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Sekewael, Serly J.
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Biochemistry, Genetics & Molecular Biology Chemistry Engineering Environmental Science

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Kinetic Study And Isoterm Adsorption Of Pb Metal In Ouw Village Clay Activated Ammonium Nitrate Salt Sekewael, Serly J.; Tehubijuluw, Hellna; Reawaruw, Delvika R.
Indonesian Journal of Chemical Research Vol 1 No 1 (2013): Edisi Pertama (First Edition)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2013.1-ser

Abstract

Kinetics studies and adsorption isotherms of Pb metal have been conducted on activated clay salts of ammonium nitrate (NH4NO3). Clays used are taken from Ouw village, Central Maluku. Clay activated by soaking in a solution of NH4NO3 700 ppm for 5 hours, then filtering and heating in a furnace at 550 oC for 4 hours. The optimum adsorption of metal ions Pb (II) by activated clay ammonium nitrate occurs at pH 4 with a contact time of 4 hours and followed the Freundlich adsorption isotherm pattern with a Kf value of 1.6193 x 10-8 mg/g and n value of 0.2059. Pb adsorption kinetics followed the pseudo-second-order Lagergren equation with the value of the adsorption rate constant (k2, ads) of 0.1248 g mg-1 min-1 and Xe value of 4.4783 mg/g.
Base Activated Clay And Its Application As Cation Exchanger To Reduce The Mg2+ AND Ca2+ Ions Concentration In The Well Bijang, Catherina M.; Sekewael, Serly J.; Koritelu, J. A.
Indonesian Journal of Chemical Research Vol 1 No 2 (2014): Edisi Bulan Januari (Edition For January)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2014.1-cat

Abstract

The research about base activated clay and its application as cation exchanger to reducing the concentration of ions Mg2+ and Ca2+ in the well water has been caried out. Base solution used for clay activation was NaOH with variation of concentration at, 0.5 M, 1 M, and 1.5 M. Particle size of clay also have been variated at 40 mesh, 60 mesh, and 80 mesh. The result of this research shown that the best cation exchanging for Mg2+ was found in clay with 60 mesh particle sizes and concentration of NaOH 0.5 M, whereas for Ca2+ was found in clay with 80 mesh particle sizes and concentration of NaOH was 1.5 M.
Synthesis Of 1-phenyl-4-(3’, 4’-dimethoxy phenyl)-1-Buten-3-on From Eugenol Tahya, Candra Y.; Sohilait, Hanoch J.; Sekewael, Serly J.
Indonesian Journal of Chemical Research Vol 2 No 1 (2014): Edisi Bulan Juli (Edition For July)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2014.2-can

Abstract

The synthesis of 1-phenyl-4-(3’, 4’-dimethoxy phenyl)-1-buten-3-one from eugenol has been done through four reaction steps. The metilation of eugenol with dimethyl sulphate yields 81.81% of methyl eugenol. Oxymercuration-demercuration of methyl eugenol with mercury acetate yields 67.27% of methyl eugenyl alcohol. Oxidation of methyl eugenyl alcohol with pyridinium chloro chromate (PCC) yields 45.31% of methyl eugenyl ketone. Aldol condensation reaction of methyl eugenyl ketone with benzaldehide catalyzed by potasium hydroxyde yields 7.38% of 1-phenyl4-(3’,4’-dimethoxyphenyl)-1-buten-3-one. The purity of compounds was tested by GC and LC. The Elucidation of structure was analyzed by FTIR, GC-MS, LC-ESI-MS, and H-NMR.
Adsorption of Cd Metal Using Active Carbon From Cacao Shell (Theobroma cacao) Sekewael, Serly J.; Latupeirissa, Jolantje; Johannes, Rosalina
Indonesian Journal of Chemical Research Vol 2 No 2 (2015): Edisi Bulan Januari (Edition For January)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2015.2-ser

Abstract

The study on production of activated carbon from cacao shell (Theobroma cacao) was conducted by added 4 M HCl as activating agent. The results show that acidity of solid carbon active before activated with adsorption weight is 3.2865x10-3 mol.g-1 and after activated is 3.5052x10-3 mol.g-1. Active carbon result is used for the application at adsorption Cd with some variantion, that are optimum concentration 20 ppm and optimum time 80 min. Cd adsorption from active carbon was analyzed by AAS. The results are coeficient correlation (r2) 100 % followed Freundlich isotherm with KF value was 9.994 and n was -0.982.
Intercalation Of Clay By Surfactant And Its Application As Adsorbent Of Lead Ion Sekewael, Serly J.; Tehubijuluw, Hellna; Lefmanut, Isabella C.
Indonesian Journal of Chemical Research Vol 3 No 1 (2015): Edisi Bulan Juli (Edition For July)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2015.3-ser

Abstract

Research on natural clay intercalation with a surfactant has been done. The surfactant used is a quaternary ammonium salt type is cetil trimethyl ammonium bromide (CTAB). Intercalation process is carried out by stirring a suspension of clay and quaternary ammonium salt for 24 hours. After the intercalation process, palmitic acid are added, then the intercalated clay is used as an adsorbent ion Pb2+ distance between layers of clay after intercalated can be analyzed using X-ray diffraction. The distance between the layers increases from 15.99 to 19.45Ã…. Intercalated surfactant used to adsorb metals Pb2+ ions in solution with a variety of conditions such as contact time and concentration. The results of the analysis indicated using AAS then used to determine the adsorption capacity based on the optimum contact time optimum concentration and absorption. Adsorption capacity is equal to 8.092 mg/g.
Ekstraksi Dan Karakterisasi Kitosan Dari Kulit Udang Windu (Penaeus monodon) Serta Proses Depolimerisasi Kitosan Dengan Hidrogen Peroksida Berdasarkan Variasi Suhu Pemanasan Tanasale, Matheis F.J.D.P.; Telussa, Ivonne; Sekewael, Serly J.
Indonesian Journal of Chemical Research Vol 3 No 2 (2016): Edisi Bulan Januari (Edition For January)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2016.3-mat

Abstract

An extraction of chitin from shell of the tiger shrimp (Penaeus monodon), a convertion chitin into chitosan and depolymerization chitosan into oligochitosan using hydrogen peroxide based on variations in heating temperature have been done. Chitosan had depolymerized and it’s molecular weight had tested by end group analysis method and it’s degree of deacetylation had tested by UV-Vis spectrophotometry method. Oligochitosan had obtained from the conversion of chitin is isolated from the shell of tiger shrimp and from commercial chitin. The content of chitin obtained in tiger shrimp shells was 35.90% while the result of the conversion of commercial chitin into chitosan amounted to 62.33%. Characterization of functional groups using FTIR spectrophotometry showed that the conversion of chitosan from chitin commercial have absorption bands of 3617.56 (OH), 3050.47 - 3127.63 (-NH stretching), 2894.24 (-CH methylene), 1679.06 (-C = O), 1564.30 (-NH bending), and 1076.30 cm-1 (-CO-). The commercial chitosan which is characterized by FTIR spectrophotometric method also supports the results of the conversion of chitosan from chitin commercial. In the process of depolymerization of chitosan by hydrogen peroxide was found that the greater heating temperature was used, the smaller the percent yield and molecular weight of oligochitosan were at 40 oC, 50 oC, 60 oC and 70 oC gained weight average molecular oligochitosan were 1030.12 g/mol, 1019, 28 g/mol, 978.12 g/mol, and 908.82 g/mol, respectively
Pengaruh Pemanasan Terhadap Kristalinitas Dan Parameter Kisi Nanokomposit Silika-Zirkonia Montmorillonit K10 Dan Silika-Besi Oksida Montmorillonit K10 Sekewael, Serly J.; Wijaya, Karna; ., Triyono
Indonesian Journal of Chemical Research Vol 6 No 1 (2018): Edisi Bulan Juli (Edition For July)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2018.6-sjs

Abstract

The thermal treatment of the silica-zirconia montmorillonite K10 and silica-ferri oxide montmorillonite K10 nanocomposites at 300 and 500 °C has been carried out, respectively as part of a study of their function as the catalyst. The heating effect on the crystallinity and the lattice parameter calculation of both nanocomposites was studied using XRD and FTIR instruments. The results showed that the nanocomposite silica-zirconia montmorillonite K10 has a thermal resistance and the crystallinity better than the silica-ferri oxide montmorillonite K10, and both have values varying lattice parameters.
Determination of Surface Acidity on The Natural and Synthetic Montmorillonite Clays by Titration Method Sekewael, Serly J.
Indonesian Journal of Chemical Research Vol 9 No 2 (2021): Edition for September 2021
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2021.9-ser

Abstract

Determination of surface acidity on the natural and synthetic montmorillonite clays has been carried out using the acid-base titration method to count the number of bound acid sites per gram of clay. The total acidity of natural and synthetic montmorillonite surfaces obtained was 4.67 and 5.33 mmol/g, respectively. FTIR analysis results indicate the presence of functional groups from the tetrahedral and octahedral constituents. Both samples have similar absorption patterns. The similarity of absorption patterns was followed by a decrease in intensity and shift in some absorption bands, and the appearance of new absorption bands.
The Sediment Profile and Heavy Metal Content of Lead (Pb), Copper (Cu), and Silver (Ag) in The Waters of Saparua Island Anakotta, Jaicson G.; Male, Yusthinus T.; Sekewael, Serly J.; Gaspersz, Nelson
Indonesian Journal of Chemical Research Vol 12 No 3 (2025): Edition for January 2025
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2024.12-ana

Abstract

This study determined the distribution levels of heavy metals Pb, Cu, and Ag in sediments in the waters of Saparua Island. It characterized the sediments in the seas of Saparua Island. Parameters are physical and chemical parameters of waters, determination of total organic carbon (TOC), and digestion of sediment samples for SSA testing. The results obtained levels of copper metal contained in the sediments from 0.1583–1.9531 mg/L and <4–78 ppm. The level of lead metal contained in the sediments in the waters of Saparua Island ranges from <12–26 ppm. Metal oxides, especially metal oxides formed from Cu, were found in sediments in the waters of Saparua Island with location points P.8 and P.9, namely CuO 0.0056% and 0.0031% and in sediments in Saparua Island waters with a value of 2Ɵ in sediment samples. P.2, P.3, P.6, P.8, P.9, and P.11 have the highest intensity which is the characterization of metal oxide 2Ɵ= 27.7464°, 29.4759, 26.2979, 26.6686, 26.7007, and 24.3695 indicate the presence of CaO (calcium oxide) phases at points P.2, P.3, and P.6. the SiO2 (silica) phase which is the most abundant metal in sediment samples P.8, P.9, and P.11 based on the XRF test.
Co-Authors Anakotta, Jaicson G. Bijang, Catherina M. Gaspersz, Nelson Hellna Tehubijuluw Ivonne Telussa Johannes, Rosalina Karna Wijaya Koritelu, J. A. Latupeirissa, Jolantje Lefmanut, Isabella C. Matheis F.J.D.P. Tanasale Reawaruw, Delvika R. Sohilait, Hanoch J. Tahya, Candra Y. Triyono . Yusthinus T. Male