• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.1
• /
• pp.133-139
• /
• 2000

In this study, activated carbon was prepared from solid residue after lignin pyrolysis by using zinc chloride as an activation agent. The steam activation method was adopted to manufacture activated carbon from solid residue after lignin pyrolysis. The effect of process operation variables such as activation temperature, activation time and mass of activation agent added to char on the pore structure and specific surface area of the activated carbon was investigated. Activated carbon with high surface area and well-developed pore structure could be prepared, when solid residue after lignin pyrolysis was mixed with zinc chloride of 300 wt% and then the mixture was activated for 1 hour at $1000^{\circ}C$ in a stream of nitrogen.

• Korean Journal of Agricultural Science
• /
• v.2 no.2
• /
• pp.381-398
• /
• 1975

Present work was executed to evaluate effects of adjuvants. stabilizers. moisture. pH and heavy metals on the stability of Fenitrothion in the emulsifiable concentrate. In addition, susceptibility ' of Fenitrothion in various formulations, to UV-irradiation has been also examined. The results are summarized as follows; 1. Xylene and benzene were found to be satisfactory solvents for Fenitrothion emulsifiable concentrate. As expected, polar sol vents such as aliphatic alcohols considerably reduced stability of the pesticides. 2. Of the two non-ionic emulsifiers, an alkyl aryl type Sorpol-1200, in contrast to sorbitan type Tweens, substantially reduced decomposition of Fenitrothion in the emulsifiable concentrates. Moisture and pH of emulsifiers. in the ranges studied. affected little if any. on the stabi ity of the Fenitrothion during the experiment periods. 3. Maleic anhydride, p-toluene sulfonic acid, sulfosalicylic acid, maleic anhydride-sulfosalicylic acid reduced decomposition of Fenitrothion in the emulsifiable concentrate. Addition of organic acids, however, increased liability of Fenitrothion in the emulsifiable concentrate. 4. Presence of either zinc or copper metals in the emulsifiable concentrate containing Tween-80 as a emulsifier, reduced stability of the Fenitrothion. 5. UV-irradiation, as expected, brought decomposition of Fenitrothion. The liability of Fenitrothion formulations decreased in the order, wettable powder ${\gg}$ dust > emulsifiable concentrate.

• Food Science and Preservation
• /
• v.16 no.6
• /
• pp.915-923
• /
• 2009

For preparation of high-quality salted mackerel using enzymatic extracts from Ecklonia cava (EEC) to process fresh mackerel caught off Jeju Island, the optimal concentration of EEC was investigated. There were no differences in proximate composition, salinity, Escherichia coli level, pH, volatile basic nitrogen content, histamine level, or peroxide value between salted mackerel samples prepared with different concentrations of EEC. However, the antiradical properties of salted mackerel, assayed by scavenging of DPPH free radicals, hydroxyl radicals, hydrogen peroxide, and alkyl radicals, increased with increasing concentrations of EEC. The optimal concentration of EEC for preparation of high-quality salted mackerel was 2% (w/w). Salted mackerel soaked in 2% (w/w) EEC was superior to commercial salted mackerel in antiradical properties, biogenic amine content, and other relevant chemical properties.

• Ecology and Resilient Infrastructure
• /
• v.2 no.4
• /
• pp.330-336
• /
• 2015

Photocatalytic degradation of bisphenol A (BPA) in aqueous solution was investigated using $TiO_2$ nanoparticles (Degussa P25) in this study. After a 3 hr photocatalytic reaction (${\lambda}=365nm$ and $I=3mW\;cm^{-2}$, $[TiO_2]=2.0g\;L^{-1}$), 98% of BPA ($1.0{\times}10^{-5}M$) was degraded and 89% of the total organic carbon was removed. In addition, BPA degradation by photolytic, hydrolytic and adsorption reactions was found to be 2%, 5% and 13%, respectively. The reaction rate of BPA degradation by photocatalysis decreased with increasing concentration of methanol that is used as a hydroxyl radical scavenger. This indicates that the reaction between BPA and hydroxyl radical was the key mechanism of BPA degradation. The pseudo-first-order reaction rate constant for this reaction was determined to be $7.94{\times}10^{-4}min^{-1}$, and the time for 90% BPA removal was found to be 25 min. In addition, acute toxicity testing using Daphnia magna neonates (< 24 h old) was carried out to evaluate the reduction of BPA toxicity. Acute toxicity (48 hr) to D. magna was decreased from 2.93 TU (toxic unit) to non-toxic after photocatalytic degradation of BPA for 3 hr. This suggests that there was no formation of toxic degradation products from BPA photocatalysis.

• Applied Chemistry for Engineering
• /
• v.16 no.3
• /
• pp.413-421
• /
• 2005

This study focused on the decomposition of toluene in a plasma-photocatalytic hybrid system. Hexagonally packed meso-structured Mn-titanosilicates (Mn-Ti-MCM-41), as the photocatalysts, have been prepared by the hydrothermal method. The physical properties of the photocatalysts were characterized using XRD, XPS, TEM, BET/ICP, and $NH_3$/Toluene-TPD. Experiments were carried out at the applied voltage of 9.0 kV and at room temperature of $20^{\circ}C$. In the plasma only system, the activity of the toluene decomposition was higher than that in the photocatalytic system. However, the amount of by-products, such as phenol, $C_2{\sim}C_4$ alkene, was also increased in the plasma only system. However, the by-products decreased remarkably in a plasma-photocatalytic hybrid system. When Mn5mol%-Ti-MCM-41 was used as a photocatalyst in a plasma-photocatalytic hybrid system, the $CO_2$ selectivity in products was increased dramatically compared to other catalysts. It was confirmed that a plasma-photocatalytic hybrid system was better for toluene decomposition compared to photocatalytic and plasma only systems.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.12
• /
• pp.858-864
• /
• 2014

In this study, The effects of empty bed contact time (EBCT) and water temperature on the biodegradation of 8 synthetic fragrances (SFs) in biological activated carbon (BAC) process were investigated. Experiments were conducted at two water temperatures (7 and $18^{\circ}C$) and three EBCTs (5, 10 and 15 min). Increasing EBCT and water temperature increased the biodegradation efficiency of SFs in BAC column. Pentalide and ambrettolide were the highest biodegradation efficiency, but DPMI and ADBI were the lowest. The kinetic analysis suggested a pseudo-first-order reaction model for biodegradation of 8 SFs at various water temperatures and EBCTs. The pseudo-first-order biodegradation rate constants ($k_{bio}$) of 8 SFs ranging from $0.1184{\sim}0.6545min^{-1}$ at $7^{\circ}C$ to $0.3087{\sim}0.9173min^{-1}$ at $18^{\circ}C$. By increasing the water temperature from $7^{\circ}C$ to $18^{\circ}C$, the biodegradation rate constants ($k_{bio}$) were increased 1.4~2.6 times.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.11
• /
• pp.739-746
• /
• 2014

In this study, The effects of empty bed contact time (EBCT) and water temperature on the biodegradation of 8 UV filters in biological activated carbon (BAC) process were investigated. Experiments were conducted at two water temperatures (7 and $18^{\circ}C$) and three EBCTs (5, 10 and 15 min). Increasing EBCT and water temperature increased the biodegradation efficiency of UV filters in BAC column. EHMC and BZC were the highest biodegradation efficiency, but BP and 4-MBC were the lowest. The kinetic analysis suggested a first-order reaction model for biodegradation of 8 UV filters at various water temperatures and EBCTs. The first-order biodegradation rate constants ($k_{bio}$) of 8 UV filters ranging from $0.2730{\sim}0.6365min^{-1}$ at $7^{\circ}C$ to $0.4824{\sim}0.8743min^{-1}$ at $18^{\circ}C$. By increasing the water temperature from $7^{\circ}C$ to $18^{\circ}C$, the biodegradation rate constants ($k_{bio}$) were increased 1.5~2.1 times.

• Applied Chemistry for Engineering
• /
• v.19 no.2
• /
• pp.199-204
• /
• 2008

Hemicellulose, consisteing of pentose as xylose and mannose, is usable as high octane fuels and heavy oil additives if depolymerized to monomer unit. In this study, thermochemical degradation by pyrolysis-liquefaction of hemicellulose, the effects of reaction temperature, conversion yield, degradation properties and degradation products were investigated. Experiments were performed in a tube reactor by varying reaction temperatures from $200^{\circ}C$ to $400^{\circ}C$ at 40 min of reaction time. The liquid products from pyrolysis-liquefaction of hemicellulose contained various kinds of ketones. Ketones, as 2,3-dimethyl-2-cyclopenten-1-one, 2,3,4-trimethyl-2-cyclopentan-1-one, and 2-methyl-cyclopentanone, could be used as high-octane-value fuels and fuel additives. However, phenols are not valuable as fuels. Combustion heating value of liquid products obtained from thermochemical conversion processes of hemicellulose was in the range of 6,680~7,170 cal/g. After 40 min of reaction at $400^{\circ}C$ in pyrolysis-liquefaction of hemicellulose, the energy yield and mass yield were as high as 72.2% and 41.2 g oil/100 g raw material, respectively.

• Food Science and Preservation
• /
• v.15 no.3
• /
• pp.361-366
• /
• 2008

This study was investigated the functional characteristic change by the enzymatic hydrolysate to improve the functionality of soybean milk. The soymilk (SM), hydrolysates of soy milk (HSM), whole soy milk (WSM) and hydrolysates of whole soy milk (HWSM) revealed composition difference whether the bean-curd removal was included or not, but nearly no change was found by the low molecule enzyme treatment. The chromaticity revealed clear difference whether the bean-curd was removed or not, but did not show any difference by the hydrolyzation. Total free sugar and oligosaccharide content was found to be 1,389.88 mg% in SM, 1,013.51 mg% in HSM, 1,539.51 mg% in WSM, and 1,331.53 mg% in HWSM by showing the reduction after the enzyme hydrolyzation. DPPH free radical scavenging activity revealed to show high activity in HSM and in HWSM which were enzymatically hydrolyzed by 49.26% and 45.34%, respectively. And the ACE inhibition activity of HSM and HWSM was found to be approximately 1.6 times higher than the control SM and HSM The superoxide radical scavenging activity revealed to show high activity at HSM and HWSM, and no difference was found by the removal of bean-curd from raw soybean. Based upon these results, the functional characteristics of HSM, WSM and HWSM were found to be excellent compared to SM and it is expected to be used as various functional sources in a future.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.7
• /
• pp.953-959
• /
• 2010

We extracted bioactive materials from Codium fragile by enzymatic hydrolysis using four different proteases (Alcalase, Flavourzyme, Neutrase, and Protamex) and seven different carbohydrases (amyloglucosidase (AMG), Celluclast, Dextrozyme, Maltogenase, Promozyme, Termamyl, and Viscozyme), and evaluated their biological activities such as antioxidant, anti-acetylcholinesterase (AChE), and anti-inflammatory effects. All enzymatic hydrolysates showed good DPPH radical scavenging capacities, in particular, Flavourzyme and Promozyme hydrolysates possessed the highest activity. The two hydrolysates also exhibited strong hydrogen peroxide scavenging activity, $Fe^{2+}$ chelating activity, and reducing power in a dose-dependent manner. Furthermore, the two hydrolysates effectively protected DNA damage induced by hydroxyl radical by measuring the conversion of supercoiled DNA to the open circular DNA. All enzymatic hydrolysates also showed high anti-AChE inhibitory activities in a dose-dependent manner, and did not showed any significant cytotoxicity on RAW264.7 cells (p<0.05). In addition, the enzymatic hydrolysates significantly (p<0.05) inhibited lipopolysaccharide induced-nitric oxide production on RAW264.7 cells. These results suggest that the enzymatic extracts from Codium fragile would be good source as an ingredient of functional foods.