Performance of Insoluble IrO2 Anode for Sewage Sludge Cake Electrodehydration Application with Respect to Operation Conditions

Abstract

The efficient management of wastewater and sewage sludge treatment are becoming crucial with industrialization and increasing anthropological effects. Dehydration of sewage sludge cakes (SSCs) is typically carried out using mechanical and electrochemical processes. Using the mechanical dehydration process, only a limited amount of water can be removed, and the resultant SSCs have a water content of approximately 70–80 wt.%, which is significantly high for land dumping or recycling as solid fuel. Dumping high-moisture-content SSCs in land can lead to leakage of hazardous wastewater into the ground and cause economic loss. Therefore, dehydration of SSCs is crucial. Contemporary treatment methods focus on the development of anode materials for the electrochemical processes. IrO2 is an insoluble anode material that is eco-friendly, less expensive, and exhibits high chemical stability, and it has been widely used and investigated in wastewater treatment and electrodehydration (ED) industries. Herein, we evaluated the performance of the ED system developed using IrO2 anode material. The operating conditions of the anode such as reaction time, sludge thickness, and voltage on SSC were optimized. The performance of the ED system was evaluated based on the moisture content of SSCs after dehydration. The moisture content decreased proportionally with the reaction time, sludge thickness, and voltage. The moisture content of 40 wt.% was determined as the optimum quantity for land dumping or to be used as recycled solid fuel.