KOVALEN: Jurnal Riset Kimia
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Evaluation of Counter Current Horizontal Screw Extractor’s Performance in Determining Leaching Equilibrium of Clitoria ternatea Anthocyanins
Full text linkAnthocyanin 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
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
Full text linkIncreasing 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
Full text linkA 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
Full text linkBiofoam 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
Kinerja Analitik Mikrokapsul Magnetit - Alginat (MNPs-ALG) untuk Analisis Ion Logam Cu(II) dan Aplikasinya pada Sampel Alam: Analytical Performance of Magnetite - Alginate Microcapsules (MNPs-ALG) for Analysis of Cu(II) Metal Ions and Their Application in Samples
Full text linkResearch 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, Fe3O4 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 FeCl2.4H2O and FeCl3.6H2O and adding concentrated ammonia at a temperature of 90οC until the solution becomes blackish in color. The dry magnetite, Fe3O4, nanoparticles were then dissolved in distilled water and thickened with Na-Alginate then dropped slowly into a 1 M CaCl2 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 >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 >90%, indicating that there is no matrix that significantly influences the measurements
Biosintesis Nanopartikel ZnO dengan Ekstrak Temu Kunci (Boesenbergia rotunda) Dibantu Gelombang Mikro, Serta Pengujian Aktivitasnya Terhadap Bakteri : Biosynthesis of ZnO Nanoparticles Using Fingerroot (Boesenbergia rotunda) Extract Assisted by Microwave and Evaluation of Their Antibacterial Activity
Full text linkNumerous ZnO nanoparticles have been successfully synthesized using diverse plant extracts, yet research utilizing B. rotunda extract as a capping agent with microwave assistance has been lacking. Hence, this study aimed to employ microwave-assisted B. rotunda extract to produce ZnO nanoparticles and test their antibacterial activity. By utilizing 10 mL of 1% (m/v) B. rotunda extract at pH 12.5 and calcinating for 3.8 hours at 200°C, coupled with 20 minutes of microwave treatment, ZnO nanoparticles averaging 78.78 nm in diameter were synthesized. Particle size was determined using the ImageJ software to analyze TEM images. UV-Vis absorption spectroscopy indicated a peak wavelength at 360 nm, while FTIR analysis identified compounds from B. rotunda extract crucial in nanoparticle formation. Antibacterial testing revealed the nanoparticles' ability to create an inhibition zone against E. coli growth
Aplikasi Edible Coating Albedo Semangka dengan Penambahan Ekstrak Etanol Daun Bandotan pada Tomat Napu: Application of Edible Coating of Watermelon Albedo with the Addition of Ethanol Extract of Bandotan Leaves on Napu Tomato
Full text linkOne of the causes of food waste is due to the lack of post-harvest handling of fruits or vegetables, therefore, an innovation is needed to overcome this problem, one of which is with edible coating. This study aimed to determine the characteristics of edible coatings from watermelon albedo pectin with the addition of Bandotan leaf extract as an antibacterial against Napu tomatoes. This study used a completely randomized design (CRD) consisting of 4 treatments, namely tomatoes (edible coating), tomatoes (edible coating + 12.5% bandotan leaf ethanol extract), tomatoes (edible coating + 25% bandotan leaf ethanol extract), and tomatoes (edible coating + 50% bandotan leaf ethanol extract). The watermelon albedo pectin characterization test results were the equivalent weight of 558.3 mg, methoxyl content of 6.1%, galacturonic acid content of 32.1%, moisture content of 11.469%, and ash content of 9.378%. From the results of tomato characterization tests for weight loss, moisture content, and microbial tests, the best treatment was produced by tomatoes (edible coating + 50% antibacterial), with consecutive results of 7.90%, 53.18%, 16.6 colonies (10-4 dilution), and 5.6 colonies (10-5 dilution)
Evaluasi dan Modifikasi Alat Penukar Ion dengan Penambahan Kolom Adsorpsi Karbon Aktif untuk Menurunkan Kesadahan : Evaluation dan Modification of Ion Exchange Equipment with the Addition of Activated Carbon Adsorption Column to Reduce Hardness
Full text linkIon 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 CaCO3 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. 
Uji Aktivitas Antioksidan dan Kandungan Fitokimia Daun Benalu (Loranthus ferrugineus Roxb.) yang Tumbuh pada Ketinggian Tempat dan Inang Berbeda : Activity Antioxidant Test and Phytochemical Content of Mistletoe Leaves (Loranthus ferrugineus Roxb.) Growing at Different Altitudes and Host Types
Full text linkRestrictions on synthetic antioxidants in several countries have caused the global community to switch to using natural antioxidants. One source of natural antioxidants is mistletoe leaves (Loranthus ferrugineus Roxb.).The presence of mistletoe in a place and host is an important aspect to pay attention to to get the best antioxidants. This research aims to determine the effect of different altitudes and host types on the antioxidant activity and phytochemical content of mistletoe leaves. This research was structured in a split-plot design with 2 factors, namely altitude (lowland and medium land) and host types (avocado, lime, cocoa, and dogfruit). Antioxidant activity test using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method and phytochemical screening using reagents. Variables observed included extract yield percentage, antioxidant activity (IC50 value), and phytochemical screening. The results showed that altitude and host type significantly affected the antioxidant activity of mistletoe leaves. Mistletoe leaves in avocado hosts in the lowlands and medium land showed the best antioxidant activity, namely 155,94 µg/mL and 156,25 µg/mL in the weak antioxidant category, and the highest phytochemical content, namely flavonoids, alkaloids, tannins, saponins, and steroids
Sintesis dan Karakterisasi Komposit Mn-N-TiO2/Bentonit untuk Degradasi Polutan Organik: Synthesis and Characterization of Mn-N-TiO2/Bentonite Composite for Organic Pollutants Degradation
Full text linkResearch has been conducted on the synthesis and characterization of Mn-N-TiO2/Bentonite composites for the degradation of organic pollutants. This study aims to synthesize the Mn-N-TiO2/Bentonite composite as a catalyst in degrading congo red in visible light and to determine the effect of irradiation time on the effectiveness of photodegradation of congo red catalyzed Mn-N-TiO2/Bentonite. The synthesis of the Mn-N-TiO2/Bentonite composite was carried out using the sol-gel method. Characterization was carried out with UV-Vis DRS, XRD, FTIR, and SEM-EDX. A photocatalytic activity test on Congo red degradation was carried out using ultraviolet and visible lamps. The results of the characterization of the Mn-N-TiO2/Bentonite configuration show that the band gap energy of Mn-N- TiO2/Bentonite with a variation of 5 g has a band gap energy of 2.14 eV with anatase crystal form. In the IR spectrum, there is a shift in wave number from 1634.49 to 1433.11cm-1, there is the vibration of the NO bond, absorption below 1000 cm-1 indicates the presence of Mn-O bonds, and absorption at wave number 1049.28 cm-1 indicates the presence of ions. manganese metal trapped in the TiO2 matrix. This spectrum indicated the presence of manganese and nitrogen. These results were confirmed by the EDX instrument, which showed the presence of 0.60% Mn and 0.04% N. SEM results show that particles that are still agglomerated and have a large size, which is influenced by water vapor in the TiO2 crystal structure. The results showed that the photodegradation activity increased significantly up to 40.9075% at 30 minutes of irradiation for the Mn-N- TiO2/Bentonite composite and 20.0225% under exposure to ultraviolet light