Advances in Mechanical Dewatering of Wastewater Sludge Treatment

Abstract

Dewatering of wastewater sludge is a difficult process. The difficulty has been attributed mainly to the fact that particles are very fine, colloidal in nature and possess a gel-like structure due to polymeric flocculation. In order to tackle the limitations in wastewater sludge dewatering, new technologies have been developed in recent years. Some technologies, such as wastewater sludge digestion, wastewater sludge mineralisation or peroxidation, allow to reduce the amount of wastewater sludge to be dewatered, or the dewaterability of the sludge, by changing the biochemical composition. Nevertheless, wastewater sludge remains hard to dewater, and therefore, an improvement in the conventional dewatering equipments is desirable. Therefore, current research tends to propose potential alternatives to enhance the dewatering ability of conventional processes, to increase the final dry solids content, and to accelerate the dewatering process with low energy consumption compared to thermal drying.