Development of a novel empirical model for optimization of sludge discharge in drinking water treatment clarifiers

Optimization of sludge discharge operation in sedimentation clarifiers is important for maintaining treatment efficiency and minimizing unnecessary water losses in drinking water treatment plants. The present study aimed to develop a novel practical operational model for estimating sludge valve opening duration based on hydraulic and sludge generation characteristics under full-scale operating conditions. Field investigations were conducted in seven surface water treatment plants in Sohag Governorate, Egypt, including P1, P2, P3, P4, P5, P6, and P7 coded treatment plants. The proposed methodology combined jar-test measurements, sludge sampling, and hydraulic measurements for determination of theoretical and actual sludge generation rates. The developed model was based on the relationship between hydraulic-operational parameters and sludge generation characteristics for calculation of sludge valve opening duration. Results indicated that the hydraulic-operational constant (C) remained relatively stable for most treatment plants and ranged from approximately 2.1 to 3.2 despite differences in plant dimensions and operating conditions. In contrast, the sludge generation ratio factor (F) showed greater variability, with values ranging from 0.009 to 0.032 under normal operating conditions. calculated valve opening duration ranged from 21 to 71 s for most investigated plants. The developed model demonstrated sensitivity to sludge discharge configuration and operating conditions and may provide a practical tool for improving sludge management efficiency and optimizing sludge discharge operation in drinking water treatment plants.