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 w as investigated. The performances of the aeration system were assessed in terms of oxygen mass transfer coefficient (k(L)a). Experiments wer e conducted to examine the effects of air flow rate, pH and water dept h in the aeration tank on the mass transfer coefficient. The mass tran sfer 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 prop osed by previous investigators. Finally, based on the experimental res ults, optimum operating conditions for the present fine bubble aeratio n system were identified.