title: Anaerobic co-digestion of kitchen waste and pig manure with different mixing ratios.
abstract: Anaerobic co-digestion of kitchen waste (KW) and pig manure (PM) with seven different PM to KW total solids (TS) ratios of 1:0, 5:1, 3:1, 1:1, 1:3, 1:5 and 0:1 was conducted at mesophilic temperature (35 ± 1 °C) to investigate the feasibility and process performance. The co-digestion of PM and KW was found to be an available way to enhance methane production compared with solo-digestion of PM or KW. The ratio of PM to KW of 1:1 got the highest biodegradability (BDA) of 85.03% and a methane yield of 409.5 mL/gVS. For the co-digestion of KW and PM, there was no obvious inhibition of ammonia nitrogen because it was in an acceptable range from 1380 mg/L to 2020 mg/L in the whole process. However, severe methane inhibition and long lag phase due to the accumulation of volatile fatty acids (VFAs) was observed while the KW content was over 50%, and in the lag phase, propionic acid and butyric acid made up the major constituents of the total VFAs. The technical digestion time (T80: the time it takes to produce 80% of the digester's maximum gas production) of the above 7 ratios was 15, 21, 22, 27, 49, 62 and 61 days, respectively. In this study, a mixing ratio of 1:1 for PM and KW was found to maximize BDA and methane yield, provided a short digestion time and stable digestion performance and was therefore recommended for further study and engineering application.
authors.affiliation: College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Hailin
authors.initials: H
authors.lastname: Tian
authors.affiliation: College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China. Electronic address: duanna@cau.edu.cn.
authors.forename: Na
authors.initials: N
authors.lastname: Duan
authors.affiliation: College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Lin
authors.affiliation: College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Mingzhu
authors.initials: M
authors.lastname: Zhong
mesh_terms: D000693:Anaerobiosis; D000818:Animals; D001673:Biodegradation, Environmental; D020148:Butyric Acid / Q000378:metabolism; D003296:Cooking; D005232:Fatty Acids, Volatile / Q000737:chemistry / Q000378:metabolism; D008372:Manure; D008697:Methane / Q000378:metabolism; D011422:Propionates / Q000378:metabolism; D034421:Sus scrofa; D013997:Time Factors; D014866:Waste Products
chemical_list: D005232:Fatty Acids, Volatile; D008372:Manure; D011422:Propionates; D014866:Waste Products; D020148:Butyric Acid; C029658:propionic acid; D008697:Methane
keywords: Anaerobic digestion; Co-digestion; Different ratios; Kitchen waste; Pig manure