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Konversi
Published by Universitas Lambung Mangkurat
ISSN : 23023686     EISSN : 25413481     DOI : -
Core Subject : Education,
Education
Arjuna Subject : -
Articles 263 Documents
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Unveiling the role of cellulose solvent systems in direct and sustainable silica amination: a new pathway beyond aminopropyl agents Ajiz, Hendrix Abdul; Widiyastuti, Widiyastuti; Setyawan, Heru; Muljani, Srie; Suryandari, Ade Sonya; Erliyanti, Nove Kartika
Konversi Vol 14, No 2 (2025): OCTOBER 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i2.23610

Abstract

The functionalization of silica surfaces using sustainable amine sources is critical for advancing environmentally friendly materials in CO2 capture technologies. In this study, bio-based organosilanes derived from coconut fiber cellulose were explored as a green alternative to conventional aminosilane. Two solvent systems DMSO/NH4OH and NaOH/urea were utilized to dissolve and regenerate cellulose, enabling direct grafting onto silica surfaces. Comparative analysis revealed that while DMSO/NH4OH-dissolved cellulose exhibited a modest amine loading of 23.43% wt, comparable to aminopropyl-based modification (22.41% wt), the NaOH/urea system significantly improved the grafting efficiency, reaching 40.52% wt. This enhancement is attributed to urea’s amphiphilic properties, which facilitate both hydrophobic interactions and carbamate formation. The use of a sulfur-free NaOH/urea system not only improves performance but also aligns with green chemistry principles. These results demonstrate the potential of biomass-derived cellulose as a viable modifying agent for silica, paving the way for scalable, low-toxicity, and circular-economy-based material design strategies.
The effect of Ni/Al2O3 catalyst mass variation and operation time on the CO2 methanation process Pratama, Yongki; Junaidi, Robert; Nugroho, Didiek Hari
Konversi Vol 14, No 2 (2025): OCTOBER 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i2.23597

Abstract

Carbon dioxide (CO2) is one of the biggest contributors to the greenhouse effect. Based on data from the International Energy Agency (IEA), greenhouse gas (GHG) emissions continue to increase, reaching 37.8 billion tons in 2024. One way to reduce carbon dioxide (CO2) is to convert carbon dioxide (CO2) into methane (CH4) through a methanation process using a Fixed Bed Reactor. This study was conducted by varying the mass of Ni/Al2O3 catalyst between 55 grams and 60 grams and the operating time between 90, 100, 110, 120, and 130 minutes, as well as adding 20 grams of Zn promoter to improve catalyst stability performance. A Multi Gas Detector Analyzer was used to analyze the methane (CH4) gas produced. The results of this study showed that the highest percentage of methane gas (CH4) produced was obtained in sample 10 with a Ni/Al2O3 catalyst mass of 60 grams and an operating time of 130 minutes, which was 58.35%.
Trans-esterification of pangansius hypolatamus tallow waste with ethanol by electrolysis process and KO0H as catalyst Afrah, Bazlina Dawami; Rendana, Muhammad; Pratama, Muhammad Yori; Putri, Tiara Maharani Ramona; Rahmadianti, Nurulia; Sabrina, Dina
Konversi Vol 14, No 1 (2025): APRIL 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i1.20859

Abstract

Consumption of fuel energy continues to increase every year. Still, the fuel used today is almost entirely derived from fossil materials that are toxic to the environment and not renewable, so they need renewability to be guaranteed. One solution to this problem is ethyl ester based on catfish (Pangasius Hypothalamus) tallow waste. The catfish fish tallow is extracted first and then in a liquid phase and then reacted with the help of a KOH catalyst (1%; 1.5%; 2%) by electrolysis method using copper electrodes with a transesterification reaction. The research was conducted on the ratio of raw materials to ethanol of 1:5, 1:6, and 1:7 with a power supply voltage of 20V. It can be seen from the research results that the mole ratio of raw material and ethanol at 1:6 produces ethyl esters with a tendency to be of better quality. The best ethyl ester yield was obtained at a ratio of 1:6 raw material and 1.5% catalyst amount, and the resulting yield was 92.4058%.
Extraction of leaves oil from fresh leaves by using microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) methods Imalia, Calaelma Logys; Simbolon, Firman; Hendra, Hendra; Junita, Nilam; Natalia, Yolanda; Nurfitri, Viola; Zahra, Nurul Afifah; Purba, Sry Oktavianty; Harni Saragih, Tresya Siti; Pribadi, Shelty Aty; Auriyani, Wika Atro; Achmad, Feerzet
Konversi Vol 14, No 2 (2025): OCTOBER 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i2.22972

Abstract

Essential oils are natural chemical compounds that are volatile and have a distinctive aroma, which are produced by plants as part of their secondary metabolites. This study aims to examine the differences in % yield content, extract pH, color, FFA value, and essential oil structure of each sample. The main materials used in this study were several types of aromatic leaves, namely lemongrass, pandan, lime, and eucalyptus leaves. The methods used were Microwave-Assisted Extraction (MAE) and Ultrasound-Assisted Extraction (UAE). The essential oil with the highest yield value and a specific gravity close to the Indonesian National Standard (SNI) is analyzed using Fourier Transform Infrared Spectroscopy (FTIR). The eucalyptus leaf sample yielded the highest percentage with the MAE method, achieving a yield of 46 %. The FTIR analysis identified a broad absorption peak at 3257.7 cm⁻¹, indicating the presence of hydroxyl groups (-OH), which suggests alcohols or phenols and possible moisture contamination. Peaks at 2124.6 cm⁻¹ and 1744 cm⁻¹ reveal methylene (C-H) and carbonyl (C=O) groups, suggesting the presence of terpenoids and oxidized compounds like esters or ketones. Additional peaks at 1640 cm⁻¹ and 1013.8 cm⁻¹ and ether (C-O) groups, with the latter confirming the presence of 1,8-cineole in eucalyptus oil.
Sonochemical-assisted biosynthesis of silver nanoparticles using cymbopogon nardus L. essential oil: advanced process optimization through response surface methodology Wira, Guardiola Rosa; Maharani, Hijria Putri; Erliyanti, Nove Kartika; Panjaitan, Renova; Pujiastuti, Caecilia
Konversi Vol 14, No 1 (2025): APRIL 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i1.21906

Abstract

This research investigates the fabrication and characterization regarding silver nanoparticles (AgNPs) utilizing essential oil derived from citronella leaves (Cymbopogon nardus L.) as a bioreductant. The synthesis method employed is sonochemistry, with variations in pH levels to determine optimal conditions for AgNPs yield. The use of essential oil as a bioreductant offers eco-friendly advantages and high efficiency in reducing metal ions. The results indicate that the highest yield of 8.67% was achieved at pH 9.0280 and 59.7190 minutes of sonochemical processing. Statistical optimization of processing parameters was conducted to maximize the yield of AgNPs, with the optimization process analyzed using Response Surface Methodology (RSM). The sequence of experimental runs, condition variations, and obtained results were determined using the Central Composite Design (CCD). The model demonstrates a strong correlation with the experimental data, exhibiting an adjusted R² value of 0.9684. A high F-value of 30.61 and a low p-value of 0.0009 suggest that the regression model is statistically significant and effectively accounts for variations in AgNPs yield. The lack-of-fit value for the model is 0.0359, indicating no significant discrepancy between the experimental data and the model's predicted values. The successful formation of AgNPs was confirmed, with absorption peaks observed within the 400–450 nm range.
Optimization of hydroxyapatite synthesis from crab shell waste using response surface methodology (RSM) Arnindi, Dinda Putri; Nisa, Assholihatun
Konversi Vol 14, No 2 (2025): OCTOBER 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i2.24333

Abstract

Hydroxyapatite (HAp) is a bioceramic material widely used in biomedical applications due to its chemical similarity to the mineral component of human bone and teeth. This study aimed to optimize the synthesis of HAp from crab shell waste as a natural calcium source using the precipitation method combined with Response Surface Methodology (RSM). The main variables investigated were calcination temperature (800–1200°C) and Na₂H.PO₄ concentration (0,75–2,95 M), while pH was maintained at 11. The optimization results showed that both factors significantly affected the Ca/P ratio, which determines the stoichiometric quality of HAp formation. The optimum condition was obtained at a calcination temperature of 858,86°C and a Na₂HPO₄ concentration of 2,949 M, producing a Ca/P ratio of 1,67 with a desirability value of 1. Verification using Confidence Interval (CI), Tolerance Interval (TI), and Prediction Interval (PI) confirmed the model’s high accuracy and reliability. These findings demonstrate that crab shell waste can be effectively utilized as a sustainable calcium source for hydroxyapatite synthesis, offering environmental and economic benefits for future biomedical applications.
Isolation and characterization of docosahexaenoic acid producing Thraustochytrids from mangrove ecosystem Humaidah, Nurlaili; Muslichatin, Wirdhatul; Setyawati, Dyah; Puspita, Niniek Fajar; Nakai, Satoshi; Purwasih, Sasanti Bhekti; Putri, Nurhalida Listiani
Konversi Vol 14, No 1 (2025): APRIL 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i1.22114

Abstract

Polyunsaturated Fatty Acids (PUFAs) are unsaturated fatty acids that include DHA fatty acids. The conventional source of DHA is derived from various species of fish in the form of fish oil. DHA content in fish oil is relatively low, ranging from 7-14%, which necessitates the use of large quantities of fish, potentially leading to overfishing. Alternative source of DHA can be obtained through the isolation of thraustochytrids. Thraustochytrids can produce relatively higher levels of DHA and does not require extensive land areas for cultivation. This study aims to identify applicable techniques for isolating and identifying Thraustochytrid strains local to mangrove areas in East Java, `to examine the growth and general fatty acid profile, and to identify the most effective methods for controlling contamination during Thraustochytrid growth. The isolation involved several steps, including sample preparation, isolation, pure culture development, and media control by adjusting pH and temperature. Visual observations were made using an inverted microscope to confirm the presence of Thraustochytrids followed by genetic analysis to identify the strain. The optimal growth was observed in L3P sample collected from brown mangrove leaves. The highest specific growth rate was 0.146 h-1 (L3P). DHA content was 172 mg/g from the dried cell weight biomass. The most effective method for isolation involved a pre-treatment step consisting of soaking the samples in pine pollen for 8-10 days. Thraustochytrid isolates were able to grow in media with a pH of 7 and at a temperature of 25°C.
Utilisation of palm oil fibre cake biomass for magnetic nanoparticle biocomposites as adsorbents in Sasirangan liquid waste treatment Ukhrawi, Syamsul Ma'arif Putra; Nata, Iryanti Fatyasari; Juwita, Rinna; Gazaly, Ahmad; Karima, Ismi Nur; Prasetya, Angga
Konversi Vol 14, No 2 (2025): OCTOBER 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i2.24322

Abstract

Palm kernel fibre (fibre cake) is a waste product from the palm oil industry that has potential as a source of natural fibre. This study aims to utilise fibre cake to produce magnetic nanoparticle biocomposites as adsorbents for reducing the lead (Pb2+) content and Total Suspended Solids (TSS) in Sasirangan liquid waste. The research produced two types of biocomposites: one without amino groups (FCB-M) and one with amino groups (FCB-MH). Observations from Scanning Electron Microscopy (SEM) showed that magnetic nanoparticles had formed on the surface of the fibre cake. Treatment of palm oil fibres with NaOH restructured amorphous cellulose into crystalline cellulose, as indicated by a 30.25% increase in the Crystalinity Index (CrI) based on X-Ray Diffraction (XRD) analysis. The Pb²⁺ content absorbed by FCB and FCB-NH₂ was 97.84 mg/g and 101.82 mg/g, respectively, for 3 hours at pH 8. The modification of amino groups on the surface of the biocomposite resulted in a 164.85% increase in adsorption. The effectiveness of TSS reduction at pH 8 was 65.8% and 62.9% for FCB-M and FCB-MH, respectively. 
Pectin extraction from nephelium lappaceum (binjai variety) peel using pulsed electric field Santoso, Ganes Aurora; Wicaksono, Luqman Agung; Kurnianto, Muhammad Alfid; Munarko, Hadi; Putra, Andre Yusuf Tisna; Priyanto, Anugerah Dany
Konversi Vol 14, No 1 (2025): APRIL 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i1.22031

Abstract

This study aims to evaluate the effects of electric field intensity, extraction time, and solvent ratio on pectin yield from binjai rambutan skin using Pulsed Electric Field (PEF). The One Factor at a Time (OFAT) method was applied in three stages: (1) determining the optimal electric field intensity (5, 10, 15, and 20 kV/cm) with a fixed extraction time of 15 minutes and a solvent ratio of 1:30 w/v; (2) assessing the effect of extraction time (5, 10, 15, and 20 minutes) while maintaining the selected electric field intensity and a solvent ratio of 1:30 w/v; and (3) evaluating the influence of different solvent ratios (1:20, 1:30, 1:40, and 1:50 w/v) using the selected electric field intensity and solvent ratio from the previous stages. Each stage was conducted in duplicate to ensure data reliability. The collected data were analyzed using Analysis of Variance (ANOVA), followed by the Duncan Multiple Range Test (DMRT) at a 95% confidence level with SPSS v.27.0.1 software. The results demonstrate that each of electric field intensity, extraction time, and solvent ratio influence pectin yield. The optimal conditions obtained were an electric field intensity of 20 kV/cm, yielding 3.41%; an extraction time of 10 minutes, yielding 3.48%; and a solvent ratio of 1:30 w/v, yielding 3.48%.
The impact of substituting water with eco enzyme in natural bar soap production Ginting, Simparmin Br; Agustian, Muhammad Rizki; Darni, Yuli; Setiawan, Aris
Konversi Vol 14, No 2 (2025): OCTOBER 2025
Publisher : Universitas Lambung Mangkurat

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/k.v14i2.24357

Abstract

The use of eco enzymes can enhance the quality of cleaning products, such as soap. These enzymes, including amylase, lipase, and protease, serve as catalysts and natural antibacterial agents, helping to break down carbohydrates, lipids, and proteins during the decomposition process. This study aims to evaluate the effect of adding eco enzymes on accelerating the saponification reaction and improving the quality of the produced bar soap. The method employed is the cold process, with variations of eco enzymes added at 0 g, 13 g, 26 g, and 39 g. All bar soap samples were analyzed according to the SNI 3532:2021 standard, and one sample that met this standard was selected for further enzymatic analysis. Of the five test parameters performed, soap products with the addition of 13 g, 26 g, and 39 g of eco enzymes complied with all SNI 3532:2021 standards. However, the soap with 0 g of eco enzymes did not meet one of the standards for total plate count microbe contamination, which produced a result of ≤ 4000 CFU/g. Additionally, lipase and protease enzymes were detected in the soap with the addition of 26 g of eco enzymes. The hardness levels of each soap variation were as follows: 1.3 N for 0 g, 1.7 N for 13 g, 2.03 N for 26 g, and 1.47 N for 39 g of eco enzymes.

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