Utilization of Electrohydrodynamic Cavitation in Primary Sludge Conditioning

This paper presents a brief characterization of the method of electrochemical conditioning of sludge, using the effect of low-temperature plasma. Primary sludge from the municipal wastewater treatment plant in Gorzów was analysed. The sludge was conditioned electrochemically, chemically with calcium hydroxide and dihydrogen dioxide, and using a combined method – electrochemical and chemical. For each conditioned sludge its settlement characteristics, hydration, dry mass content, organic and mineral substances, calculated and measured specific filtration resistance, effectiveness of filtration, iron content in ash, as well as energy-consumption in the process were determined. For the electrochemical, chemical and combined processes of primary sludge conditioning, their courses were compared. It was proved that (1) processes of conditioning cause changes in properties of primary sludge; (2) electrochemical conditioning causes mineralization and stabilization; (3) dewaterability of sludge is improved; (4) the process can be supported using additionally calcium hydroxide and dihydrogen dioxide; (5) optimization of the process can be performed only by improving the effectiveness of selected process parameters.