Effect of Coexisting Ions on the Removal of Zn2+ from Aqueous Solution Using FePO4

FePO4 material was suitably elaborated to exploit its adsorption capacity to remove Zn2+ from aqueous solution, and its structural properties were thoroughly examined using different physical chemical techniques. Plasma-induced emission spectrometer (ICP) was used to determine the concentrations of Zn2+ and heavy metals after the measurement is validated. The aim of this research is to evaluate the adsorption process of zinc ions from aqueous solutions with iron phosphate and the effect of the matrix ions on the removal by changing the pH and temperature. At the beginning, the best adsorption ratio was determined from the concentrations used for zinc ions ranged between 0.25– 2.00 mg/L. The adsorption data followed both the Langmuir, Freundlich Temkin, Dubinin–Radushkevich, Koble–Corrigan and Sigmoidal Langmuir isotherms. Maximum adsorption capacities as quantified by the Dubinin–Radushkevich parameter Qmax was 104.31 mg/g. Then a competitive mixture of metal ions was also investigated. It has been observed that it is affected by the matrix of metal ions according to the following sequence Co2+ > Cu2+ > Cd2+ > Ni2+ > Cr3+ > (Fe2+, Fe3+) > Zn2+and the adsorption increases with increasing heat. The ΔH values follow the order: Li+ > Cu2+ > Cr3+ > (Fe2+, Fe3+) > Zn2+ > Cd2+ > Ni2+ > Mn2+ > Co2+.