Removal of ibuprofen and 4-isobutylacetophenone by non-dispersive solvent extraction using a hollow fibre membrane contactor

The removal of pharmaceutical pollutants such as ibuprofen (IBU) and its metabolite 4-isobutylacetophenone (4-IBAP) from water was investigated in a laboratory scale commercial hollow fibre membrane contactor by non-dispersive solvent extraction. The effects of water and solvent flow rates (92-474 ml/min) on the shell and tube side of the hollow fibre, respectively, were investigated. The hollow fibres were found to be very efficient in reducing the concentrations (10-110 mu g/ml) of the pharmaceuticals in water by approximately 90% or greater within the first couple of minutes of experiment showing extremely fast kinetics. Faster removal was obtained when the organic phase flowed at a higher rate than the aqueous feed phase. The effect of aqueous phase pH on the removal was tested in the pH range 2-10. Ibuprofen removal was greatly affected by pH with close to 100% removal occurred at pH 2, and less than 20% removal occurred at pH 10. Removal of ibuprofen metabolite (4-isobutylacetophenone) was not affected by pH, and an average removal of 96% was achieved at both basic and acidic pH. The laboratory-scale experiments were conducted in both batch and once through modes. The mass transfer coefficients were also estimated under various operating conditions. (C) 2011 Elsevier B.V. All rights reserved.