Investigation of sludge dewatering efficiency in the thermal-hydrolysis reactor at various physical operational factors: Performance and fluid dynamic analysis

The sludge produced from various wastewater treatment is waste with various contaminants concentrated. A few decades ago, the sludge was contolled through direct discharge to the water phase, but further treatment is required due to additional environmental pollution issues. However, there are various available carbon-based resources in the sludge. The thermal hydrolysis process can reduce the discharged sludge quantity by improving the dewatering ability. The purpose of this study is to investigate the effect of the physical change factors of the thermal hydrolysis reactor (sludge amount, slope degree, stirring speed and residual oxygen quantity) on the dewatering capacity and solubilization of the thermal hydrolysis process. The highest dewatering capacity and efficiency showed when 7 kg of sludge was injected and slope control mode. The stir speed showed the best results at 150 rpm, but the increase in efficiency slowly up from 100 rpm. In addition, through CFD analysis, the high efficiency reactor slope was optimized. By investigating the performance of the thermal hydrolysis process under various physical conditions and the physical and chemical changes of final products, it is expected that it will be possible to suggest a way to vary the utilization according to the various characteristics of the sludge. Since the optimization of physical changes does not require additional economic cost input, it has the potential to secure the economic feasibility of sludge reduction technology.(C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

This study investigates the effect of physical change factors in a thermal hydrolysis reactor on the dewatering capacity and solubilization, aiming to reduce the sludge quantity produced from wastewater treatment. By adjusting factors such as sludge amount, slope degree, stirring speed, and residual oxygen quantity, the study identifies optimal conditions for achieving the highest dewatering capacity and efficiency. The findings provide insights into utilizing sludge based on its characteristics.