Chemical reactions in liquid membrane permeation-separation

An example is provided by Cahn and Li (1974), where phenol is removed from a wastewater feed into a receiving phase containing NaOH through an oily liquid membrane. The sodium phenolate is rejected completely by the nonpolar oily membrane. When the reaction is instantaneous and the concentration of A is essentially zero at the interface y = 5m, the flux of species A is simply proportional to the feed concentration of species A, Cj Le. 

Two questions are of interest here. First, phenol (species 1) is the only species permeating through the liquid membrane. Is the concentration of the phenol essentially zero in the caustic-containing receiving phcise Second, if this concentration of phenol is finite (but very small), what is this value so that, when the feed phase has this concentration, permeation will stop These questions cU e answered here using calculations available in Cahn and Li (1974). 

Phenol is a weak acid tmd it dissociates in feed water (/ = fiv) or strip water Q — sw) as follows  

Suppose the feed wastewater pH is 7 and the receiving phase contains 10 wt% NaOH (2.773 M). 

M Receiving Phase Feed Phase M Receiving Phase Feed Phase M 

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