Optimization of Thickening and Dewatering for Operator Series--Fact Sheet #6: Optimization of Thickening Equipment

Thickening is a valuable step in the wastewater treatment process, designed to increase the solids content of sludge by removing excess liquid. Unlike dewatering, which aims to produce the driest cake possible, thickening enhances sludge consistency for better handling and downstream processing. Proper optimization of thickeners reduces sludge volume, improves process efficiency, and lowers operational costs, supporting consistent and efficient daily operations. This optimization also aids in maintaining compliance with environmental regulations and contributes to environmental sustainability.

Utilities commonly use thickening centrifuges, gravity thickeners, gravity belt thickeners (GBTs), and rotary drum thickeners (RDTs) for sludge thickening (see photos of thickening devices in Figure 1). This Fact Sheet serves as an educational resource for operators, detailing the operating principles and benefits of these devices. By understanding how each type of thickener device functions, operators can maximize solids capture, optimize polymer usage, improve facility performance, and maintain a safe working environment.

For additional technical details, formulas, and case studies addressing typical performance and other pertinent information, please refer to the References and Additional Resources sections at the end of this document.