超声波预处理对牛粪厌氧消化的影响

以牛粪为研究对象,考察超声波预处理对牛粪厌氧消化的影响。结果表明,适宜强度的超声波预处理对牛粪厌氧消化有一定促进作用。与未经预处理牛粪相比,在100、175、250W超声波预处理下牛粪厌氧消化的最高产气速率从127.02mL/d分别提高到179.26、212.73、298.71mL/d,累计产气量从1 674.18mL分别提高到2 279.81、2 508.05、2 730.66mL,消化液达到最低pH的时间从30d分别缩短至25、15、10d;消化液最大溶解性COD从14 881mg/L分别提高到16 450、17 080、19 250mg/L,牛粪挥发性固体的生物降解率从44.7%分别提高到55.4%、57.3%、61.7%。超声波强度过大将对微生物造成破坏,降低生物反应活性,从而抑制牛粪厌氧消化。经325W超声波预处理后,牛粪厌氧消化的最高产气速率、累计产气量等参数均不及未经预处理牛粪。在未来实际应用中,应注意控制超声波强度,以达到最优预处理效果。

Study on the effect of ultrasound pretreatment on cow-dung anaerobic digestion

The cow-dung was selected as object to study the effect of ultrasound pretreatment on cow-dung anaerobic digestion.Results showed that the ultrasound pretreatment with proper intensity was benefited to cow-dung anaerobic digestion.Compare to the untreated cow-dung,the anaerobic digestion process of cow-dung pretreated under 100,175,250 W of ultrasound was greatly improved,with the maxim biogas production rate enhanced to 179.26,212.73,298.71 mL/d from 127.02 mL/d,accumulated gas production enhanced to 2 279.81,2 508.05,2 730.66 mL from 1 674.18 mL,the digestion time that reach to lowest pH value was shorten to 25,15,10 d from 30 d,the maxim SCOD value also increased from 14 881 mg/L to 16 450,17 080,19 250 mg/L respectively,and VS biodegradability was enhanced to 55.4%,57.3%,61.7% from 44.7%.Relative high intensity of ultrasound would damage the microorganism and reduce the biological activity,thus inhibit the cow muck anaerobic digestion.After the 325 W of ultrasound pretreatment,the anaerobic digestion performance of cow-dung was far poor than untreated cow-dung.So,in future actual application,we should control the intensity of ultrasonic so as to achieve optimal pretreatment performance.