Thickening and Dewatering

The wastewater treatment process is generally separated into the “liquid” train and the “solids” train. Solids that are allowed to settle in primary and secondary clarifiers are conveyed to solids processing systems. These systems separate water from solids and increase the concentration of solids for subsequent stabilization or hauling offsite. Facilities may also provide some type of stabilization of the solids to reduce pathogens and vector attraction potential when the solids are intended for beneficial use. Solids management represents a critical part of the overall treatment process. While stabilization processes are discussed in other WEF documents, this fact sheet provides a basic overview of solids thickening and dewatering