Adsorption isotherm, kinetic and thermodynamic studies for the removal of Pb(II), Cd(II), Zn(II) and Cu(II) ions from aqueous solutions using Albizia lebbeck pods

S Mustapha,A Sumaila,U M Mohammed,M B Etsuyankpa,M M Ndamitso,M B Nasirudeen,D T Shuaib

doi:10.1007/s13201-019-1021-x

Abstract

Powdered adsorbent prepared from Albizia lebbeck pods as agricultural waste has been used for the adsorption of Pb(II), Cd(II), Zn(II) and Cu(II) ions from aqueous solutions. The powdered adsorbent was characterized by X-ray diffraction, Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller. Effects of various parameters like contact time, solution pH, initial concentration dosage and temperature were investigated on a batch adsorption system. Equilibrium and kinetic experiments were carried out at the optimum pH of 6, 8 and 10 at 29 °C using particle size of 250 μm for Cd(II), Pb(II), Zn(II) and Cu(II) ions. Changes in free energy, enthalpy and entropy were also evaluated. The adsorption data fitted well with the Langmuir isotherm model with correlation coefficient (R^{2} > 0.94), whereas the adsorption kinetics followed the pseudo-second-order kinetics. The thermodynamic parameters proved that adsorption of metal ions is endothermic and non-spontaneous at low temperatures, while spontaneity occurred at higher temperatures. This study shows that powdered Albizia lebbeck pods prove to be a promising inexpensive adsorbent for metal ion removal from aqueous solutions.

Highlights

Industrial activities in developed, underdeveloped and developing countries in recent times have faced a lot of problems due to improper disposal of wastes
The present study has demonstrated that Albizia lebbeck pods powdered can be used as a natural, promising, economic and environmentally friendly adsorbent for Pb(II), Cd(II), Zn(II) and Cu(II) from aqueous solutions
BET, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were used to analyse for the surface area, phase identification and functional groups that are responsible for the metal ion removal from aqueous solutions

Summary

Introduction

Industrial activities in developed, underdeveloped and developing countries in recent times have faced a lot of problems due to improper disposal of wastes. Several analytical methods have been pointed out and used for the removal of heavy metals from aqueous solutions These include chemical precipitation, ion exchange, ultra-filtration, reverse osmosis, electrodialysis and adsorption (Reddy et al 2014; Zare et al 2015; Banerjee et al 2016). Albizia lebbeck (Linn.) Benth is widespread tree grown in Senegal, Kenya, Angola, South Africa and in some parts of West African countries It is called a woman’s tongue in English. The pods of the tree do not have much importance to the environment and litter the environment especially during the dry season and often constitute an environmental nuisance This calls for research efforts in using this waste as an adsorbent for wastewater treatment. Kinetics, isotherms and thermodynamic studies of the lead, cadmium, copper and zinc on this adsorbent were carried out

Materials and methods

Conclusion

Compliance with ethical standards