微波预处理对秸秆厌氧消化影响的研究

Efficiency of anaerobic digestion of straw pretreated with microwave energy

以秸秆为研究对象，比较不同的微波强度预处理作用下对秸秆厌氧消化产气特性的影响，研究日产气量、pH值、甲烷气体浓度及生物降解率4个参数的变化趋势，结果表明：微波预处理对秸秆厌氧消化有明显效果，平均日产气量由未被预处理的6．21mL／gVS上升到8．16mL／gVS，上升了31．33％，达到最大日产气量时间由原来的第12d，提前至第2～第7d不等，最大日产气量由原来的23．43mL／gVS上升到43．49mL／gVS；在360～900W范围内，微波强度越大，反应的pH值下降越快，秸秆厌氧消化最大日产气量越提前；经过微波预处理的甲烷浓度平均浓度由原来的50％提高至62％左右，其生物能范围也由未处理前的17．58MJ／m^3提高至23．46MJ／m^3，物降解率由未预处理的44．12％，提高至71．55％。

This paper briefly introduces the characteristics of the generation of high-energy biogas through anaerobic digestion of straw pretreated with microwave energy. Experiments were conducted on the change trend of daily gas production,pH value, concentration of methane in the gas and biodegradation. The main conclusions are as follows ： there was an obvious effect of pretreatment with microwave energy on the efficiency of anaerobic digestion of straw. The average daily gas production from non-pretreated and pretreated straw increased from 6.21 mL/g VS to 8.16 mL/g VS, respectively. The maximum daily gas production increased from 23.43 mL/g VS to 43.49 mL/g VS, respectively, and started after 12 and 2 to 7 d, respectively. The extent of the effects of pretreatment depended on the intensity of the microwave exposure. With exposure to microwave radiation increasing from 360 to 900 W, both the pH value of the digestion slurry and the time to maximum daily gas production decreased. Also, the CH4 concentration in the biogas increased from 50% to 62% , which was equivalent to an increase in bio-energy yield from 17.58 MJ/m^3 to 23.46 MJ/m^3. Furthermore, the extent of mineralization increased from 44.12% to 71.55%.