Kinetic and equilibrium adsorption studies of Pb and Zn ions from aqueous solution onto plantain stalk (Musa paradisiaca)

O B Eyenubo

doi:10.4314/jasem.v22i6.5

Abstract

This study presents the sorption of Pb2+ and Zn2+ from aqueous solution by Musa Paradisiaca (plantain stalk) with respect to its equilibrium and kinetic behaviour. The optimum pH was found to be 5.0 and 6.0 for the sorption of the Pb (II) and Zn (II) ions respectively. At pH 5.0, the biomass sorbed 91.7% Pb(II) and 89.85% Zn(II), while at pH 6.0, the biomass sorbed 91.16% Pb (II) and 89.55% Zn (II). The contact time for the sorption was found to be rapid in the first 5mins. The amount of metal ion sorbed was found to be rapid from the lowest concentration, 10 mg/L to the highest concentration, 500 mg/L. The Langmuir and Freundlich model for dynamic metal ion uptake proposed were well fitted for Pb2+ and not well fitted for Zn2+. The structural groups of the adsorbent were characterized by Fourier transform infrared (FTIR) Spectrometry. The following were present; hydroxyl, carbonyl, amine and phosphate groups which confirms the potential processes of sorption of the biosorbent. The first order and second order rate equation were tested and it was found that pseudo-second-order is more suitable for the sorption, having the linear coefficient of determination R2 value of 0.999. The result obtained from this study indicated that plantain stalk (Musa Paradisiaca) could be employed for the removal of heavy metal contaminants from industrial effluents.Keywords: Plantain stalk, kinetics, adsorption, biosorbent

Highlights

Despite a lot of benefits obtained from industrialization, it has been shown that is one of the major environmental pollution (Osakwe and Ibrahim, 2017)
Developing nation like Nigeria faces solid waste disposal problem, this necessitate the need for the conversion of this plantain stalk serving as waste in the environment to useful products for removal of metal ions from aqueous solution, which is a cheap adsorbent and it will be of great benefit to the environment and as well as scientific community
This study is aimed at generating useful information for the effective utilization of native agricultural byproducts such as plantain stalk (Musa paradisiaca) for the removal of metal ions from aqueous solution

Summary

Introduction

Despite a lot of benefits obtained from industrialization, it has been shown that is one of the major environmental pollution (Osakwe and Ibrahim, 2017). Hynda and Rachida, (2008), studied the biosorption of lead (II) ions from aqueous solution by biological activated dates stems, by carrying out batch experiment under varied conditions of pH, contact time, initial Pb2+ dates stems concentration and temperature. The physicochemical characteristics of biomass were studied They observed that as zinc adsorption is increasing, contact time, biomass weight, pH and agitation speed are increasing, while adsorption efficiency decreased with increasing particles sizes for temperature above 500C. Developing nation like Nigeria faces solid waste disposal problem, this necessitate the need for the conversion of this plantain stalk serving as waste in the environment to useful products for removal of metal ions from aqueous solution, which is a cheap adsorbent and it will be of great benefit to the environment and as well as scientific community. This work has looked at the kinetics of the sorption and the equilibrium modeling of the process

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Conclusion