EKSTRAK HUMAT TINJA SAPI UNTUK ADSORPSI KOMPETITIF ION LOGAM Pb(II) DAN Ni(II) DALAM LARUTAN; HUMIC EXTRACT OF COW DUNG FOR COMPETITIVE ADSORPTION OF Pb(II) AND Ni(II) IN SOLUTION

YULI NURMAYANTI, Bambang Rusdiarso

2014 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

The study of competitive adsorption between Pb(II) and Ni(II) ions on humic extract from cow dung has been done. The aims of this study are to investigate the extraction and character of humic extract, effect of medium acidity, determination of kinetics and isotherm parameters adsorption of Pb(II) and Ni(II) in solution using humic extract. Extraction were done by two pathways, with and without boiling. The identification and characterization of humic extract were carried out by FTIR spectroscopy, determination of ash content and acidity by furnace and titration method. Based on the characterizations spectra, ash content and acidity, showed that cow dung extract contains humic acid (HA) and HA produced by method 1 was better than method 2. The optimum Pb(II) and Ni(II) adsorption by HA reached at pH 4 and followed by pseudo second-order kinetic model. The adsorption rate constant Pb(II) and Ni(II) on HA were 2.116 g/mg.minute and 0.064 g/mg.minute, respectively. This adsorption isotherm followed Langmuir isotherm model. The adsorption capacities calculation based on Langmuir’s equation for Pb(II) and Ni(II) adsorption were 0.299 mmol/g and 0.175 mmol/g, respectively. Thus, HA adsorbs more selectively to Pb(II) than Ni(II) in various concentrations.

Kata Kunci : Asam Humat; Tinja Sapi; Adsorpsi Pb(II) dan Ni(II); Adsorpsi Kompetitif