DETERMINATION OF THE ULTRASONIC EFFECTIVENESS IN ADVANCED WASTEWATER TREATMENT

Ultrasonic technology may be used for water and wastewater treatment as an advanced oxidationprocess. application of this technology, leads to the decomposition of many organic compounds duringcavitation process. in this study, the efficiency of ultrasonic in advanced treatment of municipalwastewater has been investigated by use of an ultrasonic bath. cod and bods tests were used as theindicators of organic matter concentrations and three detention times for treatment were appointed at10, 30 and 60 minutes. two frequencies of 35 and 130 khz for sonication were used. results indicatedthat sonication can reduce 25% to 30% of cod in less than 60 minutes. also, it was indicated thatsuspended cod was mainly converted to soluble cod during sonication. the rate of hydrogenperoxide production and thus the efficiency of treatment were higher at 130 khz, but this efficiencywas not much increased by prolonging sonication time. in other words, maximum efficiency wasachieved at the initial time of sonication. furthermore, no considerable change in nutrientsconcentration was detected and ph variations of samples were negligible «0.3). in contrast, significanttemperature change occured which was about (18-20te increase in 60 minutes. however, thistemperature change had no considerable effect on treatment efficiency.