pH与曝气耦合调控厌氧发酵相分离技术研究

Aeration and pH Combined Regulation for the Phase Separation of Anaerobic Digestion

为验证pH调节与曝气处理对两相厌氧发酵相分离的影响,文章研究了以葡萄糖为底物,不同起始pH值(5.5,6.5,7.5)、不同间隔时间(8 h,12 h,16 h)通入不同量的空气(3 L,5 L,8 L),对厌氧发酵产甲烷的影响,并进一步研究了pH调节与曝气处理对秸秆两相厌氧发酵相分离的影响。结果表明:通过连续曝气处理可以降低反应器料液的pH、升高反应器料液的氧化还原电位,起始pH、曝气间隔时间及曝气量分别为6.0,8 h和5 L对厌氧发酵的产气量和产甲烷量的抑制有明显效果。将秸秆两相厌氧发酵系统中水解产酸相初始pH调到6.5以下,结合每天曝气3次(间隔8小时),每次曝气量≥1 L空气·L-1反应器(等于或大于容器体积),不用产甲烷相沼液作水解相消化液补充回流条件下,可以有效地抑制甲烷产生,基本实现两相有效分离。

To study the influence of the pH and aeration combined regulation on the phase separation of anaerobic diges- tion, experiments of different initial pH of 5.5, 6.5 and 7.5, different aeration interval of 8 h, 12 h and 16 h, and differ- ent aeration volume of 3 L, 5 L and 8 L, were carried out with glucose as substrate, and further more with rice straw as substrate adopting two-phase anaerobic system were evaluated. The results showed that continuous aeration could reduce the pH and elevated the redox potential. When the initial pH was 6, aeration interval was 8h, and the amount of aeration was 5 L, the methane production was obviously suppressed during the anaerobic fermentation with glucose. In the two-phase an- aerobic digestion with rice straw, if the liquid of methanogenic phase would not be refluxed to hydrolysis phase, adjusted the initial pH of the hydrolysis phase below 6.5, aerated three times daily at interval of 8h with ≥ 1 L air per L of contain- er volume, the methane production in hydrolysis phase could be effectively suppressed, and achieve the phase separation basically.