• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1183-1187
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• 2004

This study was designed to develop crosslinking of $\beta$-cyclodextrin ($\beta$-CD), and determine the optimum conditions of different factors (mixing time, mixing temperature, and mixing speed) on cholesterol reduction from milk. Crosslinked $\beta$-CD was prepared with epichlorohydrin. When milk was treated with different conditions, the cholesterol removal rate was in the range of 79.4 to 83.3% with 1 % crosslinked $\beta$-CD addition, which were not significantly different among treatments. After cholesterol removal from milk, the used crosslinked $\beta$-CD was washed for cholesterol dissociation and reused. For recycling study, the cholesterol removal rate in first trial was 81.8%, which was mostly same as that using new crosslinked $\beta$-CD. With five trials repeatedly using the same sample, the mean cholesterol removal rate was 81.2%. The present study indicated that the optimum conditions on cholesterol removal using crosslinked $\beta$-CD were 10 min mixing with 400 rpm speed at $5^{\circ}C$ with about 80% cholesterol removal. In addition, crosslinked $\beta$-CD resulted in the effective recycling efficiency almost 100%.

• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.278-288
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• 2021

The development of bioenergy through biomass has gained importance due to the increasing rates of fossil fuel depletion. Biomass is important to increase the productivity of bioethanol, and production of biomass with high biomass productivity, low lignin content, and high cellulose content is also important in this regard. Inorganic salts are important in the cultivation of biomass crops for the production of biomass with desirable characteristics. In this study, the roles of various inorganic salts in biomass and bioethanol production were investigated using an in vitro tobacco culture system. The inorganic salts evaluated in this study showed dramatic effects on tobacco plant growth. For example, H₂PO₄ substantially improved plant growth and the root/shoot (R/S) ratio. The chemical compositions of tobacco plants grown in media after removal of various inorganic salts also showed significant differences; for example, lignin content was high after Mg²⁺ removal treatment and low after K⁺ treatment and H₂PO₄ removal treatment. On the other hand, NO₃^- and H₂PO₄ treatments yielded the highest cellulose content, while enzymatic hydrolysis yielded the highest glucose concentration ratio 24 h after NH₄⁺ removal treatment. The ethanol productivity after H₂PO₄ removal treatment was 3.95% (w/v) 24 h after fermentation and 3.75% (w/v) after 36 h. These results can be used as the basis for producing high-quality biomass for future bioethanol production.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.4
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• pp.537-542
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• 2014

This study was carried out to optimize cholesterol removal in whole egg using crosslinked ${\beta}$-cyclodextrin (${\beta}$-CD) and to recycle the ${\beta}$-CD. Various factors for optimizing conditions were concentration of the ${\beta}$-CD, mixing temperature, mixing time, mixing speed and centrifugal speed. In the result of this study, the optimum conditions of cholesterol removal were 25% crosslinked ${\beta}$-CD, $40^{\circ}C$ mixing temperature, 30 min mixing time, 1,200 rpm mixing speed and $2,810{\times}g$ centrifugal speed. The recycling was repeated five times. The cholesterol removal was 92.76% when treated with the optimum conditions. After determining the optimum conditions, the recyclable yields of the crosslinked ${\beta}$-CD ranged from 86.66% to 87.60% in the recycling and the percentage of cholesterol removal was over 80% until third recycling. However, the cholesterol removal efficiency was decreased when the number of repeated recycling was increased. Based on the result of this study, it was concluded that the crosslinked ${\beta}$-CD was efficient for cholesterol removal in whole egg, and recycling is possible for only limited repeating times due to the interaction of the ${\beta}$-CD and egg protein.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.615-622
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• 2017

This study was conducted to evaluate the odor reduction efficacy of the dip injection wet scrubber (DIWS) using tap water as washing fluid. The $NH_3$ and $H_2S$ removal efficiency of 7 day batch operated DIWS was evaluated twice over a total of 14 days of experiment. The $NH_3$ removal efficiency ranged from 26 to 37%. The $H_2S$ removal efficiency was between 22 and 30%. The pH of the washing fluid maintained below 8 and the $NH_4{^+}$ concentration tended to keep constant around 350 ppm after 5 days of washing-fluid replacement. Therefore, the 5-day washing fluid replacement interval is more preferable than the 7-day interval. The $NH_4{^+}$ concentration and the electrical conductivity (EC) showed a high correlation. The EC measurement can be used as an alternative to conventional $NH_4{^+}$ concentration measurement method for real time monitoring of washing fluid condition.

• Economic and Environmental Geology
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• v.34 no.3
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• pp.301-306
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• 2001

Column tests were conducted to investigate the optimal condition of surfactant solution pH that can affect the removal efficiency in surfactant-assisted remediation. Toluene and 1,2,4-trichlorobenzene were chosen as the model hydrophobic substances. Two Iowa soils, Fruitfield sand and Webster clay loam, were leached with solutions of 4%(v/v) sodium diphenyl oxide disulfonate (DOSL, trade name Dowfax 8390), or 4%(v/v) trideceth-19-carboxylic acid (TDCA, trade name Sandopan JA36), or 4% (v/v) octylphenoxypoly ethoxyethanol (OPEE, trade name Triton X100). The test results revealed that a maximum removal of toluene and 1,2,4-trichlorobenzene was obtained at pH 10 of surfactant solution, and maximum recoveries of added toluene (94%) or 1 ,2,4- trichlorobenzene (97 %) were obtained for DOSL surfactant solution in Fruitfield sandy soil column. Increased removal efficiency by pH control of both toluene and 1,2,4trichlorobenzene was 16% and 20% for DOSL with Fruitfild sandy soil, respectively. In addition, the maximum recoveries of added toluene or I ,2,4-trichlorobenzene were 89% and 93% for DOSL surfactant solution in Webster clay loam soil column. The maximum increase of toluene and 1,2,4-trichlorobenzene removal was 26% and 19% for DOSL with Webster clay loam soil, respectively. These experimental results indicate that maintaining a high pH surfactant solution in surfactant-assisted remediation is desirable for efficient removal of NAPLs from contminated soils.

• Carbon letters
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• v.19
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• pp.12-22
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• 2016

Date palm leaflets were used as a precursor to prepare dehydrated carbon (DC) via phosphoric acid treatment at 150℃. DC, acidified with H₃PO₄, was converted to activated carbon (AC) at 500℃ under a nitrogen atmosphere. DC shows very low surface area (6.1 m²/g) while AC possesses very high surface area (829 m²/g). The removal of lisinopril (LIS) and chlorpheniramine (CP) from an aqueous solution was tested at different pH, contact time, concentration, and temperature on both carbons. The optimal initial pH for LIS removal was 4.0 and 5.0 for DC and AC, respectively. However, for CP, initial pH 9.0 showed maximum adsorption on both carbons. Adsorption kinetics showed faster removal on AC than DC with adsorption data closely following the pseudo second order kinetic model. Adsorption increases with temperature (25℃–45℃) and activation energy (E_a) is in a range of 19–25 kJ mol/L. Equilibrium studies show higher adsorption on AC than DC. Thermodynamic parameters show that drug removal is endothermic and spontaneous with physical adsorption dominating the adsorption process. Column adsorption data show good fitting to the Thomas model. Despite its very low surface area, DC shows ~70% of AC drug adsorption capacity in addition of being inexpensive and easily prepared.

• KSBB Journal
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• v.19 no.2
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• pp.143-147
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• 2004

Biodegradation of dimethyl sulfide (DMS) was studied in a batch culture using Gordonia sihwaniensis PKL-1 isolated from a compost biofilter after 100 days of operation for the removal of volatile organic compounds. Optimal pH and temperature for the removal of DMS were 7 and $25^{\circ}C$, respectively. The Michaelis-Menten kinetic constants for DMS removal, $\upsilon_{max}$ and $K_s$, were 0.0016 mg/(mg-protein)ㆍhr, and 8.05 mg/L, respectively.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.378-380
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• 2005

The waste seashells were used for the removal of hydrogen sulfide from a hot gas stream, The sulphidation of waste seashells with H$_2$S was studied in a thermogravimetric analyzer at temperature between 600 and 800${\circ}$C . The desulfurization performance of the waste seashell sorbents was experimentally tested in a fixed bed reactor system. Sulfidation experiments performed under reaction conditions similar to those at the exit of a coal gasifier showed that preparation procedure and technique, the type and the amount of seashell, and the size of the seashell affect the H2S removal capacity of the sorbents. The pore structure of fresh and sulfided seashell sorbents was analyzed using mercury porosimetry, nitrogen adsorption, and scanning electron microscopy.

• New & Renewable Energy
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• v.16 no.1
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• pp.68-76
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• 2020

Operational testing of the THIOPAQ^® facility that removes H₂S from landfill gas was performed for 746 days. The average H₂S removal efficiency was 99.4%, and the input quantities of air, NaOH, and nutrients per sulfur load were 13.1 ㎥/ton, 1.5 ㎥/ton, and 28.7 L/ton, respectively. The purity of the bio-sulfur produced from the facility was 94.8%, with 3.3% impurities, except for moisture. X-ray photoelectron spectroscopy showed that the compositional contents of amino acids and free amino acids of the bio-sulfur surface were 5,308 and 728 mg/kg, respectively. The mean particle size was 3.41 ㎛, which was much smaller than that of chemical sulfur. Based on these results, a high H₂S removal rate of more than 97% is feasible, and high value-added bio-sulfur, which is used as a fungicide because of its hydrophilic characteristics and small size, can be obtained at this facility.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.488-493
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• 2004

The effects were examined from several conditions of $TiO_2$ photocatalysis reaction to phenols degradation by changing it's reacting conditions such as phenol concentration, pH, $TiO_2$ concentration, $H_2O_2$ concentration, flow rate, and intensity of ultraviolet rays. Phenol degradation was more efficient in low concentration of phenol, neutral pH. Phenol degradation appeared to increase as concentration of $TiO_2$ photocatalyst, that of $H_2O_2$ and intensity of ultraviolet rays increased. As $TiO_2$ dosage increased, initial rate constant k linearly increased. When $H_2O_2$ was injected more than optimum, phenol removal rate didn't increase in proportional to the change of $H_2O_2$ concentration as OH radicals was being consumed. When flow rate is less than $4.75m^3/m^2$ day, phenol removal efficiency appeared to decrease as ultraviolet rays transmission rate becomes low by $TiO_2$ suspension coated in photo reaction column. Meanwhile, initial rate constant according to light intensity change in less than $25mW/cm^2$ appeared to be in proportion to light intensity ($mW/cm^2$) Removal efficiency decreased about 12% after 180 minutes of reaction time while showed stable removal efficiency of 100% after 300 minutes when using regenerated $TiO_2$.