餐厨垃圾与牛粪联合厌氧消化效率研究

Anaerobic Digestion Efficiency of Mixed Food Wastes and Cattle Manure

试验对餐厨垃圾（FW）与牛粪（CM）联合厌氧消化效率进行了研究.在初始总固体（TS）负荷为6.7％和中温（35℃）条件下,考察不同的餐厨垃圾与牛粪TS配比（0：1,1：1,2：1,3：1,4：1,1：0）对联合厌氧消化过程的影响.结果表明：FW与CM联合厌氧消化单位VS沼气产量与甲烷含量均明显提高.FW：CM为2时（T3）,沼气产量和甲烷含量均最高,分别为574.15 mL·g-1VS和69.78％.整个厌氧消化过程T1 ～ T5的pH值稳定在6.0 ～8.0之间,未出现挥发性有机酸（VFAs）抑制现象,VFM浓度随着FW的比例增加而升高,FW单独发酵时,VFAs大量累积,第7d时达到35600 mg·L-1.产甲烷菌群利用丙酸转化为甲烷的效率较低,VFAs中丙酸浓度下降的幅度明显低于乙酸、丁酸.厌氧消化过程中T1～T5也未出现氨抑制现象,氨氮浓度整体呈现先迅速升高,后缓慢下降,再缓慢升高的变化规律.在常温沼气工程应用中,初始总固体（TS）为6.7％时,建议FW与CM的TS比为2：1.

Abstract： The anaerobic digestion efficiency of mixed kitchen wastes （FW） and cattle manure （CM） were investigated in this experiment. Batch co-digestions were adopted in anaerobic bottles of 5L at initial total solid （T S） concentration of 6.7% under 35℃. The TS ratio of FW and CM were 0： 1, 1： 1,2： 1, 3： 1,4： 1, 1： 0,respectively. The experimental resuits showed that, the mixing of FW and CM could improve the daily biogas yields based on VS, and the CH4content were significantly improved. FM to CM ratio Of 2（T3） obtained the maximum total biogas yields （574.15 mL · g^-1VS ） and highest CH4 content （69.78%）. Experiment groups T1 -T5 kept the pH between 6.0 - 8.0, and no inhibition of volatile fatty acids （VFAs） appeared during the whole process. The concentration of VFAs were increased markedly with the increase of FW concentration. The VFAs, accumulated in the sole digestion of FW （ T6）, was increased to 35600 mg· L^- 1 on the 7th day of digestion. The methanogenic activity of utilizing acetic acid or butyric acid were higher than that of utilizing propionic acid. No inhibition of ammonia nitrogen were found in T1 - T5 experiment groups. The concentration of ammonia nitrogen present a rule of increasing sharply first and then decreasing slowly, finally rising up slowly. For engineering application, the initial TS concentration of 6.7%, 35℃, and the TS ration of2：1 of FW and CM, were recommended.