酸化相发酵类型对甲烷相产甲烷性能的影响

以餐厨垃圾和稻草为原料，通过调节酸化相的pH、氧化还原电位（ORP）和进料负荷（OLR），对酸化相的产酸发酵类型和不同酸化类型的产甲烷性能进行了研究。结果表明：当酸化相的pH 5.5时，发酵类型为丁酸型发酵；在乙醇型发酵和丁酸型发酵相互转换的过程中，会出现混合型发酵。从酸化效果方面来看，丁酸型发酵的产酸性能最优，酸化度为36%。同时，丁酸型发酵酸化产物的产甲烷性能最好，累计甲烷产率为535 mL·g-1 VS。通过PCR-DGGE的微生物菌群鉴定结果可知，在两相厌氧消化过程中，酸化相中的优势菌种主要以拟杆菌属（Bacteroidetes）和乳酸杆菌属（Lactobacillus）为主，甲烷相中的优势菌种以乳酸杆菌属（Lactobacillus）为主。

Effects of fermentation type of acidogenic phase on biomethane yield of methanogenic phase

The different acidifying fermentation type and the corresponding performance of methane yield were researched by controlling pH, oxidation-reduction potential (ORP) and organic loading rate (OLR) in acidogenic phase of digesting food waste and rice straw. The results showed that the ethanol-type fermentation was occurred at pH 5.5, the butyric acid-type fermentation was appeared. A mixed type fermentation was found in the transformation between butyric acid-type fermentation and ethanol-type fermentation. The best acidifying performance was butyric acid-type fermentation with the acidification degree of 36%. Meanwhile, the maximum total methane production of 535 mL·g-1 VS was obtained from digestion of the effluent of R2.Through the analysis results of PCR-DGGE, the advantage bacteria were Bacteroidetes and Lactobacillus in acidogenic phase, and Lactobacillus in methanogenic phase.