SINTESIS KOMPOSIT KITOSAN-MAGNETIT TERMODIFIKASI ASAM OLEAT DAN KAJIAN KELAYAKANNYA SEBAGAI ADSORBEN Hg(II); SYNTHESIS OF MAGNETITE-CHITOSAN COMPOSITE MODIFIED OLEIC ACID AND THE STUDY OF ITS PROPERNESS AS ADSORBENT FOR Hg(II)

Kusumaningrum, Hesty, Suyanta

2015 | Skripsi | FMIPA

Synthesis of magnetite-chitosan composite modified oleic acid (KMTAO) as adsorbent for Hg (II) had been done. This research?s purpose were to utilize shrimp shell waste as a raw material in fabrication of an useful material specifically magnetite-chitosan composite, to determine the optimum pH adsorption and to review the adsorption kinetics and capacity of the adsorbent itself. Magnetite-chitosan composite was synthesized through chitosan extraction and synthesis of magnetite modified oleic acid by coprecipitation method process, followed by composite synthesis process. The extraction of chitosan from shrimp shell was done by several steps, that were deproteination, washing and drying, demineralization, depigmentation, and deacetilation of chitin to chitosan with NaOH 60%. Magnetite synthesis was performed with coprecipitation method, by adding aqueous NH4OH to a solution containing Fe3+ and Fe2+ at pH 11.5 followed by added 3 mL oleic acid. In composite synthesis, a 0.5 g of chitosan and 1.5 g of magnetic modified oleic acid were added to 12 mL of acetic acid solution 2.0%. The mixture was treated by 10 min sonochemistry, then a 2 mL of glutaraldehyde solution 25% was added into the solution and aged for 3 hours to perform the cross-linking reaction. Composite was collected by magnetic separation and therefore washed with double distilled water and ethanol for several times. The results showed that magnetite-chitosan composite modified oleic acid was successfully synthesized confirmed by FTIR, XRD, VSM, and TEM analysis results. By using the Scherrer equation, the particle size of composite was around 19.05-42.61 nm. Characterization with TEM shows that magnetite materials were encapsulated with oleic acid, causes magnetite particles looks bigger and separated each other. The adsorption study of Hg(II) on KMTAO composite showed the maximum adsorption occurs at pH 5. The adsorption kinetic study of Hg(II) using KMTAO composite coincide well to the pseudo second order kinetic with the value of k2 2756.39 (g.mol-1.min-1). Adsorption isotherm data followed the Langmuir isotherm model with the value of adsorption capacity at 11.19 mg.g-1 (5.58×10?5 mol.g-1).

Kata Kunci : magnetite-chitosan; kinetic; capacity; adsorption Hg(II)