Adsorption of copper ions from solution using xanthate wheat straw.

To enhance adsorption capacity of wheat straw (WS) toward copper ion from solution, carbon disulfide was used to modify WS by a facile grafting method through epichlorohydrin and ethylenediamine. So WS containing xanthate groups (XWS) was obtained. The XWS was characterized using elemental analysis, X-ray diffraction, infrared spectroscopy and adsorption property of XWS toward copper ions. The results showed that S was introduced into the surface of WS. The solution pH was in favor of Cu2+ adsorption at pH 5, while NaCl existing in solution was slightly favorable for adsorption. The adsorption kinetic followed the pseudo-second-order kinetic model, while the adsorption isotherm curve was well fitted using the Langmuir model. The adsorption capacity was 57.5 mg·g-1 from experiment. The process was entropy-produced, endothermic and spontaneous in nature. The column adsorption was performed and Yan model was good to predict the breakthrough curve. XWS as adsorbent is promising to remove copper ions from solution, and this offers one way of effective utilization of waste byproduct from agriculture.