KOVALEN: Jurnal Riset Kimia
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Pemanfaatan Limbah Tandan Kosong Kelapa Sawit dan Kulit Jagung Manis menjadi Kertas Karton menggunakan Metode Organosolv: Utilization of Empty Fruit Bunch and Sweet Corn Husk Waste into Paperboard using the Organosolv Method
Full text linkPaper is generally made using cellulose, which comes from wood, as raw material. However, if wood is used without stopping, it will cause global temperatures to rise and depletion of wood resources. One alternative to replacing wood in paper production is to use empty fruit bunch (EFB) waste and sweet corn husks. This research aims to obtain optimum conditions from variations in the ratio of raw materials and cooking process solutions and to obtain cardboard paper quality under SNI 0123:2008. The method used in this research is raw material preparation, and the pulp-making process uses the organosolv method. From the results of this research, the characteristics of pulp and paperboard obtained under optimum conditions at a raw material ratio of 30:70% w/w with a cooking solution ratio of 30:50:20% v/v have a cellulose content of 60% w/w, a tensile index of 5 .83 kN/m, absorption capacity 2.35 gr/m2, and grammage 428.67 gr/m2. From these data, it can be concluded that cardboard paper is produced from EFB raw materials and sweet corn husks with a raw material ratio of 30:70 %w/w and a cooking solution ratio of 30:50:20 %w/w using the process organosolv has met SNI 0123:2008 standards on tensile index, absorption capacity and grammage regarding the quality requirements for paperboard. 
Tofu Liquid Waste Treatment Using Effective Volume of Anaerobic Sequencing Batch Reactor (ASBR)
Full text linkThe 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
Sintesis dan Karakterisasi Katalis Bentonit Termodifikasi TiO2 dan Terinpregnasi Logam Ni : Synthesis and Characterization of TiO2 Modified Bentonite Catalyst and Ni Metal Impregnated
Full text linkTiO2-modified and Ni-impregnated bentonite catalysts have been synthesized and characterized to determine their physicochemical properties. Ni(NO3)2.6H2O was used as a precursor for impregnation. The physicochemical properties determined include surface acidity by acid-base titration method, FTIR spectrum, and XRF and XRD data. The highest surface acidity value was obtained from the Ni-TiO2/bentonite catalyst sample of 1.57 mmol/g. The results of FTIR analysis showed that the peak at wave number 3441 cm-1 in TiO2/bentonite shifted to 3458 cm-1 in Ni-TiO2/bentonite. The distribution of bentonite content after being pillared with TiO2 = 8.68% and impregnated with NiO = 0.58%. The success of nickel metal impregnation into the TiO2/bentonite support was obtained from XRD data, which was marked by the appearance of a typical Ni peak at 2θ = 37.70° d = 2.38 Å, 2θ = 39.39° d = 2.28 Å, 2θ = 43.02° d = 2.10 Å, 2θ = 51.38°d = 1.77 Å
Spesiasi dan Bioavailabilitas Merkuri dalam Sedimen Teluk Palu Pasca Gempa dan Tsunami dengan Metode Diffusive Gradient in Thin Film (DGT): Speciation and Bioavailability of Mercury in Palu Bay Sediments Post Earthquake and Tsunami Using the Diffusive Gradient in Thin Film (DGT) Method
Full text linkSpeciation 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
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
Full text linkThe 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
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
Full text linkHistamine 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
Induksi Aquilaria malaccensis Menggunakan Kombinasi Fusarium oxysporum dan Asam Salisilat: Aquilaria malaccensis Induction Using a Combination of Fusarium oxysporum and Salicylic Acid
Full text linkAgarwood is a resin from agarwood-producing plants that are given certain stimulants, thus stimulating the tree's defense system. The defense system produced is in the form of a sweet-smelling phytoalexin compound, better known as agarwood. Stimulants that can stimulate the formation of Gaharu are biological inoculants and chemical inducers. In this research, the biological inoculant used the Fusarium oxysporum fungus, and the chemical inducer used salicylic acid. This research aims to determine the effectiveness of using a combination of Fusarium oxysporum and salicylic acid in producing agarwood resin. The combination treatment of Fusarium oxysporum and salicylic acid was carried out using the injection method on Aquilaria malaccensis tree branches, and induction was carried out for 3 months. This research shows that the TLC test results in all treatments contain aloes, which is proven by the discovery of phenolic and terpenoid compounds. The combination treatment produces a color change intensity that is not darker and has a broader color change zone compared to the single treatment. Therefore, it can be concluded that the combination of Fusarium oxysporum and salicylic acid is less effective in producing Gaharu than the single treatment
Pengaruh Ukuran Partikel dan Suhu Terhadap Derajat Asetilasi dan Yield Pada Ekstraksi Kitin dari Belalang Melalui Green Method: The Effect of Particle Size and Temperature on the Degree of Acetylation and Yield in Chitin Extraction from Grasshoppers Using the Green Method
Full text linkGrasshoppers 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%
Adsorpsi Logam Cu(II) dengan Hidrogel CMC/Pektin Komposisi 2:1 Menggunakan Metode Freeze-Thaw: Adsorption of Cu(II) Metal by Hydrogel CMC/Pectin Composition of 2:1 Using The Freeze-Thaw Method
Full text linkThe 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 m2/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%
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
Full text linkThe 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