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All Journal Jurnal Kimia (Journal of Chemistry) The Journal of Pure and Applied Chemistry Research IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Science and Technology Indonesia IJEMS (Indonesian Journal of Environmental Management and Sustainability) Molekul: Jurnal Ilmiah Kimia Jurnal Ilmiah Berkala: Sains dan Terapan Kimia Aceh International Journal of Science and Technology Karunia: Jurnal Hasil Pengabdian Masyarakat Indonesia Bumi: Jurnal Hasil Kegiatan Sosialisasi Pengabdian Kepada Masyarakat

Risfidian Mohadi

Department of Chemistry, Faculty of Mathematic and Natural Sciences, Universitas Sriwijaya, Indralaya (OI), Sumatera Selatan 30662, Indonesia

Author-ID : 361521

Agriculture, Biological Sciences & Forestry Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Energy Engineering Environmental Science Health Professions Materials Science & Nanotechnology Medicine & Pharmacology Physics Public Health Social Sciences

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Thermal Activated of Indonesian Bentonite as A Low-Cost Adsorbent for Procion Red Removal from Aqueous Solution Tarmizi Taher; Dedi Rohendi; Risfidian Mohadi; Aldes Lesbani
The Journal of Pure and Applied Chemistry Research Vol 7, No 2 (2018): Edition May-August 2018
Publisher : Chemistry Department, The University of Brawijaya

Abundant and inexpensive Indonesian natural bentonite was activated by thermal activation at 500 oC for removal of procion red dye as one of the most used synthetic dye in the traditional songket fabric production around Palembang city. Activated bentonite product was characterized by FT-IR, XRD, and thermal analysis. The adsorption process was conducted in batch adsorption system by applying various adsorption parameter condition including, initial pH condition, contact time, and initial dye concentration. The activated bentonite characterization indicates that during the activation process, the structure of the original bentonite was not changed significantly and the result of the thermal analysis revealed that thermal activation at 500 oC was draining the water content without destructing the silica-alumina framework of bentonite. The adsorption kinetics study shows that the procion red adsorption into the activated bentonite follows the pseudo-second order kinetic model. The isotherm adsorption study revealed that procion red adsorption into activated bentonite adapted the Langmuir adsorption isotherm.

A Comparative Study on The Adsorption Behavior of Congo Red on to ZnAl and ZnCr Layered Double Hydroxides Tarmizi Taher; Nyanyu Ummu Hani; Neza Rahayu Palapa; Risfidian Mohadi; Aldes Lesbani
The Journal of Pure and Applied Chemistry Research Vol 9, No 2 (2020): Edition May-August 2020
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jpacr.2020.009.02.519

In this work, two synthetic layered double hydroxides (LDH) consists of Zn2+ as M2+ cation with different M3+ cation, i.e., Al3+ and Cr3+ were used as an adsorbent for Congo Red removal aqueous solution. Both Zn-Al and Zn-Cr LDH were characterized by X-ray diffraction, FT-IR, and BET surface area analyzer. The effect of contact time, initial dye concentration, and temperature were evaluated in a batch technique in order to investigate the characteristic of Congo Red adsorption onto both adsorbents. The experimental data were assessed according to the parameter of adsorption kinetics, isotherm, and thermodynamics. The results of LDH characterization showed that Zn-Al LDH has a higher interlayer distance than Zn-Cr LDH, although Zn-Cr LDH has a higher surface area. The FT-IR analysis indicated the interlayer space of both Zn-Cr and Zn-Al LDH was dominated by CO32- as the interlayer anion species. The adsorption kinetics study of Congo Red on both LDH revealed that the adsorption process followed the pseudo-second-order model. For the adsorption isotherm, the experimental data fit well with the Freundlich model rather than the Langmuir model. The thermodynamic study indicated that the adsorption process that occurred on both adsorbents was spontaneous with exothermic nature.

STUDI INTERAKSI ION LOGAM Mn2+ DENGAN SELULOSA DARI SERBUK KAYU Risfidian Mohadi; Adi Saputra; Nurlisa Hidayati; Aldes Lesbani
Jurnal Kimia (Journal of Chemistry) Vol. 8, No. 1 Januari 2014
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Separation of cellulose from sawdust using methanol and hydrocloric acid in various acid concentrations has been carried out. Cellulose from sawdust was characterized using FT-IR Spectroscopy and XRD difractometer. The cellulose was used as adsorbent for Mn2+ and Co2+ metal ions in aqueous medium. Adsorptions process was studied through variation of time interaction, concentration and separation desorption. FT-IR Spectrum shows that cellulose with 5% acid concentration has similarity with FT-IR cellulose standard. The XRD difractometer pattern of cellulose shows that cellulose has amorf structure. The adsorption rate constant of Mn2+ on cellulose from sawdust shows adsorption rate constant in cellulose is higher than in sawdust. Adsorption energy of Mn2+ metal ion in cellulose from sawdust was about 26.21 kJ/mol. The adsorption capacity of Mn2+ in cellulose is higher than in sawdust. The desorption of Mn2+ metal ion using H2O, Na-EDTA, Amonium acetic, and HCl shows that the adsorption mechanism of Mn2+ on cellulose and sawdust is dominated by chemical interaction.

STUDI REAKSI SIKLOPENTILSILAN DENGAN 4-IODIDA THIOANISOL MENGGUNAKAN KATALIS PALADIUM Aldes Lesbani; Risfidian Mohadi; Elfita Elfita
Jurnal Kimia (Journal of Chemistry) Vol. 7, No. 2 Juli 2013
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

A study on cyclopentylsilane reaction in tetrahydrofuran with 4-iodo thioanisol has been carried out using palladium as catalyst under argon atmosphere at room temperature. The results showed that the product was tris(4-thioanisyl)cyclopentylsilane (1) which was obtained from recrystallization using methanol with the yield 35%. The Compound (1) has a melting point of 91.5-92.0 oC. Analysis using GC-MS found m/z 466 with six equivalent protons and eight carbons peak obtained from 1H and 13C NMR.

SINTESIS DAN KARAKTERISASI SENYAWA OKSOTRINUKLIR [Ru2Co(O)(OOCCH3)6(C5H5N)3](ClO4) Aldes Lesbani; Risfidian Mohadi; Nurlisa Hidayati
Jurnal Kimia (Journal of Chemistry) Vol. 6, No. 2 Juli 2012
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (220.583 KB)

The oxotrinuclear compound [Ru2Co(O)(OOCCH3)6(C5H5N)3](ClO4) has been synthesized using RuCl3?nH2O at room temperature under oxygen atmospheric condition. The oxotrinuclear complex was characterized by FT-IR spectrophotometer and mass spectrometer with cold spray ionization (CSI) method. The FT-IR spectra of the resulted oxotrinuclear compound show has specific vibration at 692 cm-1. This absorption is related to M3O vibration (M= metal). CSI-mass spectra of the oxotrinuclear compound show that pyridine as ligand was fragmented in oxotrinuclear compound.

The Seasional Trends of Dissolved Oxygen and pH in Sugihan River, South Sumatra, Indonesia Noormaisyah Saleh; Risfidian Mohadi; Agus Dwi Saputra
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 1, No 3 (2016): October 2016
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v1.i3.78

Abstract: The concentrations of DO and pH of Sugihan Rivers from the upstream at Riding, Pangkalan Lampam, OKI to the offshore region of Sugihan Estuary were analyzed at 15 sampling points during dry and rainy seasion. All measurements of DO and pH were direct analysis at the river stream. The concentrations as the average values of DO in dry seasion was 1,97 mg / L while in rainy seasion was 2,57 mg / L, and for the pH degree was 3,63 in dry seasion and 4,04 in rainy seasion, respectively. Based on the DO and pH values, this study shown the natural forests and peat lands gave contribution to the low of pH degree. The low of DO values also influenced by the pH, because decomposition in the peatlands made higher solubility of biomass to the rivers stream and decreasing the ability of oxygen to penetration into the waterbody.Keywords: DO, pH, Sugihan river, natural forest, peatland Abstrak (Indonesian): Konsentrasi DO dan pH Sungai Sugihan dari hulu di Kuda, Pangkalan Lampam, OKI ke wilayah lepas pantai Sugihan Muara dianalisis pada 15 titik sampling selama musim kering dan hujan. Semua pengukuran DO dan pH adalah analisis langsung di aliran sungai. Konsentrasi sebagai nilai rata-rata DO di musim kering adalah 1,97 mg / L sedangkan di musim hujan adalah 2,57 mg / L, dan untuk tingkat pH adalah 3,63 di seasion kering dan 4,04 di musim hujan. Berdasarkan nilai-nilai DO dan pH, penelitian ini menunjukkan bahwa hutan alam dan lahan gambut berkontribusi pada rendahnya tingkat pH. Rendahnya nilai DO juga dipengaruhi oleh pH, karena dekomposisi di lahan gambut membuat kelarutan yang lebih tinggi dari biomassa ke aliran sungai dan penurunan kemampuan oksigen untuk penetrasi ke aliran sungai tersebut. Kata kunci: DO, pH, Sungai Sugihan, hutan alam, lahan gambut

Thermal Stability and Acidity of Silica Supported Keggin Type Polyoxometalate K4[-SiW12O40]•nH2O Welinda Me; Risfidian Mohadi; Aldes Lesbani
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 1, No 1 (2016): February 2016
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v1.i1.24

Silica supported polyoxometalate K4[a-SiW12O40]·nH2O was prepared systematically using tetraethyl ortho silicate by sol gel method to form K4[a-SiW12O40]·nH2O/Si. Compound K4[a-SiW12O40]·nH2O/Si was characterized by diffraction, spectroscopic, and acidity analyses follow by thermal activity test at higher temperature up to 600 oC. Analysis of FTIR spectrum showed all unique vibration of polyoxometalate K4[a-SiW12O40]·nH2O was appeared at wavenumber 800-1000 cm-1 before and after supporting process. Crystallinity of K4[a-SiW12O40]·nH2O and K4[a-SiW12O40]·nH2O/Si were also similar without changing Keggin structure. Compound K4[a-SiW12O40]·nH2O/Si showed higher acidity than K4[a-SiW12O40]·nH2O probably due to Lewis acidity species. Keggin structure of K4[a-SiW12O40]·nH2O/Si was still retained up to 600 oC showing thermal stability of K4[a-SiW12O40]·nH2O/Si at high temperature.Keyword : Keggin polyoxometalate, tetraethyl ortho silicate, thermal stability, acidity

Modification of Cellulose with 4.4 Diaminodiphenylether-O-Hydroxibenzaldehide as Adsorbent and Its Application for Adsorbing Metalic Ion of Cd2+ In Aqueous Solution Nurlisa HIdayati; Risfidian Mohadi; Euis Marsitho; Ahmad Fatoni
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 1, No 2 (2016): June 2016
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v1.i2.47

This research on the modification of cellulose using 4,4-diaminodiphenylether and o-hydroxybenzaldehyde and its application to adsorb Cd2+ in aqueous solution has been done. The adsorption studies of cellulose and modified cellulose were done by using batch technique. The cellulose and modified cellulose were characterized by FTIR. The FTIR spectra revealed characteristic bands of 1573 cm-1, 1280 cm-1, 3749 cm-1 and 1056 cm-1. It indicates function group of C=N, C=O, O-H and Si-OR bond, respectively. The FTIR spectra of cellulose and modified cellulose which interacted to Cd2+, it were indicated by the shift in wavenumber 3410 cm-1 to 3371 cm-1. This spectral shift indicating Cd2+ bound to OH-group. In this research, interaction between modified cellulose with Cd2+ confirmed by intensities spectral changes at 1620 cm-1. The adsorption capacity and energy from adsorption of Cd2+ ions toward cellulose were 71,43 mg/g and 4,142 kJ/mol, while toward modified cellulose were 55,56 mg/g and 0,13 kJ/mol, respectively. Keywords: cellulose, 4,4-diaminodiphenylether-o-hydroxybenzaldehyde, adsorption, Cd2+

Preparation and characterization of calcium oxide from crab shells (Portunus pelagicus) and its application in biodiesel synthesis of waste cooking oil, palm and coconut oil Minaria Minaria; Risfidian Mohadi
Science and Technology Indonesia Vol. 1 No. 1 (2016): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Preparation of calcium oxide from Portunus pelagicus through thermal decomposition for 3 hours at various temperature 700°C, 800°C,900°C,1000°C, and 1100°C. The calcium oxidefrom decomposition was carried out and characterized by X-Ray Diffractometer (XRD), FT-IR spectrophotometer and SEM-EDX analyses. The result of XRD show decomposition Portunus pelagicus at 1000°C have diffraction pattern agree with the CaO diffraction standard with 2θ value 32.4º, 37.5º, 64.3º, and 67,5º. The FT-IR spectrum show vibration of CaO at wavenumber 354.9 cm-1. SEM-EDX data indicated the surface morphology calcium oxide of Portunus pelagicus more homogen than Portunus pelagicus before decomposition. The decomposition of CaO at 1000°C was applied in the syntesis of biodiesel from waste cooking oil, palm oil, and coconut oil. The biodiesel products have density 0.8621, 0.8725, and 0.8688 g/cm3. Viscosity are 5.27, 3.71, and 2.45 mm2/s(cst). Acid values respectively are 0.3069, 0.2423 and 0.2100 mg/KOH and Iodine numbers 39.48, 36.12 and 9.24 g I2/100g. All characteristic of biodiesel from waste cooking oil, palm oil, and coconut oil are agree with SNI standard. The best biodiesel product derived from coconut oil is agree to the parameter value of biodiesel standard. Keywords: biodiesel. Portunus pelagicus. calcium oxide. catalyst.

Preparation of polyoxometalate compound (NH4)6(β-P2W18O62)/SiO2 by sol-gel method and its characterization Osin Restinawaty Tambunan; Risfidian Mohadi
Science and Technology Indonesia Vol. 2 No. 1 (2017): January
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Preparation of polyoxometalate compound of (NH4)6(β-P2W18O62)nH2O supported with silica derived from the hydrolysis of tetraethyl orthosilicate by sol-gel method has been conducted. The compound was synthesized and characterized using FT-IR spectrophotometer, crystallinity using XRD analysis and the determination of acidity via quantitatively and qualitatively. Qualitative analysis was performed using ammonia and pyridine adsorption and quantitative analysis using potentiometric titration. FT-IR spectrum of (NH4)6(β-P2W18O62)nH2O appeared in wavenumber 786.96 cm-1 (W-OC-W), 918.12 cm-1 (W-Oe-W), 964.41 cm-1 (W=O), 1087.85 cm-1 (P-O), 3572.17 cm-1 (O-H), 1404.18 cm-1 (N-H) reinforced with wavenumber 1612.49 cm-1 with show vibration NH dari NH+, and to (NH4)6(β-P2W18O62)nH2O/SiO2 appears in wavenumbers 794.67 cm-1 (W-Oc-W), 918.12 cm-1 (W-Oe-W), 1049.28 cm-1 (W=O), 1087.85 cm-1 (P-O), 3564.15 cm-1 (O-H), 470.63 cm-1 (Si-O). Diffraction pattern of (NH4)6(β-P2W18O62)nH2O and (NH4)6(β-P2W18O62)nH2O/SiO2 compound show high crystanillity. The acidic properties showed (NH4)6(β-P2W18O62)nH2O/SiO2 more acidic than (NH4)6(β-P2W18O62)nH2O. Analysis of the effect of temperature on the stability of the compounds polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2 show that the temperature of 600ºC the shift in wavenumbers of the compounds caused by vibration W=O, W-OC-W, W-Oe-W has been lost. This shows that at a temperatures of 600ºC on heating can cause changes in the structure of polyoxometalate (NH4)6(β-P2W18O62)nH2O/SiO2. Keywords : (NH4)6(β-P2W18O62).nH2O, Polyoxometalate, SiO2

Co-Authors Adi Saputra Adipati Napoleon Agus Dwi Saputra Ahmad Fatoni Aldes Lesbani Azhar Kholiq Bakri Rio Rahayu Dedi Rohendi Desnelli Desnelli Doni Setiawan Elfita Elfita Endri Junaidi Euis Marsitho Hermansyah Hermansyah Hilda Zulkifli Jeri Ramadhan Komala Syari Marieska Verawaty Melantina Melan Oktriyanti Menik Setyowati Miksusanti Miksusanti Minaria Minaria Mirza Firdyah Astari Muhammad Said Neza Rahayu Nirwan Syarif Noormaisyah Saleh Nurlisa Hidayati Nurlisa Hidayati Nyanyu Ummu Hani Osin Restinawaty Tambunan Puteri Kusuma Wardhani Rananda Vinsiah Sabat Okta Ceria Sitompul Santa Oktavia Ginting Sri Haryati Syaflina Lamin Syafrina Lamin, Syafrina Tarmizi Taher Theresia Debora Simbolon Tiara Armita Triayu Septiani Welinda Me Yosine Susi Zazili Hanafiah

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