Sewage sludge disintegration by electrocoagulation

Abstract

In this research, reduction of sludge production and improvement of sludge stabilization degree were aimed, and in this regard, the samples received from an urban wastewater treatment plant were subjected to electrocoagulation (EC) as a disintegration technique. A monopolar EC reactor was designed and iron electrode was used for sludge disintegration. The effect of reaction time, pH and varying current densities on disintegration degree (DD) was determined, and the optimum conditions were found as pH 7, 30 min (reaction time), and 150 A/m2 (current density). DD was found as 84.23%, and soluble chemical oxygen demand was found as 675.2 mg/L under optimum conditions. In this research, the disintegration stage of sludge was defined with the best second-order kinetic model. The operating cost was estimated as 0.078 €/m3 for optimum conditions. Also, the EC-induced disintegration ability of sludge was determined using total suspended solids, total organic carbon, capillary suction time, particle size distribution, specific surface area and viscosity. The findings showed that EC technique can be an effective means for sludge disintegration. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.