Abstract: | An experimental investigation of the foam separation of E. coli from distilled water suspension using a cationic surface-active agent, ethylhexadecyldimethyl-ammonium bromide (EHDA-Br) is presented. Results are evaluated in terms of total cell count, using a membrane filtration technique. Cell concentrations in the initial suspensions are varied from 5.0 × 105 to 1.0 × 108 cells/ml. Surfactant concentrations in the initial cell suspensions are varied from 0.015 to 0.040 mg./ml., and foaming times are varied from 2 to 20 min. The residual quantity of cells decreases exponentially with foaming time to about 0.02% of the initial quantity after 20 min. The cell enrichment ratio, varying from 10 to 1,000,000, is an inverse power function of the initial surfactant concentration and an exponential function of foaming time. Foaminess decreases with increasing initial cell concentrations, and for an initial surfactant concentration of 0.030 mg./ml., the residual cell concentration is a linear function of the initial cell concentration. |