餐厨垃圾厌氧干发酵处理产甲烷潜力及动力学研究

Methane Potential and Kinetics of Kitchen Waste via Dry Anaerobic Fermentation

研究采用中温厌氧干发酵反应器,针对餐厨垃圾厌氧干发酵过程中p H,VFA,COD和产气量的变化,结合修正Gompertz方程分析厌氧干发酵产甲烷的动力学过程。在中温厌氧干发酵系统负荷和初始条件下,分析厌氧干发酵产甲烷过程变化,建立厌氧干发酵产甲烷模型,对其预测和试验验证及误差进行分析。结果表明,在中温厌氧干发酵过程中p H先下降后上升,VFA浓度先增加后减少,COD去除率保持在76.02%~90.28%之间;修正Gompertz动力学模型,可以较好地分析餐厨垃圾厌氧干发酵产甲烷过程(决定系数R^2>0.99),经拟合,具有较高的产甲烷能力,且与试验结果显著相关;在检验水平a=0.05条件下,其方差分析的P值为0.938,大于0.05的显著性,表明模型能较好地预测厌氧干发酵累积产甲烷量。

The dry anaerobic fermentator is used to treat kitchen waste at temperature 35 ℃. The variations of pH, VFA, COD and biogas production are investigated during the process of the dry anaerobic fermentation. The underlying kinetics and mechanism are analyzed in the dry anaerobic fermentation process via the modified Gompertz equation. Considering sys- tem loading and the initial conditions, the dry anaerobic fermentation methane model is established, the model is verified by the experimental data and the errors are analyzed during the process of the dry anaerobic fermentation. The results show that pH raises firstly and then goes down, the concentration of VFA goes firstly up and then down and after the dry anaerobic fer- mentation, the removal rate of COD maintains at 76.02 - 90.28% . The modified model is appropriately fitted about the cu- mulative methane yield with R2 〉 0.99. The methane production potential of kitchen waste treated is approached. These fit- ting parameters at this stage are met to the experimental results. ANOVA P value is 0.938 and the level of test is the signifi- cance over 0.05. The predicted results are consistent with the experimental data, and the model indicates that it can predict the methane cumulative amount of dry anaerobic fermentation well.