Abstract
Oil droplets collection characteristics of an electro-floatation machine with a rotating electrodes-cum-impeller has been studied in the hope that the machine might be used for waste water treatment. Bubble size does not depend on the concentration of Na2SO4 (electrolyte). Bubbles become smaller with the increase in the rotational speed of the impeller. When bubbles are not generated, the emulsion remains stable without the rotation of impeller. The collection rate increases gradually as the rotational speed increases. When bubbles are generated by electrolysis, the collection rate rises considerably. The collection rate increases with a rise in current intensity, though the proportion of the collected droplets decreases under the same amount of electricity. The collection rate increases with increasing rotational speed, asymptotically approaching a fixed rate. The concentration of the coagulant exerts a great influence on the collection rate. When the concentration becomes larger than 5×10-8mol/m3, the collection rate is independent of the concentration.
