Pembuatan komposit magnet oksida besi-karbon aktif sebagai adsorben Cs dan Sr

Abstract

Iron oxide and iron oxide-activated carbon magnetic composites have been prepared by co-precipitation method at temperature 70oC. The magnetic composite were prepared with ratios of 1:1, 1:2, and 1:3 by weight. The magnetic composites were made to obtain adsorbent which can be responsive to magnetic field so that it can be separated by simple magnetic procedure. The result from X-ray diffraction characterization showed a similarity of diffraction peak of iron oxide and magnet composite with specific peak in PCDFWIN program data base no 11-0614, which is iron oxide of magnetite (Fe3O4). Magnetization value of iron oxide and magnetic composites measured by vibrating sample magnetometer were 76.59, 25.6, 18.9, and 11 emu/g, respectively. Magnetization value decreased due to the lowering iron oxide fraction in the sample. Characterization using scanning electron microscope showed little particle of iron oxide. Microstructure of activated carbon showed large pores, while magnetic composite revealed iron oxide particles that cover and surround on the pores of the activated carbon. Surface area measured by Brunauer, Emmett, and Teller equipment showed decreasing surface areas of the activated carbon after composited with iron oxide. Adsorption experiment showed that higher Cs and Sr adsorption capacity occured at adsorbent 0.0125 g and initial concentration 200 ppm. Optimum pH for Cs adsorption occured at pH 7, while that of Sr adsorption was lower at pH 6.