title: Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure.
abstract: In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37±1 °C) anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9-70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others.
authors.affiliation: Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640 , China; School of Environmental Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Jingqing
authors.initials: J
authors.lastname: Ye
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Yongming
authors.initials: Y
authors.lastname: Sun
authors.forename: Guohui
authors.initials: G
authors.lastname: Wang
authors.forename: Zhenhong
authors.initials: Z
authors.lastname: Yuan
authors.forename: Feng
authors.initials: F
authors.lastname: Zhen
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D056804:Biofuels; D005232:Fatty Acids, Volatile / Q000032:analysis; D005240:Feasibility Studies; D005735:Garbage; D006863:Hydrogen-Ion Concentration; D008372:Manure; D012275:Oryza; D013552:Swine
chemical_list: D056804:Biofuels; D005232:Fatty Acids, Volatile; D008372:Manure
keywords: Biogas; Co-digestion; Kitchen waste; Pig manure; Rice straw