Extraction and Recovery of Phenol from its Aqueous Solution Using Vegetable Oil as Liquid Membrane

Abstract

In this work an attempt has been made for extraction of phenol from its aqueous solution with minimal use of carrier or no carrier at all. Studying the effects of various parameters such as feed phase concentration, feed phase pH, carrier concentration, strip phase concentration and temperature have been the key objectives along with the effect of salt loading in the transport process. Aqueous solution of phenol (C6H5OH) was used as the feed phase, sunflower oil was the preffered solvent used as the liquid membrane phase in the current work. Aqueous solution of NaOH was found to be the best solvent for the stripping of phenol. Performances of various carriers has been investigated and Trioctyl phosphine oxide (TOPO) was found to be the suitable carrier in facilitating the transport process. The transport mechanism was found to be effective in a low pH of 2 in the feed phase and the equilibrium time was 12 hrs for both presence and absence of carrier. The optimized feed concentration, strip concentration were 100 ppm and 1.25 N for both the cases (with and without carrier). In presence of carrier, when temperature was increased, the extraction and recovery percentages decreased from 94.9 % and 85.2 % at 300C to 56.1 % and 48.69 % at 450C respectively. Whereas in absence of carrier, the extraction and recovery percentages increased from 74.7 % and 74.1 % at 300C to 85.23 % and 84.7 % at 450C. Further increase in temperature upto 500C resulted in decrease in extraction as well as recovery (64.52 % E and 49.38 % R). The presence of inorganic salts in the aqueous phase such as NaCl and KCl, enhances the extraction of phenol.