|
|
|
| Effect of grease on acid fermentation of kitchen waste by single phase anaerobic methods |
|
|
|
|
Abstract Under the optimum reaction conditions (pH 6.0, the temperature of 35 ℃), batch experiments were carried out to determine the effect of grease content on volatile fatty acid (VFA) concentration and composition during anaerobic acidogenesis of kitchen wastes. The grease content was controlled at 0.0g/L, 5.0g/L, 15.0g/L, and 25.0g/L. The results showed that, the effect of grease on VFA concentration was significantly, and maximum VFA concentration decreased with the amount of grease improved. When the amount reached 5.0g/L,15.0g/L and 25.0g/L, VFA maximum concentration reached 38.84g/L,33.88g/L and 23.22g/L, which was only 92.5, 80.7and 55.3percent of not adding grease. Second, the grease may arrest acid production, under the grease content of 5.0g/L, 15.0g/L and 25.0g/L, the half of highest VFA concentration required 49.4h, 56.4h, 58.8h, which was lag 27.1h, 34.1h, 36.5h relative to the group without adding grease. Also grease can affect the proportion of each component of VFAs. It changed acid-type from butyric acid type fermentation to propionic acid type fermentation with improving the propionic acid content. When the amount of grease reached 5.0, 15.0 and 25.0g/L, the proportion of propionic acid reach up to 32.2%, 23.0% and 20.5%, which was only 8.7percent in control experiment.
|
|
Received: 08 October 2014
|
|
|
|
|
|
|
