Kajian Sensitisasi Asam Fulvat pada Fotoreduksi Cr(VI) Menjadi Cr(III) oleh Fotokatalis TiO2
ABSTRACT: Sensitization of
fulvic acid (FA) on photoreduction of Cr(VI) to Cr(III) by TiO2 photocatalyst
has been studied. Parameters influencing the sensitization, i.e., pH of medium,
as well as FA concentrations, TiO2 concentrations and initial Cr(VI)
concentrations were critically evaluated. Extraction of FA from peat soil
sampled in Gambut, South Kalimantan, Indonesia, was performed using Amberlite
XAD-7 resin. The FA extract then was purified by cation exchange method using
Amberlite IRA-120 resin. The TiO2 produced by Merck was used as semiconducting
photocatalyst and two 30-W UV lamps (Philips® model TUV) were used as photon
source. The results showed that presence of FA on TiO2 suspensions could
sensitize the photoreduction of Cr(VI), enhancing of the amount of reduced
Cr(VI) more significantly than the sensitization by humic acid. The
effectiveness of this sensitization increased with increasing initial
concentrations of FA, TiO2, or Cr(VI) until certain concentration, but no
further improvement can be observed in excess FA, TiO2, or Cr(VI)
concentrations. On the contrary, the effectiveness of this sensitization
decreased with increasing of the medium pH.
Penulis: Uripto Trisno
Santoso, Kamilia Mustikasaria, Sri Juari Santosa, Dwi Siswanta
Kode Jurnal: jpkimiadd070080
