Study On Treatment Of Sludge With Ultrasonic Combined Flocculant

Currently. The main method to deal with sludge is biochemical method. With the quantity of waste water increasing, more and more sludge was produced. The treatment of sludge is a major concern. This study had researched on sludge setting and dewatering used ultrasound and flocculant、the composite flocculant by CST、SV、SCOD、water content of centrifugal sludge and supernatant centrifugal transmittance as indicators for comparisons.The main contents and conclusions are as follows:1、This study include ultrasonic frequency, ultrasonic power, ultrasonic time and three factors effect on sludge setting and dewatering. The influence of ultrasonic frequency relative to the power and time. The result showed when ultrasound was used alone and frequency was20Hz、power was60w、time was20s, dewatering performance was improved.2、This study used a modification of natural products of cationic guar gum CGG combine with PAM to effect on sludge setting and dewatering. The effect of sludge setting and dewatering was well when the dosage of CGG and PAM were900mg/L and150mg/L, first added CGG, after mixed PAM. It can reduce the dosage of PAM when the sludge was treated by the composite flocculant.3、The stirring speed and stirring time were researched when the sludge was treated by composite flocculant. When CGG combine with PAM to effect on sludge, the primary and secondary order of stirring time and speed is:slow stirring speed, fast mixing speed, fast mixing time, slow time. To determine the best the level of combination is:slow stirring speed was90r/min, fast mixing speed was350r/min, fast mixing time60s, slow mixing time was10min.4、This study research the ultrasonic combine with composite flocculant to effect on sludge setting and dewatering. When the ultrasound was used with CGG and PAM, it had better setting performance and dewatering performance. When the dosage of CGG and PAM were300mg/L and150mg/L,CST and SV were lower, it had good economy.5、After the ultrasonic treatment, it had better setting performance and dewatering performance when the FeCl3modified diatomaceous earth with PAM、C16H33(CH3)3NBr modified diatomaceous earth with PAM effect on sludge. Composite flocculant can enhance the dewatering performance, but not significantly improve the setting performance. The dewatering performance and the setting performance were greatly improved after the treatment of ultrasonic and composite flocculant.