**2. Adsorption bubble separation technique**

The term "adsorptive bubble separation technique" was developed by Lemlick et al. who called it the "Adsorption bubble technique." The disparity in surface behaviour is the basis for this technique [5]. The disparity in surface behaviour is the basis for this technique. Material of various sizes, including molecular, colloidal, and macro particulates, is selectively adsorbed or added at the surface of growing bubbles in the liquid, and thereby accumulated or isolated. A material that is not surface-active will often be rendered surface-active by combining with or adhering to a surface-active collector. Colligend is the name for the material that has been extracted. Foamate is a small amount of collapsed foam that is used to concentrate or separate the material [6]. This makes the adsorption bubble isolation approach applicable to a broader variety of compounds, such as ions, molecules, precipitate, active carbon, nano particle, proteins, and bacteria [6].

## **3. Characteristics of an adsorptive bubble column**

Porous frit creates bubbles on a continuous basis, providing a broad surface region for substance movement from the bulk solution. The bubble diameter is observed to be a high function of the orifice diameter and a weak function of the gas velocity in the orifice at low gas velocity (0.5 cm/sec) [7]. The diameter of a bubble at high gas velocity is determined by the gas flow rate. It's important to note that the presence of an electrolyte in a solution has an effect on the bubble scale. In the presence of electrolytes in the water, smaller bubbles form due to surface tension and the electrostatic potential of the resulting ions at the gas–liquid interface. The size of the bubble is determined by the electrolyte concentration and form. Foam Separation and Non-Foaming Separation are the two major types of adsorptive bubble separation methods. To take away liquid, foam separation necessitates the development of a foam or froth. The separating of products using a non-foaming

*Separation of Bovine Serum Albumin (BSA) Protein by Foam Fractionation Technique DOI: http://dx.doi.org/10.5772/intechopen.99943*

process would not necessitate the use of foam [7]. Bubble fractionation and solvent sublation are two subsets of the Non foaming Adsorptive Bubble Separation Process. The movement of fluid inside a liquid by adsorption or addition on the bubble surface, accompanied by deposition of material at the top of the liquid as the bubbles leave, is known as bubble fractionation. Solvent sublation refers to the transition of substance from one miscible liquid to another, or from one miscible liquid to an immiscible liquid mounted on top of the main liquid. Foam fractionation and froth flotation are two different types of foam separation. The foaming off of dissolved content from a solution through adsorption at the bubble surfaces is known as foam fractionation. The removal of particulate material by frothing is known as froth flotation. Based on the material, which can be molecular, colloidal, or microparticulate, froth flotation can be separated into many branches. Mineral extraction from ores using froth flotation in a special situation. Macroscopic particles are separated using macro flotation. The separation of microscopic particles, especially colloid or microorganisms, by foaming is known as micro flotation. Precipitate flotation is the practise of removing a precipitate using a surfactant that is not the precipitating agent. Ion flotation is the isolation of surface inactive ions by foaming with a catcher, which produces an unsolvable liquid, especially whenever the substance is extracted as scum. Molecular flotation, on the other hand, is the isolation of surface inactive molecules by foaming with collectors and resulting in an insoluble substance. Finally, adsorbing colloid flotation is the separation of a solute through adsorption on colloid particles followed by flotation. The following methods can be used to operate the Adsorptive Bubble Separation Process [8]. (a) Simple continuous flow, (b). Simple Batch, (c) Combined enriching and stripping, (d) Continuous flow stripping, (e) Continuous flow enriching by reflux, (f) Staged operation [8].
