Iono-molecular Separation with Composite Membranes V. Nitro-phenol separation on n-alkyl alcohols supported liquid membranes

In this work are ongoing recent related studies on the separation of nitrophenols by composite membranes using this time an HFCLM membrane based on n-lower alkyl alcohols (C-6, C-8 si Ci(10)) on a well-characterized tubular polypropylene support. The results of nitrophenol separation, at a concentration of 5 mg/L in the source phase of pH 4.8, indicate the following optimal parameters of hydrodynamic regime, solvent and pH: source phase flow of 4.0 L/min, receiver phase rate 0.3 L/min; n-octanol, membrane solvent; the pH of the receiving phase that ensures maximum separation efficiency between 10 and 11; pH that ensures selective separation of m- and p-nitrophenols from m-nitrophenol between 8 and 10. The efficiency of nitrophenol separation through polypropylene capillary polymeric n-alcohol composite membranes reaches more than 90% at established working conditions, but operation below pH 12 will be considered in order not to cause membrane instability on the support.