E ABDI - Department of chemistry, Faculty of science, University of zanjan, Zanjan, ۴۵۳۷۱- ۳۸۷۹۱, Iran
N DALALI - Department of chemistry, Faculty of science, University of zanjan, Zanjan, ۴۵۳۷۱- ۳۸۷۹۱, Iran
N VAEZI - Department of chemistry, Faculty of science, University of zanjan, Zanjan, ۴۵۳۷۱- ۳۸۷۹۱, Iran

Heavy metal pollution is one of the major environmental problems today that threatens human health and ecological systems. One of the most dangerous heavy metals is Cd with high level of toxicity and stability [1]. Heavy metals present in wastewaters are normally removed by different treatments, including chemical precipitation, reverse osmosis, electro dialysis, ion exchange and biosorption [2]. The biosorption process involves a solid phase (biological material) and a liquid phase containing dissolved species to be adsorbed due to higher affinity of biosorbents for the adsorbate species [3]. Daylily is a flowering plant in the genus Hemero Callis. The presented method is based on the sorption of dissolved cadmium ions from aqueous solution by Daylily investigated as function of initial pH, agitation rate, initial concentration of dissolved Cd(II), amount of adsorbent and contact time. The optimum conditions for the preconcentration were obtained as 10 mg of adsorbent, pH of 4, agitation rate of 300 rpm, concentration of Cd(II) solution is 1 mg L-1, contact time 30 min, The extracted cadmium was determined by flame atomic absorption spectrometry. Under the optimum conditions The relative standard deviation (RSD) was obtained as 0.69.