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Chitosan nanoparticles from three-spot swimming crab shells for cupric ion adsorption from synthetic wastewater
(2024-11-01)
Kengchuwong, Metta
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Ketwong, Chatyapha
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Trisupakitti, Somsuk
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Ponkham, Pornpimol
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Ketwong, Panuwat
Chitosan (CT) and chitosan nanoparticles (CTNP), extracted from three-spot swimming crab (Portunus sanguinolentus) shells by deacetylation and then ionic gelation, were used to removed pollutants from wastewater. Chitin deacetylation yield to form chitosan was ~75%, measured from FT-IR spectral peak area. After forming CTNP, the FT-IR spectra showed overlapped peaks for COO− of gum arabic, used for gelation, and NH3+ at 1,417 cm-1 and the amino group at 1,554 cm-1 of chitosan. Adsorption and kinetics for Cu2+ removal by both CT and CTNP were compared. CTNP adsorption matched a Langmuir isotherm. Cu2+ adsorption by CTNP followed a second-order reaction, indicating bonding of Cu2+ to the nanoparticles. CTNP was much more effective and faster in adsorbing Cu2+ than CT by 52%, after only a 5-minute reaction time. When using CTNP, the optimum loading was 0.5 g/100 L, at pH 5, 300 rpm and 30 min.
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Bio-oil production via fast pyrolysis of cassava residues combined with ethanol and volcanic rock in a free-fall reactor
(2023-01-01)
Rueangsan, Koson
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Heman, Adcha
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Kraisoda, Pakkip
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Tasarod, Homhuan
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Duanguppama, Keyoon
Pyrolysis of waste biomass to produce usable energy has the potential to, in part, alleviate the consumption of limited fossil fuel resources. We describe bio-oil production via fast pyrolysis of cassava residues, a mostly wasted byproduct of cassava crops. The waste biomass was combined with two readily available additives—volcanic rock and ethanol—in a free fall reactor to generate bio-oil, char and syngas. Using cassava stems as the raw feed-stock we tested pyrolysis reaction temperatures in the range 450–500 °C in a free fall reactor using a N<inf>2</inf> flow. Analysis of the pyrolysis products should little variation in this range, so analyses for the effects of ethanol and volcanic rock as additives were tested at 500 °C. The bio-oil yield ranged between 58 and 60%, char represented 17–19% and gas 21–24%. With volcanic rock, the higher heating value was significantly higher at 23.6 MJ/kg compared to ~19 MJ/kg for cassava alone or added ethanol. Readily available, inexpensive, naturally occuring zeolites in the volcanic rock led to significant extra degradation of the biomass, under the same experimental conditions, leading to this improvement.
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Rubber Wood Sawdust Waste Converted to Activated Carbon for Heavy Metal Removal from Wastewater
(2023-01-01)
Kengchuwong, Metta
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Ketwong, Chatyapha
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Nuasri, Chompoo
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Wanich, Suchana
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Trisupakitti, Somsuk
In this study, we characterized activated carbon prepared from rubber wood sawdust waste and determined optimum conditions for removing copper ions from synthetic wastewater. Rubber wood sawdust was calcined at 600°C for 30 min and then activated with commercial vinegar (5%v/v acetic acid) or 5% lime juice for 24 hr. Three characteristics of the activated carbon were evaluated: (i) to study the ability to remove copper ions versus exposure time, pH and the amount of adsorbent, (ii) adsorption isotherms and (iii) adsorption kinetics. A Langmuir isotherm indicated that the activated carbon adsorbed a monolayer of Cu(II) ions, K<inf>L</inf> = 7.91 mg/L with a capacity to adsorb 0.37 mg Cu(II)/g. The optimum conditions for usage was found at 20 g/L activated carbon in wastewater, pH 5 and 60 min adsorption time. Adsorption kinetics were consistent with a pseudo-second order reaction. The results of the study suggest that converting rubber wood sawdust waste to activated carbon allows it to become useful to remove heavy metal pollutants from wastewater.
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Fast pyrolysis of Dipterocarpus alatus Roxb and rubber wood in a free-fall reactor
(2022-01-01)
Rueangsan, Koson
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Trisupakitti, Somsuk
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Senajuk, Watchara
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Morris, John
Dipterocarpus alatus Roxb, sometimes called the ‘diesel tree’, because its resin has been reported to run small engines directly, has not been studied as a source of bio-oil from pyrolysis, although considerable waste is generated from furniture making. Here, we compared it with rubber tree waste, using cassava rhizomes (already extensively studied as a bio-oil source) as a reference. Our free-fall pyrolysis system used a conventional cooled condenser, as well as an electrostatic precipator, to capture bio-oil. Total bio-oil yields were: D alatus, 62% w/w of input biomass, cassava 61%, rubber wood and leaves, 59%. The electrostatic precipitator was responsible for ~20% of the total bio-oil yield: adding the precipitator increased overall yield significantly. HHV values wre highest for rubber wood (21–22 MJ/kg), but only slightly lower for D alatus and cassava (19–20 MJ/kg). Small differences in the properties of the bio-oil from both condensers confirmed that different fractions of the oils were collected in the two condensers. Overall, D alatus showed good potential as a high yielding source of bio-mass for pyrolysis.
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Bio-oil and char obtained from cassava rhizomes with soil conditioners by fast pyrolysis
(2021-11-01)
Rueangsan, Koson
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Kraisoda, Pakkip
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Heman, Adcha
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Tasarod, Homhuan
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Wangkulangkool, Monchawan
We studied the properties of the bio-oil and char from fast pyrolysis of cassava rhizomes in a free-fall reactor, catalyzed by adding various soil conditioners (or improvers) as catalysts to the reactor at 500 °C and 200 g/h feed rate. Four conditioners were evaluated - granular TPI pH11 soil conditioner, volcanic rock, TPI pelletized organic fertilizer and super dolomite - and added at 50% (w/w) of the rhizomes. Bio-oil and gas yields decreased, whereas char yields increased, yielding bio-oil 57–59%, gas 14–20% and char 23–28%. With the catalysts, the bio-oil higher heating value increased, while that of char decreased: for cassava rhizomes with volcanic rock the bio-oil high heating value increased from 19.4 to 23.6 MJ/kg, whereas rhizomes with dolomite led to an increased viscosity from 27 to 34 × 10−3 mm2/s.
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Effects of Zinc and Aluminum on the CuO Crystalline Size for Direct Dimethyl Ether Synthesis from Syngas
(2021-09-01)
Thongkam, Montree
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Piyabunditgul, Nanchapak
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Trisupakitti, Somsuk
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Rungrojchaipon, Pesak
The effects of zinc and aluminum on the CuO crystalline size for direct dimethyl ether (DME) synthesis from syngas were investigated. Metal oxide catalysts were synthesized with various molar ratios of CuO by the precipitation method, and by the co-precipitation method with CuO/ZnO (CZ), CuO/ZnO/Al<inf>2</inf>O<inf>3</inf> (CZA), and CZA at ratios of 1:1, 2:2:1, and 6:3:1, respectively. The acid catalysts (γ-Al<inf>2</inf>O<inf>3</inf>, HZSM-5) were added to the metal oxide catalysts by physical mixing. The catalysts were characterized morphologically and their acidities were determined. Loading of zinc and aluminum at different ratios showed that CZA (2:2:1) gave the smallest CuO crystalline size, appropriate for the methanol synthesis reaction. γ-Al<inf>2</inf>O<inf>3</inf> has a weak to moderate acidity range, suitable for DME synthesis. Moreover, the bifunctional catalyst, CZA (2:2:1)/γ-Al<inf>2</inf>O<inf>3</inf>, had the highest surface area as well as the highest %CO conversion and %DME selectivity.
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Adsorption kinetic of direct dyes from aqueous solution on zeolite lta
(2021-01-01)
Thongkam, Montree
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Trisupakitti, Somsuk
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Palama, Thongsuk
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Senajuk, Watchara
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Nausri, Chompoo
The analysis of adsorption relies on the equilibrium state of the mass. It is the relationship between the concentration of the adsorbate in the liquid phase and the concentration of the adsorbate in the solid phase. The relationship is written as an isotherm of the adsorption graph. Zeolite LTA was used as adsorbent to remove dye from solution in a batch adsorption system. The adsorption isotherm showed that the Langmuir model was better than the Freundlich model. Adsorption of adsorbate consists of a diffusion process through the fluid layer around the adsorbent material and the diffusion in the cavity. This research found that a pseudo-second order model was a better fit to measured adsorption data.

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