Removal of Copper from Aqueous Solutions by Adsorption on Elemental Selenium Nanoparticles

The removal of copper from aqueous solutions using elemental selenium nanoparticles (nanoSe(0)) was presented. The uptake of copper by nanoSe(0) depended on reducing agents, such as ascorbic acid (Vc) which reduced Cu(II) to Cu(I). The results of scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) indicated that nanoSe(0) adsorbed copper by interacting between nanoSe(0) and cuprous ions to form copper selenide (Cu2Se) on the surface of nanoSe(0). The effects of the mass of nanoSe(0), contact time, pH, initial Cu(II) concentration, and temperature on the removal of copper were investigated. The adsorption kinetics was well-described by the pseudosecond-order equation which suggested that the model was indicative of a chemical adsorption mechanism. The adsorption isotherm was better fitted by the Langmuir equation. The maximum adsorption capacity of nanoSe(0) for copper was found to be 0.89 g.g(-1) at 298.15 K. The nanoSe(0) coexisting with Vc was a promising adsorbent for the removal copper ions from aqueous solutions. Moreover, the semiconductor materials Cu2Se could be obtained.