Pilot scale study was carried out to produce Volatile Fatty Acids with primary sludge from municipal wastewater treatment
plant. An acid fermenter was operated at pH 9, 35℃, SRT of 3.5-4.25d, using a final effluent as elutriating water(Mode-Ⅰ)
and pH 9, SRT 5d, temperature of 35℃(Mode-Ⅱ), 55℃(Mode-Ⅲ), using a primarily treated water as elutriating water.
Although solubilization rate was enhanced with the increase of temperature, the VFAs production rate was decreased. The
VS reduction was shown approximately 56%, and the sludge volume reduction was 93%. The optimal conditions for
solubilization was obtained at pH 9, 35℃ and SRT of 5d.