LAUSR

The layer-by-layer technique (LbL) is an efficient and sustainable low-cost methodology for the removal of heavy metal ions from various matrixes. The present work is focused, for the first time, on the evaluation of the extraction processes of Ni(II) and Zn(II) by the LbL technique with respect to the studies of the solvent effect, reaction kinetics, adsorption isotherm models and thermodynamic parameters. The extraction of Ni(II) and Zn(II) was based on the design of multilayers of these metal complexes with 8-hydroxyquinoline (8HQ) due to the formation of Ni(8HQ)2 and Zn(8HQ)2 complexes, respectively. The efficient sorption of metal ions was found to follow the dissolution order of 8HQ in methanol > ethanol >1-propanol >1-butanol > acetonitrile. The surface adsorptive removal processes of Ni(II) and Zn(II) from aqueous solution were evaluated by four different kinetics models and were found to be better fit to the pseudo-second-order model with R2 corresponding to 0.9891 and 0.9995, respectively. The i...