MODIFIKASI ABU DASAR BATUBARA MENGGUNAKAN 8-HIDROKSIQUINOLIN SEBAGAI ADSORBEN ION Cu(II) DAN Cd(II); COAL BOTTOM ASH MODIFICATION USING 8-HYDROXYQUINOLINE AS AN ADSORBENT FOR Cu(II) AND Cd(II) IONS

NURHIDAYATI, Nurul Hidayat Aprilita

2015 | Disertasi | FMIPA

A research on adsorption of Cu(II) and Cd(II) ions coal bottom ash modified 8-hidroksiquinolin (CBAQ) had been conducted. This research aimed to examine the ability of CBAQ to adsorb Cu(II) and Cd(II) ions of the solution by using comparator adsorbent of activated coal bottom ash (CBAA). Some adsorption parameter i.e. initial pH, adsorbent mass, adsorption kinetics, and adsorption isotherm were examined in the adsorption processes. The adsorbents were characterized by scanning electron microscope (SEM) to show morphology of adsorbent, energy dispersive spectrometer (EDS) to calculate chemical composition onto bottom ash, powder X-ray diffraction (XRD) to describe the mineral constituent of CBAA and CBAQ crystalinity, fourier transform infrared (FTIR) to identify functional groups on the adsorbent, and Gas Sorption Analyzer (GSA) to determine pore properties including the BET surface area, pore volume, pore size distribution, and pore diameter. The experimental results showed that the optimum adsorption capacity was achieved at pH 6 for the both adsorbents. Adsorption capacity of CBAM was always greater than CBAA in all conditions. Besides, the adsorption affinity for Cu(II) was also greater than those for Cd(II) in all adsorbent types. Optimum contact time of CBAA was achieved in 180 minutes, and 90 minutes for CBAQ. The higher the concentration adsorbate used, the greater the adsorption capacity value of the resultant and begin to achieve the optimum of 70 ppm. The adsorption kinetic parameter of Cu(II) and Cd(II) ions on CBAA and CBAQ reached highest linearity in the equation pseudo-second order kinetic. Rate constant value (k) on adsorption using CBAA obtained 0.04 g mg-1 for Cu(II) and 0.01 g mg-1 for Cd(II). On other hand, rate constant value (k) on adsorption using CBAQ obtained 2.49×10-3 g mg-1 for Cu(II) and 8.53×10-4 g mg-1 for Cd(II). The Freundlich isotherm was best represented the equilibrium sorption of CBAA with KF value 0.04 mg L-1 and 0.03 mg L-1 for Cu(II) and Cd(II), respectively. CBAM was represented by Langmuir isotherm with KL value obtained 0.48 mg L-1 for Cu(II) and 0.11 mg L-1 for Cd(II). The differences of the adsorption constant values showed that adsorption capacity of Cu(II) and Cd(II) increase after modification.

Kata Kunci : 8-hydroxyquinoline, adsorption, bottom ash, cadmium, copper