Jurnal Pendidikan Kimia
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Impact of Albizia Wood (Albizia Chinensis) Adsorbent on the Reduction of Pollutants and Copper in Industrial Wastewater
Get PDFThis paper investigated the possibility of using mothball tree wood to absorb copper from industrial wastewater. The adsorbent is made from sawdust, activated with 3N H3PO4 for 24 hours to increase its porosity and surface area, and examined its morphology and microstructure by Scanning Electron Microscope (JEOL-6510A). Pollution abatement experiments were carried out with uncontrollable samples from these three original rivers contaminated by textile, laundry, and industrial revenues. Copper content was determined by Atomic Absorption Spectroscopy (AAS); as well as various parameters such as the dissolved oxygen (DO), BOD5,codconsumed nitrates nitrogen, TDS, and TSS measured. As a result of the adsorption process, a significant reduction of pollutants was achieved. The concentrations of copper in samples reduced to lower than measurable levels or became "trash elements," while initial Cu content turned to 0.017ppm, 0.006ppm, and 0.026ppm. Gains included incorruptible DO rates (54.17% textile)d5 BOD falls by 50.05%, 58.56%, and 68.94%, respectively. COD decreased by 33.33%, 50.00%, and 25.00%. Lower TDS enrolled 3.9%, 12.9%, 57.4% TSS went down to 96.38%, 79.17%, 39.76%. These results illuminate the potential of using Albizia wood as an adsorption medium in wastewater treatment, with pollution reductions evident. Future research can further this by using more advanced analysis methods such as XRD,FTIR, turbidity tests and looking at other natural adsorbent materials for improving water treatment
The Influence of Fe and Cr Dopant in the Synthesis of Ca3Co4O9 Thermoelectric Material on Crystal Structure, Crystal Size, Thermal Conductivity, and Electrical Conductivity
Get PDFIn this work, we study, by sol-gel method, CCO doped with Fe and Cr dopants, the implications for the aspects, crystal structure, crystal size, thermal conductivity, and electrical conductivity. Nevertheless, CCO has low thermoelectric efficiency and thus still longs for optimization in response to the performance, stability, and ecological environment requirement, which needs improvement. Dope would enhance the concentration of charge carriers without modifying the material structure itself. X-ray diffraction (XRD) to characterize the crystal structure and the Williamson–Hall (WH) method to calculate the crystal size were performed. SEM-EDS analyses provide surface morphology, particle size distribution, and elemental composition. The results show that the dopants change, among others, crystal size, microstrain, crystallinity index, and thermal and electrical conductivity, but no change in the crystal structure itself for any of these dopants. Fe doping increased the crystal size of CCO to 144.816 nm (versus 143.382 nm for pure CCO). Compared to Cr doping, the crystal's size was reduced to 65.232 nm. Where the estimated thermal conductivity increased for both dopants, attaining a value of 1.985967 W/mK for CCO-Fe and 1.952233 W/mK for CCO-Cr, concerning the value of 1.740633 W/mK of undoped CCO. Electrical conductivity also expanded (14.50 S/cm for CCO; 14.67 S/cm for CCO-Fe; 14.83 S/cm for CCO-Cr). These improvements highlight the potency of Fe and Cr dopants to fine-tune the CCO for thermoelectric usage
Formulation, characterization, and antibacterial testing of cream supplemented with Aloe vera (Aloe vera L.) gel and Nutgrass (Cyperus rotundus L.) rhizome ethanol extract
Get PDFVarious brands and forms offer a wide array of cream-based cosmetic products. However, only some of these products meet safety specifications. Aloe vera and nutgrass, two plants rich in bioactive compounds, possess anti-inflammatory, soothing, and antibacterial properties, making them ideal for health-safe cosmetic formulations. This research was conducted to develop antibacterial cream formulations incorporating these natural additives. The study focused on quality, organoleptic testing, and the formulated cream's antibacterial assessment. The research methodology encompassed several key processes: preparation of Aloe vera gel and nutgrass rhizome ethanol extract, formulation of the cream, quality testing by SNI 16-6069-1999 standards, organoleptic testing as per SNI 01-2346-2006, and antibacterial activity testing using Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 bacterial strains. Results indicated that the cream formula enriched with Aloe vera gel and nutgrass rhizome ethanol extract meets the standards for skin-lightening creams and exhibits significant antibacterial capabilities. Furthermore, it was observed that the antibacterial effectiveness of the cream increases with the concentration of the nutgrass rhizome ethanol extract. These findings highlight the potential for integrating natural ingredients into modern cosmetic formulations, providing therapeutic and aesthetic benefits. This approach not only ensures compliance with safety standards but also leverages the natural properties of Aloe vera and nutgrass to enhance the product's functionality in skin care application
Comparative Analysis of Caffeine Content in Cold and Hot Brewed Robusta Coffee Using High-Performance Liquid Chromatography (HPLC)
Get PDFCoffee is one of the most popular beverages globally, cherished for its unique taste, aroma, and the stimulating effects of its caffeine content. The proliferation of creative coffee shops has introduced various new methods for enjoying coffee, including cold and hot brew techniques. These processing techniques can significantly influence the physicochemical characteristics of coffee, particularly its caffeine content. This study compares the caffeine content in Robusta coffee using cold and hot brewing techniques. The hot brew coffee was prepared using water at approximately 96°C with a French press for six minutes. In contrast, the cold brew method involved brewing with water at room temperature (20-25°C) using a French press, followed by storage for 12 hours in a refrigerator (2-8°C). Qualitative analysis involved examining the color reaction, while quantitative analysis was conducted using High-Performance Liquid Chromatography (HPLC). HPLC is a highly accurate method that is extensively used in the food and pharmaceutical industries. The results indicated that the caffeine content in cold-brewed Robusta coffee was significantly higher, with a concentration of 44.63 μg/mL ± 0.199% and a Relative Standard Deviation (RSD) of 0.4459%. Conversely, hot-brewed coffee showed a caffeine concentration of 23.96 μg/mL ± 0.278%, with an RSD of 1.1602%. The parametric Analysis of Variance (ANOVA) revealed a significance value of 0.000 (p < 0.05), indicating a significant difference in caffeine levels between hot-brewed and cold-brewed coffee. These findings suggest that the choice of Robusta coffee processing technique can be crucial for individuals with specific health conditions seeking to manage their caffeine intake
Analysis of Chemistry Podcast Implementation in Learning Hydrocarbons and Petroleum for Inclusive Students
Get PDFThis research aims to conduct a feasibility analysis of a chemistry podcast, referred to here as “PodChem,” and to examine the impact of PodChem on learning hydrocarbons and petroleum. This study employs a pre-experimental method. The podcast media were developed using Anchor software and evaluated through a survey using a podcast media assessment questionnaire. The evaluation was carried out by lecturers as validators and students as podcast users. The assessed aspects include content, functionality, and appearance as complementary media in learning hydrocarbons and petroleum. The results indicate that the chemistry podcast PodChem was successfully produced using Anchor software. The findings suggest that PodChem is valid and suitable for educational use. The audio quality produced using Anchor is clear, and its accessibility is broad. Additionally, students reported that the content is relevant and enhances their understanding of the subject matter. Most students also found the podcast to be easily accessible and effective in conveying the concept. In terms of appearance, students agreed that the podcast title is engaging, the delivery is captivating, and the duration is appropriate. The implementation of PodChem in chemistry learning received positive feedback from students, with the majority accepting the use of podcast media in the classroom. Furthermore, 88.9% of respondents expressed a desire for podcasts to be used as complementary media in future learning, as they found podcasts to be more interesting, insightful, and easy to understand. These conclusions are supported by the results of student questionnaires and the assessment of assignments conducted by teachers in class
The Effect of Variation Concentration of Simplex Syrup on the Physicochemical Stability of Nanosilver Syrup
Get PDFInulin from Gembili has been identified as an effective bioreductor for forming nanosilver with a size of 481.4 nm, stable for 30 days when stored at 4°C. Inulin nanosilver exhibits immunomodulatory properties and has been proven safe through acute toxicity evaluation at a dose of 4 mg/kgBB. A drug delivery system needs to be developed for its use as a supplement. Syrup was chosen due to its alcohol-free nature, better taste, and ease of measuring the active substance compared to elixirs, solutions, and suspensions. Simplex syrupus, used as a syrup base, influences stability by potentially forming crystals during storage. This research aims to determine how varying concentrations of simplex syrupus affect the physicochemical properties of inulin nanosilver syrup. The study involved the biosynthesis process using Gembili's inulin, nanosilver characterization, formulation, and stability testing. Inulin nanosilver syrup was prepared with simplex syrupus concentrations of 20%, 40%, and 60%. The physicochemical stability of the syrup, including organoleptic properties, pH, and viscosity, was tested before and after storage at 4°C and 40°C over six cycles. The selected formula was evaluated for sugar reduction content and FT-IR profile. Data analysis was performed using SPSS 21.0 for Windows with One-way ANOVA and Paired T-Test. Results indicated that higher concentrations of simplex syrupus led to increased consistency, pH, and viscosity. A 60% concentration of simplex syrupus met the physicochemical stability requirements, with a medium-thick consistency, pH of 5.25±0.03, and viscosity of 92±2.6 cps. The reducing sugar content was 20.59% ±0.002, and the FT-IR profile confirmed the presence of inulin nanosilver, indicated by Ag-N groups compared to silver nitrate solution. This product has the potential to be developed as a health supplement
Synthesis of Polystyrene Fiber Membranes Prepared by Electrospinning: Effect of AgNO3 on the Microstructure
Get PDFPolystyrene (PS) is commonly employed in insulation, packaging, filters, and medical equipment, with recent studies exploring its potential in fiber membrane production. The electrospinning technique is discussed to synthesize PS fiber membranes with high porosity and controllable diameter. Additionally, incorporating silver nitrate into PS composite fibers is explored for enhanced functionalities such as catalytic activity, high electrical conductivity, and antibacterial activity. However, PS composite fiber membranes with silver nitrate (AgNO3) metal variations are rarely observed. This research aims to modify the microstructure of PS fiber membranes produced using electrospinning by adding silver nitrate (AgNO3) with varying concentrations. PS-Ag fiber membranes are produced using N,N-dimethylformamide (DMF) solvent, which serves as a solvent and a reducing agent for Ag. The results show that the effect of Ag affected the diameter of the PS-Ag fiber membrane, with an average diameter of around 3.67 - 6.93 micrometers. Degradation occurred in these samples at a strong broadening peak near ~1300 cm-1 until ~1600 cm-1 from the Raman results. The FTIR results show that the wavelength of ~3500 cm-1 indicated the presence of OH. The presence of OH indicates that the PS-Ag fiber membrane has the potential for water filtration applicatio
Enhancing Conceptual Understanding of Buffer Solutions with an Intertextual E-Book Prototype
Get PDFThe intertextual-based e-book prototype helps students understand buffer solutions by connecting the three levels of chemical representation: macroscopic, submicroscopic, and symbolic. This connection allows students to visualize chemical phenomena from simple to complex. The study aims to enhance students' conceptual understanding using this e-book prototype. The research and development (R&D) method followed five stages: research and information gathering, product development planning, initial product development, limited trials, and initial product revision. This process yielded a highly validated e-book prototype that promotes innovation. The validation results showed high feasibility in substance (85.71%), instructional methods (90.90%), and language (100%). Experts deemed the e-book prototype highly effective in improving conceptual understanding through its intertextual approach. Pretest and posttest assessments of 30 students indicated improved conceptual understanding after using the e-book. Initially, students demonstrated macroscopic and symbolic level abilities without associating the three levels of representation. After using the e-book, they could connect these levels, enhancing their understanding and conceptual understanding. The N_Gain scores for pretest and posttest assessments were 0.48 for the high category, 0.45 for the medium category, and 0.44 for the low category, showing moderate improvement. The t-test results (Sig. (2-tailed) = 0.000 < 0.05) confirmed the effectiveness of the e-Book. Teacher and student responses averaged 90% and 85.5%, respectively, indicating that the intertextual-based e-book on buffer solutions is highly suitable as a self-learning resource to improve conceptual understanding
Effectiveness of the pH Master Application on Acid-Base Concepts as a Digital Alternative to Conventional Laboratory Practices for Enhancing Student Learning Outcomes"
Get PDFTraditional Chemistry Laboratories, such as acid-base reactions, are hard to demonstrate for present-day students in their lab classes when they need to have the knowledge exchange we had, graduating (and teaching) with mortar boards lined up and ready for weddings. The Evaluation Of The Digital Platform “pH Master” For Enhancing Chemistry Student Performance Through A Virtual Imitation of Traditional Lab Practices The study used Akker's research and development model, including initial studies, product design, testing products, and trials. Validation was done using the Aiken formula by two expert validators and three practitioners for all items with a V value greater than 0.87. Surveys for needs analysis involved 45 students, and the
learning effects were assessed with 90 students across three
schools. Results Students responded favourably to the pH Master app and perceived ineffable pedagogical value. Most students agreed on the necessity of doing practical activities about what was being learned, and almost all also had trouble understanding study materials specifically related to acids and bases. The results showed a statistically higher mean n-gain value in the experimental group than in control one (0.6622 versus 0.5691) by independent t-test across three schools at p < 0,001 significance level between the two groups. This then confirms that the media created did support student learning. This study highlights the potential of the pH Master app to enhance student learning experience and active involvement in chemical education, which suggests a promising approach towards digitalising conventional practical work
The Project-Based Learning’s Key Characteristic: How STEAM Sparks Creativity and Curiosity in Cultivating Daphnia sp. Acid-Based Chemistry
Get PDFThis study explores the integration of STEAM (Science, Technology, Engineering, Arts, Mathematics) with Project-Based Learning (PBL) to enhance creativity and curiosity in high school students within the context of chemistry education. The research involved 11th-grade students designing a Daphnia sp. cultivation pond, a project aimed at applying interdisciplinary knowledge and fostering essential 21st-century skills. Using a qualitative case study approach, data were collected through questionnaires, interviews, and student worksheets. The study focuses on an in-depth analysis of six key characteristics of STEM-PBL including driving questions, learning goals, scientific practice, collaboration, using a technological tool, and creating an artifact—creativity and curiosity as key outcomes. The results indicate a significant positive correlation between creativity and students' cognitive performance, highlighting the effectiveness of the STEAM-PBL approach in promoting innovative thinking and problem-solving skills. However, the study found no significant relationship between curiosity and cognitive scores, suggesting that curiosity may develop independently of direct academic outcomes within this framework. Despite these positive findings, the study also identified challenges such as limited resources, insufficient teacher training, and resistance to traditional educational methods. The study recommends further exploration into the long-term impacts of STEAM-PBL and its applicability across different educational contexts