**5. pH's impact**

Ion flotation is especially vulnerable to some of these parameters because variations in pH have a significant impact on the nature and charge of both collector and colligend. Several researchers mention some part of this dependence; the following are the consequences that can be observed when the pH is changed. Hydrolysis or the forming of other complexes can cause a change in the charge on the colligends. Ionisation of the collector can change; acids and amines, for example, can lose their charge at low and high pH values, respectively. They either stop being collectors or change their collecting mode. If ion flotation is preferred, the colligend can be precipitated as a hydroxide and then extracted by precipitate flotation instead of ion flotation. If ion flotation is desired, a difference in the pH can result in a change in the design of the method. The enhanced ionic strength that occurs when the pH is adjusted to extreme values will suppress flotation. The consistency of the foam that supports the sublate could deteriorate, resulting in re-dispersion.

### **6. Temperature**

When the foam durability of surface-active materials varies with temperature, temperature has been proposed as an operating variable. If the binding of the collector to the mineral surface is due to physical adsorption, surfactant adsorption and hence flotation could be assumed to decrease with an increase in temperature in the case of froth flotation of minerals. If somehow the adsorption is caused by chemical forces between the surfactant and the mineral particles, the result could be the reverse. Temperature, on the other hand, was observed to have no impact in the ion flotation and foam fractionation processes in many cases.

### **7. Gas flow rate**

The removal of dissolved compounds is heavily influenced by the gas flow rate, although steady state removals are unaffected. The distribution or division of

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

dissolved substances between the gaseous and aqueous phases is needed for their removal. The volume and size of gas bubbles, which increase interfacial space, cause an increase in removal at any given moment, depending on the gas flow rate. Low enrichment, on the other hand, increases as the loss of solution increases with a high gas flow volume. Of course, there must be enough gas flow to sustain the foam height, which is necessary for effective separation. The maximum flow rate, on the other hand, is calculated by the surfactant concentration and the foam's nature.

### **8. Other auxiliary reagents are present**

For better separation, many reagents are successfully used in foam separation techniques. In some situations, the results are due to particulate flocculation or collector activation for increased adsorption. Alum, ferric salts, and organic polyelectrolytes are the most widely used flocculation agents in foam separation. Using these flocculating reagents, for example, improved the removal of phosphate and suspended solids from waste water. Activators that facilitate preferential adsorption of the collector on a specific material are often used in the foam separation process.

### **9. Surface area of bubbles**

Spargo and Pinfold made an assumption, which Lemlich et al. addressed. In the flotation cell, they used a pore diameter of 10 μ for the frit. The smallest diameter of this method was 10 μ diameter, and the overall size was about 40 μ. As the flow rate grew, these values increased as well.

## **10. Foam height**

The isolation of albumin is influenced by the foam height, with the effect being more noticeable near the foam liquid interfaces. The foam stream changed dramatically as the foam height was increased from 3 to 17cms. The amount of the solution taken away in the shape of foam was 24 ml/min at a foam height of 30cms, and 10 ml/min at a foam height of 17cms. Furthermore, it was discovered that increasing the foam height resulted in a slight reduction in the process' productivity. At good operating conditions, the height of the transfer unit (HTU) varies slightly with column length for counter current lengths of 10 to 28cms.

### **11. Foam density**

The density of the foam is critical to the operation's progress. When the foam concentration is too high, the bubbles cannot rise to the surface as a result of the pressure, resulting in no separation. High densities of bubbles are seen when there is a large concentration of molecules in solution as well as a large concentration of collections.

### **12. Foam drainage**

While doing a foam separation, the extract must be condensed to a minimum amount as necessary. Foam drainage is usually accomplished by forcing foam upward across a stretch of extended column diameter. Sweitzer P.A. et al. designed a foam separating mechanism that allows the foams to migrate almost horizontally. He discussed about how this system is better than the vertical system. To begin with, the vertical portion of gas velocity is reduced to 0, and the distance from which the liquid must drain can be rendered uniform and set at any desired value. Second, laboratory experiments with static foams will estimate the drainage that occurs.
