Use of Agro-Industrial Wastes for Removal of Basic Dyes from Aqueous Solutions

The biosorption potential of three different agro-industrial waste materials of lignocellulosic origin, i.e., coir pith (CP), sawdust (SD) and sugarcane fiber (SF), is investigated in the case of basic dyes, i.e., crystal violet (CV) and rhodamine B (RB). The uptake of dyes from aqueous solutions is found to be rapid when using these candidate biosorbents. The application of various kinetic models reveals good correlation of a pseudo-second order kinetics model with the experimental data. Equilibrium adsorption data have been analyzed using nonlinearized forms of the Langmuir, Freundlich and Redlich-Peterson isotherms, to determine the best fit equation for the adsorption process. Experimental results show that all of the adsorbents are effective for the removal of dyes from aqueous solutions and their adsorption capacities are comparable with other reported adsorbents. Since the agricultural solid waste materials used in the present investigation are freely and abundantly available, the adsorption process is expected to be economically viable for wastewater treatment.