Removal of phenylalanine from water with
calcined CuZnAl−CO3 layered double hydroxides
calcined CuZnAl−CO3 layered double hydroxides
(1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. Changsha Research Institute of Mining and Metallurgy CO., LTD. Changsha 410012, China)
2. Changsha Research Institute of Mining and Metallurgy CO., LTD. Changsha 410012, China)
Abstract: Cu−Zn−Al−CO3 layered double hydroxide (LDH), with a Cu to Zn mole ratio of 5:1 and a (Cu+Zn) to Al mole ratio of nearly 2, was prepared and its calcined product (CLDH) was obtained. Batch sorption studies were conducted to investigate removal of phenylalanine from water with CLDH. The results show that CLDH can be used as an effective adsorbent and its sorption capacity is higher than that of Mg−Al−CO3−LDH. The maximum adsorption was observed at pH 6.7. A maximum adsorption capacity is 37.25 mg/g. The adsorption processes follow the Lagergren’s first order kinetic model. The adsorption data are fitted well with the Langmuir isotherm equation. The thermodynamic parameters were calculated, and the negative and positive indicate that the adsorption processes are spontaneous endothermic in nature. The mechanism of adsorption also suggests that the benzoate molecules are tilted, forming an angle with the hydroxyl layers.
Key words: Cu−Zn−Al−CO3−LDH; phenylalanine; adsorption; mechanism