IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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The Effect of Using Wet Ash as a Substitute for Quicklime in Improving the Quality of Acid Mine Drainage from Coal Mining
No full textAcid Mine Drainage (AMD) management uses the active treatment method with the addition of alkaline neutralizing chemicals such as lime (CaCO3, CaO) although the cost is more expensive. Several previous studies indicate that the application of boiler ash can increase pH and nutrient content because it is alkaline. The boiler ash used in this study came from the remaining burning of bark at a Medium Density Fiberboard industrial. Boiler ash containing water is known as Wet Ash and is strongly alkaline (pH 11.92). The purpose of this study was to analyze the effect of adding wet ash and to analyze the effectiveness of AMD processing on pH, Total Suspended Solids (TSS), Fe and Mn. The method this study: wet ash samples of 2.5 g, 5 g, 7.5 g, 10 g, 12.5 g and 15 g were mixed with 10 liters of AMD, homogenized for 10 minutes, then analyzed in the laboratory to determine its characteristics. The results of the study on the characteristics of wet ash treatment of 15 g/L with pH = 7.21, TSS = 326 mg/L, Fe = <0.018 mg/L, Mn = 6.42 mg/L is the best treatment because all parameters meet the quality standards
Synthesis of Bentonite-TiO2 Bionanocomposite for Photodegradation of Used Lubricating Oil
No full textUsed lubricating oil waste contains heavy metal components which, if they enter the water, will block light. Used lubricants include toxic and hazardous waste (B3) so they need further processing before being reused or thrown away, because they are dangerous for human health and the environment. This research aims to determine the ability or effectiveness of the Bentonite-TiO2 composite in degrading used lubricating oil. The research began by synthesizing Bentonite-TiO2 where the composite results obtained were characterized. Based on the results of the FTIR spectrum analysis of Bentonite-TiO2, Ti was successfully modified in bentonite because the wave number 1419.84 cm-1 shows the presence of Al-O groups and the wave number 1423.92 cm-1 shows the presence of Ti-O-Ti vibrations. The results of XRD characterization show that TiO2 has formed in the bentonite-TiO2 composite, this makes the bentonite-TiO2 more stable and can be used as photocatalysis in the processing of used lubricating oil. The results of SEM-EDX analysis of Bentonite-TiO2 show the chemical composition of C, O, Al, Si, Ca, and Ti. In photodegradation, the mass variation viscosity value with an optimum time of 5 hours is the highest viscosity value, namely with a viscosity value of 5.11 cSt
Effect of Hydrogen Flow Rate on MEA Performance with a Three-Catalyst-Layer Pt/C Configuration
No full textAn essential component in Proton Exchange Membrane Fuel Cells (PEMFCs) is the Membrane Electrode Assembly (MEA), which facilitates the electrochemical reaction between hydrogen and oxygen to generate electrical energy. This study examines the effect of varying hydrogen gas flow rates on the performance and durability of a Pt/C-based MEA. The MEA used in this research measures 6.5 cm × 30 cm with a catalyst loading of 2 mg/cm². The electrode is constructed in three layers of catalysts to maximize interfacial contact within the catalyst layer. The tested hydrogen flow rates were 100, 200, 300, and 400 mL/min. Performance evaluation was conducted through polarization (I–V) and power (I–P) curve measurements. The results indicated optimal performance at a 200 mL/min flow rate, with a maximum power density of 3.563 mW/cm² and a current density of 10.256 mA/cm². Durability testing was carried out under a constant current of 2 A for 12 hours and showed a voltage drop of 24.35% after 10 hours of operation. Electrochemical characterization using Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), and Linear Sweep Voltammetry (LSV) yielded an Electrochemical Surface Area (ECSA) of 1.477 × 10⁻⁵ m²/g, electrical conductivity of 3.218 × 10⁻⁴ S/cm, and an electric charge of 4.2 × 10⁻⁶ C
Harnessing Electrochemical Processes for Enhanced Struvite Crystallization: A Comprehensive Review
Full text linkThe recovery of nutrients from contaminated water and wastewater can effectively mitigate both the nutrient burden on water resources and the associated environmental issues affecting aquatic ecosystems. This approach presents a valuable solution towards achieving environmental and societal sustainability. Consequently, struvite crystallization technology has emerged as a promising method for nutrient recovery, as the resulting precipitate can be recycled as a natural fertilizer. This review aims to elucidate the characteristics of struvite and provide insight into the fundamental process of crystallization. Furthermore, it comprehensively discusses the various variables that influence struvite crystallization, with a special focus on its application in urine-contaminated water using electrochemical methods. The review also highlights the advantageous on environmental and economic aspects. In addition, the limitations of struvite crystallization technology are examined, and future research prospects are explored, particularly in the context of electrochemical techniques which offer innovative solutions for controlled nutrient extraction. Ultimately, this work serves as a foundational resource for the future utilization of struvite crystallization technology in nutrient recovery, in response to the escalating environmental challenges and depletion of natural resources.Keywords: Struvite formation, electrochemical process, magnesium anode, struvite crystallization, natural fertilize
Synthesis and Characterization of Terephthalic Acid MOF as a Catalyst for Biodiesel Production from Waste Cooking Oil
Full text linkUtilization of waste cooking oil as a raw material for biodiesel production is an effective solution to reduce environmental pollution and produce renewable energy. The high free fatty acid content in waste cooking oil is a major problem in the industry, so it requires an effective catalyst in the biodiesel production process. Zn terephthalate MOF has a large surface area, porous structure, and good thermal stability, making it very effective as a heterogeneous catalyst for the biodiesel esterification process. This study aims to synthesize and characterize Zn terephthalate MOF using a hydrothermal method with a Teflon autoclave, and evaluate its effectiveness as a catalyst. The analysis was carried out by testing the acidity of the Zn terephthalate MOF catalyst characterized by XRD, TGA, PSA, and the ability to convert waste cooking oil into biodiesel. The results showed that the obtained MOF-5 had an acidity of 4.33 mmol/g, the XRD results showed a 2 theta angle and the catalyst intensity was the same as JCPDS no. 96-432-6738. TGA results showed that the Zn terephthalate catalyst had thermal stability up to 300OC, and PSA results showed particles distributed at 8428.62 nm. This proves that the Zn terephthalate MOF catalyst can reduce the FFA value of waste cooking oil and convert it into biodiesel with a conversion rate of 94.18%, and the catalyst can be reused up to five times with relatively stable performanc
Comparison of Alum and Coal-Based Activated Carbon for the Treatment of Raw Water
Full text linkThe availability of clean water is an essential element for supporting the life cycle and sustainable development. The efficiency of providing raw water sources is an important factor for adequate water quantity and quality. This study examines the effectiveness of alum compared with coal-based activated carbon in the removal of Fe, Mn, and turbidity in raw water from the Lematang River, Muara Enim Regency. Activated carbon in this study was produced using a KOH activator with varying activation temperatures (700 °C, 800 °C, and 900 °C). The research results showed that the quality of the third activated carbon met the active carbon quality standards (moisture, ash content, Methylene blue dye and iodine adsorption capacity), but the activated carbon with activation at a temperature of 800 °C had the largest surface area. Activated carbon was proven more effective in reducing Fe and Mn concentrations than alum, while alum was superior in reducing turbidity. After three cycles of activated carbon regeneration, the reduction in Fe and Mn remained below 5%. These results show that activated carbon is a cost-effective and eco-friendly option for raw water treatment.Keywords: Coal, activated carbon, alum, raw water, regeneratio
Antibacterial Activity of Nanocomposite Chitosan-Silver Nanoparticle with Cymbopogon citratus Extract as a Bioreductor Against Staphylococcus aureus
No full textNanocomposites are materials formed by combining two components, one or both of which are on the nanometer scale. The nanocomposite in this study is a combination of chitosan and silver nanoparticles produced through the synthesis of silver nitrate using Cymbopogon citratus extract. Silver nanoparticles have antibacterial abilities that can be utilized to overcome various diseases. However, their antibacterial properties may be reduced due to the tendency of silver nanoparticles to agglomerate. This can be overcome by the addition of chitosan as a stabilizing agent to prevent agglomeration and maintain the antibacterial effectiveness of silver nanoparticles. This study aims to evaluate the antibacterial activity of a nanocomposite formed by combining chitosan and silver nanoparticles synthesized using Cymbopogon citratus extract against Staphylococcus aureus through the diffusion method. The samples used included nanocomposites at concentrations of 6.25 mg/mL, 12.5 mg/mL, 15 mg/mL, 25 mg/mL, and 50 mg/mL, amoxicillin as a positive control, Acetic acid, and distilled water as negative controls. The results of antibacterial activity testing showed that all nanocomposite test concentrations had the ability to inhibit the growth of Staphylococcus aureus as evidenced by the formation of an inhibition zone around the disc paper. However, the highest antibacterial activity shown by the nanocomposites was still lower compared to the antibacterial activity of amoxicillin Keywords: Antibacterial activity, Chitosan, Cymbopogon citratus, Silver nanoparticles, Staphylococcus aureu
Effects of Crosslinker and Silicon to Enhance Taber Abrasion and Physical Properties of Finished Leather for Upholstery Furniture
No full textFinishing is one of the stages in leather processing. The addition of silicone and crosslinker in the top coat of the finishing stage of leather upholstery furniture is used to increase abrasion resistance, which is a critical factor in determining the life and quality of leather furniture. The aim of this study was to determine the influence of silicone and crosslinker additions on the abrasion resistance and physical properties of leather upholstery furniture. The leather material used is dyed crust leather with a thickness of 1.2-1.4 mm with an area of 1.5 sqft. The addition of crosslinker and silicone is applied only to the top coat. The analyses performed include physical skin analysis (adhesion test, rubbing fastness, glossy test, and flexing) and organoleptic tests (abrasion and smoothness tests). The addition of crosslinker and silicone can affect the physical and organoleptic quality of leather. The addition of crosslinker and silicone to the top coat showed the best results on upholstery leather sample D (3% crosslinker and 4% silicone).The results of statistical tests using the multinomial logistic regression method in organoleptic testing and ANOVA in physical testing showed that only crosslinker had a significant effect on the response.
Review of Carbon Capture Technology and Its Potential Application to Reduce Emissions In Heavy Equipment Exhausts
Full text linkCarbon emissions from diesel engines, particularly those from heavy equipment, are a significant greenhouse gas emitter in industries such as construction, mining, and logistics. As global efforts toward decarbonization intensify, carbon capture technologies offer a solution to reduce global emissions. This paper conducts a literature review to explore current carbon capture technologies—including chemical sequestration, physical sequestration, and membrane separation—and evaluates their potential for integration with heavy equipment exhaust systems. Key considerations include system size, energy requirements, maintenance, and operational compatibility. Integration of exhaust heat recovery systems is also assessed as a complementary solution to address the high energy demands of carbon capture in the environment. Technical, economic, and regulatory challenges are discussed, along with potential innovations and use cases that could support future deployments. The findings indicate that although carbon capture is still in its infancy, targeted applications and modular designs supported by policy incentives could enable practical implementation in the near future. This review provides a foundation for future research, pilot projects, and system designs aimed at enabling sustainable operation of heavy equipmen
Thermal and Kinetic Study of Fine Coal And Palm Kernel Shell Gasification Using TGA Analysis
Full text linkIndonesia is rich in natural resources, including coal and palm kernel shells (PKS), which can be used in the gasification process. This study compares the gasification potential of palm kernel shells and fine coal, focusing on their thermal properties and activation energy. Thermogravimetric Analysis (TGA) shows that PKS have higher volatile matter (67.25%) and lower fixed carbon (20.90%) than fine coal (33.53% volatile matter, 32.98% fixed carbon). at 450 °C, PKS lose 11% of their mass in one hour and reach a 78% loss by the end of the process, while fine coal loses 70% after more than 200 minutes. The activation energy for PKS is lower (38.925 J/mol) than fine coal (41.012 J/mol). In gasification, palm kernel shells produce more hydrogen (26% mol) and less carbon dioxide (11% mol) than fine coal, which produces more methane (28% mol) and carbon dioxide (22% mol). These results suggest that PKS are a more efficient and eco-friendly option for gasification.Keywords: Fine coal, palm kernel shells, activation energy, thermogravimetric analysis (TGA), gasificatio