCOD/gVSS) was obtained in deflocculated sludge than the flocculated (0.20 gCOD/gVSS) and control (0.073 gCOD/gVSS). Economic assessment of this study provides a net profit of about 131.9 USD/Ton in deflocculated sludge. (C) 2015 Elsevier Ltd. All rights reserved.