Effects of the feeding ratio of food waste on fed-batch aerobic composting and its microbial community

• Published in: Bioresource technology Vol. 224; pp. 397 - 404
• Main Authors: Wang, Xiaojun, Pan, Songqing, Zhang, Zhaoji, Lin, Xiangyu, Zhang, Yuzhen, Chen, Shaohua
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2017
• Subjects: Actinobacteria; Aerobiosis; Bacteria - metabolism; Batch Cell Culture Techniques - methods; Bioreactors - microbiology; Cluster Analysis; Fed-batch aerobic composting; Feeding ratio; Food; Food waste; Humidity; Microbial community; Oils - analysis; Operating strategy; Phylogeny; Soil; Soil Microbiology; Temperature; Waste Products - analysis; Food waste; Operating strategy; Fed-batch aerobic composting; Microbial community; Feeding ratio
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2016.11.076

•Fed-batch composting was achieved with feeding ratios of 5% and 10% but not 15%.•The thermophilic conditions were obtained due to bacterial self-heating.•The compost failure at the 15% treatment was mainly ascribed to excessive moisture.•Firmicutes et al. were the dominant degraders in the food waste compost.•Temperature was the key environmental factor for community succession. To determine the suitable feeding ratio for fed-batch aerobic composting, four fermenters were operated by adding 0%, 5%, 10% or 15% of food waste every day. The results showed that the 5% and 10% treatments were able to maintain continuous thermophilic conditions, while the 15% treatment performed badly in regard to composting temperature, which was probably due to the negative effects of excessive moisture on microbial activity. As composting proceeded, both the 5% and the 10% treatments reached maturity and achieved weight losses of approximately 65%. High-throughput sequencing results indicated that Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria were the dominant phyla of the community structure. The communities sampled at the thermophilic phases had high similarity and relatively low diversity, while species diversity increased in the maturity phase. This study was devoted to optimizing the fed-batch composting process and assessing bacterial communities, both of which were supplied as a reference for practical application.