Optimization of the oil sludge collection process based on analysis of composition and sedimentation behavior

Treatment of industrial wastewater prior to discharge into the environment is essential due to the presence of toxic compounds, high organic load, and complex pollutants. This study investigates the characteristics of oily sludges and examines practical methods for their collection in the ponds of the Mahshahr refinery. Effluent samples were collected after the primary sedimentation stage, and their BOD and COD parameters were measured under environmental conditions of 22.6 °C temperature, 43.9% humidity, and 756 mm Hg pressure. The results indicated that wastewater treatment and waste management processes in refineries are fundamentally similar, allowing the use of a unified treatment approach for both. The application of sludge pumps proved effective in improving environmental cleanliness and operational efficiency. For sludge recovery, the thermal pyrolysis method was employed, which not only reduced sludge volume but also enabled the production of reusable liquid fuel and combustible gases. Overall, the findings suggest that the application of thermal technologies can serve as an efficient and sustainable approach for managing oily refinery sludges.