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All Journal VALENSI Reaktor Makara Journal of Science International Journal of Renewable Energy Development
Rika Tri Yunarti
Department Of Chemistry, Faculty Of Mathematics And Natural Science, Universitas Indonesia, Jl. Lingkar Kampus Raya, Depok, West Java, Indonesia
Chemical Engineering, Chemistry & Bioengineering Chemistry Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering Materials Science & Nanotechnology

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Adsorption of Phosphate Ion in Water with Lithium-Intercalated Gibbsite Sihombing, Riwandi; Krisnandi, Yuni Krisyuningsih; Widya, Rahma; Luthfiyah, Siti Zahrotul; Yunarti, Rika Tri
Makara Journal of Science Vol. 19, No. 4
Publisher : UI Scholars Hub

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Abstract

In order to enhance adsorption capacity of gibbsite (Al(OH)3 as an adsorbent for the adsorption of phosphate in water, gibbsite was modified through lithium-intercalation. The purification method of Tributh and Lagaly was applied prior to intercalation. The Li-Intercalation was prepared by the dispersion of gibbsite into LiCl solution for 24 hours. This intercalation formed an cationic clay with the structure of [LiAl2(OH)6]+ and exchangeable Cl- anions in the gibbsite interlayer. A phosphate adsorption test using Lithium-intercalated gibbsite (LIG) resulted in optimum adsorption occurring at pH 4.5 with an adsorption capacity of 11.198 mg phosphate/g LIG which is equivalent with 1.04 wt% LIG. The adsorption capacity decreased with decreasing amounts of H2PO4-/HPO4- species in the solution. This study showed that LIG has potential as an adsorbent for phosphate in an aqueous solution with pH 4.5–9.5.
Grass-Like Structured Mesoporous Carbon as an Acid Red 119 Dye Adsorbent Krisnandi, Yuni Krisyuningsih; Priantini, Tania; Faisal, Muhammad; Yunarti, Rika Tri; Saragi, Indah Revita; Gunlazuardi, Jarnuzi
Makara Journal of Science Vol. 23, No. 4
Publisher : UI Scholars Hub

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Grass-like structured mesoporous carbon was prepared by the soft-template method using triblock copolymer Pluronic F127, affording an organic–organic composite structure between phloroglucinol and formaldehyde. Thermogravimetric analysis revealed that the as-synthesized mesoporous carbon is stable to 900 °C, and X-Ray Diffraction (XRD) analysis confirmed the presence of carbon material structures at 2θ values of 22.020° and 42.420°. A hysteresis loop at relative partial pressures (P/Po) between 0.45 and 0.85 was observed in the N2 adsorption isotherm, indicating that the solid material exhibits mesoporous characteristics, with a homogeneous pore size distribution of 8.863 nm. Scanning Electron Microscope (SEM) images revealed that the bulk carbon surface exhibits a uniform grass-like structure. Furthermore, the as-synthesized mesoporous carbon was investigated for the adsorption of a diazo dye Acid Red 119, and it exhibited an adsorption capacity of 217.7389 mg/g; this capacity is 1.53 times greater than that of commercial activated carbon. Therefore, this mesoporous carbon is a potential adsorbent for the treatment of synthetic coloring waste.
Development Study of Binding Agent in Diffusive Gradient In Thin Films (DGT) Technique for Absorption of Phosphate Compounds using Nano-La2O3 Hanna Shafira; Rika Tri Yunarti; Asep Saefumillah
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 8, No. 2, November 2022
Publisher : Syarif Hidayatullah State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v8i2.26952

Abstract

The abundance of phosphate is a concern because it causes problems in aquatic ecosystems. The diffusive gradient in thin films (DGT) technique is a promising method for phosphate absorption because it can be used in situ. The DGT device consists of a membrane filter, a diffusive gel, and a binding gel. The presence of a binding agent in the binding gel makes the specific analyte bound to the binding gel. One of the binding agents that can be used for phosphate absorption is La2O3. Binding gel La2O3 was successfully synthesized that proven by the similarity of FTIR peaks of the diffusive gel and binding gel. The typical absorption of La-O also proves it from the binding gel at 642 cm-1 and 423 cm-1. La2O3 binding gel was made of N,-N'-methylenebisacrylamide as a cross-linker with an elution factor of 97.4%. DGT-La2O3 proved capable of adsorption for 72 hours, with phosphate absorbed at 1.91 x 105 ng. DGT-La2O3 also has the optimum ability to absorb phosphate at pH 3 of 1.93 x 105 ng.
Effectiveness of Iron Fortification on Soy-Based Foods Using Ferrous Bisglycinate in the Presence of Phytic Acid Yunarti, Rika Tri; Zulys, Agustino; Harahap, Lina Yuliana; Pramukti, Mai Saroh Ambar
Makara Journal of Science Vol. 17, No. 1
Publisher : UI Scholars Hub

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ANION EXCHANGE CAPACITY OF CHROMATE ON MODIFIED ZEOLITE CLINOPTILOLITE WITH HDTMA-Br AND ITS REGENERATION Wibowo, Widajanti; Utari, Tresye; Yunarti, Rika Tri
Makara Journal of Science Vol. 15, No. 1
Publisher : UI Scholars Hub

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Abstract

Zeolite Clinoptilolite from Lampung, located in South of Sumatra, had been modified with surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) as chromate anion exchanger. Surfactant modified zeolite (SMZ) Clinoptilolite in particle size range of 1.5 - 2.0 mm, which contained 196.7 mmol HDTMA-Br/kg zeolite, was used for anion exchange of chromate at neutral pH. This experiment was conducted in a glass column filled with 5 gram SMZ. The breakthrough chromate exchange capacity was found 1.262 mg/g SMZ, while the total capacity was found 2.107 mg/g SMZ. The regeneration of SMZ saturated with chromate was conducted using a mixed solutions of 0.28 M Na2CO3 and 0.5 M NaOH, compared with using a solution of 0.01 M Na2S2O4. The desorption of chromate achieved 92% with the mixed solutions of Na2CO3 and NaOH and 90% with the Na2S2O4 solution. The regenerated SMZ with Na2CO3-NaOH solutions was prior washed with HCl solution to remove the carbonate from SMZ, before being used for chromate sorption again. Its breakthrough capacity was reduced to 1.074 mg/g SMZ, and to 0.724 mg/g SMZ when regenerated with Na2S2O4 solution. These results indicated that regeneration of SMZ affected its exchange capacity for anion chromate. However, it is still could be acceptable, when Na2CO3/NaOH solutions were used for the regeneration of SMZ saturated with anion chromate.
Synthesis of Copper (II) Oxide Nanoparticles using Vitis vinifera L. Leaf Ex-tract and its Application as a Catalyst in Doebner Reaction Kurniawan, Felie Virgayani; Cahyana, Antonius Herry; Yunarti, Rika Tri
Makara Journal of Science Vol. 27, No. 3
Publisher : UI Scholars Hub

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Abstract

Plant extracts can be used to synthesize nanoparticle because it is efficient, economical, and friendly to the environment. Copper oxide nanoparticles (CuO NPs) were synthesized using an aqueous fraction of Vitis vinifera L leaf extract and Cu(NO3)2 solution as a precursor. This fraction contains secondary metabolites as a reduction agent and stabilizing agents to formed CuO NPs. CuO NPs can be used as a catalyst in a chemical reaction, one of which is the Doebner reaction, which is a simple and efficient reaction of aniline, aromatic aldehydes, and pyruvic acid under reflux conditions to produce derivatives quinoline-4-carboxylic acid. CuO NPs were effectively used in the Doebner reaction and yielded a product is 79.84%. The CuO NPs characterized by Fourier Transform Infra-Red (FTIR), and X-ray Diffraction (XRD) which showed CuO NPs were formed with a size of 24.39 nm. The product synthesized was characterized by TLC (Thin Layer Chromatography), FTIR, UV-Vis Spectrophotometry, and Liquid Chromatography Mass Spectrometry (LC-MS) and confirmed 2-phenylquinoline-4-carboxylic acid was formed.
Effect of various silica-supported nickel catalyst on the production of bio-hydrocarbons from oleic acid Riyandi, Rafly; Rinaldi, Nino; Yunarti, Rika Tri; Dwiatmoko, Adid Adep; Simanjuntak, Fidelis Stefanus Hubertson
International Journal of Renewable Energy Development Vol 13, No 4 (2024): July 2024
Publisher : Center of Biomass & Renewable Energy (CBIORE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61435/ijred.2024.60054

Abstract

The conversion of fatty acids into bio-hydrocarbons can be carried out through a deoxygenation (DO) reaction. Catalytic deoxygenation of fatty acids can occur through three reaction pathways: decarbonylation, decarboxylation, and hydrodeoxygenation. In this study, three kinds of silica were prepared: (i) silica obtained from the rice husk ash (RHA); (ii) synthetic mesoporous silica SBA-16; and (iii) commercial silica. All prepared silica was used as supported nickel (Ni) catalyst for bio-hydrocarbon production through DO reaction of oleic acid. The objective of this study was to investigate the effect of variations of silica on the reaction pathway and final products composition of DO reaction of oleic acid. The catalysts were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), surface area analysis, and NH3-temperature-programme desorption. Based on XRF and XRD analysis results, it can be concluded that nickel was successfully impregnated into all silica. All samples of catalysts were used in a reaction carried out at temperature of 285 °C under a pressure of 40 bar H2 for 2h. The results showed that all catalysts were able to convert oleic acid to bio-hydrocarbon with differences in products composition. The highest oleic acid conversion of 98.25% was achieved with Ni/RHA catalyst but the obtained liquid products was the lowest among other catalysts. It is found that this phenomenon was closely related to the acidity properties of the catalyst.
Synthesis of Isatin-based Chalcone Derivatives and Their Activity as Antioxidants Saputri, Yosephine Liliana Intan Danar; Cahyana, Antonius Herry; Yunarti, Rika Tri
Reaktor Volume 23 No.2 August 2023
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.23.2.62-70

Abstract

The body needs antioxidants to combat free radicals and guard against their damaging effects on healthy cells that might result in degenerative disorders. Several degenerative diseases include hypertension, heart disease, diabetes, stroke, and cancer. The human body can deal with free radical attacks caused by radiation, stress, cigarette smoke, and environmental pollution, so it requires additional external antioxidants to protect against free radical attacks. Chalcone is a compound that has an α,β-unsaturated carbonyl system, which makes chalcone compounds have biological activity. Chalcone compounds may be used in pharmacology as antioxidants, antifungals, antibacterial agents, anticancer agents, and for other biological activities. This study aims to synthesize a chalcone derivative, namely 3-(2-oxo-2-phenylethylidene)indolin-2-one and 5-chloro-3-(2-oxo-2-phenylethylidene)indolin-2-one containing a chloro substituent, as well as test the potential of these compounds as antioxidants. The reflux method of claisen-schmidt condensation of isatin and acetophenone was used to create chalcone derivatives. Spectroscopy was used to characterize the produced chemicals (UV-VIS, IR, and LCMS) and their antioxidant activity using the DPPH method. This study showed that the antioxidant activity of 3-(2-oxo-2-phenylethylidene)indolin-2-one and 5-chloro-3-(2-oxo-2-phenylethylidene)indolin-2-one compounds is very weak at low concentrations.
Co-Authors Agustino Zulys Antonius Herry Cahyana Asep Saefumillah Dwiatmoko, Adid Adep Hanna Shafira Harahap, Lina Yuliana Jarnuzi Gunlazuardi Kurniawan, Felie Virgayani Lina Yuliana Harahap Luthfiyah, Siti Zahrotul Mai Saroh Ambar Pramukti Muhammad Faisal Nino Rinaldi Pramukti, Mai Saroh Ambar Priantini, Tania Riwandi Sihombing, Riwandi Riyandi, Rafly Saputri, Yosephine Liliana Intan Danar Saragi, Indah Revita Simanjuntak, Fidelis Stefanus Hubertson Tresye Utari Tresye Utari, Tresye Widajanti Wibowo Widajanti Wibowo Widya, Rahma Yuni Krisyuningsih Krisnandi, Yuni Krisyuningsih