关键词: 氢氧化镁, 重金属离子, 吸附热力学, 动力学

Abstract: The thermodynamics and kinetics for magnesium hydroxide on adsorption of Cu(Ⅱ) and Zn(Ⅱ) were studied.The effects of magnesium hydroxide on dealing with heavy metal ions in wastewater were summarized.The results showed that the concentrations of Cu(Ⅱ) and Zn(Ⅱ) are below the National Standards for Discharge of Water Pollutants when the dose of magnesium hydroxide are 0.35 g/L and 0.60 g/L.Magnesium hydroxide has a better adsorption capacity of Ⅱ) and Zn(Ⅱ), and the adsorption isotherm accords with Langmuir mode.The maximum adsorption amount is 76.92 mg/g and 37.04 mg/g respectively.Thermodynamic parameter ΔG are -29.32 kJ/mol and -32.20 kJ/mol for Cu(Ⅱ) and Zn(Ⅱ) after calculation.The second-order kinetic equation can well describe the dynamics characteristics of Cu(Ⅱ) and Zn(Ⅱ) absorption with Magnesium Hydroxide with a related coefficient of 1.000.The current research results showed that the adsorption isotherm of Ni(Ⅱ), Cd(Ⅱ) and Cr(Ⅲ) et al with magnesium hydroxide were all consistent with the Langmuir model and the adsorption effects were distinct.

Key words: Magnesium hydroxide, Heavy metal ions, Adsorption thermodynamics, Kinetics