Selection of Sludge Conditioning Chemicals and Filter Media for Vacuum Filter Dewatering of Sludge at the Atlantic Wastewater Treatment Plant

A literature review was conducted to determine the types of vacuum filter systems available for sludge dewatering, the characteristics of wastewater sludge which are important to dewatering, and the methods of sludge conditioning for vacuum filtration which are available. Capillary suction time and Buchner funnel tests were performed to determine the dewatering characteristics of sludge conditioned with ferric chloride and lime, polymer, polymer and lime, and polymer and incinerator ash. Filter leaf tests were performed to determine filter cake release characteristics of various conditioned sludge and the performance characteristics of several filter media. It was determined that ferric chloride and lime should be used to condition sludge for vacuum filtration and that a polypropylene filter cloth with a 40 to 100 cubic foot per minute porosity should be used for the filter media