Investigation of dye removal from aqueous solutions by Preyssler assisted-ultrafiltration: UV-visible and photoluminescence study

The aim of this work is to study the interaction between preyssler type polyoxometalate K-14 [NaP5W29Mo1O110] (P5M30) and crystal violet (CV) dye using UV-visible (UV-vis) and photoluminescence (PL) spectroscopy. The complexation-ultrafiltration method is also studied in order to retain CV from aqueous solution using for the first time the P5M30 as complexing agent. The addition of P5M30 polyanions to the CV solution leads to the formation of metachromatic complex. They revealed by the blue shift of the absorption maxima of the dye. This variation is attributed to the formation of dye H-aggregates. The emission spectra show a progressively decrease in the intensity band as function of P5M30 concentration increase which indicate that there is an interaction between dye and P5M30. The Preyssler assisted-ultrafiltration reveals that the CV retention was significantly enhanced from 10% to 98% following the addition of P5M30. The effect of chemical additives such as P5M30, NaCl and CTAB concentrations, the pH and the applied pressure on the dye retention and permeate flux have been also investigated.