P13-08 : Effect of Different Pretreatment Methods to Remove Extracellular Polymeric Substances for Enhanced Methane Production from Waste Activated Sludge

MOHD YASIN Nazlina Haiza¹,NGUYEN Minh Tuan¹,Maeda Toshinari¹
1Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology
Extracellular polymeric substances (EPS) are a complex high molecular weight polymer produced by microorganisms and the matrix is abundant in waste activated sludge (WAS). EPS plays an important role for sludge flocculation and integration. However, roles of EPS in WAS on methane production are still unclear. In this study, we investigated the effect of removing EPS in WAS by different pretreatment methods such as EDTA treatment, autoclave, and sonication to see if it influences methane production. Anaerobic digestion was carried out at 37 ºC using EPS-free treated sludge and untreated sludge (control). The results obtained showed that 2% EDTA treatment was able to extract 300 mg / g dry weight of EPS compared to autoclave (100 mg / g dry weight) and sonication (50 mg / g dry weight) Moreover, EPS removal by 2% EDTA influences sludge hydrolysis resulted in 2 fold higher methane production and sludge reduction In conclusion, EPS removal from WAS by 2% EDTA enhanced the dispersion and hydrolysis of WAS; thereby, showed higher methane production.

keywords:,,,,