LAUSR

Abstract Rhamnolipid-layered double hydroxide (RL-LDH) nanocomposite for simultaneous adsorption of p -cresol and Cu 2+ from aqueous solution was synthesized through delamination/reassembling process. The characteristics of the obtained RL-LDH nanocomposite was analyzed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, inductively coupled plasma atomic emission spectrometry, CHN elemental analysis, specific surface area, zeta potential, and transmission electron microscopy, confirming that RL − anions were successfully introduced into the interlayers of LDH. The adsorption of p -cresol and Cu 2+ in single and binary systems by RL-LDH was studied in detail. The effect of factors including RL-LDH dosage, initial solution pH, contact time, initial p -cresol/Cu 2+ concentration, and temperature on the adsorption were investigated. The results showed that (1) the adsorption capacities of RL-LDH for both p -cresol and Cu 2+ were much larger than that of LDH; (2) the pseudo-second-order kinetic model fitted well with the adsorption of p -cresol (or Cu 2+ ) on RL-LDH; (3) the p -cresol (or Cu 2+ ) adsorption isotherm could be well described by Freundlich model. The RL-LDH nanocomposite after adsorption was characterized by XRD, FTIR, and X-ray photoelectron spectroscopy, and the adsorption mechanism was discussed. Efficient p -cresol (and Cu 2+ ) adsorption was mainly due to the hydrophobic interaction of p -cresol (and the complexation of Cu 2+ ) with RL − anions in the interlayer of RL-LDH.