Effects of Heat Treatment and Hydrogen Peroxide (H2O2) on the Physicochemical and Rheological Behavior of an Activated Sludge from a Water Purification Plant

In this work we describe the effects of heat treatment and of the addition of hydrogen peroxide on the physicochemical and rheological behavior of activated sludge produced in a water purification plant. An increase in temperature and dosing with H2O2 both induce a reduction in Chemical Oxygen Demand (COD) of the sludge. At the same time they cause a reduction in the ratio between volatile matter in suspension and total suspended matter (VM/SM). To describe the rheological behavior of the sludge, the Bingham model was used for modeling the viscoelastic behavior of the sludge. The non-Newtonian parameters of the Bingham model decreased with increasing temperature, and at the same time the apparent viscosity of the sludge decreased according to an exponential law.