P16 超音波照射を利用する水中フミン酸の沈殿除去(ポスターセッション)

抄録

We have found a new removal method of humic acid from water by utilizing ultrasonic irradiation in the previous works. By the method, where ultrasound with a frequency of 200kHz is directly applied to water containing a very small amount of humic acid and then the treated water is held at a constant temperature, humic acid is precipitated in water, and its concentration dramatically decreases. (The brown aqueous solution of humic acid is decolorized as the precipitation of humic acid occurs.) In this study, to verify the validity of this method, experiments on ultrasonic treatment of humic acid solutions were performed under various conditions. The results obtained show that decrease in humic acid concentration in water is affected by the operating conditions such as ultrasonic irradiation power and ultrasonic reaction atmosphere. When the formation of OH radical in water is above 5.0×10^<-5>M during ultrasonic irradiation, humic acid is precipitated and its concentration in water decreases to blow 20% in the holding process.