Synthesis And Characterization Of Calcium Bentonite Xanthan Gum Composite As Slow Release Fertilizer Fe(III)

Abstract

The purpose of this study was synthesis calcium bentonite-xanthan gum composites, characterization of composites, and determine of adsorption and desorption capacity of composites on Fe(III). Characterization of the composites is done by determine the functio nal group using FT-IR, determine the crystallinity using XRD, and determine major and minor element using XRF. In this study, the release of Fe(III) and potential as a slow release fertilizer were analyzed using UV-Vis spectrophotometry. The adsorpstion capacity of calcium bentonite-xanthan gum composites on Fe(III) was carried out for 1 hour with variatio n adsorbate concentrations of 18, 21, 24, 27 and 30 ppm. The results show that the maximum composite adsorption ability were obtained at concentration of 27 ppm. Chemical equilibr ium follows the Langmuir isotherm model with an adsorption capacity of 10.416 mg/g. Slow release test using desorption method with destilled water to calcium bentonite-xanthan gum composite at 27 ppm concentration. Slow release Fe(III) test from the composite used time variation of 0, 15, 30, 45, 60, 90, 120 and 180 minutes. The result is Fe(III) carry out from the bentonite pore structure. Peak time of Fe(III) desorption is 30 minutes which amount of Fe(III) being desorption at 4.64 ppm.