Equilibrium study of dried orange peel for its efficiency in removal of cupric ions from water

ABSTRACT

Excess of copper ion (>2 mg/L) in water is toxic to human beings and the ecosystem. Various water treatment technologies for copper remediation have been investigated in the past. Along with industrial effluents, Bordeaux mixture is also a noteworthy copper contamination source in the agricultural ecosystem. In our study, the biosorbent efficiency of dried orange peel was investigated through an environment-friendly process for the removal of cupric ions. Effects of pH, adsorbate concentration, adsorbent dosage, and temperature for the removal of Cu (II) were studied. Slightly acidic environment (pH = 6) was found to be optimum for removal of copper. The equilibrium data were well fitted with the Langmuir and Freundlich isotherms. The surface morphology of the adsorbent was studied using scanning electron microscope. Crystalline nonhomogenous surface was observed after copper adsorption. Desorption study indicated that 0.1N H₂SO₄ is the best eluent for the removal of adsorbed copper from the powdered dried orange peel.

KEYWORDS:

• pH
• isotherm models
• dried orange peel powder biosorbent
• copper biosorption
• Atomic Absorption Spectroscopy (AAS)

Acknowledgments

This research was supported by the department of PG Studies & Research in Chemistry, and Department of PG Studies & Research in Biotechnology, St. Aloysius College, Mangaluru, Karnataka. We would like to thank Dr. Leo D'Souza SJ for manuscript review.