Indonesian Journal of Chemical Studies

Study of Anaerobic and Aerobic Fertilizers of Organic Waste Treatment

Dian Mira Fadela — 2024-10-28

Phosphorus is a critical nutrient for plant growth, significantly enhancing agricultural productivity and ecosystem sustainability. Organic waste-based fertilizers offer a sustainable solution to boost soil phosphorus levels while addressing waste management challenges. This study evaluated the phosphorus content of anaerobic and aerobic fertilizers derived from organic waste, focusing on factors that influence phosphorus dynamics during composting. Composting methods and feedstock composition affected phosphorus transformation and availability, with temperature, moisture, aeration, and microbial activity playing pivotal roles in mineralization, immobilization, and solubilization. The experiment used market waste, pineapple peel, dry leaves, sawdust, water, sugar, manure, and EM4. The composting process involved weekly monitoring of pH, temperature, and compost height. The results showed that the pH of the anaerobic compost ranged from 7.2 to 7.4, meeting the SNI 19-7030-2004 standard. The mature compost color was brownish-black, which also complied with the standard. Phosphorus contents as P₂O₅ were 1712 mg/kg in aerobic fertilizer and 2653 mg/kg in anaerobic fertilizer. Phosphorus is crucial for root development, water, and nutrient absorption, and enhances plant tolerance to drought. It also affects flower and fruit formation, affecting crop yield quality and quantity. This study highlighted the importance of understanding phosphorus dynamics to optimize nutrient management and improve organic waste utilization in agriculture. Future research should explore the phosphorus transformation mechanisms and innovative composting techniques to enhance phosphorus availability for plant uptake

Novel Natural Deep Eutectic Solvent (NaDES) Yellow Choline Chloride and Molecular Docking Soybean Extract (Glycine max) as Diabetes Drugs Candidate

Rizky Yulion — 2024-10-29

Natural Deep Eutectic Solvent (NaDES) is an environmentally friendly extraction method to obtain soybean bioactive compounds, focusing on genistein compounds as drug candidates. The use of environmentally friendly extraction solvents could support green extraction to ensure the safety of natural medicinal candidates. HBA (Hydrogen Bonding Acceptor), yellow choline chloride (supplement in animal feed), and HBD (Hydrogen Bonding Donor) lactic acid. A UV-Vis spectrophotometer was used to detect genistein. MoE 2022.02 software was used in the molecular docking simulation, and the docking scoring methods affinity ΔG and GBVI/WSA (induced fit) were used. The PDB ID used was: 5nn8 (alpha glucosidase) and PDB ID: 7vsi (SGLT-2 Inhibitor). The results of genistein were obtained by 92,670 mg (0.9267%) in the 75 ⁰C, 30 min ultrasonic NaDES extraction in HBD lactic acid. Genistein exhibited an affinity for the 5NN8 (alpha-glucosidase) and 7VSI (SGLT-2 Inhibitor) receptors of -6,230 and -8,768, respectively. These affinity values did not exceed the interaction values of the native ligands acarbose (alpha-glucosidase) and Empagliflozin (SGLT-2 Inhibitor), which were -8,988 and -12,302, respectively. Genistein compounds had the lowest RMSD value of 0.819 at 7vsi (SGLT-2 Inhibitor). These results suggested the possibility of a genistein pathway as a candicate diabetes drug. The NaDES extraction method demonstrated great potential for development into a green action that supported the green extraction process, and genistein was an isoflavone compound that could be a candidate for diabetes drugs.

Development of Adhesive Materials from Polystyrene Foam Waste

Ahmad Dzaky Mualim — 2024-12-31

Polystyrene is a type of plastic that is difficult to decompose naturally, leading to waste that contributes to environmental pollution. This study developed adhesive materials based on polystyrene waste to reduce environmental impacts while addressing the need for eco-friendly adhesives. The adhesives were prepared by dissolving polystyrene foam waste in gasoline and acetone with various compositions. The solvents with a composition ratio of gasoline and acetone of 100:0; 90:10; 80:20; 70:30; 60:40; and 50:50 were coded as A, B, C, D, E, and F. Tests were carried out to determine the solubility of polystyrene foam in various solvent compositions and the mechanical properties of samples, including shear force, shear strength, and strain (elongation). Paper, cardboard, and wood were used as gluing materials. The adhesive strength was also compared with that of commercial adhesives. The adhesive samples were then characterized using Fourier-Transform Infrared Spectroscopy (FTIR). The shear strength results obtained for samples code A, B, C, D, E, and F were 119.95 kPa, 103.68 kPa, 96.64 kPa, 124.56 kPa, 150.08 kPa, and 157.80 kPa, respectively. The findings showed that the adhesive sample coded F synthesized using a solvent composition of 50: 50 gasoline: acetone exhibited superior adhesive ability than other variations. This sample can potentially serve as a substitute for commercial adhesives that are suitable for bonding various materials.

Carbon Paste Electrode Modified Zeolite-Iron as a Chromium(VI) Detection Medium

Zulhan Arif — 2024-12-31

Chromium exists in two dominant species in nature, Cr(III) and Cr(VI). Both are stable; however, Cr(VI) exhibits significantly higher toxicity than Cr(III). Existing measurement methods could not differentiate between these two chromium species. Therefore, a more sensitive and selective measurement method was required for their speciation, particularly for Cr(VI) detection. In this study, a carbon paste electrode modified with zeolite and iron was developed for Cr(VI) measurement using the voltammetry method. The electrode was prepared by mixing graphite, iron-modified zeolite, and liquid paraffin. Measurements were conducted using cyclic voltammetry within a potential range of -1.2 V to 1.2 V. A 0.05 M KCl solution was used as the electrolyte. Electrode characterization was carried out concerning three parameters: the effect of analyte pH, preconcentration time, and the composition of iron-modified zeolite. The optimum Cr(VI) measurement was achieved in a 50 μM Cr(VI) solution at pH 3 using a carbon paste electrode with 20% iron-modified zeolite and a preconcentration time of 25 min. Under these optimal conditions, a cathodic peak current of 5.22 μA was obtained.

Yellow-Flare Performance Improvement of PVC Addition into Mg-Sodium Nitrate-Based Pyrotechics

Gunaryo Gunaryo — 2024-12-31

Light pyrotechnics is one strategic defence equipment for civil and military purposes. Additives act as one of the factors that affect the flame in pyrotechnics. Additives were used to slow down the combustion rate so that the flare could burn for a long time without drastically reducing the flame performance of the flare. This study focused on the performance of pyrotechnic flames with variations of PVC as a density-increasing material because it was in the form of a polymer and had high-chlorine content, resulting in a mixture that is difficult to burn. The experiment results exhibited that pyrotechnics without PVC showed intensity with an emission spectrum of 577-585 nm, light intensity of 723-1184 lux, and burning rate of 3.22-3.31 g/s. Increasing the PVC additive composition to 1.5 gr showed emissions with a wavelength of 596-597 nm, decreased intensity from 91-183 lux, and a slower burning rate of 0.72-0.88 g/s. The use of PVC was effectively applied in the 1.76-10.21% fraction and was actively able to slow down the rate of combustion of pyrotechnic mixtures. Hence, PVC could slow down the burning rate and increase density. Adding PVC in yellow pyrotechnics would slow down the burning rate of the pyrotechnic sample with the side effect of reducing the brightness of the yellow color and the intensity of the light.

Exploring the Potential of Carbon-based Radar Absorbing Material Innovations

Mirad Fahri — 2024-12-31

This review explored the potential of carbon-based radar-absorbing materials (RAM), which had gained significant attention due to their superior properties and performance. In response to the growing demand for stealth technology in the military and civilian sectors, traditional radar-absorbing materials encountered limitations: weight, cost, and effectiveness. Carbon-based materials, such as carbon nanotubes, graphene, and various composites, offered lightweight, flexible, and tunable solutions that enhanced electromagnetic wave absorption across a wide frequency range. This paper examined the underlying mechanisms of radar wave absorption in carbon-based materials, highlighting their advantages over conventional options. In addition, recent advancements in fabrication techniques, including 3D printing and hybrid composite development, were also discussed, emphasizing their role in optimizing performance and sustainability. By synthesizing current research findings, this review aimed to provide a comprehensive understanding of the carbon-based RAM potential in advancing the future of stealth technology. Ultimately, this study presented insights that contribute to the continuing investigation in advanced materials science, suggesting a potential way to develop materials that can enhance radar absorption capabilities and extend their applications in modern technology.

Comparative Analysis of FABA Waste Composition in Various Coal-Fired Power Plant Industries in Several Countries and Indonesia: A Review

M. Sulthon Nurharmansyah Putra — 2024-12-31

Fly Ash and Bottom Ash (FABA) is the waste from burning coal in coal-fired power plants and consists of chemical compounds, such as SiO₂, Al₂O₃, Fe₂O₃, and CaO. This waste poses an environmental challenge and an opportunity for the construction industry. This study conducted a comparative analysis of the composition of FABA from several coal-fired power plants in Indonesia and other countries, such as Thailand, China, Malaysia, France, Italy, and Portugal. In particular, this study assessed the XRF data from several other references. The XRF test data showed significant variations in the FABA content, influenced by coal type, combustion method, and emission management technology. The high SiO₂ content in the Cirebon and Teluk Sirih coal-fired power plants showed potential for pozzolanic applications. Meanwhile, the high Fe₂O₃ in Tanjung Enim and Sudimoro had the potential for metallurgical applications. In addition, the high CaO content of Teluk Sirih allowed its use in lime production and soil stabilization. However, high levels of SO₃, especially in Cirebon, required more attention in processing because of its impact on concrete quality and environmental pollution. With proper processing, FABA could be a valuable resource in various industries, reducing reliance on natural raw materials. This study highlighted the potential for the sustainable use of FABA and proposed management measures to address environmental challenges. The optimal use of FABA reduced negative environmental impacts and opened up significant economic opportunities, supporting the circular economy in the energy and construction sectors.