title: Hydrolysis and acidification of agricultural waste in a non-airtight system: Effect of solid content, temperature, and mixing mode.
abstract: A two-phase digestion system for treating agricultural waste is beneficial for methane production. This study explored the effect of solid content, temperature, and mixing mode on the process of hydrolysis and acidification using rice straw and cow dung launched in non-airtight acidogenic system. The results showed that the substrate could be hydrolyzed efficiently in the initial stage, the hydrolysis coefficient (k) of maximum cellulose and hemicellulose can be increased by 217.9% and 290.5%, respectively, compared with those of middle and last stages. High solid content played a leading role in promoting hydrolysis, resulted in hydrolysate content (sCOD) that was significantly higher than in treatments with low solid content (P<0.01), and led to organic acids accumulation up to 5.8 and 6.7g/L at mesophilic and thermophilic temperatures. Thermophilic temperature stimulated the hydrolysis and acidification of low solid content (P<0.05), and improved organic acid accumulation of high solid content only during the middle stage (P<0.01). Mixing mode was not a major factor, but increasing the mixing time was necessary for organic acid accumulation during the last stage (P<0.05). In addition, the study comprehensively analyzed a series of corresponding relationships among each operating parameter during the whole treatment process using canonical correspondence analysis.
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors: Jiadong
authors: J
authors: Yu
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors: Yubin
authors: Y
authors: Zhao
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors: Huan
authors: H
authors: Zhang
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors: Binbin
authors: B
authors: Hua
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors: Xufeng
authors: X
authors: Yuan
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors: Wanbin
authors: W
authors: Zhu
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
authors: Xiaofen
authors: X
authors: Wang
authors: Center of Biomass Engineering/College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China. Electronic address: acuizj@cau.edu.cn.
authors: Zongjun
authors: Z
authors: Cui
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008031:Lignin / Q000737:chemistry; D016014:Linear Models; D008372:Manure; D008697:Methane / Q000737:chemistry*; D012275:Oryza; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D013696:Temperature
chemical_list: D008372:Manure; D012722:Sewage; C036909:lignocellulose; D008031:Lignin; D008697:Methane
keywords: Acidification; Hydrolysis; Lignocellulosic substrate; Mixing mode; Solid content; Temperature