Open AccessKinetics and Isotherms of a Green Method for the Sorption of Metal Ions from Aqueous Solution
Author(s) -
Hatem Asal Gzar,
K. M. Kseer,
Mohsin J. Nasir
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/888/1/012077
Subject(s) - adsorption , freundlich equation , sorption , gibbs free energy , enthalpy , aqueous solution , langmuir , chemistry , standard molar entropy , metal ions in aqueous solution , metal , thermodynamics , organic chemistry , physics
Owing to their toxicity, the existence of heavy metals in the environment has become a major global concern. In this study, the ability of albizia-lebbeck tree leaves (ALTL) as green and low cost adsorbent to remove Pb 2+ , Zn 2+ and Cd 2+ from Synthetic wastewater by adsorption was investigated. The initial metals’ concentrations of 10-80 mg/l, adsorbent dosage of 0.3-1.0 gm, pH of 3-8, contact time of 30-240 min, and shaking speed of 200 rpm, have been studied by batch adsorption technique. Four ranges of adsorbent particle size were tested: 75-150; 150-300; 300-600; 600-1000 μm. Five different temperatures (20, 30, 40, 50 and 60°C) were selected to demonstrate the influence of temperature on metals’ adsorption onto ALTL. Langmuir and Freundlich models were used to analyze the experimental data. Equilibrium data fitted well with the Freundlich isotherm model with maximum adsorption capacity of 9.124 mg/g at 20°C for metals’ concentration of 40 mg/L. Pseudo-first-order and pseudo-second-order equations were utilized for analysis of the kinetic data. The second-order model was fitting very well with the experimental data. Thermodynamic parameters like entropy, enthalpy and Gibbs free energy changes were estimated to determine the spontaneity of the sorption process. The results revealed that the ALTL adsorbent performed good removal of metals.