Author(s)

Che Randy Nangah^1,2, Tagne Guy Merlain², Ndi Julius Nsami², Chongwain Paul Tubwoh³, Josepha Foba-Tendo⁴, Ketcha Joseph Mbadcam¹

¹Physical and Theoretical Chemistry Laboratory, Department of Inorganic Chemistry, University of Yaounde I, Yaounde, Cameroon.
²Local Materials Promotion Authority (MIPROMALO), Ministry of Scientific Research and Innovation, Yaounde, Cameroon.
³Department of Chemistry, Faculty of Science, University of Bamenda, Bamenda, Cameroon.
⁴Department of Chemistry, Faculty of Science, University of Buea, Buea, Cameroon.

This study reports on the adsorption efficiency of a natural iron oxide from Mballam-Cameroon in comparison with synthesized goethite to simulta-neously remove cobalt and nickel ions from aqueous solutions. Chemical analysis on the natural iron oxide sample revealed iron as the main element and hematite (58.52%) goethite (19.42%), kaolinite (12.69%) and quartz (7.79%) as the component phases in the iron oxide sample. The iron oxide was found to be microporous (BET surface area 43.27 m²/g) with fairly spherical polydisperse particles. Results show maximum absorption for Co(II) and Ni(II) ions for both adsorbents occurred at an equilibrium contact time of 80 mins, dose rate of 0.1 g/L, and pH = 7. Goethite was slightly more efficient at removing target metal ions with maximal adsorbed quantities at 117.8 mg/g of Co(II) and 100.6 mg/g of Ni(II), and 103.9 mg/g of Co(II) and 85.2 mg/g of Ni(II) ions for natural iron oxide. Equilibrium modelling presented the Freundlich isotherm as the best fit model for both adsorbents and metal ions, indicating heterogeneity of the surface binding sites during adsorption. The pseudo-second order kinetic model was the best-fit model, indicating chemical adsorption between the adsorbent surface and metal ions, hence a good correlation between equilibrium and kinetics. The findings indicate that the efficacy of the natural iron oxide from Mballam is almost equivalent to that of synthetic goethite, validating its applicability for the simultaneous removal of cobalt and nickel ions from aqueous solution.

Adsorption, Iron Oxide, Goethite, Powder Diffraction, Heavy Metals, Water Treatment

Nangah, C. , Merlain, T. , Nsami, N. , Tubwoh, C. , Foba-Tendo, J. and Mbadcam, K. (2019) Synthesized Goethite and Natural Iron Oxide as Effective Absorbents for Simultaneous Removal of Co(II) and Ni(II) Ions from Water. Journal of Encapsulation and Adsorption Sciences, 9, 127-147. doi: 10.4236/jeas.2019.93007.