Comparison of biodiesel production from sewage sludge obtained from the A2/O and MBR processes by in situ transesterification. (March 2016)

• Record Type: Journal Article
• Authors: Qi, Juanjuan; Zhu, Fenfen; Wei, Xiang; Zhao, Luyao; Xiong, Yiqun; Wu, Xuemin; Yan, Fawei
• Is Part Of: Waste management. Volume 49(2016)
• Page Start: 212
• Page End: 220
• Publication Date: 2016-03
• Subjects: Biodiesel -- Sewage sludge -- In situ transesterification; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2016.01.029
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: The yield of biodiesel from A 2 /O sludge was higher than that from MBR sludge. Temperature is the most important factor on the biodiesel yield from A 2 /O sludge. Methanol-to-sludge ratio is the most important factor on the biodiesel yield from MBR sludge. In this research, A 2 /O sludge is a better resource for biodiesel production. FAMEs from MBR sludge have more unsaturated fatty acids. Abstract: The potential of two types of sludge obtained from the anaerobic–anoxic–oxic (A 2 /O) and membrane bioreactor (MBR) processes as lipid feedstock for biodiesel production via in situ transesterification was investigated. Experiments were conducted to determine the optimum conditions for biodiesel yield using three-factor and four-level orthogonal and single-factor tests. Several factors, namely, methanol-to-sludge mass ratio, acid concentration, and temperature, were examined. The optimum yield of biodiesel (16.6% with a fatty acid methyl ester purity of 96.7%) from A 2 /O sludge was obtained at a methanol-to-sludge mass ratio of 10:1, a temperature of 60 °C, and a H2 SO4 concentration of 5% (v/v). Meanwhile, the optimum yield of biodiesel (4.2% with a fatty acid methyl ester purity of 92.7%) from MBR sludge was obtained at a methanol-to-sludge mass ratio of 8:1, a temperature of 50 °C, and a H2 SO4 concentration of 5% (v/v). In this research, A 2 /O technology with a primary sedimentation tank is more favorable for obtaining energy from wastewater than MBR technology.