Removal of copper ions from dilute synthetic solution using staple ion exchange fibres: Equilibrium and kinetic studies

The removal of heavy metals like copper (Cu²⁺ ions) from industrial waste streams is necessary so as to prevent detrimental effects to the environment and human health. One of the effective adsorbents that can be used for the removal of heavy metals are ion exchange fibres (IEFs). Therefore, this paper focuses on equilibrium and kinetic studies of the Cu²⁺ ions removal process using IEFs. In addition, selectivity and elution tests were also conducted. The equilibrium and kinetic behaviour of Cu²⁺ ions removal was best described by the Temkin and the pseudo-second-order model, respectively. The results also indicated that the IEFs had a higher selectivity for Cu²⁺ ions than the other ions (cobalt (Co²⁺), nickel (Ni²⁺), zinc (Zn²⁺), manganese (Mn²⁺) and magnesium (Mg²⁺)) studied at pH 3 and 62 mg of Cu²⁺ ions per gram of IEFs were loaded at this pH. It was also found that the percentage of metal eluted from IEFs increased with an increase in eluent concentration. Furthermore, the ion exchange rate was found to be dependent on the number of ionizable functional groups as suggested by the pseudo-second-order model.