Abstract
Amoxicillin in the municipal water system needs to be removed due to the toxicity towards creatures. In this work, Mg-Al LDH/cellulose nanocomposite beads (LDH@CB) were synthesized by an in situ coprecipitation procedure and were used as novel adsorbents for amoxicillin removal in the aqueous phase. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), The specific surface area test (BET), scanning electron microscopy (SEM), ζ potential, X-ray electron energy (XPS) were employed to confirm the success load of LDH onto CB. The large specific surface area (76.46 m2 g−1), high water content (92.05%) and high porosity (94.75%) of LDH@CB made the adsorbent suitable in water treatment. The adsorption process was kinetically fitted with the pseudo second-order kinetic model while isothermally fitted with the Freundlich isotherm model. It was found that the maximum adsorption capacity of LDH@CB qm was 138.3 mg g−1. Meanwhile, the results from XPS and ζ potentials revealed the AMX removal mechanism: Under natural pH conditions, AMX was negatively charged and LDH@CB was positively charged, the contaminant and the adsorbent were linked by electrostatic interaction through OCO⋯M (Mg/Al). These results showed that the adsorbent design method had a wide application prospect in the water purification field.
•In-situ coprecipitation method was used to design Mg-Al LDH@CB.•Porous cellulose matrix provided confined synthesis spaces for Mg-Al LDH particles.•Adsorption affinity between amoxicillin and Mg-Al LDH@CB was electrostatic force.•Amoxicillin was adsorbed by Mg-Al LDH@CB with the highest capacity of 138.3 mg g−1.