超声预处理污泥对厌氧消化的影响

Effect of Ultrasonic Pretreatment on Sludge Anaerobic Digestion

为了提高污泥的破解效果及改善其厌氧消化性能,采用双频超声波对污泥进行预处理后再进行厌氧消化试验,分别考察超声时间、声能密度和污泥pH对污泥破解效果以及厌氧消化性能的影响。结果表明:在污泥超声预处理试验中,超声时间、声能密度和污泥pH对污泥溶解性化学需氧量增加值(SCOD+)和污泥溶出率(DDSCOD)有显著影响,对氨氮(NH3-N)影响不显著;超声时间为55min、声能密度为125W·L-1及pH为9时,SCOD+和DDSCOD均达到最优值。在厌氧消化试验中,处理组污泥产气高峰期比未处理组污泥出现晚,但产气量高于未处理组,当超声时间为25min、声能密度为75W·L-1和污泥pH为8时,累计产气量均最多。该研究得出的结论可在污泥资源化和能源化方面有参考价值。

In order to enhance the disintegration efficiency of wastewater sludge and improve the performance of anaerobic digestion, the impacts of sludge's disintegration and the performance of anaerobic digestion on ultrasonic time, power density and pH of sludge were investigated through double frequency ultrasound pretreatment, and the anaerobic digestion experiments were performed. In the sludge ultrasonic pretreatment experiments, ultrasonic time, power density and pH of sludge had significant impacts on the increase of soluble chemical oxygen demand(SCOD+) and disintegration degree of sludge(DDSCOD), and had no significant impacts on NH3-N. When ultrasonic time, power density and pH of sludge were respectively 55 min, 125 W·L-1and 9,the values of SCOD+and DDSCODall got the best. In the anaerobic digestion experiments, compared with untreated sludge, the peak of daily biogas production of treated sludge occurred later, but with high total biogas production. When ultrasonic time,power density and pH of sludge were respectively 25 min, 75 W·L-1and 8, the cumulative biogas production was the highest.This study would have a contribution on recycling and energy technology of sludge.