Adsorptive removal of 2, 4 dichlorophenol by polysulfone/graphene oxide blended microcapsules immobilized with CYPHOS® IL 103 ionic liquid

Abstract

2,4-Dichlorophenoxyacetic acid (2,4-D), a phenoxyalkanoic acid herbicide, is among the most widely distributed pollutants in the environment. 2,4-Dichlorophenol (2,4-DCP), as the main metabolite which frequently detected in the environment resources. The toxicity of 2,4-DCP is more severe than that of its parent 2,4-D at any concentration levels. In this study, removal of 2,4-DCP from aqueous solution using graphene oxide (GO) + Trihexyl(tetradecyl) phosphoniumdecanoate [CYPHOS® IL 103] ionic liquid entrapped in polysulfone (PSF) capsule as an adsorbent (GO/IL/PSF microcapsule) is reported. Various techniques such as X-Ray diffraction, Fourier transform infrared spectroscopy, Field emission scanning electron microscopy and Brunauer-Emmett-Teller have been used to identify and confirm the formation of GO, functional group, surface morphology and surface area of the capsule. The adsorption capacity has been investigated under different experimental conditions including pH (2-10), initial 2,4-DCP concentration (20-100 mg L−1), temperature (293-313 K) and at 250 rpm. It has been found that 97% of 2,4-DCP removed from aqueous solutions with adsorption capacity (qe) of 388 mg.g-1 at optimized experimental conditions. The equilibrium adsorption of 2,4-DCP on capsule can be best described by Langmuir isotherm model, with a maximum adsorption capacity (qmax) of 398 mg.g-1 at room temperature. The adsorption kinetics is well described by the pseudo-second-order kinetic model than pseudo first order model and Freundlich kinetic. These results shows that capsule have promising application for adsorption of 2,4-DCP from aqueous solution.According to desorption research, the IL/GO/PSF may be renewed six times with a 1 N sodium hydroxide solution. IL/GO/PSF microcapsule is appropriate for use in fixed bed columns, which treat huge volume of wastewater.