Efficient copper ions adsorption property of the composite sepiolite-based polyethyleneimine alginate microspheres in wastewater treatment

Heavy metal ions widely existing in the surface water systems can cause serious harm to humans and the environment. The present work has been carried out and presents the novel fabrication processes of sepiolite-based polyethyleneimine alginate microspheres (SPEIAM) and the characterizations of Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy for this composite material. SPEIAM has been efficiently utilized to remove copper ions from the simulated copper-containing industrial wastewater through adsorption method. The adsorption behaviors of SPEIAM for copper ions, including the effect of pH, the effect of adsorbent dosage, adsorption isotherm, adsorption kinetics, adsorption selectivity properties have been investigated. The results indicate that the adsorption kinetics of SPEIAM for copper ions at different temperatures can be modeled by the pseudo-second-order rate equation, the experimental data fit well with the Langmuir isotherm model which indicates the monolayered way of the adsorption and the maximum adsorption capacity of SPEIAM for copper ions could reach 490.20 mg/g, which is much higher than those values of other adsorbents reported in the literatures, and the extraordinary features of SPEIAM for copper ions removal can ensure their applicability and feasibility in the indust rial scale.