Comparison of Municipal and Coke Wastewater Sludges in Disintegration and Acidogenesis by Microwave

Abstract

This work experimentally determined the effect of microwave treatment on the disintegration and acidogenesis of waste-activated sludges (WAS) from municipal and coke wastewater treatment plants. Sludge samples (500 g) were heated for 0, 3, 5, 7, 9, 11, and 15 min in a microwave oven (2,450 MHz, 700 W). The degree of sludge solubilization [soluble chemical oxygen demand (SCOD)/COD] increased asymptotically with microwave irradiation time from 1.5% at 0 min to 22.3% at 15 min for WAS from a municipal wastewater treatment plant (WAS(M)) and 1.5% to 5.1% for WAS from a coke wastewater treatment plant of a steel manufacturing industry (WAS(C)). The calcium concentrations in both sludges also increased with microwave irradiation time. The biochemical acidogenic potentials (BAP) increased from 3.70 to 4: 44 gCODL(-1) for WAS(M) and 1.19 to 1.67 gCODL(-1) for WAS(C). The results show that microwave irradiation increases the solubilization and BAP of sludges and that WAS(M) had a higher degree of solubilization and BAP than WAS(C). DOI: 10.1061/(ASCE)EE.1943-7870.0000379. (C) 2011 American Society of Civil Engineers.