Lipid profiling in sewage sludge.
High value-added reutilization of sewage sludge from wastewater treatment plants (WWTPs) is essential in sustainable development in WWTPs. However, despite the advantage of high value reutilization, this process must be based on a detailed study of organics in sludge. We used the methods employed in life sciences to determine the profile of lipids (cellular lipids, free fatty acids (FFAs), and wax/gum) in five sludge samples obtained from three typical WWTPs in Beijing; these samples include one sludge sample from a primary sedimentation tank, two activated sludge samples from two Anaerobic-Anoxic-Oxic (A2/O) tanks, and two activated sludge samples from two membrane bioreactor tanks. The percentage of total raw lipids varied from 2.90% to 12.3%. Sludge from the primary sedimentation tank showed the highest concentrations of lipid, FFA, and wax/gum and the second highest concentration of cellular lipids. All activated sludge contained an abundance of cellular lipids (>54%). Cells in sludge can from plants, animals, microbes and so on in wastewater. Approximately 14 species of cellular lipids were identified, including considerable high value-potential ceramide (9567-38774 mg/kg), coenzyme (937-3897 mg/kg), and some phosphatidylcholine (75-548 mg/kg). The presence of those lipid constituents would thus require a wider range of recovery methods for sludge. Both cellular lipids and FFAs contain an abundance of C16-C18 lipids at high saturation level, and they serve as good resources for biodiesel production.
School of Environment and Natural Resources, Renmin University of China, 100872 Beijing, China. Electronic address: zhufenfen@ruc.edu.cn.
Fenfen
F
Zhu
School of Environment and Natural Resources, Renmin University of China, 100872 Beijing, China.
Xuemin
X
Wu
Shougang Institute of Technology, 100043 Beijing, China.
Luyao
L
Zhao
School of Life Sciences, Tsinghua University, 100084 Beijing, China.
Xiaohui
X
Liu
Development and Reform Commission of Bomi County in Linzhi Area, 860300, China.
Juanjuan
J
Qi
School of Life Sciences, Tsinghua University, 100084 Beijing, China.
Xueying
X
Wang
Research Center, Beijing Drainage Group, 100124 Beijing, China.
Jiawei
J
Wang
D056804:Biofuels; D019149:Bioreactors; D008055:Lipids; D012722:Sewage; D014865:Waste Disposal, Fluid; D062065:Wastewater
D056804:Biofuels; D008055:Lipids; D012722:Sewage; D062065:Wastewater
Biodiesel; Cellular lipids; Free fatty acid; Lipid profile; Sewage sludge; Wastewater treatment