title: Optimization of methane production in anaerobic co-digestion of poultry litter and wheat straw at different percentages of total solid and volatile solid using a developed response surface model.
abstract: Poultry litter (PL) can be good feedstock for biogas production using anaerobic digestion. In this study, methane production from batch co-digestion of PL and wheat straw (WS) was investigated for two factors, i.e., total solid (2%, 5%, and 10%) and volatile solid (0, 25, and 50% of WS), constituting a 3 × 3 experimental design. The results showed that the maximum specific methane volume [197 mL (g VS)(‑1)] was achieved at 50% VS from WS at 5% TS level. It was estimated that the inhibitory threshold of free ammonia was about 289 mg L(--1), beyond which reduction of methanogenic activity by at least 54% was observed. The specific methane volume and COD removal can be expressed using two response surface models (R(2) = 0.9570 and 0.9704, respectively). Analysis of variance of the experimental results indicated that the C/N ratio was the most significant factor influencing the specific methane volume and COD removal in the co-digestion of these two materials.
authors.affiliation: a Biological and Agricultural Engineering, University of Arkansas , Fayetteville , Arkansas , USA.
authors.forename: Jiacheng
authors.initials: J
authors.lastname: Shen
authors.affiliation: a Biological and Agricultural Engineering, University of Arkansas , Fayetteville , Arkansas , USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000641:Ammonia; D000693:Anaerobiosis; D000818:Animals; D001131:Arkansas; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D056804:Biofuels / Q000382:microbiology*; D004063:Digestion; D005285:Fermentation; D008372:Manure / Q000382:microbiology*; D008697:Methane / Q000096:biosynthesis*; D018547:Plant Stems / Q000737:chemistry*; D011200:Poultry; D012037:Refuse Disposal / Q000379:methods*; D014908:Triticum / Q000737:chemistry*
chemical_list: D056804:Biofuels; D008372:Manure; D000641:Ammonia; D008697:Methane
keywords: Ammonia inhibition; anaerobic co-digestion; methane; poultry litter; response surface model; wheat straw.