KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen <p><strong>KOVALEN: Jurnal Riset Kimia</strong> is a peer-reviewed journal of chemistry that published by the Chemistry Department, Tadulako University, Indonesia. This journal concern with publishing the original research articles, review articles, and the current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December. KOVALEN has been established since 2015 with volume 1 no 1 (December 2015) and has been <strong>accredited by DIKTI in the SINTA 4 category (No. 164/ E/ KPT/2021)</strong>.</p> <p><strong>ISSN:&nbsp;<strong><strong>2477-5398 (electronic)</strong></strong></strong></p> <p>The Scope of this journal including:<br>1. Theoretical and environmental chemistry study<br>2. Material and biomaterial synthesis, including their application&nbsp;<br>3. Isolation, purification, and modification of the natural product<br>4. Development and validation of analytical methods<br>5. Isolation and application of enzyme</p> en-US pasjan82@gmail.com (Pasjan Satrimafitrah) jr.hardi0803@gmail.com (Jaya Hardi) Wed, 01 May 2024 02:39:38 +0000 OJS http://blogs.law.harvard.edu/tech/rss 60 Evaluasi dan Modifikasi Alat Penukar Ion dengan Penambahan Kolom Adsorpsi Karbon Aktif untuk Menurunkan Kesadahan https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16556 <p>Ion exchange is one of the water treatment methods used to reduce hardness. To improve the performance of the ion exchange columns, modification can be done by adding an activated carbon column placed after the ion exchange column to adsorb ions that were not exchanged by the resin so that the treated water met boiler feed water quality standards. The purposes of this study were to determine the best flow rate to reduce hardness in the configuration of the ion exchange and activated carbon columns, determine the saturation time of each column, and determine their exchange/adsorption capacities. The steps of this study included modifications and repair of equipment, leak tests, and configuration system performance tests. Performance tests were conducted by varying the feed flow rates by 0.2; 0.4; 0.6; 0.8; 1 GPM and analyzed the efficiency of hardness reduction. The results of this study showed that the best flow rate to reduce the initial hardness of 499 mg/ L CaCO<sub>3</sub> was a flow rate of 0.6 GPM or 2.2 LPM. The efficiency of hardness reduction in the configuration system was 100%. The conductivity of the effluent of anion column and activated carbon column decreased compared to the conductivity of the effluent of cation column with an average decrease of 33.17% in the anion column and 18.35% in the activated carbon column. The saturation time of the configuration system was 168 minutes in cation resin, 46.4 minutes in anion resin, and 159 minutes in activated carbon. Furthermore, the adsorption capacity of cation resin, anion resin, and activated carbon were 35.28 mg/g, 43.98 mg/g, and 9.61 mg/g, respectively. The addition of activated carbon in the configuration system lowers the conductivity of the effluent and decreases hardness.&nbsp;</p> Endang Kusumawati, Retno Dwi Jayanti, Lestari Herlianti Putri, Nurul Annisa, Tifa Paramitha Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16556 Wed, 01 May 2024 02:33:15 +0000 Molecular Docking Senyawa Aktif Ekstrak Daun Melinjo (Gnetum gnemon) dalam Penghambatan Enzim Histidin Dekarboksilase https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16603 <p>Histamine in fish is formed due to histidine decarboxylase which occurs due to decay by bacteria. In the Maluku community, <em>melinjo </em>leaves (<em>Gnetum gnemon</em>) are used as boiled water in processing rotten fish so that the decay process is inhibited. The compound content of <em>melinjo</em> leaves is tethered to the macromolecule decarboxylase PDB ID (4E1O). Test ligands, seven components of melinjo leaves were optimized using Gaussian. Ligands were bound to the receptor with AutoDock-Vina in grid box size and evaluated with Discovery Studio. The tethering results showed no ligand with affinity exceeding the standard ligand. However, three test ligands were close to the standard such as, dehydrovomifoliol affinity -6.7 kcal/mol, inhibition constant 1.2269 x 10-5. P-cumaric acid and gnetumal affinity -6.1 kcal/mol, inhibition constant 3.3778 x 10-5. Amino acid residue interactions showed hydrogen and hydrophobic bonding. The results of the binding affinity of the test ligand have not been able to be equivalent to the affinity of the standard ligand. However, the dehydrovomifoliol ligand is close to the affinity of the standard with a value of -6.7 kcal/mol and an RMSD of 2 Å. Thus, dehydrovomifoliol compounds from <em>melinjo</em> leaves show antihistamine effects as histidine decarboxylase inhibitors with promising potential.</p> Nelspon Gazpersz, Rahma El, Muhammad Daswar Ardian Baharudin, Zulaika Izmatul Hawa Bastio, Agnisia Indasari Ipaenin, Mario R. Sohilait Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16603 Wed, 01 May 2024 02:33:52 +0000 Kinerja Analitik Mikrokapsul Magnetit - Alginat (MNPs-ALG) untuk Analisis Ion Logam Cu(II) dan Aplikasinya pada Sampel Alam https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16574 <p>Research has been carried out regarding the synthesis of Magnetite-Alginate microcapsules (MNPs-ALG) and applied to Cu (II) metal ions. The nature of magnetic nanoparticles, Fe<sub>3</sub>O<sub>4</sub> which easily form aggregations can be overcome by this encapsulation process, but a very efficient separation process is also very much needed in the analytical separation process.The process of making magnetite nanoparticle compounds is carried out first using FeCl<sub>2.</sub>4H<sub>2</sub>O and FeCl<sub>3</sub>.6H<sub>2</sub>O and adding concentrated ammonia at a temperature of 90<sup>ο</sup>C until the solution becomes blackish in color. The dry magnetite, Fe<sub>3</sub>O<sub>4</sub>, nanoparticles were then dissolved in distilled water and thickened with Na-Alginate then dropped slowly into a 1 M CaCl<sub>2</sub> solution. The results of characterization using SEM showed that there were differences in morphology before and after contact, and there was 0.98% mass of Cu elements on the EDS results.The microcapsule adsorption optimization test gave results for the best adsorption percentage &gt;90% on a mass variation of magnetite (MNPs) of 0.3 grams; pH 5; contact time of 30 minutes and retention capacity of 185.95 mg/gram, at a Cu(II) concentration of 800 ppm. Analytical performance shows the best results with linearity parameters with a correlation coefficient of 0.999; the detection limit and quantitation limit are 0.0516 ppb and 0.1720 ppb with a lifetime of four times. The application of samples in the form of river water samples shows a percent recovery value of around &gt;90%, indicating that there is no matrix that significantly influences the measurements.</p> Ika Yekti Lianasari; Aman Sentosa Panggabean, Bohari Yusuf, Alimuddin; Soerja Koesnarpadi Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16574 Wed, 01 May 2024 02:34:30 +0000 Tofu Liquid Waste Treatment Using Effective Volume of Anaerobic Sequencing Batch Reactor (ASBR) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16478 <p>The tofu industry produces liquid waste containing high organic compounds. Organic compounds in liquid waste can threaten aquatic ecosystems if discharged directly into water bodies. One of the most effective wastewater treatment systems is the treatment using Anaerobic Sequencing Batch Reactor (ASBR). Besides being able to reduce the content of organic compounds, ASBR can produce biogas, and its decomposing microorganisms do not flow into the effluent stream. The purpose of this study was to evaluate the performance of ASBR at an effective reactor volume according to the design. This is because the use of ASBR in previous studies had not reached the operational stage and did not use an effective volume reactor. The stages of waste treatment using ASBR include the seeding, acclimatization, and operation stages. Waste treatment took place at room temperature in the reactor with an effective volume of 6 L. The operating parameters tested were MLVSS, COD, BOD, pH, and cumulative biogas volume. The results obtained show that the seeding process took 56 days, acclimatization took 10 days, and the operation lasted for 17 days. The efficiency of reducing COD concentration was 60%, the efficiency of reducing BOD concentration was 35.65%, and the cumulative volume of biogas produced was 24,120 mL at the operating stage. The use of the ASBR system at an effective volume of 6 L resulted in the successful processing of tofu liquid waste.</p> Herawati Budiastuti, Anissa Nurul Rachmawati, Delliana Agustin, Tifa Paramitha, Rusdianasari Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16478 Wed, 01 May 2024 02:35:07 +0000 Uji Cemaran Logam Mangan (Mn), Tembaga (Cu), dan Mikroba pada Air Minum dalam Kemasan https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16642 <p>The presence of metal contaminants such as Manganese (Mn) and Copper (Cu) and microbial contaminants in bottled drinking water (AMDK) that are potentially harmful to human health must be maintained so as not to exceed the set limits. The standard method of testing for Mn and Cu metal contamination in bottled water involves the use of Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) which refers to SNI 3554:2015. Microbial contamination testing in bottled water was carried out by measuring several parameters such as total plate count (ALT), <em>Coliform</em> test, <em>E.coli</em> test and <em>Pseudomonas aeruginosa</em> test with methods referring to SNI 3554:2015. The test results show that the level of Mn metal in AMDK is 0.001 mg/L with a very low relative variation (%RSD 0.00%), and the level of Cu metal is 0.004 mg/L with the same low relative variation (%RSD 0.00%). In addition, the microbial contamination test results for total plate counts were &lt;1 CFU/mL, and the average test results for <em>E.coli</em>, <em>Coliform</em>, and <em>P.aeruginosa</em> bacteria were 0 colonies/250 mL samples. These results illustrate that the levels of Mn and Cu metal contamination and microbial contamination found in AMDK do not exceed the limits set in SNI 3553: 2015. Based on the tests conducted, bottled drinking water is proven safe from Mn and Cu metal contamination and microbial contamination.</p> Tita Rosita, Inne Sadiyah Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16642 Wed, 01 May 2024 02:35:49 +0000 Selektivitas Adsorpsi Campuran Biner Fe(II)/Cu(II) Menggunakan Karbon Aktif dari Sekam Padi dan Serbuk Gergaji Kayu Jati https://bestjournal.untad.ac.id/index.php/kovalen/article/view/17060 <p>Increasing human needs cause an increase in production on an industrial scale and can have an impact on increasing contamination of the aquatic environment. Efforts to improve water quality can be made by removing contaminants using renewable activated carbon originating from agricultural waste such as rice husks and teak sawdust. This research aims to examine the adsorption capacity of activated carbon from rice husks (RHAC) and teak sawdust (TSAC) on a binary mixture of Fe(II)/Cu(II) as well as the level of selectivity of each adsorbent on Fe(II) and Cu(II) ions. RHAC and TSAC activated carbon are produced through carbonization processes (T=400 °C, t=60 minutes), reflux (NaOH 2N, T=100 °C, t=120 minutes), chemical activation using H<sub>3</sub>PO<sub>4</sub> (30%, 1:3, b/b) and physics (furnace). The results of this research are that RHAC and TSAC activated carbon have the functional groups O-H (str), C-H (str), C≡C, C=C, C-O (str), and C-O-P (str). The surface character of RHAC and TSAC activated carbon is dominated by the elements C, O, and P. The results of the Fe(II) and Cu(II) ion adsorption treatment using RHAC and TSAC activated carbon follow PSO kinetic modeling with R<sup>2</sup> values of 0.9221 and 0.9565 on RHAC and 0.9915 and 0.97 on TSAC. TSAC-activated carbon more selectively adsorbs Fe(II) and Cu(II) ions compared to RHAC-activated carbon with adsorption percentages reaching 97.34% and 87.82%, respectively.</p> Cucun Alep Riyanto, Jose D Michael Yonggulemba, Delvi Anandhia Stefani, Tirza Widyamurti Brotosudarmo, Diki Anggaran, Yehez Kiel Sandy Pradana, Yohanes Ariesto, Fidelis Tertius Aluh Christyawardana, Iga Permata Sari, Nicho Vernanda Wina Puspita, Lutiyono Lutiyono Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/17060 Wed, 01 May 2024 02:36:30 +0000 Sintesis dan Karakterisasi Polivinil Alkohol (PVA) Terlapis Polieugenol https://bestjournal.untad.ac.id/index.php/kovalen/article/view/17088 <p>A study has been conducted on materials containing polyvinyl alcohol (PVA) coated with poly eugenol. This research aims to explore the synthesis process and properties of PVA coated with poly eugenol. Characterization of PVA includes tensile strength measurement and surface observation using SEM. Additionally, the antioxidant activity of PVA was also tested using the DPPH method. In this study, PVA films were obtained by dissolving PVA in a water solvent. The characterization results indicate that the tensile strength ranges from 25.56 to 271.10 Mpa, elongation reaches 315.20 to 320%, and the young modulus ranges from 4.05 to 6.27 Mpa. Surface observation with SEM shows a smooth surface without pores. The antioxidant activity test shows IC50 values ranging from 84.11 to 175.37 ppm.</p> Erwin Abdul Rahim, Ahmad Ridhay, Sitti Nur Halizah, Indriani, Husain Sosidi, Khairuddin, Nov Irmawati Inda, Nurakhirawati, Moh. Mirzan, Aini Auliana Amar Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/17088 Wed, 01 May 2024 02:37:17 +0000 Reduksi Kandungan Zat Aktif Anionik dalam Limbah Laundry dengan Memanfaatkan Kombinasi Zeolit dari Tongkol Jagung dan Pseudomonas aeruginosa https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16982 <p>The increasing environmental pollution is one of the consequences of human activities that continue to expand. The environment has limitations in coping with pollutants generated by humans, such as waste from the laundry industry. This research aims to evaluate the combined effect of zeolite produced from corn cobs and the use of microorganisms capable of degrading anionic surfactants, with the goal of reducing the concentration of anionic surfactants in laundry wastewater. The methods used include adsorption using corn cobs as adsorbents and biodegradation using surfactant-degrading bacteria. Morphological observations using Scanning Electron Microscope (SEM) indicate that the produced zeolite has a crystal structure that stacks up like clumps of cubes. X-ray Diffraction (XRD) analysis shows that zeolite synthesized with a silica extraction ratio from corn cobs and sodium aluminate of 20:20 mL has been successfully conducted. The biodegradation process of anionic surfactants in laundry wastewater using a combination of synthesized zeolite and <em>Pseudomonas aeruginosa</em> bacteria employing the Methylene Blue Alkyl Substance (MBAS) method has shown a decrease in concentration to 1.66 mg/L and degradation of 33.55%, especially in sample 3 with variations of 7.5 grams of corn cob zeolite and 15% microorganisms, during a 5-day experiment.</p> Sirah Diniati Nea, Nurhaeni, Dwi Juli Puspitasari, Prismawiryanti, Nov Irmawati Inda, Ni Ketut Sumarni, Ruslan Copyright (c) https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16982 Wed, 01 May 2024 02:37:58 +0000