超声波预处理对牛粪与玉米秸秆混合厌氧发酵特性的影响

为了探索超声波预处理提高厌氧发酵产气量的机理、优化超声波预处理工艺及分析超声波预处理的能量效益,利用因子分析法和通径分析研究不同发酵阶段各环境因子对发酵过程的影响,以及发酵初始环境与甲烷产量之间的关系.同时,用响应面优化法优化超声波预处理工艺,并且分析了超声波预处理的能量效益.结果表明,在40 k Hz和0.20 k W下,适宜的超声波预处理能显著提高厌氧发酵总产气量(p0.05),牛粪预处理17.68 min后与玉米秸秆预处理19.94 min混合发酵,甲烷产量最高为177.20 L·kg-1(以TS计),显著高于CK(未经预处理组,p0.05),其能量效益也最高,为1835.14 k J·kg-1(以TS计).超声波预处理通过改变发酵初始环境之间的相互关系和发酵过程环境的主要影响因素来使发酵系统更加稳定从而提高产气量.超声波预处理是一种能量输入的预处理方式,产气量高于CK处理组,但其能量效益不一定大于零.因此,在优化超声波预处理条件时必须对其能量效益进行分析.研究结果能为超声波预处理条件的优化方式提供理论依据.

Influence of ultrasonic pretreatment on characterization of anaerobic co-digestion of dairy manure and maize straw

In order to explore the reason why ultrasonic pretreatment (UP) could improve the total methane production in anaerobic digestion, optimize the parameters and analysis energy benefit of UP. Factors analysis and path analysis were used to analyze the different influences of environmental factors on different stages in the digestion process and the relationship between the initial digestion environment and total methane production. The response surface optimization method was used to optimize UP parameters, and energy benefit of the UP was analyzed. The results showed that, under 40 kHz and 0.20 kW, the optimal UP could significantly improve the total methane production (p<0.05).When dairy manure pretreated 19.94 min to mix with the maize straw pretreated 17.68 min, the total methane production was the highest of 177.20 L·kg^-1 TS, significantly higher than that of CK (un-pretreated sample, p<0.05), its energy benefit was also the highest of 1835.14 kJ·kg^-1 TS. UP increases the total methane production by changing the relationship between the initial digestion environment and its relationship between total methane production, as well as the main influencing factors of the digestion process environment to make the digestion system more stable. UP is an energy input pretreatment, total methane production of treatments higher than that of CK, their energy benefit were not always higher than zero. Therefore, the energy benefit must be analyzed when the conditions of UP was optimized.