KAJIAN SELEKTIVITAS SORPSI MAGNETIT TERLAPIS HIBRIDA MERKAPTO-SILIKA TERHADAP ION Au(III) DALAM CAMPURAN Au(III)-Ni(II); STUDY ONSORPTION SELECTIVITY OF MERCAPTOSILICAHYBRID COATED MAGNETITE TOWARD ION Au(III) IN THE MIXTURES Au(III)-Ni(II)

DAMANIK, DEDDY RONALD, Nuryono

2016 | Skripsi | FMIPA

A selective sorption of Au(III) in a mixed system of Au(III)-Ni(III) on mercapto-silica hybrid coated magnetite (M-HMS) has been investigated. Magnetite was synthesized through coprecipitation method from a mixture of salt Fe2+ /Fe3+ with NH4OH solution as a precipitated agent. Magnetite coating was done by sol-gel method with a solution of sodium silicate precursor extracted from rice husk ash and 3-mercaptotrimetoksisilane (MPTMS) with the addition of NH4OH and HCl to adjust pH 7. Sorption of Au(III) and Ni(II) was performed through a batch system at pH 3. The metal ions of Au(III) and Ni(II) adsorbed quantitatively were calculated based on the difference of metal concentration before and after adsorption analyzed with Atomic Adsorption Spectrophotometer (AAS). Desorption of Au(III) and Ni(II) was conducted by eluting the ions with solution of thiourea in HCl at various time. Result showed that Au(III) was adsorbed on M-HMS more than Ni (II). Desorption of Au(III) and Ni(II) both single and binary systems Au/Ni followed kinetics mode of pseudo-second-order with a higher value of rate constant (k) for Au(III than that for Ni(II). Desorption selectivity of Au(III) toward Ni(II) gave selectiv ity coefficient ? of 3.676 .

Kata Kunci : gold, adsorption, desorption, mercapto, thiourea