Adsorption of Orange II dye from aqueous solutions using phosphoric-acid modified clam shell powder

Abstract

In this study, the clam shell, a waste biomaterial, was modified with phosphoric acid to improve the adsorption amount of Orange II dye. The effects of initial concentration, contact time, and temperature on the adsorption were studied. The equilibrium adsorption data of Orange II on the phosphoric acid-modified clam shell powder (PCSP) were adequately represented by Langmuir isotherm with an adsorption capacity of 1,017.13 mg/g, which is higher than that obtained using raw clam shell powder. Adsorption kinetics followed the pseudo-second-order rate expression. Thermodynamic parameters show that the process is exothermal, feasible, and spontaneous. The effect of temperature inferred that the type of adsorption in the study is a physical adsorption. Therefore, PCSP is an efficient and economical adsorbent for dye removal.

Keywords:

• Adsorption
• Orange II
• Clam shell
• Wastewater treatment
• Dye

Acknowledgments

This study was supported by the Project of National Natural Science Foundation of China (Nos 21007005 and 20907038), a Project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, and Technology Innovation Team of Colleges and Universities Funded Project of Jiangsu Province (2011-24).