Removal of Pb2+ ions from aqueous medium by using chitosan-diatomite composite: equilibrium, kinetic and thermodynamic studies

Abstract

Abstract: In this study, a novel, low-cost, natural, and highly effective adsorbent, chitosan (Ch) -diatomite (D) composite was synthesized. Ch-D composite was tested as an effective and alternative adsorbent for the removal of Pb²⁺ ions. The Ch-D composite was characterized by FT-IR, SEM-EDX and PZC analyses. The adsorption process of Pb²⁺ ions onto Ch-D as initial lead concentration, solution pH, temperature, contact time and recovery was investigated. From the adsorption process results, it has been observed that the highest removal efficiency is approximately 95% at a contact time of 4-hour, initial Pb²⁺ concentration of 500 mg L^-1 and agitation speed of 150 rpm at natural pH 4.0. The maximum Pb²⁺ adsorption capacity from the Langmuir model was found as 0.154 mol kg^-1 at 25 ^oC. Besides, adsorption kinetics was also explained with pseudo-first-order models. Adsorption thermodynamics have shown that Pb²⁺ adsorption onto Ch-D is possible, spontaneous and exothermic. Ch-D composite can become an alternative adsorbent for the treatment of lead ions in the wastewater.

Keywords

• Diatomite,chitosan,composite,adsorption,lead

Supporting Institution

Sivas Cumhuriyet Üniversitesi

Project Number

ZARA004

Thanks

The present study (Project no: ZARA004) was supported by the Cumhuriyet University Scientific Research Projects Commission. The authors strongly declare that no scientific and/or financial conflicts of interest, exists with other people or institutions.

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