Effects of temperature and liquor concentration on the high-concentration anaerobic hydrolysis and acidogenesis of dairy manure

High-concentration anaerobic fermentation of dairy manure was investigated by anaerobic batch reactors under laboratory conditions at 20℃. A further study on the effects of temperature and liquor concentration on the high-concentration hydrolysis and acidogenesis of dairy manure was conducted on the basis of former study when temperature, liquor concentration and fermentation time were 32℃, 35℃ and 40℃, 9% and 10% and 12 days respectively. To find an optimal condition for anaerobic hydrolysis and acidogenesis was also included. Experimental results showed that the D-value among every main ingredient of hydrolysis and acidogenesis products was rather small when the temperatures were 32℃, 35℃ and 40℃, seperately. But the productive rate of daily average COD_VFA at 32℃ was far more than those at 35℃ and 40℃. The largest D-value could reach 452 mg/(L·d) between 32℃ and 40℃, which amounted to 37% of the largest productive rate 1227.00 mg/(L·d) of daily average COD_VFA. The D-value among every main ingredient of hydrolysis and acidogenesis products was rather small when the liquor concentrations were 9% and 10% seperately. But the productive rate of daily average COD_VFA at 9% was far more than that at 10%. The largest D-value could reach 463.38 mg/(L·d), which amounted to 37.77% of the largest productive rate 1227.00 mg/(L·d) of daily average COD_VFA. Therefore, the optimal technics condition in the process of high-concentration hydrolysis and acidogenesis of dairy manure was temperature 32℃, liquor concentration 9%, and fermentation time 6 days.