Xu J.,Shanghai JiaoTong University |
Yuan H.,Shanghai JiaoTong University |
Lin J.,Shanghai JiaoTong University |
Yuan W.,Shanghai Institute for Design and Research on Environmental Engineering Co.
Journal of the Taiwan Institute of Chemical Engineers | Year: 2014
Anaerobic digestion was regarded as one of the ways to recover energy from waste activated sludge in this study. After applying thermal-, thermal-alkaline-, electrochemical- and alkaline-pretreatments to waste activated sludge to promote the digestion efficiency, biogas yield and volatile solid (VS) removal were investigated to evaluate the effectiveness of the pretreatments for the purpose. The highest biogas production (647. L/kg VS) was achieved after pretreatment by electrochemical method. The highest daily biogas production rate was obtained through alkaline pretreatment. Biogas production has no positive relationship with the solubilization degree of sludge. The highest VS removal rate could be got by the pretreatment of thermo-alkaline and electrochemical methods, and the sludge achieved the stabilization after the shortest digestion time with the treatment of electrochemical. © 2014 Taiwan Institute of Chemical Engineers.
Li Y.,Tongji University |
Zhou T.,Tongji University |
Chen S.-P.,Shanghai Institute for Design and Research on Environmental Engineering Co. |
Zhang J.,Tongji University |
And 2 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2016
This study carried out batch experiments to explore the effects of temperature at 25, 35, 45, 55℃ on acetic acid and volatile fatty acids production from food wastes with yeast and acetic acid bacteria as inoculums during micro-aerobic fermentation. The results showed that the concentration of acetic acid fermentation is the maximum of 0.59 g/L at 25℃ after eight days' fermentation, much higher than those at 35, 45 and 55℃, with the highest concentration of VFA up to 34.49 g/L at 25℃. VFA thus produced contains acetic acid mostly, with a few amount of propionate and butyrate. The optimum temperature on acetic acid production of food wastes inoculated yeast and acetic acid bacteria during micro-aerobic fermentation is 25℃. With the temperature gradually increased, TS and VS removal rate increased at first and then decreased. At 35℃, TS and VS removal rate of fermentation substrates is the highest, about 30% and 60%, respectively. © 2016, Chinese Society for Environmental Sciences. All right reserved.