Study on the adsorption performance of La(III) and Y(III) on malic acid-kaolinite nanocomposite

摘要

This paper reported an innovative method for the preparation of kaolinite nanocomposites and the application in the adsorption of rare earth elements (REEs). This method firstly inserted malic acid into the kaolinite layers, then the malic acid-kaolinite intercalation complex was calcined with Na2CO3 and malic acid at a high tem-perature. The power provided by the neutralization reaction promoted malic acid between the kaolinite layers to decompose thermally, and finally obtained the malic acid-kaolinite nanocomposite (EKMA). This method overcame the problem of kaolinite with low adsorption efficiency, which was owing to strong hydrogen bonding between kaolinite layers. The specific surface area of EKMA was significantly increased, and the adsorption capacity for La(III) and Y(III) were as high as 128.5 mg/g and 145.2 mg/g respectively. The pseudo-second-order model and Langmuir model fitted the adsorption kinetics and isotherm well. Therefore, EKMA was expected to be applied in the treatment of REEs waste in industrial wastewater.