https://bestjournal.untad.ac.id/index.php/kovalen/issue/feedKOVALEN: Jurnal Riset Kimia2024-09-01T02:32:59+00:00Pasjan Satrimafitrahpasjan82@gmail.comOpen Journal Systems<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 is concerned with publishing original research articles, review articles, and 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: <strong><strong>2477-5398 (electronic)</strong></strong></strong></p> <p>The Scope of this journal includes:<br>1. Theoretical and environmental chemistry study<br>2. Material and biomaterial synthesis, including their application <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>https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16629Optimalisasi Limbah Serbuk Gergaji Kayu Jati (Tectona grandis L.f) Sebagai Adsorben Logam Berat Kobalt (Co) dengan Metode Aktivasi Kimia2024-08-31T18:42:19+00:00Faradin Faradinfaradfraday@gmail.comAsti Muhartifaradfraday@gmail.comNazwa Jinanti Dinafafaradfraday@gmail.comHolisha Widiyantofaradfraday@gmail.com<p>Teak wood <em>(Tectona grandis L.f.)</em>, 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.</p>2024-08-31T18:31:52+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17005Evaluation of Counter Current Horizontal Screw Extractor’s Performance in Determining Leaching Equilibrium of Clitoria ternatea Anthocyanins2024-08-31T18:42:20+00:00Laily Isna Ramadhanilaily.isna@polban.ac.idIrwan Hidayatullohirwan.hidayatulloh@polban.ac.idNurcahyonurcahyo@polban.ac.idDhyna Analyes Trirahayudhyna.analyes@polban.ac.id<p>Anthocyanin compounds as natural coloring substances contained in <em>Clitoria ternatea</em> 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 <em>Clitoria ternatea</em> 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 <em>Clitoria ternatea</em> 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.</p>2024-08-31T18:32:47+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17028Sintesis dan Karakterisasi Zeolit X dari Fly Ash Batu Bara Menggunakan Metode Sintesis pada Suhu Rendah2024-08-31T18:42:20+00:00Yuried Rieswanayuried409312ipa1@gmail.comAurela Naura Aisyahyuried409312ipa1@gmail.comSanisani.tk@upnjatim.ac.idSuprihatinsani.tk@upnjatim.ac.id<p>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 SiO<sub>2</sub> 52%, Al<sub>2</sub>O<sub>3</sub> 31.86%, Fe<sub>2</sub>O<sub>2</sub> 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 SiO<sub>2</sub> 55.54%. The resulting zeolite product has a typical peak at 2ϴ 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 Al<sub>2</sub>O<sub>3 </sub>0,5-1,5 moles.</p>2024-08-31T18:33:37+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17104Modifikasi Biofoam Berbasis Pati Singkong dengan Serat Eceng Gondok dan Variasi Konsentrasi Plasticizer2024-08-31T18:42:20+00:00Sarawinda Hutagalungsarawinda.hutagalung@uksw.eduJames Sibaranijames_sibarani@unud.ac.idResia Yoan Pramesti sarawinda.hutagalung@uksw.eduTheresia Hellen Renata Puspaningtyasarawinda.hutagalung@uksw.edu<p>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<sup>-1</sup>, 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.</p>2024-08-31T18:34:30+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17273Adsorpsi Logam Cu(II) dengan Hidrogel CMC/Pektin Komposisi 2:1 Menggunakan Metode Freeze-Thaw2024-08-31T18:42:20+00:00Nabila Maharani Maelan2010631230044@student.unsika.ac.idNurazizah Melani Dewi2010631230046@student.unsika.ac.idSri Andini2010631230054@student.unsika.ac.idMeka Saima Perdanimeka.perdani@ft.unsika.ac.idAulia Wahyuningtyasaulia.wahyuningtyas@ft.unsika.ac.id<p>The Citarum River is included in the category of the most polluted river in the world because it contains chemicals that can reduce air quality. This pollution not only affects air quality but also threatens public health and the surrounding ecosystem. Heavy metals, especially Cu(II), are one of the contaminants that have exceeded the threshold and can cause serious health impacts, including organ damage and nervous system disorders. Hydrogel is an alternative adsorbent that is widely used in various fields, especially in the field of air purification. Hydrogel has the ability to absorb and adsorb contaminants. In particular, Carboxymethyl Cellulose (CMC) hydrogel and pectin hydrogel have attracted much attention for safe water purification because they are non-toxic and have good biodegradability and biocompatibility. The researchers conducted a study on the adsorption of Cu(II) metal using a Carboxymethyl Cellulose (CMC) hydrogel adsorbent and pectin in a 2:1 composition through the Freeze-thaw method. FTIR analysis of the CMC/pectin hydrogel confirmed the presence of C-O-, O-H, C=O, C-H, OH bending, and COOH stretching vibrations. Based on BET analysis, the hydrogel has micropores, a type 1 isotherm, and a surface area of 1,889 m<sup>2</sup>/g. The Langmuir isotherm model was used to determine the ideal adsorption conditions to be a concentration of 298 ppm, an adsorption capacity of 1,0918 mg/g, and an adsorption efficiency of 13,485%.</p>2024-08-31T18:35:37+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17288Uji Aktivitas Antioksidan dan Kandungan Fitokimia Daun Benalu (Loranthus ferrugineus Roxb.) yang Tumbuh pada Ketinggian Tempat dan Inang Berbeda 2024-09-01T02:32:59+00:00Seswita Iwitseswitaiwit07@gmail.comArdiseswitaiwit07@gmail.comAuzar Syarifseswitaiwit07@gmail.com<p>Restrictions 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 (<em>Loranthus ferrugineus</em> 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 (<em>2,2-diphenyl-1-picrylhydrazyl</em>) method and phytochemical screening using reagents. Variables observed included extract yield percentage, antioxidant activity (IC<sub>50</sub> 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.</p>2024-08-31T18:36:30+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17229Biosintesis Nanopartikel ZnO dengan Ekstrak Temu Kunci (Boesenbergia rotunda) Dibantu Gelombang Mikro, Serta Pengujian Aktivitasnya Terhadap Bakteri 2024-08-31T18:42:21+00:00Yusup Junaediyusupjunaedi@apps.ipb.ac.idPurwantinigsih Sugitapurwantiningsih@apps.ipb.ac.id Muhamad Faridfaridsidik64@gmail.com<p>Numerous ZnO nanoparticles have been successfully synthesized using diverse plant extracts, yet research utilizing <em>B. rotunda</em> extract as a capping agent with microwave assistance has been lacking. Hence, this study aimed to employ microwave-assisted <em>B. rotunda</em> extract to produce ZnO nanoparticles and test their antibacterial activity. By utilizing 10 mL of 1% (m/v) <em>B. rotunda</em> 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 <em>B. rotunda</em> extract crucial in nanoparticle formation. Antibacterial testing revealed the nanoparticles' ability to create an inhibition zone against <em>E. coli</em> growth.</p>2024-08-31T18:37:29+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17268Pengaruh Ukuran Partikel dan Suhu Terhadap Derajat Asetilasi dan Yield Pada Ekstraksi Kitin dari Belalang Melalui Green Method2024-08-31T18:42:21+00:00Meila Savitrimeilasavitri97855@gmail.comSafina Handayani Pangestoeminsafff26@gmail.comHilman Imadul Umamhilman.imadul@ft.unsika.ac.idMeka Saima Perdanimeka.perdani@ft.unsika.ac.idTeguh Pambuditeguh.pambudi@ft.unsika.ac.id<p>Grasshoppers are insects that are pests for agriculture. In recent years, humans have begun to realize the broader economic value of insects, which are not only used as animal feed but also as sustainable biopolymers, such as chitin and chitosan. Grasshoppers' body organs contain chitin, including the digestive tract (intestine), trachea system, and exoskeleton (outer skeleton). Currently, the chitin extraction process using the green method with Deep Eutectic Solvent (DES) is more popular because it reduces the use of dangerous chemicals, reduces waste, and is overall more environmentally friendly than using chemical and biological methods. In the chitin extraction process, process parameters, such as reaction time, temperature, and particle size of the raw material, are adjusted to obtain the desired properties of chitin. This research aims to determine the effect of particle size and temperature on chitin yield and degree of acetylation (DA). The research results show that the yield values and DA values produced in this research are not by similar references which have described the characteristics of chitin. However, there is one sample showing that the most optimal DA value is the BSC 7 150 mesh 90°C sample, at wavelengths of 1560 cm-1 and 2875 cm-1, producing a DA value of 55.79514% and DD 44.20485933%. The best yield value was BSC 2 110°C 50 mesh, with a value of 22.1%.</p>2024-08-31T18:38:33+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17169Pemanfaatan Limbah Karbon-Aktif Melalui Reaktivitasi Termal Sebagai Adsorben Ion Kadmiun pada Lindi TPA2024-09-01T02:20:19+00:00Bambang Sardibambang.sardi@untad.ac.idAnggie Putry Afrilyabambang.sardi@untad.ac.idSitti Maghfirah Andrianibambang.sardi@untad.ac.idTry Novikabambang.sardi@untad.ac.idFadlia Azzahrabambang.sardi@untad.ac.idWahyu Hidayatbambang.sardi@untad.ac.id<p>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 H<sub>3</sub>PO<sub>4</sub> 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 H<sub>3</sub>PO<sub>4</sub> 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.</p>2024-08-31T18:39:24+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17264Spesiasi dan Bioavailabilitas Merkuri dalam Sedimen Teluk Palu Pasca Gempa dan Tsunami dengan Metode Diffusive Gradient in Thin Film (DGT)2024-08-31T18:42:21+00:00Husain SosidiRuslan_abdullah66@yahoo.co.idKhairuddinRuslan_abdullah66@yahoo.co.idPutri DwiyanaRuslan_abdullah66@yahoo.co.idRuslan Ruslanruslan_abdullah66@yahoo.co.id<p>Speciation and bioavailability of mercury in the sediments of Palu Bay after the earthquake and tsunami were conducted using fractionation and Diffusion Gradient in Thin Films (DGT). This method has been conducted using sediment samples from the estuary of the Pondo River, Palu. Heavy metal speciation of mercury ions was conducted by looking at the distribution of mercury ions in various species by sequential extraction and heavy metal bioavailability of mercury ions. This method was conducted by looking at the migration of mercury ions from sediments into the seawaters using a Diffusive Gradient in Thin Films (DGT). The speciation of mercury ions concentration with sequential extraction as EFLE (easily, freely, leachable, exchangeable) fraction is about < 0.0005 ppm, the oxidizable fraction is about < 0.0005 ppm and the resistant fraction is between < 0.0005 ppm to 0.0063 ppm. The results of DGT experiments to study the migration of mercury ions from sediments into the seawaters during 3 days of immersion is between 0.01003 ppm and 0.01748 ppm. The availability of mercury ions concentration in the sediments allows for the migration of mercury ions into water.</p>2024-08-31T18:40:10+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimiahttps://bestjournal.untad.ac.id/index.php/kovalen/article/view/17343Fitoremediasi Air Tercemar Nikel (Ni) dan Merkuri (Hg) Menggunakan Tanaman Azolla filiculoides Lam.2024-08-31T18:42:21+00:00Sri Utami Rudywahyu.harso@gmail.comWahyu Harsowahyu.harso@gmail.comRamadanilwahyu.harso@gmail.comMoh. Iqbalwahyu.harso@gmail.comPrismawiryantiprismawiryanti@gmail.co.id<p style="text-align: justify; text-justify: inter-ideograph; margin: 0in 0in 6.0pt 0in;"><span lang="IN" style="font-size: 9.0pt; font-family: 'Arial',sans-serif;">Water pollution from settlements, agriculture, and industry is a significant issue, as it introduces pollutants like heavy metals into water bodies, harming both humans and aquatic ecosystems. Phytoremediation is a cost-effective, eco-friendly technology for reducing heavy metals in water bodies. This study aimed to assess <em>Azolla filiculoides</em> plants' ability to absorb heavy metals nickel and mercury. The plants were grown in a hydroponic solution contaminated with 0.25 ppm of nickel and 0.5 ppm of mercury. The growth of the plants was measured based on their wet and dry weight, and the nickel and mercury content in the plant tissue was analyzed using Atomic Absorption Spectrophotometry (AAS). The study found that the growth of <em>A. filiculoides</em> plants was unaffected by the concentration of either nickel or mercury. The amount of nickel absorbed by the plants was 0 µg/g plant dry weight, while for mercury, it was 1654.82 µg/g. Based on the results, <em>A. filiculoides</em> plant is more promising for use as a phytoremediation agent for water bodies contaminated with mercury heavy metals rather than nickel heavy metals.</span></p>2024-08-31T18:40:59+00:00Copyright (c) 2024 KOVALEN: Jurnal Riset Kimia