STUDI ADSORPSI-DESORPSI ANION FOSFAT, SULFAT DAN NITRAT PADA ZEOLIT TERMODIFIKASI CTAB; ADSORPTION-DESORPTION STUDIES OF PHOSPHATE, SULPHATE, AND NITRATE ANIONS ON CTAB MODIFIED ZEOLITE

MAYA SARI ANANDA POHAN, Sutarno

2015 | Disertasi | FMIPA

The aims of modify natural zeolite Klaten with CTAB (cetiltrimetilammonium bromide) on these research is to make anionic adsorbent for phosphate, sulphate and nitrate contaminants. Desorption of phosphate, sulphate and nitrate on water and citric acid 0.33 M medium to know the potential of modified zeolite as slow release fertilizer has been studied. The research was started by preparation, activation and modification of natural zeolite. Natural zeolite, activated zeolite and modified zeolites were then charactherized by XRD, FTIR, SEM-EDS and determination of cation exchange capacity. The modified zeolites were then used to adsorption of phosphate, sulphate and nitrate. Study of phosphate sorption include influence of pH, contact time, kinetic and adsorption isoterm. After adsorption, anions were desorbed in water and citric acid 0.33 M medium. Concentration of phosphate, sulphate and nitrate was determined using spectrometer UV-Vis. The results show that modification of natural zeolite with CTAB caused surface of zeolite covered by CTAB, so it can adsorp the anion phosphate, sulphate and nitrate. The maximum adsorption of phosphate was at pH=5, contact time=60 minute. The sorption equilibrium data are in good agreement with the Ho kinetic model (adsorption rate=0.112 g mmol-1 minute -1) and the Langmuir isotherm model with adsorption capacity=8.873 x 10-5 mol g-1 and K=28.972 x 105 g mol-1. Amount of desorption in citric acid 0.33 M medium was higher than in water medium, following the sequence: sulphate> phosphate ? nitrate. Based on these results, CTAB modified zeolite that adsorbed anions have potential to be applied as slow release fertilizer.

Kata Kunci : zeolite; modified; adsorption; desorption