Effects of Surfactants and Suspended Solids on Oxygen Transfer under Various Operating Conditions

Aeration using fine bubble membrane aerators in a tank of 2 m height was investigated. The performances of the aeration system were assessed in terms of oxygen mass transfer coefficient (kLa). Experiments were conducted to examine the effects of air flow rate, pH and water depth in the aeration tank on the mass transfer coefficient. The mass transfer coefficients for the present fine bubble membrane aerator and the conventional coarse bubble type were compared. Also investigated were the effects of several anionic surfactants and SS simulated by using kaolin and diatomaceous earth on the oxygen mass transfer coefficient. An attempt was made to account for the effects based on theories proposed by previous investigators. Finally, based on the experimental results, optimum operating conditions for the present fine bubble aeration system were identified.