BENTONIT TERMODIFIKASI MAGNETIT DAN APLIKASINYA SEBAGAI ADSORBEN Hg(II); BENTONITE MODIFIED WITH MAGNETITE AND ITS APPLICATION AS ADSORBENTS OF Hg(II)

RETNO AGNESTISIA, Suyanta

2014 | Disertasi | PROGRAM STUDI S2 ILMU KIMIA

In this research natural bentonite was activated with solution of HCl 5 M, modificated with magnetite and then applicated as adsorbent of Hg(II) in water medium. Modification was done by coprecipitation method in the molar ratio Fe2+: Fe3+ = 1 : 2 of various concentration molar Fe2+: Fe3+ (0.05 : 0.1; 0.025 : 0.05; 0.125: 0.025). In addition, temperature was varied (25?C; 50?C; 85?C) at the optimal concentration of Fe2+ : Fe3+. Characterizations of materials were done using FTIR, XRD and N2 fisiorption methods. In the adsorption of Hg(II), the optimum pH, kinetic and equilibrium aspects of adsorption were studied.The result showed that acid activation process decreased the impurities minerals and increased the montmorillonite content from 61.88% to 66.94% and increased surface area from 11.986 m2/g to 116.475 m2/g. Modification of bentonite with magnetite optimum at ratio concentration molar Fe2+: Fe3+ of 0.025 : 0.05 and temperature 85?C. The activated and modified of bentonite can adsorbed Hg(II) from aqueous phase, with the maximum adsorption at pH 5. Adsorption of on those of adsorbent followed the kinetic eqution of pseudo order 2 proposed by Ho and McKay (1999) with reaction rate constant for activated and modified of bentonite was 1,316 x 10-3 dan 2,125 x 10-3 g/mg.menit, where as the isotherm adsorption according to Langmuir isotherm. Modification of bentonite with magnetite increased the adsorption capacity until about two time and accelerated the adsorption of adsorbent from aqueous phase using external magnet field.

Kata Kunci : bentonit; modifikasi; magnetit; adsorpsi