固相餐厨垃圾厌氧发酵特性

Characteristics of anaerobic digestion with solid kitchen waste

为了研究固相餐厨垃圾厌氧发酵产甲烷特性,对固相餐厨垃圾进行批式厌氧发酵实验,主要考察了p H、VFA、COD以及纤维素酶活的变化情况,并运用修正Gompertz模型对其产气模型进行动力学拟合。实验结果表明,缓冲溶液的添加可明显促进厌氧发酵产甲烷。在添加缓冲溶液条件下,污泥与餐厨垃圾比例为2∶1,1∶1,2∶3和1∶2时,餐厨垃圾都能很好地进行厌氧发酵产甲烷,最大产甲烷产量分别为594.66、449.74、392.93和333.36 m L/g TS。采用修正Gompertz模型分别对2∶1、1∶1、2∶3和1∶2实验组产甲烷曲线进行拟合,得到产甲烷潜力分别为567.57、437.89、381.12和305.60 m L/g TS,最大产甲烷速率分别为89.38、59.81、47.26和25.80 m L/(d·g VS)。对厌氧发酵过程中纤维素酶活的变化进行了研究,结果表明,CMC酶活性在提高餐厨垃圾厌氧发酵过程中纤维素的降解起重要作用。

In order to study characteristics of anaerobic digestion with solid kitchen waste,biochemical methane potential( BMP) of the kitchen waste was evaluated by series of batch anaerobic fermentation,the performances of p H,VFA,COD and cellulose enzyme were investigated,and also methane production was fitted with the modified Gompertz model to assess the characteristics of the anaerobic digestions. Results indicate that methane production under anaerobic digestion was improved by adding of buffer solution. Good anaerobic digestion performance was obtained with a maximum methane yield of 594. 66,449. 74,392. 93 and 333. 36 m L / g TS at the inoculum substrate ratio 2 ∶ 1,1 ∶ 1,2 ∶ 3 and 1 ∶ 2 with buffer solution. The model fitting results showed that the BMP were 567. 57,437. 89,381. 12 and 305. 60 m L / g TS,respectively,and the maximum methane production rate were 89. 38,59. 81,47. 26 and 25. 80 m L /( d·g VS) when the inoculum substrate ratios were 2 ∶ 1,1 ∶ 1,2 ∶3 and 1 ∶ 2. Results of cellulose enzymes activities showed that CMC enzymes activity played an important role in degradation of cellulose during anaerobic digestion.