鸡粪中高温厌氧甲烷发酵产气潜能与动力学特性

采用富含氮素的鸡粪为原料，包括原料鸡粪、鸡粪固相部分和鸡粪液相部分，选取以鸡粪为原料连续稳定运行超过90d的中高温厌氧反应器新鲜出料为接种污泥，在中温（35℃）和高温（55℃）条件下开展动力学和产甲烷潜能试验.采用Gompertz模型、一级动力学模型和两阶段模型对鸡粪中高温累积产甲烷量进行拟合.结果表明，鸡粪中高温甲烷发酵均呈现明显的快速产气期和慢速产气期两阶段特征，快速产气期的动力学常数K₁分别为0.4174和0.2104d^-1，快速产气分别在4.5和6.5d结束，快速产气量占到总产气量的69%和58%.原料鸡粪和液相部分的中温发酵动力学常数（K₁）分别为0.4177和0.2330d^-1，均高于高温的0.1721，0.2214d^-1，发酵产气速率较快.鸡粪固相部分中温发酵的动力学常数为0.1960d^-1，低于液相中温发酵的0.2330d^-1和固相高温的0.2310d^-1，中温条件下，水解过程是限制鸡粪甲烷发酵速率的主要因素之一.鸡粪固体和鸡粪液体高温发酵的动力学常数K分别为0.2310，0.22214d^-1，鸡粪固体发酵产甲烷的速率快于液相部分，水解过程不是限制鸡粪高温发酵产甲烷速率的最主要因素.产甲烷潜能试验表明鸡粪在中温和高温下产甲烷潜能分别为212，177mL/gTS.因此，仅从发酵效率的角度考虑，鸡粪中温发酵比高温发酵的产甲烷潜能更高，产甲烷速率更快.

Biogas production potential and kinetics of chicken manure methane fermentation under mesophilic and thermophilic conditions

A batch experiment of 48days was carried out under the conditions of mesophilic (35℃) and thermophilic (55℃) by using raw chicken manure (RCM), solid part of chicken manure (SCM) and liquid part of chicken manure (LCM) to test the biogas production dynamics and potential when the seed sludge obtained from the effluent of chicken manure methane fermentation reactors under mesophilic and thermophilic conditions, correspondingly. It's worth noting that both reactors were continuously operated more than 90days, which domesticated microorganisms in the reactors adapted to the methane fermentation of chicken manure. An obvious two-stage characteristic with RCM methane fermentation biogas production simulated by Gompertz model, first order kinetics model and two-stage model under mesophilic and thermophilic conditions was analyzed. The K₁ of fast biogas production stage kinetics under mesophilic and thermophilic conditions were 0.4174 and 0.2104d^-1, when the methane production during fast biogas production stage took 69% and 58% of total methane production, respectively. And then it entered slow biogas production stage in 4.5 and 6.4d. The first-order kinetic rate constants of RCM and LCM mesophilic methane fermentation were 0.4177 and 0.2330d^-1, which higher than those getting from RCM and LCM thermophilic methane fermentation. Thus, compared to thermophilic methane fermentation, RCM and LCM mesophilic fermentation had a faster methane production rate. But the first-order kinetic rate constants of SCM mesophilic methane fermentation was only 0.4177d^-1, which lower than those getting from LCM mesophilic methane fermentation and SCM thermophilic methane fermentation. So the hydrolysis process maybe one of the main factors limiting the methane production rate of chicken manure under mesophilic condition. The first-order kinetic rate constant of SCM and LCM thermophilic methane fermentation were 0.2310 and 0.22214d^-1. So SCM thermophilic methane fermentation had a faster methane production rate than LCM thermophilic methane fermentation, which saying that the hydrolysis process was not the main factor limiting the methane production rate of chicken manure under thermophilic condition. The methane production potential of RCM under mesophilic and thermophilic conditions were 212.9 and 177.4mL/gTS. Therefore, compared with those in thermophilic condition, the methane production potential and the maximum methane-producing rates were higher and faster under mesophilic condition.