Facile fabrication of spherical flower-like Mg(OH)2 and its fast and efficient removal for heavy metal ions

Spherical flower-like Mg(OH)2 was fabricated from MgSO4 effluent and its adsorption performance for heavy metal ions was evaluated. The appropriate fabrication conditions are as follows: Mg2+/NH4OH molar ratio of 1:0.5, temperature of 120 degrees C and time of 1 h at Mg2+ concentration of 2 mol/L. Spherical flower-like Mg(OH)2 composed of ultra-thin sheets exhibits an excellent adsorption ability for Ni2+, Cu2+, Zn2+, Pb2+, Fe3+ and Co2+, and the adsorption reaches the equilibrium in 6 min. The maximum adsorption capacities of the studied heavy metal ions onto Mg(OH)2 at 20 degrees C are 58.55, 85.84, 44.94, 485.44, 625.00 and 27.86 mg/g, respectively. The adsorption is well fitted by the Langmuir model, indicating that the adsorption is monolayer. The adsorption kinetics follows the pseudo-second -order model. Chemisorption is the operative mechanism. Spherical flower-like Mg(OH)2 is a qualified candidate for heavy metal ions removal.

Automated summary

In this study, spherical flower-like Mg(OH)2 material was successfully fabricated and its adsorption performance for heavy metal ions was evaluated. The experimental results showed that the material exhibited excellent adsorption ability for Ni2+, Cu2+, Zn2+, Pb2+, Fe3+ and Co2+ and reached equilibrium in a short time. Furthermore, the adsorption followed the Langmuir model and pseudo-second-order kinetics, suggesting chemisorption as the operative mechanism.