Study of Efficiency of Natural Clinoptilolite Zeolite in Cadmium Removal from Aqueous Solutions and Determination of Adsorption Isotherms

Nowadays, potential risks have been well known for human health which associated with toxic heavy metals in environment.Cadmium is one of the most important heavy metals that its presence in aquatic environment have created many concerns due to high toxicity at low concentrations and the ability to accumulate in living tissues. several methods have been studied to remove of heavy metals but, using low prices absorbents has been considered by researchers to remove these metals in recent years. in this research, we will study cadmium removal by natural clinoptilolite zeolite. Material s &

The experiments were conducted with natural zeolite discontinuous. To determine the characteristics of zeolite, Scanning Electroni Microscop (SEM) and X-ray diffraction Device (XRD) have been used. effect of some parameters have studied on efficency of cadmium elimination and adssorption isotherms, including: PH (2,4,6,8,10), contact time (30, 60, 90, 120, 150 min), adsorbant dosage (0.2,0.5,0.8,1,2 gr) and mtetal ion concentration (10, 50, 100 mg/L).

According to absorption of cadmium process results, The optimum PH was equal 6 with removal efficencies of 83.3% and equiliberium time of 90 minuts with removal efficencies of 93.1%,. As expected, The amount of absorbed cadmium ereduced by increasing the concentration of cadmium. Between both models Langmuir and Freundlich isotherm, Langmuir model have described cadmium adsorption of cadmium on the adsorbent better than Freundlich.

The results of current study have indicated that natural linoptilolite zeolite can be used as an efficient and I nexpensive absorbent to elemination of cadmium in aquatic environments.