Efficiency of anaerobic digestion of kitchen waste by low intensity ultrasound pretreatment
低强度超声波预处理对厨余垃圾厌氧消化的影响

The characteristics of the high-energy biogas generation through anaerobic digestion (AD) of kitchen waste pretreated by low intensity ultrasound were introduced. Gas production rate,pH value, SCOD,methane concentration and biodegradability were monitored during AD experiment. The results show that there was an obvious effect of pretreatment with low intensity ultrasound on the anaerobic digestion of kitchen waste, under the same ultrasound intensity(100,175 and 250 W) and treating time(20 and 40 min),the gas production rate,accumulated gas production,decline of pH and increase of SCOD were along with ultrasound intensity and treating time. Under ultrasound intensity of 250 W and treating time of 60 min, there was a inhibitory effect on AD. There was a best efficiency under ultrasound intensity of 250 W and treating time of 40 min, the accumulating gas production increased by 42.6%, from 3 513 to 5 007 mL, the CH4 concentration and biodegradability increased from 51.25% to 58.8% and 58.11% to 73.5%, respectively.