Transportation of Catechin (±C) Using Physiologically Benign Vegetable Oil As Liquid Membrane

This paper presents an experimental study on the simultaneous extraction and recovery of catechin through bulk liquid membrane (BLM). Various environmentally benign solvents, namely vegetable oils, have been used as liquid membrane along with various transport-enhancing carrier agents to identify the best solute-carrier combination that would yield optimum performance of the BLM. Tributyl phosphate (TBP) (carrier) in sunflower oil (SFO) (solvent) is found to be the best among the tested combinations. Initially two-phase (feed-Membrane) equilibrium studies have been carried out in order to study the effects of operating conditions, namely pH, temperature, initial feed concentration, and carrier concentration, on the equilibrium distribution. Based on these results, simultaneous extraction and recovery of the catechin have been carried out in a BLM type liquid membrane configuration using ethanol as the stripping agent and the optimum operating conditions are redefined accordingly. Seventy percent extraction and 44% recovery of the catechin have been achieved respectively at the optimum conditions of the parameters namely 0.36 M TBP in the membrane phase, 0.2 M ethanol as stripping agent, 400 rpm stirring speed, and 25 degrees C temperature from an initial aqueous feed of 4.0 pH and 100 mg L-1 concentration. Maximum fluxes of the extraction and recovery were found as 5.7 x 10(-9) g cm(-2) s(-1) and 4.9 X 10(-9) g cm(-2) s(-1), respectively.