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Genotypic Variations in Ferulic Acid, Antioxidant Capacity and Yield Components of Thai Landrace Rice Genotypes
(2022-01-01)
Aninbon, Chorkaew
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Srihanoo, Chayut
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Phakamas, Nittaya
Ferulic acid is a potent antioxidant in rice. The objective of this study was to evaluate the variations in ferulic acid and antioxidant capacity among landrace rice genotypes. The experiment is conducted under paddy field conditions in two locations. It uses a randomized complete block design with three replications, and the treatments consist of 24 landrace rice genotypes. Data are collected for yield and yield components, ferulic acid, and antioxidant capacity. Rice genotypes are significantly different for plant height, number of panicles per plant, number of seeds per panicle, 1,000-seed weight and grain yield. Grain yields of 24 rice genotypes ranged from 1,476.9 to 4,348.1 kg/ha, and G24 is a good source for high grain yield. Variations in ferulic acid content and antioxidant capacity are found among genotypes. Ferulic acid contents range from 11.56 to 45.68 mg/100 g seed, and antioxidant capacity determined by the DPPH method ranged from 15.46 to 86.26%. G4 has the highest ferulic acid content and antioxidant capacity. These two genotypes are promising for parents in breeding programs targeting improved ferulic acid content, antioxidant capacity, and yield.
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Optimization of lignin conversion to phenol via partial oxidation of synthesized wastewater containing lignin
(2020-12-01)
Sriprom, Pongsert
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Leephisuth, Pornyamon
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Assawasaengrat, Pornsawan
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
This work was to optimize operating parameters for phenol production via partial oxidation. The essential settings, NaOH loading of 4–20 g/L, reaction temperatures of 140–180 °C, and time of 15–45 min, were set as the independent parameters for designing the experiments. A set of tests was generated using Box–Behnken Design (BBD) and performed in a high-pressure reactor at the constant air pressure of 2 bars. A produced phenol concentration was assigned as a response target for evaluating an optimal condition. From the results, a quadratic model of actual data was fit with high accuracy (R2 of 94.1%). A response surface methodology (RSM) was used to evaluate the operating parameters effect on the phenol formation. It showed that the temperature rising affected phenol formation due to the creation of aldehydes at low temperatures and phenol re-polymerization. The presence of NaOH plays an essential role in the production of phenol. It may increase the hydroxyl group's rate to an aromatic ring that yields a high percentage of phenol production. For the reaction time, the longer time gave a higher yield of phenol. However, it slightly increased after 30 min. The predicted optimal condition was determined at the temperature of 161 °C, the NaOH loading of 16.4 mg/L, and the reaction time of 36.2 min. Three experiments were performed at the optimal point to verify the prediction. It was found that the phenol concentration of 30 ± 1 mg/L was yielded at this condition. Moreover, the reaction temperature and the initial pressure of air were not severe. It indicates that the partial oxidation of aqueous lignin solution can produce phenol at mild conditions.
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Partial oxidation of synthesized wastewater containing lignin to vanillin and phenol under mild conditions
(2020-02-01)
Sriprom, Pongsert
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Leephisuth, Pornyamon
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Neramittagapong, Arthit
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Neramittagapong, Sutasinee
Partial oxidation of synthesized wastewater containing lignin to form phenol and vanillin was investigated. The reactions were carried out in a high-pressure reactor at various temperatures in the range of 140–200 ° C and under the air atmosphere with the initial air pressure of 2 bar for 75 min. The addition of NaOH has a strong effect on the formation of vanillin and phenol. The results showed that the highest vanillin concentration of 23.4 ppm and the highest phenol production of 30 ppm were obtained at a temperature of 140 °C and 200 °C, respectively. The vanillin and phenol can be produced from the partial oxidation of wastewater containing lignin at mild conditions.
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A novel catalyst from water treatment sludge for catalytic ozonation to degrade phenol
(2019-05-01)
Sukmilin, Apiradee
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Boonchom, Banjong
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Jarusutthirak, Chalor
Water treatment sludge (WTS) from a water treatment plant has been successfully converted into a novel catalyst. Catalytic ozonation using the WTS as a catalyst for degradation of phenol was studied. Water treatment sludge was dried naturally for 7 days, then grounded and sieved through a standard mesh with a size no. of 100, equivalent to less than 150 micron in size. The WTS was characterized by X-ray fluorescence spectrometer (XRF) and X-ray diffractometer (XRD). The XRF analysis showed that water treatment sludge contained silica of 49.90%, Al<inf>2</inf>O<inf>3</inf> of 24.40 %, and Fe<inf>2</inf>O<inf>3</inf> of 10.40 %. The XRD analysis illustrated that the structure of water treatment sludge was similar to that of kaolin clay. Factors affecting phenol removal efficiency including reaction time (0, 5, 10, 15, 30, 60, 90 and 120 min), pH (3, 7, and 11) and catalyst dosage (1, 3 and 5 g/L) were investigated. At the optimum conditions, i.e. reaction time of 120 min, pH of 11, and catalyst dosage of 3 g/L, the removal efficiency of phenol was 59.16% which was higher than that of sole ozonation (44.61%). According to kinetic analysis, it was found that the experimental data fit well with pseudo-first order kinetic model with a rate constant (K<inf>obs</inf>) of 0.0347 min-1 while that of sole ozone was 0.0162 min-1.
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Catalytic ozonation using iron-doped water treatment sludge as a catalyst for treatment of phenol in synthetic wastewater
(2019-04-01)
Sukmilin, Apiradee
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Boonchom, Banjong
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Jarusutthirak, Chalor
In this study, iron (Fe)-doped water treatment sludge, designated as Fe/WTS, was prepared by a hydrothermal method using phosphoric acid and impregnation with ferric nitrate. The results from X-ray diffraction (XRD) confirmed the presence of Fe loaded on the WTS support, while Brunauer-Emmett-Teller (BET) analysis indicated an increase of specific surface area of the WTS from 37.37 m2/g to 118.51 m2/g after acid modification. The Fe/WTS was successfully used as a catalyst in catalytic ozonation for degradation of phenol in synthetic wastewater. Factors affecting phenol removal efficiency including reaction time, pH, catalyst dosage, and Fe content were investigated. At the optimum condition, i.e., reaction time of 120 min, pH of 11, catalyst dosage of 1 g/L, and Fe content of 2% (w/w), the removal efficiency of phenol was 99.16% which was higher than that of sole ozonation (44.61%). The results of kinetic analyses indicated that the reactions of catalytic ozonation in the presence of Fe/WTS and WTS catalysts followed pseudo-first order kinetic model with rate constants of 0.0362 and 0.0065 min-1, respectively, while that of sole ozone was 0.0046 min-1. This finding presented the potential use of Fe/WTS as a novel catalyst for catalytic ozonation.
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Oxidative cracking of aromatic compounds related to lignin constituents with steam using ZrO2-Al2O3-FeOx catalyst
(2010-10-22)
Yoshikawa, Takuya
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Na-Ranong, Duangkamol
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Tago, Teruoki
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Masuda, Takao
The catalytic activity of iron oxide composite catalyst (ZrO <inf>2</inf>-Al<inf>2</inf>O<inf>3</inf>-FeO<inf>x</inf>) was investigated for converting aromatic compounds derived from plant biomass into useful aromatics. Catalytic cracking of lignin constituent-related di-aroatics such as diphenyl ether, diphenyl methane, and 2-benzyloxyphenol, and mono-aromatics such as guaiacol, acetophenone, and 1-phenyl-1-propanol was carried out over ZrO <inf>2</inf>-Al<inf>2</inf>O<inf>3</inf>-FeO<inf>x</inf>. The catalytic reactions were conducted in a fixed-bed reactor at 773 K under atmospheric pressure. Diphenyl ether and diphenyl methane were stable, whereas 2-benzyloxyphenol was thermally decomposed, followed by the production of toluene and phenol over ZrO<inf>2</inf>-Al<inf>2</inf>O<inf>3</inf>-FeO <inf>x</inf>. Guaiacol and acetophenone were selectively converted into 54 C-mol% of phenol and 29 C-mol% of benzene, respectively. The methoxy and carbonyl groups were decomposed into gaseous products mainly consisting of CO<inf>2</inf>, whereas dehydration of the aliphatic hydroxyl group in 1-phenyl-1-propanol mainly occurred to produce 1-phenyl-1-propene. ZrO <inf>2</inf>-Al<inf>2</inf>O<inf>3</inf>-FeO<inf>x</inf> catalyst is effective for degrading alkyl ether bonds between aromatic rings, and the ring substituent methoxy and carbonyl groups.

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