Thermophilic Solid-State Anaerobic Digestion of Corn Straw, Cattle Manure, and Vegetable Waste: Effect of Temperature, Total Solid Content, and C/N Ratio

• Published in: Archaea (Vancouver) Vol. 2020; no. 2020; pp. 1 - 10
• Main Authors: Zhang, Longjiang, Zhen, Guangyin, Ji, Rongting, Liu, Chenwei, Sun, Xu, Su, Lianghu, Chen, Mei
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 2020; Hindawi; Hindawi Limited; Wiley
• Subjects: Advertising executives; Agricultural pollution; Agricultural wastes; Alternative energy sources; Anaerobic digestion; Anaerobic treatment; Anaerobiosis - physiology; Analysis; Animal wastes; Animals; Bacteria - growth & development; Bacteroidetes; Biofuels - microbiology; Biogas; Biomass; Biomass energy; Bioreactors - microbiology; Carbon - chemistry; Carbon/nitrogen ratio; Cattle; Cellulose; Community structure; Corn; Crop residues; Design of experiments; Digestion; Effluents; Experimental design; Farmyard manure; Firmicutes; High temperature; Lignocellulose; Manure - microbiology; Manures; Mathematical models; Metabolism; Microbiota - physiology; Microorganisms; Moisture content; Next-generation sequencing; Nitrogen - chemistry; Optimization; Parameters; Process parameters; Raw materials; Relative abundance; Response surface methodology; Solid state; Straw; Temperature; Temperature effects; Vegetables; Vegetables - chemistry; Water quality; Zea mays - chemistry; China; Germany
• ISSN: 1472-3646; 1472-3654
• DOI: 10.1155/2020/8841490

Thermophilic solid-state anaerobic digestion (SS-AD) of agricultural wastes, i.e., corn straw, cattle manure, and vegetable waste, was carried out in this study. The effects of temperature (40-60°C), initial solid content (ISC, 17.5-32.5%), and C/N ratio (15-32 : 1) on biogas production were evaluated using a Box-Behnken experimental design (BBD) combined with response surface methodology (RSM). The results showed that optimization of process parameters is important to promote the SS-AD performance. All the factors, including interactive terms (except the ISC), were significant in the quadratic model for biogas production with SS-AD. Among the three operation parameters, the C/N ratio had the largest effect on biogas production, followed by temperature, and a maximum biogas yield of 241.4 mL gVS-1 could be achieved at 47.3°C, ISC=24.81%, and C/N=22.35. After 20 d of SS-AD, the microbial community structure under different conditions was characterized by high-throughput sequencing, showing that Firmicutes, Bacteroidetes, Chloroflexi, Synergistetes, and Proteobacteria dominated the bacterial community, and that Firmicutes had a competitive advantage over Bacteroidetes at elevated temperatures. The biogas production values and relative abundance of OPB54 and Bacteroidia after 20 d of SS-AD can be fitted well using a quadratic model, implying that OPB54 and Bacteroidia play important roles in the methanogenic metabolism for agricultural waste thermophilic SS-AD.