Facile fabrication of spherical flower-like Mg(OH)2 and its fast and efficient removal for heavy metal ions
(1. Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), School of Metallurgy, Northeastern University, Shenyang 110819, China;
2. Liaoning Key Laboratory for Metallurgical Sensor and Technology, Northeastern University, Shenyang 110819, China;
3. School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, China)
2. Liaoning Key Laboratory for Metallurgical Sensor and Technology, Northeastern University, Shenyang 110819, China;
3. School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, China)
Abstract: 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 °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 °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.
Key words: MgSO4 effluent; flower-like Mg(OH)2; heavy metal ion; adsorption