A Study of Kinetics on Induced-Air Flotation for Oil-Water Separation

Abstract

Induced-air flotation makes use of the centrifugal force of a high-speed backspin impeller through which gas is introduced at the top and liquid at the bottom. The gas and liquid become fully intermingled and, after passing through a disperser outside the impeller, form a multitude of gas bubbles, thus completing the flotation separation process of a liquid-solid or liquid-liquid heterogeneous separation process of a liquid-solid or liquid-liquid heterogeneous system. The flotation machine used for treating oily sewage generally belongs to the four-cell series. Its good points are that the machine has a high removal efficiency for oil separation, shortens retention time, and has great treatment capacity. The device has been widely used in treating oily sewage in recent years (1, 2). In order to provide a basis for establishing a method of design computation and for screening appropriate chemicals, this study was initiated to gain an understanding of the variables controlling the induced-air flotation process for oil-water separation. An experimental device for simulating tests has been developed. In order to analyze its mechanism, a kinetic model of oil-water separation has been put forward. By the use of the experimental result, correlative equations, which can estimate the parameters of the model, have been obtained.