Fluid Dynamics Modeling of Rotating Drum Thickener Performance in Municipal Sludge Dewatering Operations

Abstract

Efficient sludge thickening is a critical component of municipal wastewater treatment operations, directly influencing sludge handling efficiency, energy consumption, and downstream dewatering performance. This study presents a fluid dynamics modeling approach for evaluating the performance of rotating drum thickeners used in municipal sludge dewatering operations. The proposed investigation integrates computational fluid dynamics (CFD) techniques with sludge transport and separation analysis to examine the hydraulic behavior, solids concentration distribution, and thickening efficiency within the rotating drum system. A three-dimensional numerical model was developed to simulate fluid flow characteristics, sludge settling behavior, drum rotational effects, and filtration performance under varying operational conditions. Key parameters, including feed flow rate, sludge concentration, drum rotational speed, screen permeability, and retention time, were analyzed to determine their influence on solids capture efficiency and dewatering performance. Simulation results demonstrated that optimized drum rotation and controlled hydraulic loading significantly improve sludge thickening efficiency and reduce solids loss during continuous operation. The study further revealed that flow recirculation zones and uneven sludge distribution adversely affect filtration performance and operational stability. Comparative analysis between conventional operating conditions and optimized configurations indicated enhanced solids concentration, improved hydraulic uniformity, and reduced energy requirements in the thickening process.