初始pH值对泔脚发酵产氢余物甲烷化的强化研究

以城市生活垃圾厌氧消化污泥为接种物,考察了初始pH值为5、6、7和8时对泔脚发酵产氢余物中温（36℃）批式厌氧消化的影响。结果表明,当初始pH值低于7时,随着初始pH值的增大,产氢余物的产甲烷能力也随之增大;而当初始pH值高于7时,体系的产沼能力却受到了极大的抑制。结合Gompertz模型拟合结果,初始pH值为7为泔脚发酵产氢余物沼气化的最佳初始pH值,其沼气化的延迟时间λ、产甲烷率、生物气中甲烷的最高体积含量分别为： 4.02 d,379.28 mL/g VS,82.2％。厌氧消化结束后,除初始pH值为5的以外,厌氧消化余物的pH值在 6.8～6.9之间,这为沼气中甲烷的高体积含量（高于常规厌氧消化的最高甲烷体积含量75%）提供了证据。

Study on methanogenesis with fermentative biohydrogen production residue for food residues by initial pH value

Using an inoculum for anaerobic digested sludge of municipal solid waste, the effect of batch anaerobic digestion fermentative biohydrogen production residue for food residues on the intermediate temperature（36℃）was investigated when the initial pH value was 5,6,7 and 8,respectively. As a conclusion, when the initial pH value is below 7, the methanogenesis is farthest as the initial pH value rises; and when the initial pH value exceeds 7, the methanogenesis of the system is suppressed. Considering the results of Gompertz model, the optimum initial pH value for methanogenesis with fermentative biohydrogen production residue for food residues is 7, under which the lag phase time(λ) of biogas produced is 4.02 d, the specific methane potential is 379.28 mL/g VS,and the maximum volume content of methane is 82.2％, respectively. When the anaerobic digestion ends, the pH values of residues are 6.8～6.9, except the case of whose initial pH value is 5.The result proves that the volume content of methane in biogas is higher than the volume (75%) of conventional anaerobic digestion.