超声时间对污泥脱水性能的影响

Effects of ultrasonic duration on performance of sludge dewatering

污泥絮体紧紧包裹大量结合水,导致污泥脱水性能很差。超声波处理是改善污泥脱水性能的有效处理方法之一。针对超声时间对污泥脱水性能的影响进行了一系列研究。超声波作用在液相中产生瞬时高温高压,其声空化和水力剪切作用通过裂解污泥絮体,将难以去除的结合水释放出来,改善污泥脱水性能。同时,也释放了胞内大量的有机酸或碳酸类物质,改变了污泥的pH值。但是,超声波作用存在最优作用时间,无限延长超声波作用时间,污泥絮体和微生物细胞将变得更加破碎,污泥脱水性能会恶化。

Sludge flocs tightly wrapping a large amount of bound water results in poor performance of sludge dewatering.The ultrasonic treatment is one of the effective methods to improve performance of sludge dewatering.The effects of ultrasonic time on performance of sludge dewatering are studied.The ultrasonic waves generate instantaneous high temperature and pressure in the liquid phase,which the acoustic cavitation and hydraulic shear effects can break down sludge flocs,release bound water that is difficult to remove,and improve performance of sludge dewatering.At the same time,it also releases a large amount of organic acids or carbonates in the cells,which changes the pH value of the sludge.However,there is an optimal action time for ultrasound.If the ultrasound action time is infinitely extended,the sludge flocs and microbial cells will become more fragmented,and the sludge dewatering effects will deteriorate.