Seasonal Variation in the Physicochemical Characteristics and Biochemical Methane Potential of Cattle Manure

Abstract

The livestock industry produces large volumes of cattle manure, which can be used as an organic fertilizer after composting and renewable energy after anaerobic digestion. In the anaerobic digestion process, cattle manure is usually stored in a cowshed until it is transferred to treatment facilities, and its physicochemical characteristics vary depending on this storage environment. Any change in these characteristics acts as a source of instability in the operation of an anaerobic digester. This study investigated the physicochemical characteristics and biochemical methane potential of cattle manure between seasons. The total solid content of Hanwoo (Korean beef) cattle manure and dairy cattle manure was 29.1 ~ 33.8 and 21.1 ~ 29.5% (by wet wt.), respectively, while the biochemical methane potential was 113.3 ~ 180.8 mLCH₄/g-VS for Hanwoo cattle manure and 94.0 ~ 166.2 mL-CH₄/g-VS for dairy cattle manure. The amount of methane generated per wet weight of cattle manure, taking into account the change in volatile solid content and biochemical methane potential, differed by 42.8% for Hanwoo cattle manure and 129% for dairy cattle manure. No distinct seasonal patterns in the physicochemical characteristics of the manure were observed due to the influence of other factors (e.g., the storage period). Overall, these results indicate that it is important to design treatment facilities that consider variations in the physicochemical properties and methane generation of cattle manure.