Waste Cotton and Cotton/Polyester Yarns as Adsorbents for Removal of Lead and Chromium from Wastewater

Abstract

The possibility of using waste cotton and cotton/polyester yarns to remove lead and chromium ions from polluted water was investigated in this work. Structural, morphological, and adsorption properties of yarns were determined by iodine sorption, water retention scanning electron microscopy, Fourier transform infrared spectroscopy, and streaming potential method for determination of an isoelectric point. It was found that the presence of polyester component negatively affects adsorption capacity, through the reduced porosity of cotton/polyester yarn surface, increased surface, and structural crystallinity. Relatively fast adsorption of lead and chromium ions from binary mixture onto cotton and cotton/polyester yarns follows the pseudo-second order kinetic, while equilibrium data fitted better with the Langmuir isotherm model, with maximal adsorption capacity from 259.0 to 824.7 mu g/g. Although, cotton yarn shows slightly higher maximal adsorption capacities, both cotton and cotton/polyester yarns can be utilized as cheap and highly efficient adsorbents for removal of lead and chromium ions from water.