Development of Low Cost Adsorbent from Cow Horn for the Biosorption of Mn (II), Ni (II) and Cd (II) Ion from Aqueous Solution

Abstract

Development of low cost adsorbent from cow horn for the biosorption of Mn (II), Ni (II) and Cd (II) ion aqueous solution was carried out by batch adsorption experiment at 32°C. Parameters such as pH, contact time, metal ion concentrations as well as temperature were monitored. The residual concentration of Mn (II), Ni (II) and Cd (II) were determined using Atomic Absorption Spectrophotometer. The results revealed that maximum Ni (II) and Cd (II) ion removal occurred at pH of 6 while Mn (II) ion occurred at pH of 7 respectively. Langmuir and Temkin adsorption isotherm were used to describe the equilibrium data. The equilibrium data fitted well to Langmuir isotherm than Temkin isotherm. Thermodynamic investigation showed that standard Gibbs free energy (ΔGº) was positive indicating the feasibility and non-spontaneous of the process. The positive value of standard Enthalpy (ΔHº) implies that the reaction was endothermic and the negative standard Entropy (ΔSº) signifies decrease in the randomness at the solid/solution interface of the adsorbent during the adsorption process. The kinetic study revealed that adsorption of Mn (II), Ni (II) and Cd (II) could be best described by pseudo-second model. This study demonstrated that adsorbent developed from cow horn could be used as an alternative to commercial activated carbon in the removal of Mn (II), Ni (II) and Cd (II) ions from aqueous solution.