Influence of Filter Cell Configuration and Process Parameters on the Electro-Osmotic Dewatering of Sewage Sludge

Abstract

This article shows a laboratory parametric study carried out for optimizing the electro-dewatering (EOD) of agro-industrial sludge. The sludge dry matter reached 40% w/w after 3 hours of EOD with current density of 80 A/m², against 20% w/w after 11 hours of mechanical compression. The electricity consumption was 0.27 kWh/kg of water removed. Another advantage of EOD lies on the depolluting effect observed. The chemical oxygen demand of sludge was decreased by 64% probably due to oxidization reactions at anode. 97% of sodium and 63% of iron contained in sludge were also transferred to the filtrate during the treatment.

Keywords:

• agro-industrial sludge
• electroosmotic dewatering
• filter-press
• mechanical dewatering

ACKNOWLEDGEMENTS

The authors gratefully acknowledge the financial support received for this research from the Agence Nationale de la Recherche (ANR-08-ECOT-018-004).