Thickening of Biological Sludge by Electro-Coagulation-Flotation Process

• Published in: International journal of electrochemical science Vol. 10; no. 5; pp. 3746 - 3756
• Main Authors: Yazdanbakhsh, Ahmad Reza, Kashefiasl, Morteza, Zareh, Hosein, Agaiani, Ehsan, Sardar, Mahdieh, Sheikhmohammadi, Amir
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2015
• Subjects: Biological sludge; COD; Electro-Coagulation-Flotation process; Suspended solids concentration; Turbidity; Suspended solids concentration; COD; Electro-Coagulation-Flotation process; Biological sludge; Turbidity
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/S1452-3981(23)06576-8

The present study is to investigate the thickening of hospital wastewater biological sludge by the Electro-Coagulation-Flotation (ECF) process. The electrochemical thickening of biological sludge has been studied by batch electrolysis experiments under different conditions. The various parameters like effect of pH (2-11), current density (0.5-3 mA cm-2), and reaction time (2 to 60 min) on increase of sludge suspended solids concentration and also the removal efficiencies of Chemical Oxygen Demand (COD) and turbidity from the biological sludge were studied. The results indicated that the maximum COD and turbidity removals were achieved in acidic pH level and electrolysis time of 30 minutes. With increasing current density from 0.5 to 3 mA cm-2 at the optimum conditions of operation, the removal efficiencies of COD and turbidity reached from 65.1 to 75.6% and 56 to 96.4% respectively during the ECF. In addition, in the above-mentioned conditions, suspended solids concentration increased to 2.1 percent. Mean energy consumption and current efficiency were figured at about 0.03 kWh m-3 and 200%, respectively.