The Study On Recovery Of Proteins From Wastewater Using Single/Dual Foam Fractionation

Foam fractionation is a kind of separation technology emerging in recent decades.It has some advantages such as simple equipment,low investment,high efficiency and suitable for dilute solution etc.Owing to these advantages,foam fractionation has a very broad application prospects and widely used in mineral flotation,chemical engineering,biological engineering,biomedical,environmental engineering and so on.During the conventional foam fractionation process(CFFP),the foam are no longer present spherical owing to the interaction between bubbles.A self-organized non-equilibrium bubble system,complex foam structures,size polydispersity(the diameter of most foam from 1 to 7 mm),random location of bubbles and liquid refractive index of far greater than that of the gas cause complex refractions and total reflections between bubbles and bubble borders,making it is difficult in studying on a bubble.A single/dual stream foam separation device was constructed to simplify the CFFP by minimizing the interactions between bubbles,for the purpose of understanding the fundamentals.The research mainly includes the following aspects:1.A single/dual-stream foam fractionation device was designed and optimized.Ultimately,the device meet the requirements of our experiment and gain the single and dual stream foam successfully.2.Experiments were carried out to investigate the influences of the operating conditions,such as the inlet protein concentration,surfactant concentration,pH,the height of foam column.The experimental results showed that these parameters had a great influence on dual-stream foam fractionation(DSFF).We also found that the E of DSFF is much higher than single-stream foam fractionation(SSFF).Analyzed the structure of single and dual-stream foam,the conclusion that the middle drainage channel plays a key role in the enrichment phenomena was gained.3.With the help of microscope and ImageJ(?),the thickness which was difficult to measure in CFFP was acquired easily in SSFF and DSFF.Based on the material conservation,the simple mathematical model of liquid content and protein concentration of a bubble at different height of column was achieved.The result present that the agreement of experimental and predicted data is excellent.