Removal of Zn(Ⅱ) ions from aqueous solution using chemically modified Annona reticulata seeds: kinetics, isotherm and thermodynamics

摘要

In the present study, the removal of Zn(II) ions from synthetic effluent has been studied using sulphuric acid-modified Annona reticulata seeds (SMARS) as a biosorbent. The characteristics of the SMARS have been analyzed with scanning electron microscopy and X-ray diffraction analyses. The adsorption influencing parameters such as pH, initial metal ion concentration, time, mass of SMARS and temperature have been experimented and optimized. The optimum conditions for the maximum removal of Zn(II) ion for an initial Zn(II) ion concentration of 50 mg/L was measured as: pH of 6.0, adsorbent dose of 1.0 g/L, contact time of 30 min and temperature of 30 degrees C. The results of the optimization studies have been utilized to analyze the kinetics, equilibrium and thermodynamics on the removal of Zn(II) ions by SMARS. The results of the present research showed that the pseudo-first order and Freundlich models were best obeyed with the experimental data based on the higher correlation coefficient and low error values. The Langmuir maximum monolayer adsorption capacity of SMARS for the removal of Zn(II) ions was calculated as 223.1 mg g(-1). The thermodynamic results indicated that the adsorption was found to be spontaneous and exothermic process. The prepared SMARS can be utilized as an effective material for the removal of pollutants from the aquatic systems.