Separation Behavior of Penicillin in Aqueous Two-Phase Flotation

Based on the application of aqueous two-phase flotation (ATPF) in the separation and concentration of penicillin from aqueous phase, the separation behavior of penicillin in the ATPF process is investigated. The kinetic behavior and the penicillin status in organic phase are studied under the conditions of room temperature, 300 mL penicillin aqueous solution of 2.5 g L−1, initial pH 7.0, ammonium sulfate concentration of 350 g L−1, and 10 mL polyethyleneglycol (PEG) aqueous solution (50%, w/w). Using three flow rates, the kinetic results showed that there are two stages in the separation process of ATPF: (1) precipitation flotation and (2) molecular adsorption flotation, and both of them follow the first-order kinetics equation. Moreover, the differential spectrum of organic phase showed that penicillin ion could directly dissolve into PEG phase. This is the reason that the separation efficiency of ATPF is significantly higher than that of the traditional extraction techniques.