Multi-angle evaluation of the anaerobic digestion of Molasses vinasse using two different feeding patterns
Xinqiang Chen, Huipeng Mao, Yunwei Cui, Yanbo Jiang, Jiantao Liu, Xianghon Zha, Luodong Huang, Peihong Shen
Abstract
Molasses vinasse (MV) is a waste burden in alcohol production due to its high organic matter content. However, it represents a potential source of energy recovery if adequately treated. In this study, two feeding patterns (pulse feeding: 8 L/4 h and semi-continuous feeding: 8 L/23 h) were evaluated for their effects on MV anaerobic digestion from multiple perspectives in a laboratory-scale reactor. The results demonstrated that semi-continuous feeding not only achieved a higher soluble chemical oxygen demand (sCOD) removal rate of 78.48% but also increased the production of biogas and methane by 20.04% and 51.48%, respectively. In addition, the chemical composition analysis suggested that the semi-continuous feeding pattern degraded the majority of lignin/CRAM and aromatic substances more effectively than the pulse feeding pattern. Moreover, the microbial analysis revealed that semi-continuous feeding increased the number of dominant bacteria, including Chloroflexi, Synergistetes, and Cloacimonetea, and methanogenic archaea, including Methanosaeta and Methanosarcina. The findings of this study, therefore, confirm that the semi-continuous feeding model is more effective and has good application potential, laying the groundwork for the MV anaerobic industrial processes.