Stabilized Oily-Emulsion Separation Using Modified Induced Air Flotation (MIAF): Factor Analysis and Mathematical Modeling

Abstract

The objective of this work was to study the treatment of oily-wastewater by the combination of induced air flotation and coagulation or the modified induced air flotation (MIAF). Effects of bubble hydrodynamics and mixing were analyzed along with the treatment performance for separation different stable oily wastewaters, including cutting oil, lubricant oil, palm oil. The results suggested the necessity of coagulation for the efficient separation of these emulsions. Different alum concentrations were required for good separation due to the variation of oil concentration. The maximum efficiencies of higher than 85% can be attained under the optimal air flow rate of 0.3 L/min air flow rate for 10 minutes with appropriate alum dosage. Moreover, the result from factor analysis indicated the importance of coagulant dosage, mean droplet size, and hydrodynamic condition in term of a/G ratio on the treatment performance. Both individual and jointed impacts of these parameters on the separation efficiency can be seen. Finally, a good correspondence was obtained from the experimental data and the mathematical modeling at which identified the correlation between the treatment efficiency and these key factors with the mean absolute percentage error (MAPE) of at 14%.