Soerja Koesnarpadi
Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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KINETIKA ADSORPSI Cr(VI) MENGGUNAKAN ADSORBEN MAGNETIT (Fe 3 O 4 ) DAN MAGNETIT TERLAPIS ASAM HUMAT (Fe 3 O 4 /AH) Koesnarpadi, Soerja; Tarigan, Daniel
PROSIDING SEMINAR KIMIA SEMINAR NASIONAL KIMIA 2014
Publisher : PROSIDING SEMINAR KIMIA

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Abstract

The adsorption kinetics of Cr(VI) by two adsorbents, i.e. magnetite (Fe 3 O 4 ) and magnetite coated humic acids (Fe 3 O 4 /HA) have been studied. Adsorbent of Fe 3 O 4 and Fe 3 O 4 /HA were synthesized by co-precipitation method and then characterized by FT-IR, XRD and TEM image measurements. The acidity of the solution was adjusted to pH 3, comparasion on the adsorption kinetics of Cr(VI) on Fe 3 O 4 between Fe 3 O 4 /HA. The FT-IR spectra revealed the presence of main fuctional groups of Fe-O and C-O at free carboxylate acid in Fe 3 O 4 /HA and those of only Fe-O in Fe 3 O 4 . The two adsorbent had similar diffraction peaks at 2θ. The TEM image demonstaretd that Fe 3 O 4 were spherical in shape and uniform distribution and then Fe 3 O 4 /HA had no uniform size. Adsorption of Cr(VI) by Fe 3 O 4 was much faster than Fe 3 O 4 /HA at the acidity of pH 3, with adsorption rate constant (k) of 0.013 g.mg -1 .menit -1 for Fe 3 O 4 and 0.0062 g.mg -1 .menit -1 for Fe 3 O 4 /HA. The two adsorbents were giving a model of adsorption kinetics Ho (pseudo order 2).
Synthesis, Characterization of Cellulose Modified with 2-Mercaptobenzothiazole and Its Adsorption To Cu(II) Ion in Aqueous Solution Fatoni, Ahmad; Koesnarpadi, Soerja; Hidayati, Nurlisa
Indonesian Journal of Chemistry Vol 15, No 2 (2015)
Publisher : Universitas Gadjah Mada

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Abstract

The modification of cellulose with 2-mercaptobenzhotiazole (MBT) through grafting and impregnating methods has been done. Modified cellulose used as adsorbent for Cu(II) ion in aqueous solution. The aims of research were modification cellulose with 3-chloropropyltrimethoxysilane and 2-mercaptobenzhotiazole (MBT), characterization of the modified cellulose with FTIR, SEM and XRD and adsorption study between cellulose-MBT adsorbent with Cu(II) ion in aqueous solution. The adsorbent of cellulose-MBT was synthesized by reflux process. Adsorption study between cellulose-MBT adsorbent with Cu(II) ion was investigated based on influence of pH solution, interaction time and initial concentration of Cu(II) ion. The result showed that activated cellulose can be modified with MBT to become cellulose-MBT adsorbent. The functional group of –C=N appeared at wavenumber 1658 cm-1 attributed to functional group of -C=N- is Schiff base of MBT. Presence functional group of S-H at cellulose-MBT adsorbent was not detected. The surface morphology of cellulose-MBT adsorbent after being interacted with Cu(II) ion was different before being interacted with Cu(II) ion. The diffractogram of cellulose-MBT adsorbent has similarity with cellulose-MBT adsorbent-Cu(II) ion. The optimum adsorption of Cu(II) ion was observed at pH 7.0 and 150 min of interaction time. Percentage of Cu(II) ion was absorbed by cellulose-MBT adsorbent tended to be constant after Cu(II) ion concentration 100 ppm.
Humic Acid Coated Fe3O4 Nanoparticle for Phenol Sorption Koesnarpadi, Soerja; Santosa, Sri Juari; Siswanta, Dwi; Rusdiarso, Bambang
Indonesian Journal of Chemistry Vol 17, No 2 (2017)
Publisher : Universitas Gadjah Mada

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Abstract

The coating Fe3O4 using humic acid (HA) to form HA-coated Fe3O4 (Fe3O4/HA) was conducted and applied for phenol sorption. Fe3O4/HA was prepared using co-precipitation method in an alkaline condition using ammonium hydroxide and the addition of HA with mass ratios of Fe3O4 and HA=20:1, 10:1, 10:2, 10:3. The HA from peat soil in Sambutan village, East Kalimantan, Indonesia and was extracted in NaOH 0.1 M solution. The FT-IR characterization indicated that the coating of HA on the surface of Fe3O4 was successfully synthesized by forming a bond between the carboxylate group of HA and iron of Fe3O4. The coating of HA on the surface of Fe3O4 did not change the crystal structure of Fe3O4, but had lower peak intensities than Fe3O4 if added with HA with mass ratios 20:1, 10:1, 10:2, 10:3. The saturation magnetization of Fe3O4 decreased with the increased content of HA. SEM image indicated the magnetic particle size was almost homogenous by 10-18 nm. Iron and HA in Fe3O4/HA materials synthesized using different mass ratios were stable in pH range of 3.0-11.0 and 1.0–11.0, respectively. The phenol sorption on Fe3O4 was optimum at pH 5.0 and on Fe3O4/HA with mass ratios of 20:1, 10:1, 10:2, 10:3 were optimum at pH 5.0-6.0. The kinetics model for phenol adsorption on Fe3O4 and Fe3O4/HA with mass ratios of 20:1, 10:1, 10:2, 10:3 could be described using pseudo second-order equation and was in accordance with the Langmuir isotherm model with maximum adsorption capacity of 0.45 mmol/g for Fe3O4 and 0.55, 0.56, 0.58, 0.56 mmol/g respectively for Fe3O4/HA with mass ratios of 20:1, 10:1, 10:2, 10:3. The adsorption capacity increased with the increased content of HA, but the adsorption energy decreased except Fe3O4/HA with a mass ratio of 10:3. Generally, the performance of Fe3O4/HA materials was much higher than of bare Fe3O4.