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Pepi Helza Yanti
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Mathematics

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DEGRADASI SENYAWA METANIL YELLOW SECARA FOTOKATALITIK MENGGUNAKAN TiO 2 DAN HNO3 Azkia Alma Ayesha; Akmal Mukhtar; Pepi Helza Yanti
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Abstract

Photocatalysis  with  TiO2 -UV  can be  used  to  reduce the content of  waste  dye in the water. Degradation of metanil yellow solution had  been done by photocatalytic using TiO2 as catalyst and  HNO3 as  an oxidator.  Photocatalytic  method used  radiation of  30 watt  UV light  with λ = 437 nm. Degradation of metanil yellow was  done with  several reaction parameters such as time of radiation reaction, mass of  TiO2 , and addition of HNO3. The result of  this research  showed that  metanil yellow 10 ppm  have  degraded 30,755% after 120 minutes radiation,  wheareas  with similiar consentration by addition 0,008  mass of  TiO2 degraded  54,689% with radiation time  up to 45 minutes.  HNO3 as an  oxidator  in degradation without UV radiation can affect the percentage rate of degradation.
PREPARASI MANGAN OKSIDA HASIL PERTUKARAN KATION Mg 2+ DENGAN K-BIRNESSITE YANG DISINTESIS MENGGUNAKAN REDUKTOR MALTOSA Anna Ridha Utami; Amir Awaluddin; Pepi Helza Yanti
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Todorokite is a naturally occurring manganese oxides having tunnelled structure (3x3) with pore size of 6,9 Å. This type of manganese oxide could be synthesized from birnessite precursor by reflux method. The exchangeable cation K + in interlayer of birnessite can be replaced with Mg 2+ ions to produce a Mg-birnessite, which then could be converted into todorokite through calcination. The products were then characterized by X-ray Powder Diffraction (XRD) to determine their phases, crystallinity and purity. Data from Absorption Atomic Spectroscopy (AAS) indicated that the 70,63% replacement of K + with Mg 2+ was achieved within contact time of 14 h. Analysis for todorokite have been done with different contact time of 18, 20 and 24 hours. The results of XRD showed that the main phases were birnessite with todorokite as minor product that was obtained at reaction time of 20 hours.
STUDI XRD MANGAN OKSIDA BIRNESSITE YANG DIPREPARASI MELALUI METODE SOL-GEL DAN KERAMIK Dian Anggraini; Amir Awaluddin; Pepi Helza Yanti
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Birnessite  is a naturally occurring layered manganese oxide found as a manganese nodules  in sea floor or    soil deposit. In this study, birnessite was synthesized  using two types of methods, solid state ceramic  approach and sol-gel reaction both KMnO4 and maltose were used as reactants in these two methods.  The products were then characterized using XRD for determination of phases, crystallinity and purity. The results showed  the both techniques lead to  the  formation of birnessite with different crystallinity and purity. The ceramic method produced  more crystalline and pure birnessite than that of sol-gel.  The typical reaction parameters for the synthesis birnessite by the ceramic method were 3:1 mole ratio (KMnO4over maltose) calcination at  700o C for 7 hours with  the  93,7%  purity  of  birnessite. However,  by  the sol-gel  method birnessite  produced only  31,8%  with the following condition  4:1 mole  ratio (KMnO4 over maltose) and calcination temperature of 450o C for 2 hours.
Co-Authors Akmal Mukhtar Amir Awaluddin Anna Ridha Utami Azkia Alma Ayesha Dian Anggraini