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Preparation of Vegetable Waste-Derived Paper Incorporated with Activated Carbon for Delay Mango Ripening and its Application
(2026-01-01)
Sriprom, Pongsert
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Thongkham, Phaewa
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Taweesukyingjaroen, Jurairat
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Somphan, Apiruk
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Manamoongmongkol, Kanjana
In this study, the vegetable waste-derived paper was developed from vegetable waste-derived fiber and Mahachanok mango seed-derived activated carbon to extend the shelf life of Golden Nam Dok Mai mangoes. Vegetable waste was subjected to alkaline processing using sodium hydroxide to extract plant-based fibers, which were then formed into paper sheets. Activated carbon, derived from Mahachanok mango seeds by carbonization at 450°C and activated by potassium permanganate (KMnO4), was incorporated into the vegetable waste-derived paper to enhance ethylene adsorption efficiency. Three formulations of ripening delay paper were prepared: paper without activated carbon, paper containing 10 g of activated carbon, and paper containing 20 g of activated carbon. The physical properties of the papers were evaluated in terms of tensile strength and water drop absorption. The vegetable waste-derived paper incorporated with 20 g activated carbon showed the highest performance among the developed papers (1.20 ± 0.24 MPa and 0.74 seconds, respectively). Application tests on Golden Nam Dok Mai mangoes showed that the 10 g activated carbon formulation was the most effective in preserving flesh color, maintaining firmness, and balancing total soluble solids (TSS) and titratable acidity (TA), indicating a delayed ripening process. Therefore, ripening delay paper synthesized from vegetable fiber and supplemented with 10 g of activated carbon per 1 kg of fruit was proven to effectively prolong mango shelf life by up to 3 days, demonstrating its potential as a biodegradable solution for postharvest quality preservation.
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Low-Cost Activated Carbon for Methylene Blue Adsorption Using Inert Gas-Free Carbonization and Microwave Activation
(2025-01-01)
Kongtragoul, Pornprapa
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Keeratirawee, Kanchalar
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Choola-Aied, Orasa
-This study investigated the preparation of activated carbon from spent coffee grounds for methylene blue adsorption using inert gas-free carbonization and microwave activation. Spent coffee grounds were obtained from a local coffee shop in Pathio, Chumphon, Thailand. The coffee grounds were pretreated with 1M H<inf>2</inf>SO<inf>4</inf> before undergoing carbonization at 600 ºC for 3 h in a limited-oxygen atmosphere. The obtained carbon materials were chemically activated with zinc chloride (ZnCl<inf>2</inf>) and physically activated using a microwave-assisted method at 300 W for 180 seconds. The adsorption of methylene blue was evaluated using a batch method. Methylene blue adsorption contact time, effect of pH, and initial concentration were investigated. The maximum adsorption capacity of the activated carbon for methylene blue removal was found to be 29.24 mg/g. The prepared activated carbon exhibited a BET surface area of 70.08 m2/g and reached equilibrium in 120 min at the optimum pH of 9. The adsorption isotherm was consistent with the Freundlich model, while the adsorption kinetics followed a pseudo-second-order model. The findings indicate that activated carbon is a cost-effective and efficient adsorbent for methylene blue removal from aqueous solutions.
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Preparation of Low-Cost Activated Carbon from Spent Coffee Grounds for Rhodamine B Removal
(2025-01-01)
Keeratirawee, Kanchalar
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Choola-aied, Orasa
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Kongtragoul, Pornprapa
A low-cost coffee-based activated carbon for Rhodamine B (RhB) removal was investigated. Spent coffee grounds obtained from a local coffee shop in Pathio, Chumphon, Thailand, were utilized as the raw material to produce biochar. The coffee grounds were pre-treated by washing with 1M H2SO4 before carbonization at 600 ºC for 2 h under a limit-oxygen atmosphere. The acid washing process was found to be a promising method for preparing activated carbon without requiring an inert gas flow during the carbonization. This approach resulted in activated carbon free of ash after carbonization. The carbonized coffee grounds were activated using a microwave-assisted process with KOH as the activating agent. The performance of the prepared activated carbon for Rhodamine B adsorption was evaluated using the batch method. Key parameters, including initial concentration of Rhodamine B (3-11 mg/L), pH (3-11), and contact time (15-150 min), were optimized. The maximum adsorption capacity was 16 mg/g of adsorbents. The optimal pH for Rhodamine B adsorption was found to be 7. The adsorption of Rhodamine B onto the adsorbent fits a Langmuir isotherm and a pseudo-second-order kinetic model. The study revealed that the prepared activated carbon from waste coffee grounds is an efficient and affordable solution for removing Rhodamine B contaminants from the water system.
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Enhanced CO2 Capture Potential of Chitosan-Based Composite Beads by Adding Activated Carbon from Coffee Grounds and Crosslinking with Epichlorohydrin
(2024-08-01)
Loryuenyong, Vorrada
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Nakhlo, Worranuch
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Srikaenkaew, Praifha
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Yaidee, Panpassa
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Buasri, Achanai
Carbon dioxide (CO<inf>2</inf>) capture has been identified as a potential technology for reducing the anthropic emissions of greenhouse gases, particularly in post-combustion processes. The development of adsorbents for carbon capture and storage is expanding at a rapid rate. This article presents a novel sustainable synthesis method for the production of chitosan/activated carbon CO<inf>2</inf> adsorbents. Chitosan is a biopolymer that is naturally abundant and contains amino groups (–NH<inf>2</inf>), which are required for the selective adsorption of CO<inf>2</inf>. Spent coffee grounds have been considered as a potential feedstock for the synthesis of activated coffee grounds through carbonization and chemical activation. The chitosan/activated coffee ground composite microspheres were created using the emulsion cross-linking method with epichlorohydrin. The effects of the amount of chitosan (15, 20, and 25 g), activated coffee ground (10, 20, 30, and 40%w/w), and epichlorohydrin (2, 3, 4, 5, 6, 7 and 8 g) were examined. The CO<inf>2</inf> capture potential of the composite beads is superior to that of the neat biopolymer beads. The CO<inf>2</inf> adsorbed of synthesized materials at a standard temperature and pressure is improved by increasing the quantity of activated coffee ground and epichlorohydrin. These findings suggest that the novel composite bead has the potential to be applied in CO<inf>2</inf> separation applications.
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Effect of Carbonization Temperature on Physical Properties and Specific Capacitance of Activated Carbon Derived from Banana Stem and Its Application as Supercapacitor Electrodes
(2023-01-01)
Dulyaseree, Paweena
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Sama, Hasanee
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Sada, Suraida
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Ukkakimapan, Pundita
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Yordsri, Visittapong
In this work, activated carbons (ACs) for electrodes supercapacitor applications were successfully synthesized from banana stem. Banana is one of the popular fruits that is easy to grow and most parts of the plant can be used. However, banana cultivation generates a lot of wastes, especially from the stem. Thus, using banana stem as raw material for ACs was investigated. The synthesis of AC consisted of 2 processes; carbonization and activation. The advantage of a two-step synthesis was the low weight loss of charcoal. Firstly, the carbonization process was conducted by varying the temperature between 300-600°C, and then inorganic elements were removed by treatment with 1 M sulfuric acid. After that, activation was conducted at 720°C under an argon atmosphere. The electrochemical properties of banana stem-derived ACs (BCH-ACs) were studied using sodium sulfate as an electrolyte. The BCH-ACs carbonized at 400°C showed the highest performance with a specific capacitance of 55.45 Fg-1, an energy density of 7.70 Whkg-1 and a power density of 133.94 Wkg-1. The highest specific capacitance of the BCH400-AC was likely due to the increase in the amount of oxygenated functional group, which facilitated the access of electrolyte ions into the electrode. These results suggest that banana stem can be used to synthesize ACs via carbonization at 400°C, and the ACs generated can be applied as electrode in supercapacitors.
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Lithium Amount Effect of Li-Inserted Ultra-Surface Area-Activated Carbon and Improvement of the Electrochemical Performance with Magnetic Field for Li-Ion Capacitors
(2022-12-27)
Otgonbayar, Zambaga
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Areerob, Yonrapach
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Yang, Sunhye
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Kim, Ick Jun
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Oh, Won Chun
It is possible that controlling the lithium-ion amount may relate to the high energy and the specific capacitance of active materials into a single device. As the cathode for Li-ion capacitors (LICs) using nonaqueous electrolytes, we investigated surface functionalization of ultra-surface area-activated carbon (UAC) powder. An increase in capacitance was observed, from 1.25 × 104 to 8.10 × 104 F/g with controlling of lithium amount, as well as an increase in the area explicit capacitance per BET surface region from 657.57 to 1605.25 m2/g, which indicates that redox responses and their remarkable potential might enhance the capacitance for LICs. The pseudocapacitive redox reaction at C=O destinations is mostly attributed to capacitance enhancement. As with the improvement in capacitance, it was discovered that the arrangement of the electrolytes depends on the wetting behavior and particle size that can be adjusted. This study suggests the way for a low-cost and widely used UAC powder with controlling of lithium amount and a magnetic field for LICs. The 6LUAC samples treated with a magnetic field showed excellent specific capacity and energy density compared to samples not treated with a magnetic field under the same test conditions. Finally, we expect that this method may contribute to improvement of the electrochemical performance of materials.

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