Novel modified chitosan nanocomposites for Co(II) ions removal from industrial wastewater

Abstract

Herein, novel and efficient nanocomposites of modified chitosan (Cs) with citric acid (Cit.) and beta-cyclodextrin (Beta CD) were manufactured and explored, first-ever, to remove cobalt ions (Co) pollutant from wastewater. The prepared adsorbents, Cs-Cit and (Cs-Cit)-Beta CD were scrutinized via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The uptake capacities of Co2+ using different samples were studied. Factors influencing the sorption of Co2+; for example, time, pH, dosage of adsorbent, preliminary ions concentration, and temperature were studied. The maximum adsorption capacities of Co2+ using raw Cs, Cs-Cit, and (Cs-Cit)-Beta CD were found to be 6.90, 18.50, and 43.95 mg.g−1, respectively. Kinetics pursued a pseudo-second-order paradigm and thermodynamic studies suggested that Co2+ sorption on the modified chitosan adsorbents was exothermic compared to the endothermic nature of the raw Cs adsorption. Adsorption–desorption experiments affirmed the renewability and competitiveness of the prepared materials as adsorbents for Co2+ removal. As well, applications of these adsorbents were investigated for cobalt ions elimination from real water samples (tap, Nile, industrial water samples) confirming they are considered virtuous candidates for wastewater treatment.