预处理沼液与餐厨废弃物的厌氧产气发酵特性

Characteristics of pretreatments sludge on hydrogen and methane production by anaerobic fermentation

为了实现对餐厨废弃物能源化的梯度利用,将沼液进行水浴加热、超声波和曝气等预处理后与餐厨废弃物混合,在中温(35±1)℃条件下进行产氢和产甲烷梯度厌氧发酵实验。考察了不同预处理沼液对产氢率、产氢相缓冲能力、产氢过程可溶性代谢产物成分以及其进行产甲烷发酵的潜力。结果表明,未经处理的沼液与餐厨废弃物混合发酵的产氢率很低,并且相分离不彻底有甲烷产生;各预处理组的产氢率均明显高于未处理组,并很少或几乎没有甲烷产生,其中超声波处理组产氢率最高为52.3 m L·g^(-1)VS。水浴加热和超声波处理组的产氢流出液经产甲烷发酵,可以获得与餐厨废弃物直接进行产甲烷发酵相当的甲烷产率。这表明,将餐厨废弃物进行产氢和产甲烷梯度厌氧发酵可获得更高的能源化效率。

To realize gradient energy utilization on food waste（ FW） through anaerobic fermentation,FW and different digested sludges,which were pretreated by either heat-shock,aeration,or ultrasound,were combined to study the characteristics of hydrogen and methane（ CH4） production. The experiment was operated under mesophilic（ 35 ± 1） ℃ conditions. The parameters of hydrogen production rate and pH,volatile fatty acids,and methane production were the main indices to measure in the different pretreatment slurries during anaerobic fermentation to produce biogas. The results showed that the nonpretreatment digested sludge,which was mixed with FW,had a low hydrogen production rate and its biogas contained CH4. The pretreatments enhanced the efficiency of hydrogen production,and the maximum hydrogen production（ 52. 3 m L·g^-1VS） was obtained with the ultrasonic pretreatment. The effluent sludge from hydrogen production,which was used as a substrate to produce CH4,had an equal CH4 yield to the FW. This shows that the FW produced hydrogen and that CH4 production from anaerobic fermentation obtained higher energy efficiency.