ADSORPSI Au(III) PADA MATERIAL MAGNETIK PASIR BESI TERLAPIS SILIKA TERMODIFIKASI ETILENDIAMINA; ADSORPTION OF Au(III) ON MAGNETIC MATERIAL OF IRON SAND COATED WITH ETHYLENEDIAMINE MODIFIED SILICA

Heroyanto, Nuryono

2016 | Skripsi | FMIPA

Adsorption of Au(III) on iron sand (PB) magnetic material coated with silica (SiO2) modified using ethylenediamine (ED) group (PB@SiO2@ED) was done. Sodium silicate solution (Na2SiO3) was used as silica source and N-[3-(trimethoxysilyl)propyl]ethylenediamine (EDPTMS) as ethylenediamine source. The coating was carried out by mixing 0.5 g of magnetic material, obtained from iron sand, with 2 mL of Na2SiO3 solution (26.5% SiO2; 10.6% Na2O) and 1 mL of EDPTMS, followed by addition of HCl solution to form gel at pH 7. The synthesized materials were characterized by Fourier Transform Infrared (FTIR) spectrophotometer. Experimental parameters affecting Au(III) adsorption onto PB@SiO2@ED includes pH, contact time, and initial concentration were investigated. Characteristic of PB@SiO2@ED for adsorption included determination of rate constant of adsorption on several kinetic models and determination capacity and energy of adsorption using models of Langmuir and Freundlich adsorption isotherms were evaluated. The characterization with FTIR spectrophotometer showed there were specific absorption bands of functional groups from PB@SiO2@ED such as Fe-O, Si-O-Si, Si-OH, N-H, and C-H. Adsorption of Au(III) on PB@SiO2@ED was optimum at pH of 3 and contact time of 150 minutes. The rate constant of adsorption was 3 × 10-5 L mg-1 min-1. The adsorption followed the second order kinetics. The capacity and energy of adsorption were 140.845 mg/g and 23.809 kJ/mol and followed Langmuir isotherm model.

Kata Kunci : iron sand, silica, ethylenediamine, adsorption