Coagulation-assisted ultrasonic refinement of bilge water treatment sludge

Abstract

Current treatment methods often fail to meet stringent landfill acceptance criteria for real bilge water sludge, necessitating novel, scalable solutions. Managing bilge water sludge remains a significant concern for port reception facilities, primarily due to its elevated levels of organic pollutants and dissolved salts. Many conventional treatment techniques struggle to meet the stringent requirements of Class 1 landfill acceptance, particularly in parameters such as dissolved organic carbon (DOC), total dissolved solids (TDS), and chloride. Unlike most earlier studies that relied on synthetic waste samples and small-scale laboratory setups, this research directly used real bilge water sludge collected from an operating port reception facility. As a result, the findings carry immediate practical relevance, showing a scalable treatment strategy that can be seamlessly adapted to real-world industrial conditions. To address this, the present work examines a combined method involving ultrasonic pre-treatment followed by coagulation using potassium methoxide. The integrated process achieved a DOC reduction of up to 39.12%, while also successfully lowering TDS and chloride to within Class 1 limits. The use of ultrasonic energy enhanced coagulation efficiency, which may help reduce both sludge volume and overall disposal demands. A preliminary economic evaluation suggests that this technique could cut annual sludge management costs by 10-15%, potentially saving around 22,500 USD per year. Thanks to its modular design, the proposed reactor setup shows strong potential for upscaling to real-world operations, offering a practical and environmentally sound solution for managing port sludge.