生活垃圾快速好氧发酵预处理及其对厌氧消化影响的动力学研究

Fast Aerobic Fermentation Pretreatment of Municipal Solid Waste and Its Effect on Anaerobic Digestion Kinetics

文章研究了生活垃圾快速好氧发酵过程其理化特性变化规律,并通过批式厌氧消化试验分别对未预处理和快速好氧发酵预处理的生活垃圾的厌氧消化过程动力学进行了研究。结果表明,经过快速好氧发酵预处理,生活垃圾浸出液p H值上升至7.80,水溶性化学需氧量和挥发性脂肪酸含量均出现不同程度下降;生活垃圾中易降解有机组分获得初步降解;难降解有机组分,如木质纤维素和粗蛋白所占比例有所增加。厌氧消化阶段,利用修正Gompertz方程和一级动力学方程对厌氧消化过程进行曲线拟合,两种方程拟合得到的预处理后生活垃圾单位VS累积产甲烷量分别为189.62 m L^241.75 m L和188.87 m L^238.12 m L,分别比未处理生活垃圾单位VS累积产甲烷量高0.75%~32.55%和7.66%~41.22%。同时,预处理后生活垃圾厌氧消化周期缩短明显,厌氧消化系统的稳定性也有所提升。

The characteristic changes of municipal solid waste（ MSW） during fast aerobic fermentation were investigated.The kinetics of the mesophilic anaerobic digestion of organic fraction of municipal solid waste（ OFMSW） were studied. The results showed that after fast-aerobic fermentation,p H of the leaching liquor was up to 7. 80,soluble chemical oxygen demand（ SCOD） and volatile fatty acid（ VFA） were lower than the raw MSW. Those easily degradable substance were primarily degraded. However,the proportion of lignocellulose and crude protein were raised. The two equations,modified Gompertz equation and first-order kinetic equation,were used to fit the anaerobic digestion process,and obtained the accumulative biogas yield of 189. 62 mL ～ 241. 75 mL and 188. 87 mL ～ 238. 12 mL respectively for treated MSW,which were0. 75% ～ 32. 55% and 7. 66% ～ 41. 22% higher than those of untreated MSW respectively. Meanwhile,the treated OFMSW could also shorten the digestion period comparing with the unpretreated OFMSW,and the stability of anaerobic digestion system was also improved.