Removal of two textile dyes from aqueous solutions onto calcined bones

The adsorption of textile dyes such as Direct Red 75 and Direct Red 80 onto calcined bone was studied for their removal from aqueous solutions. The adsorption of Direct Red 75 and Direct Red 80 occurred by studying the effects of adsorbent amount, dye concentration, contact time, pH media and temperature. The adsorption rate data were analyzed using the intraparticle diffusion model, pseudo first order and the pseudo second order kinetic models to determine adsorption rate constants. The isotherms of adsorption data were analyzed by various adsorption isotherm models such as Langmuir, Freundlich and Tempkin. All results found concluded that calcined bone could be effectively employed as an effective new low cost adsorbent for the removal of textile dyes from aqueous solutions.