槽式双频超声波发生器改善污泥脱水性能研究

研究利用槽式双频超声波发生器改善二沉池污泥脱水效果,采用正交试验方法研究最优操作参数,并探讨各操作参数的影响规律.根据试验要求设计了槽式双频超声波发生仪,在试验中改变超声波的频率、声能密度、处理时间与发生方式,比较污泥处理前后含水率的变化.试验结果表明,在超声波改善污泥脱水性能的影响因素中,影响最大为处理时间,其次为声能密度,最小为频率.超声波作用的最佳操作条件是频率为19kHz,声能密度为0.050W/mL,处理时间为30s,此时污泥脱水性能提高14.3%.低频率、低声能密度与较短的处理时间,有利于提高污泥的脱水性能;操作参数超出一定范围反而会恶化污泥的脱水性能.超声波发生方式对污泥脱水性能的改善有影响,低频率条件下单频优于双频,高频率下双频优于单频.

Study on Improvement of Dewaterability of Sludge by Double-frequency Ultrasonic Generating Trough

Double-frequency ultrasonic generating trough was applied to improve dewaterability of sludge from secondary settling tanks, and optimal operating parameters of ultrasonic generator were studied by orthogonal experiment. The ultrasonic generator could adjust frequency, energy density and treating time flexibly in order to compare sludge dewaterability under different conditions. According to the results, treating time had the most significant influence on sludge dewaterability, energy density was less important than it and frequency was the least. The optimal operating parameter was frequency of 19kHz, energy density of 0.050W/mL, and treating time of 30s. Improvement of sludge dewaterability requires low frequency, low energy density and short treating time. Or sludge dewaterability will be worsened when operating parameters are beyond a certain scale. Ultrasonic generating method has impact on sludge dewaterability. When the frequency was low, single-frequency ultrasonic achieved higher dewaterablity; when the frequency was high, double-frequency ultrasonic had better results.