Study on the effect factors of butyric acid content in the process of high-concentration hydrolysis and acidogenesis of dairy manure

In order to improve the butyric acid content of hydrolysis and acidogenesis, high-concentration anaerobic fermentation of dairy manure was investigated by anaerobic batch reactors under laboratory conditions at 20°C. In this present study, butyric acid content was used as response function, and three factors, namely, temperature, liquor concentration and retention time were selected as input variables in the process of hydrolysis and acidogenesis of dairy manure using a central composite rotatable orthogonal experimental design. Experimental results showed that butyric acid content was greatly influenced by retention time, temperature was second to it and liquor concentration was the least. Butyric acid content was more than 15% under the condition of 25°C to 27°C, concentration 9% to 10% and retention time 9 to 11 days. Butyric acid content was less than 13% under the condition of 28°C to 31°C, concentration 7% to 8% and retention time 3 to 7 days.