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 (Cu 2 Se) 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 Cu 2 Se could be obtained.