Activation of Malatya Hekimhan zeolites with mechanochemical method and usage in heavy metal adsorption

In this study, the removal of heavy metals (Pb, Ni and Cd) from groundwater and wastewater was investigated. The removal of such heavy metals, which causes toxic effects on the body when exceeding a certain limit of concentration, was investigated by using natural zeolite, obtained in Malatya/Hekimhan region, as an adsorbent. This study was carried out in three stages. In the first stage, the zeolite was milled down to a size of -150 microns by grinding in a classical ball mill. XRD and SEM analyzes were performed for the characterization of the ground zeolite. In the second stage, synthetic solutions of heavy metals were prepared. Adsorption tests were carried out with the prepared synthetic solution. The optimum adsorption parameters were determined by performing experiments in different parameters such as pH, mixing time, temperature and mixing speed acting on adsorption. In the third stage, grinding operations by using planetary ball mill were carried out to increase the surface area and pore structure of the natural zeolite. Grinding with planetary ball mill was carried out at 180 rpm for 180 minutes and at 540 rpm for 120 minutes. The same experimental parameters applied to natural zeolites of -150 microns in the adsorption tests were then applied to the planetary ball milled zeolites. For the natural zeolite, the highest adsorption values of three heavy metals were found at pH 11. The maximum adsorption efficiencies of 78% for Pb, 67% for Ni and 54% for Cd were obtained. Natural zeolites milled in planetary ball mills showed that the maximum adsorption yields were 93% for Pb, 72% for Ni and 57% for Cd at pH 9.