Effect of Batch Removal of Copper from Aqueous Solutions Using Tannin-immobilized Hide Collagen

Abstract

This study is aimed at preparing collagen fiber from cow hide and to utilize it as cheap, effective and alternative adsorbent against the more expensive and relatively less effective techniques for the removal of Cu(II) ion from aqueous solution and to find a suitable pH, equilibrium isotherm, kinetic model and thermodynamics using a batch mode. A novel adsorption membrane was therefore prepared by immobilizing Acacia nilotica tannin onto hide collagen (ANTIHC). The results obtained in this study showed that the uptake of the metal ions increased with increase in initial metal ion concentration and pH. The optimum contact time of 40 min was achieved in this study. The equilibrium data fit well with the Freundlich isotherm (R2 = 0.93) than the Langmuir isotherm (R2 = 0.65) and the Temkin isotherm fairly described the adsorption. The results of pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion equation work showed that the pseudo-second order provides the best correlation (R2 =1) for the adsorption process, whereas the Elovich equation did not fit the experimental data (0.08) Thermodynamic study showed that the reaction was non-spontaneous because the value of Gibb’s free energy was positive while the value of ∆H indicate exothermic nature. Also, the adsorption increases as the temperature increases indicating that the process is chemisorptions. The adsorbents were characterized with SEM analysis which was used to obtain the characteristics of the adsorbates; EDAX analysis confirmed that immobilized tannin gained additional functional groups while the FT-IR analysis showed functional groups such as amine, hydroxyl, carbonyl and carboxyl groups that were responsible for the sorption of the metal ions onto the biomasses. The results of this study however revealed that ANTIHC can be used as suitable biosorbent for the removal of Cu ion and it may be an alternative to more costly methods used for removal of heavy metal ions from waste waters and aqueous solution in a batch mode system. The results also showed that ANTIHC have excellent adsorption properties that are probably due to increase in surface active sites for adsorption.