温度对厨余垃圾两相厌氧消化中水解和酸化过程的影响

实验考查了厨余垃圾在4个温度(25℃、37℃、40℃、50℃)条件下的水解率、挥发酸(VFA)产量和速率、乳酸产量和有机酸的组成.结果表明:温度对水解和酸化过程均有较大影响,在小于37℃范围内水解率和酸化率均随温度升高而增加,最大的VFA浓度在37℃下获得,达34.4g/L.超过37℃,酸化率下降而水解率继续增加,最大水解率在50℃下获得达82%.VFA中以甲酸和乙酸为主,并有少量丙酸和丁酸产生,同时乳酸浓度一直较高.通过实验确定了厨余垃圾水解酸化过程的最优温度条件为37℃.

Influence of Temperature on Hydrolysis and Acidogenesis of Kitchen Wastes in Two-Phase Anaerobic Digestion

The experiment evaluated the solubilization rate and VFA production rate of kitchen wastes with controlled-temperature at 25 degrees C, 37 degrees C, 40 degrees C and 50 degrees C, and subsequently investigated the lactic acid production and constituents of individual organic acids at various temperature levels. Results show that the increase of temperature when below 37 degrees C may improve both hydrolysis and acidogenesis rates and acidogenesis rate decreases while hydrolysis rate increases above 37 degrees C. The maximum VFA concentration of 34.4 g x L(-1) was achieved at 37 degrees C and a higher hydrolysis rate of 82% was obtained at 50 degrees C. Formic and acetic acid were predominant VFA, while propionic and butyric acid took a relatively little part. And lactic acid concentration remained relatively high. Accroding to the experiment an optimum temperature to optimize both hydrolysis and acidification is 37 degrees C.