A novel facial composite adsorbent for enhanced copper(II) detection and removal from wastewater

In this study, novel ligand immobilized facial composite adsorbent was prepared for sensitive and selective copper (Cu(II)) ions detection and removal from wastewater samples. Several effects such as initial pH, Cu(II) ions concentration, shaking time, foreign ions and regeneration was determined and systematically discussed. The process also allowed visual Cu(II) ions detection by a colorless to blackish change. The Cu(II) ions were detected and removed at pH 7.0. In the acidic pH region, Cu(II) ions was not detected and removed due to the high concentration of hydrogen ions. As an optical material, the composite adsorbent responded quickly to the addition of Cu(II) ions, and recognized the Cu(II) ions at ultra-trace level. Under optimum conditions, the limit of detection by the composite adsorbent for Cu(II) was 0.15 mu g/L. The presence of foreign ions did not interfere with Cu(II) detection, indicating the high selectivity toward Cu(II) ion at pH 7.0. The sorption equilibrium was achieved within a short contact time, which showed the superior properties among different forms of adsorbents. The maximum sorption capacity was 176.27 mg/g based on the Langmuir sorption isotherm study. The ion selectivity was also performed in the presence of diverse competing ions and Cu(II) ions was preferentially removed in a competitive environment. Moreover, adsorption-elution cyclic results demonstrated that Cu(II) adsorbed composite adsorbent could be effectively regenerated by a HCl acid, and the regenerated composite adsorbent could be employed for repeated use without significant deterioration in its real performances, demonstration the good stability of the adsorbents. Therefore, the composite adsorbent can be used potentially to detect and remove Cu(II) ions from water samples in practical applications for environmental remediation. (C) 2015 Elsevier B.V. All rights reserved.