抄録
Operating characteristics of an air-lift type tubular wastewater treatment contactor were quantitatively investigated. First, the liquid circulation rate by the air-lift action was predicted by using the head balance equation and correlated with the air flow rate sparging into the inner tube. Then, dissolved oxygen concentrations in tank were predicted for two cases where the oxygen transfer in liquid phase to the microbial film was rate controlling and where the oxygen supply rate carried along with circulating liquid to the supporter part of the microbial film was rate controlling.
The power economy, which was defined as the amount of oxygen supply per unit power needed to air sparging into the inner tube were calculated and correlated with the oxygen demand per unit surface area of the microbial film and that per unit volume of the apparatus.
It was concluded from the view of the power economy characteristics that the tubuler contactor was not suited for the ordinary secondary treatment of wastewater and should be applied for the tertiary treatment.
