The viscoelastic characterisation of thermally-treated waste activated sludge

It was also found that the effect of short-time thermal treatment at high temperature on viscoelastic properties of sludge is similar to the effect of long-time thermal treatment at low temperature. This indicates that the amount of supplied thermal energy was the key controlling parameter of the evolution of rheological properties and the degree of organic matter solubilisation. A linear proportionality was also established between a dimensionless form of the released soluble COD and a dimensionless form of both G′ and G″. This suggests a possibility of controlling thermal treatment processes via rheological measurements.