Using an Amylase Pretreatment of Pig Manure to Enhance Biogas Production

An experimental study was conducted that promoted the efficiency of anaerobic digestion by hydrolyzing pig manure in advance with amylase before loading it into the digester. A modified Gompertz equation was applied to determinate the kinetic parameters of biogas production. The results showed that the removal percentage of TS and VS, the biogas production potentials and rates have been improved through an amylase pre-treatment. Especially through a amylase and γ-amylase pretreatment together, the removal percentage of TS and VS, as compared with control group, was increased by 10.84% and 11.11% respectively, biogas production potential increased by 13.10%, and specific biogas production rate increased by 9.30%. Experimental results also indicate that the digestive process goes through four stages: lag stage, peak stage, sub-peak stage, and fade stage. Different stages which occurred in this experiment might reflect the characteristics of sequential bio degradation of different organic substrates from easy and simple to difficult and complex.