cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Jaya Hardi
Contact Email
jr.hardi0803@gmail.com
Phone
+6281341314717
Journal Mail Official
kovalen.journal@gmail.com
Editorial Address
Program Studi Kimia Fakultas MIPA, Uniiversitas Tadulako Jl. Soekarno-Hatta Km. 9, Tondo Palu, 94117
Location
Kota palu,
Sulawesi tengah
INDONESIA
KOVALEN: Jurnal Riset Kimia
Published by Universitas Tadulako
ISSN : -     EISSN : 24775398     DOI : https://doi.org/10.22487/kovalen
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
KOVALEN: Jurnal Riset Kimia is a peer-reviewed journal of chemistry published by the 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.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 325 Documents
 28   29   30   31   32 
Molecular Docking Senyawa Aktif Ekstrak Daun Melinjo (Gnetum gnemon) dalam Penghambatan Enzim Histidin Dekarboksilase: Molecular Docking of Active Compounds in Melinjo Leaf Extract (Gnetum gnemon) in Inhibiting the Histidine Decaboxylase Enzyme Gazpersz, Nelspon; El, Rahma; Baharudin, Muhammad Daswar Ardian; Bastio, Zulaika Izmatul Hawa; Ipaenin, Agnisia Indasari; Sohilait, Mario R.
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 1 (2024): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i1.16603

Abstract

Histamine in fish is formed due to histidine decarboxylase which occurs due to decay by bacteria. In the Maluku community, melinjo leaves (Gnetum gnemon) are used as boiled water in processing rotten fish so that the decay process is inhibited. The compound content of melinjo 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 Ã…. Thus, dehydrovomifoliol compounds from melinjo leaves show antihistamine effects as histidine decarboxylase inhibitors with promising potential.
Optimalisasi Limbah Serbuk Gergaji Kayu Jati (Tectona grandis L.f) Sebagai Adsorben Logam Berat Kobalt (Co) dengan Metode Aktivasi Kimia: Optimization of Teak Wood Sawdust Waste (Tectona grandis L.f) as Heavy Metal Adsorbent of Cobalt (Co) by Chemical Activation Method Faradin, Faradin; Muharti, Asti; Dinafa, Nazwa Jinanti; Widiyanto, Holisha
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i2.16629

Abstract

Teak wood (Tectona grandis L.f.), a high-quality wood commonly used in Indonesia, specifically in the Cilegon area, has the potential to be used as an alternative to reduce environmental pollution. This research aimed to test teak wood sawdust waste as an adsorbent for cobalt heavy metal, create activated charcoal from the sawdust waste for the same purpose, and determine the optimal conditions for treatment with and without chemical activation. Industrial waste samples were found to contain 50.7 ppm of cobalt metal through ICPS testing. Activated chemical adsorption, without activation and with industrial wastewater mixture, resulted in a decrease in cobalt metal concentration by 78.2% or 11.08 ppm. The optimal conditions for activated chemical adsorption were found at a pH of 5, an adsorbent mass of 600 mg, and a time of 40 minutes, resulting in decreases of 60.9% (21.2751 ppm), 71% (15.7821 ppm) and 67.7% (17.5812 ppm), respectively. The results show that teak wood sawdust waste can effectively adsorb cobalt heavy metal, providing a potential solution for industrial wastewater treatment.
Uji Cemaran Logam Mangan (Mn), Tembaga (Cu), dan Mikroba pada Air Minum dalam Kemasan : Testing for Manganese (Mn), Cooper (Cu), and Microbial Contamination in Bottled Drinking Water Rosita, Tita; Sadiyah, Inne
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 1 (2024): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i1.16642

Abstract

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), Coliform test, E.coli test and Pseudomonas aeruginosa 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 <1 CFU/mL, and the average test results for E.coli, Coliform, and P.aeruginosa 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.
Reduksi Kandungan Zat Aktif Anionik dalam Limbah Laundry dengan Memanfaatkan Kombinasi Zeolit dari Tongkol Jagung dan Pseudomonas aeruginosa: Reduction of Anionic Surfactant Content in Laundry Wastewater by Utilizing a Combination of Zeolite from Corn Cobs and Pseudomonas aeruginosa Nea, Sirah Diniati; Nurhaeni; Puspitasari, Dwi Juli; Prismawiryanti; Inda, Nov Irmawati; Sumarni, Ni Ketut; Ruslan
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 1 (2024): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i1.16982

Abstract

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 Pseudomonas aeruginosa 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.
Evaluation of Counter Current Horizontal Screw Extractor’s Performance in Determining Leaching Equilibrium of Clitoria ternatea Anthocyanins Ramadhani, Laily Isna; Hidayatulloh, Irwan; Nurcahyo; Trirahayu, Dhyna Analyes
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i2.17005

Abstract

Anthocyanin compounds as natural coloring substances contained in Clitoria ternatea flowers have higher antioxidant activity than anthocyanins from other flower extracts. Obtaining anthocyanin extract from Clitoria ternatea flower can be done using the solid-liquid extraction method. The objectives of this study include making a leaching equilibrium diagram of Clitoria ternatea flowers and determining the optimum L/S ratio and the number of equilibrium stages in the counter current horizontal screw extractor. In the maceration process, a leaching equilibrium diagram is produced, which is then used to design and determine the number of equilibrium stages. The equilibrium diagram of anthocyanins from Clitoria ternatea flowers with a gradient slope to the right is in accordance with the literature so that the equilibrium diagram can be used in the design of the extraction unit and the calculation of the theoretical stage of the multi-stage extraction unit. Based on the equilibrium diagram, the Number of Transfer Units (NTU) of 4 stages and the Height of the Transfer Unit value of this process is 0.105 m.
Sintesis dan Karakterisasi Zeolit X dari Fly Ash Batu Bara Menggunakan Metode Sintesis pada Suhu Rendah: Synthesis and Characterization of Zeolite X From Fly Ash Waste Using Synthesis Method at Low Temperature Rieswana, Yuried; Aisyah, Aurela Naura; Sani; Suprihatin
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i2.17028

Abstract

Many industries in Indonesia have switched to using coal fuel. The use of coal at PT PLTU Paiton has reached 250 tons per hour and produces 4% of waste by-products of combustion contained from bottom ash by 25% and fly ash by 75%. Fly ash waste will harm the environment and health. Fly ash contains many components, including SiO2 52%, Al2O3 31.86%, Fe2O2 4.89%, CaO 2.68%, and MgO 4.66%. This research aims to synthesize and characterize zeolite X from PT Paiton fly ash using a low-temperature synthesis method. Zeolite X synthesis in this study has 3 steps: The pretreatment process, silica synthesis process, and zeolite synthesis process. The results of silica synthesis obtained SiO2 55.54%. The resulting zeolite product has a typical peak at 2Ï´ 28.72. Zeolite x has a wavelength of 430, 570, 695,7, and 965,7, which respectively indicates Si-O-Si and Si-O-Al bonds, double ring bonds, T-O ring symmetric strain (internal), and asymmetric (internal). The results of zeolite X crystal synthesis in this study could not be formed in the variable of adding time of 3-5 hours with a variation of moles of Al2O3 0,5-1,5 moles.
Selektivitas Adsorpsi Campuran Biner Fe(II)/Cu(II) Menggunakan Karbon Aktif dari Sekam Padi dan Serbuk Gergaji Kayu Jati: Adsorption Selectivity on Binary Mixture of Fe(II)/Cu(II) Using Activated Carbon from Rice Husks and Teak Sawdust Riyanto, Cucun Alep; Yonggulemba, Jose D Michael; Stefani, Delvi Anandhia; Brotosudarmo, Tirza Widyamurti; Anggaran, Diki; Pradana, Yehez Kiel Sandy; Ariesto, Yohanes; Christyawardana, Fidelis Tertius Aluh; Sari, Iga Permata; Puspita, Nicho Vernanda Wina; Lutiyono, Lutiyono
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 1 (2024): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i1.17060

Abstract

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 H3PO4 (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 R2 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.
Sintesis dan Karakterisasi Polivinil Alkohol (PVA) Terlapis Polieugenol: Synthesis And Characterization of Polyvinyl Alcohol (PVA) Coated with Polyeugenol Rahim, Erwin Abdul; Ridhay, Ahmad; Sitti Nur Halizah; Indriani; Sosidi, Husain; Khairuddin; Inda, Nov Irmawati; Nurakhirawati; Mirzan, Moh.; Amar, Aini Auliana
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 1 (2024): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i1.17088

Abstract

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.
Modifikasi Biofoam Berbasis Pati Singkong dengan Serat Eceng Gondok dan Variasi Konsentrasi Plasticizer: Modification of Cassava Starch-Based Biofoam with Water Hyacinth Fiber and Concentration Variation of Plasticizer Hutagalung, Sarawinda; Sibarani, James; Pramesti , Resia Yoan; Puspaningtya, Theresia Hellen Renata
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i2.17104

Abstract

Biofoam is a plant-based alternative packaging. The biofoam was prepared by using the extrusion method and baking process. This research aims to determine the lowest ratio of PVA and glycerol in absorbing water and testing the mechanical properties of biofoam (tensile strength, biodegradation test and FTIR analysis. The best biofoam composition in absorbing water was obtained at a ratio of PVA: glycerol 8%. The results of biofoam characteristics obtained by the water absorption test were 9.76%, maximum bending strength was 9.20 MPa and biofoam can be degraded 100% on day 15. The results of FTIR analysis showed the presence of absorption spectra at wave numbers 3410,15 cm-1, which is a typical region of O-H functional groups (strong and broad) carbohydrates and polyphenols. Modification of starch with fiber and plasticizer in research improves the physicochemical characteristics of biofoam in terms of increasing water absorption and biofoam biodegradation. In contrast, in terms of mechanical properties, the bending strength of biofoam requires further research referring to the characteristics of biofoam mechanical properties toward SNI standards.
Pemanfaatan Limbah Karbon-Aktif Melalui Reaktivitasi Termal Sebagai Adsorben Ion Kadmiun pada Lindi TPA: Utilization of Activated Carbon Waste Through Thermal Reactivity as a Cadmium Ion Adsorbent in Landfill Leachate Sardi, Bambang; Afrilya, Anggie Putry; Andriani, Sitti Maghfirah; Novika, Try; Azzahra, Fadlia; Hidayat, Wahyu
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2024.v10.i2.17169

Abstract

The leachate produced at the Kawatuna landfill, managed without proper waste treatment systems, has been found to contain heavy metals like cadmium (Cd), which contaminate groundwater and pose significant health risks. This study investigates the reduction of Cd ions in leachate through adsorption using activated carbon (AC) waste. The AC waste was reactivated via thermal methods, including phosphoric acid immersion, heating, and washing. Morphological analysis was conducted using scanning electron microscopy (SEM), and adsorption efficacy was evaluated with atomic absorption spectroscopy (AAS). The findings indicate that AC waste with a pore diameter of 2.95 µm can be effectively reused as an adsorbent through thermal reactivation. Specifically, AC treated with H3PO4 immersion and heating exhibited a pore diameter of 3.24 µm, while heating and washing resulted in a pore diameter of 2.29 µm. The Cd concentration in leachate treated with AC immersed in H3PO4 followed by heating showed a modest reduction, whereas the heating and washing treatment led to a significant decrease in Cd levels, achieving an adsorption capacity of 3.92 mg/L within 50 min. This method presents a viable alternative for managing landfill leachate at the Kawatuna site.

Page 30 of 33 | Total Record : 325

 28   29   30   31   32 

Filter by Year

2015 2025


Reset
Filter By Issues
All Issue Vol. 11 No. 2 (2025): December Edition Vol. 11 No. 1 (2025): August Edition Vol. 10 No. 3 (2024): December Edition Vol. 10 No. 2 (2024): August Edition Vol. 10 No. 1 (2024): April Edition Vol. 9 No. 3 (2023): December Edition Vol. 9 No. 2 (2023): August Edition Vol. 9 No. 1 (2023): April Edition Vol. 8 No. 3 (2022): December Edition Vol. 8 No. 2 (2022): August Edition Vol. 8 No. 1 (2022): April Edition Vol. 7 No. 3 (2021): Edisi Desember Vol. 7 No. 2 (2021): Edisi Agustus Vol. 7 No. 1 (2021): Edisi April Vol. 6 No. 3 (2020): Edisi Desember Vol. 6 No. 2 (2020): Edisi Agustus Vol. 6 No. 1 (2020): Edisi April Vol. 5 No. 3 (2019): Edisi Desember Vol. 5 No. 2 (2019): Edisi Agustus Vol. 5 No. 1 (2019): Edisi April Vol. 4 No. 3 (2018): Edisi Desember Vol. 4 No. 2 (2018): Edisi Agustus Vol. 4 No. 1 (2018): Edisi April Vol. 3 No. 3 (2017): Edisi Desember Vol. 3 No. 2 (2017): Edisi Agustus Vol. 3 No. 1 (2017): Edisi April Vol. 2 No. 3 (2016) Vol. 2 No. 2 (2016) Vol. 2 No. 1 (2016) Vol. 1 No. 1 (2015) More Issue