STUDI ADSORPSI KOMPETITIF LOGAM Ag(I), Cu(II) DAN Cr(III) PADA ASAM HUMAT; COMPETITIVE ADSORPTION STUDY OF Ag(I), Cu(II) AND Cr(III) ON HUMIC ACID

LENI LASMI, Eko Sugiharto

2013 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

This research was carried out to investigate the ability of humic acid to adsorp Ag(I), Cu(II), and Cr(III) as a single and multiple metal ions. For this purpose, humic acid was isolated from peat soil that was taken from Pontianak, West Kalimantan. This study included the isolation of humic acid; the influence of acidity, time, and concentration to metals adsorption; and the competition of metals in their optimum conditions. Humic acid was extracted using base and was precipitated using acid. Then, the isolate of humic acid was characterized by means of infra red (FTIR), UV-Vis, and X-Ray Diffraction (XRD) spectrophotometry. Characterization of humic acid by means of FTIR spectrofotometry showed the bands of OH, C-H aliphatic, C=O carboxylic acid, and C=C aromatic. Based on UV-Vis spectrophotometry, showed only a slightly peak that seen at 260-280 nm. Diffractogram XRD showed that the humic acid was amorph. The influence of acidity to metals adsorption showed that Ag(I) was maximum adsorbed at pH 8, Cu(II) at pH 4, and Cr(III) at pH 3. On the study influence of contact time showed that Ag(I) reached the equilibrium at the 120th minute, Cu(II) at the 60th minute and Cr(III) at the 80th minute. Adsorption of ion Ag(I) reached equilibrium at 40 ppm, Cu(II) at 150 ppm, and Cr(III) at 10 ppm. Adsorption of Ag(I) followed the first-order kinetic, meanwhile Cu(II) and Cr(III) followed the second-order kinetic. Isotherm adsorption of Ag(I) and Cu(II) followed the equation of Langmuir, while Cr(III) followed the equation of Freundlich. Metals competition of Ag(I), Cu(II), and Cr(III) showed that in both competition of two metals or three metals, Ag(I) was maximumly adsorbed in acidity conditions. Cu(II) and Cr(III) were optimaly adsorbed in their each optimum conditions at two metals competition

Kata Kunci : ADSORPSI; KOMPETITIF LOGAM; Ag(I); Cu(II); Cr(III); ASAM HUMAT