Abstract:We use an inexpensive adsorbent produced from orange residue found to remove the Cr(Ⅵ) from an aqueous solution. We investigate the factors influencing adsorption performance and the adsorption mechanism of the orange residue adsorbance of Cr(Ⅵ). The results show that the contact time, pH, and initial Cr(Ⅵ) solution concentration affect the adsorption process. At pH 4 and 40℃, the equilibrium is attained in about 11 hours, and adsorption quantity of the adsorbent is 12.85 mg/g with liquid/solid (hexavalent chromium vs. adsorbent) of 18 mg/g. The ideal saturated amount is 13.74 mg/g as determined by the linear least squares method. The adsorption process fits the Bangham adsorption kinetics model. At a low concentration range, the process also follows the Langmuir and Freundlich adsorption isotherms. Experimental results and the adsorption mechanism show that the orange residue adsorbent is an effective treatment for wastewater containing Cr(Ⅵ).