Removal of basic dyes from aqueous solutions using calix[4]resorcinarene carboxylic acid derivatives

Abstract

Water-insoluble calix[4]resorcinarenes derivative 1 and 2 were synthesized and used as sorbents to extract selected basic dyes rhodamine B (RB), methylen blue (MB) and methyl violet (MV). The isolated complex: calix[4]resorcinarene 1-dye were characterized by Fourier transform infrared spectroscopy, Fluorescence spectroscopy, PDRX and Differential scanning calorimetric analysis. The dye adsorption experiments were carried out from an aqueous solution in a batch reactor. The effect of several parameters has been determined to obtain the best experimental conditions. The equilibrium adsorption data were interpreted using Langmuir and Freundlich isotherms models (best correlation: R2 > 0.997). The calculated maximum adsorption capacity (qmax) for the RB at 25 °C were 29.49 mg/g at pH=8.3. The mechanism of adsorption onto the calix[4]resorcinarene is considered to be due to a host-guest interaction between the dye and azo-calix[4]resorcinarene molecular cavity. The results showed that calix[4]resorcinarene (1) can be considered as potential adsorbents for basic dye from dilute aqueous solution