【Paper】
Characteristics of Mesophilic Methane Fermentation of High-Solid Content Cow Manure
Kuninobu Sakurai*, Yu-You Li* and Tatsuya Noike*
* Tohoku University Graduate School of Engineering
† Correspondence should be addressed to Yu-You Li:
（06 Azaaoba, Aramaki, Aoba-ku, Senndai-shi, Miyagi, 980-8579 Japan）

Abstract
Characteristics of mesophilic methane fermentation of cow manure were investigated using a completely-mixed reactor. The experiment was conducted at a temperature of 35℃ and a constant influent TS level of 10％ at hydraulic retention times（HRT）from 7.5 days to 30 days. The substrate was fed 2 to 8 times a day using a timer-controlled pump. The removal efficiencies of total CODCr were in the range of 25-45％, and 1 kg of influent TS produced 0.18-0.32m3 of digestion gas and 0.11-0.20m3 of methane gas. The first-order reaction was found suitable for describing the degradation rate of the organic matter in terms of VS, COD and carbohydrates.

Key words: anaerobic digestion, methane fermentation, high-solid content cow manure, mesophilic, kinetics