Improving methane production and anaerobic digestion stability of food waste by extracting lipids and mixing it with sewage sludge

Dalal E Algapani; Jing Wang; Wei Qiao; Min Su; Andrea Goglio; Simon M Wandera; Mengmeng Jiang; Xiang Pan; Fabrizio Adani; Renjie Dong

doi:10.1016/j.biortech.2017.08.087

Improving methane production and anaerobic digestion stability of food waste by extracting lipids and mixing it with sewage sludge

Bioresour Technol. 2017 Nov;244(Pt 1):996-1005. doi: 10.1016/j.biortech.2017.08.087. Epub 2017 Aug 18.

Authors

Affiliations

¹ Biomass Engineering Center, College of Engineering, China Agricultural University, Beijing 100083, China.
² Biomass Engineering Center, College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee (BGFuels), Beijing 100083, China. Electronic address: qiaowei@cau.edu.cn.
³ Gruppo Ricicla - DiSAA - University of Milan, via Celoria 2, 20133 Milano, Italy.
⁴ Biomass Engineering Center, College of Engineering, China Agricultural University, Beijing 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee (BGFuels), Beijing 100083, China.

PMID: 28847110
DOI: 10.1016/j.biortech.2017.08.087

Abstract

Anaerobic digestion (AD) of FW shows instability due to both the presence of high lipids and accumulation of volatile fatty acids. In this study, AD of food waste (FW) was optimized by removing lipids (LRFW) and by co-digestion with sewage sludge (1:1w/w on dry matter). The results obtained showed that lipids extraction increased FW methane yield from 400 to 418mL-gVS_added^-1 under mesophilic conditions (35°C) and from 426 to 531mL-gVS_added^-1 in thermophilic conditions (55°C). Two degradation phases (k₁ and k₂) described FW and LRFW degradation. In the thermophilic, LRFW-k₁ (0.1591d^-1) was slightly higher than that of FW (k₁ of 0.1543d^-1) and in the second stage FW-k₂ of 0.0552d^-1 was higher than that of LRFW (k₂ of 0.0117d^-1). The majority of LRFW was degraded in the first stage. FW and sewage sludge co-digestion reduced VFA accumulation, preventing media acidification and improving process stability.

Keywords: Anaerobic digestion; Co-digestion; Food waste; Kinetic modeling; Lipid extraction.

MeSH terms

Anaerobiosis
Bioreactors*
Lipids*
Methane
Sewage

Substances

Lipids
Sewage
Methane