添加蚯蚓粪对餐厨垃圾厌氧消化过程的影响

以餐厨垃圾为研究对象,在(37±1)℃的条件下,研究了蚯蚓粪的5种不同添加量对餐厨垃圾厌氧消化过程的影响,并考察了在这过程中pH、溶解性化学需氧量(SCOD)、挥发性脂肪酸(VFAs)、总磷(TP)和产气量的变化规律.研究结果表明:当蚯蚓粪的添加量(w,均以湿基计)为0、3%、6%、9%、12%、15%时,餐厨垃圾厌氧消化系统的累积产量分别为14 700、16 074、15 702、16 056、16 414和16 485 mL,产气率分别达到466.35、504.84、488.02、494.03、499.67、496.69 mL.g-1,与不添加蚯蚓粪相比产气率分别提高了8.25%、4.60%、5.93%、7.14%和6.51%,其中当添加量(w)为3%时对餐厨垃圾厌氧消化效果最明显.研究还发现,蚯蚓粪的添加能显著提高各处理的pH和餐厨垃圾的水解酸化速率.可见,添加蚯蚓粪有助于抑制VFAs的累积,使pH更稳定,从而提高沼气产量.

Effect of Addition of Earthworm Manure on Anaerobic Digestion Processes of Food Waste

The influences of five different added dosages of earthworm manure on anaerobic digestion of food waste were investigated at(37±1)℃.The variations of pH,SCOD,VFAs,TP and biogas yield in the anaerobic digestion processes were studied.The experimental results showed that the accumulations of biogas yield were 14 700,16 074,15 702,16 056,16 414 and 16 485 mL and the biogas yield rate reached 466.35,504.84,488.02,494.03,499.67 and 496.69 mL·g-1 when the earthworm manure added were 0,3%,6%,9%,12% and 15%(w,wet substrate),respectively,and their outputs were increased by 8.25%,4.60%,5.93%,7.14% and 6.51%,respectively.The earthworm manure could enhance the biogas production most significantly at the dosage of 3%.During the process of the anaerobic digestion,the addition of earthworm manure could improve the pH value and the hydrogensis and acidogenesis rate of food waste significantly.Therefore,the addition of earthworm manure could prevent VFAs accumulation,buffer the decrease of pH value and increase the biogas yield.