• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.287-298
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• 2022

This study evaluated the efficacy of chlorine dioxide (ClO₂) as an oxidant to reduce malodor emission from chicken feces. Two experiments were performed with the following four treatments in parallel: 1) fresh chicken feces with only distilled water added as a control, 2) a commercial germicide as a positive control, and 3) 2,000 or 4) 3,000 ppm of ClO₂ supplementation. Aluminum gas bags containing chicken feces sealed with a silicone plug were used in both experiments, and each treatment was tested in triplicate. In Experiment 1, 10 mL of each additive was added on the first day of incubation, and malodor emissions were then assessed after 10 days of incubation. In Experiment 2, 1 mL of each additive was added daily during a 14-day incubation period. At the end of the incubation, gas production, malodor-causing substances (H₂S and NH₃ gases), dry matter, pH, volatile fatty acids (VFAs), and microbial enumeration were analyzed. Supplementing ClO₂ at 2,000 and 3,000 ppm significantly reduced the pH and the ammonia-N, total VFA, H₂S, and ammonia gas concentrations in chicken feces compared with the control feces (P<0.05). Additionally, microbial analysis indicated that the number of coliform bacteria was decrease after ClO₂ treatment (P<0.05). In conclusion, ClO₂ at 2,000 and 3,000 ppm was effective at reducing malodor emission from chicken feces. However, further studies are warranted to examine the effects of ClO₂ at various concentrations and the effects on malodor emission from a poultry farm.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.604-608
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• 2014

This study investigated influence of dissolved organic nitrogen (DON) in natural organic matter (NOM) on the formation of organic chloramines upon monochloramination. Ratios of dissolved organic carbon (DOC) to DON of the 16 NOM isolates ranged from 7 to 47 mg-C/mg-N. Levels of organic chloramines maxed in 24 hours at $0.16mg-Cl_2/mg-N$ in average. The yields were relatively lower, but decay of organic chloramines were slower than those upon chlorination. Organic chloramines formed upon monochloramination decreased by 56% in average in 120 h. NOM with lower DOC/DON ratios formed more organic chloramines. NOM fractions such as hydrophobic, hydrophilic, transphilic, and colloidal did not significantly impact formation of organic chloramines. As the monochloramine doses increased, more organic chloramines were produced ($R^2=0.91$). Overestimation of disinfection capacity due to the formation of organic chloramines may not be concerns for monochloramine systems since only 6% of monochloramine could be converted to organic chloramines upon monochloramination of NOM.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.12
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• pp.15-20
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• 1972

There are still many problems on the physiological role of silicon in rice plants, although, it has been reported that silicate slag is the most effective fertilizer for the improvement of Akiochi soils. This experiment is carried out to investigate the effect of silicate of the mineral nutrition uptake by rice plants, using Ca45, P32, C136, and Mn54. The obtained results are summerized as follows; 1. Contents of mineral nutrients except silicon were higher in the rice plant grown in minus Si-culture solution a than in plus Si-plot. 2. Transpiration amounts appeared to be greater in the low content plant of silicon. 3. The rate of translocation to shoot of each ion absorbed by roots depended on the rate of transpiration. 4. It seemed that only CI uptake was found small in minus Si-root. 5. Silicate fetilizer did not affect the solubility of mineral ions in soils.

• Membrane Journal
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• v.17 no.4
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• pp.381-386
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• 2007

Hollow fibers were made using the nickel slurry containing nickel particles and polymers by phase inversion method. And then, metallic filters were fabricated by sintering method at $1,150^{\circ}C$ under reduction condition. Metallic microfiltration membranes were prepared by coating nickel particles on the metallic filter. The properties of the metallic hollow fiber filters and microfiltration membranes such as pore size and strength were investigated. The metallic membrane showed good resistance against acid, base and chlorine. It was observed that the membrane exhibited good recovery rate by back washing.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.578-584
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• 2021

This study comparatively analyzed the properties of hydration reaction and strength development of four types of pond ash(PA) and fly ash(FA), aiming for the effective use of PA. The PA whose chlorine content was highest due to the seawater movement method had a faster setting time, higher cumulative heat, and greater initial strength development than those of FA due to the acceleration of the cement hydration reaction. However, the activity factor increase rate decreased after seven days of curing due to the rapid generation of early hydrates. The PA that contained impurities, such as a large amount of unburned carbon, had a delayed setting time due to the lower hydration reaction. Moreover, the strength was degraded in all curing ages. The PA whose chlorine content was lower due to the freshwater movement method and the amorphous content exhibited similar hydration reactivity and strength development characteristics compared to that of FA. The thermogravimetric analysis results verified that it had a similar level of Ca(OH)₂ consumption and pozzolanic reactivity with that of FA. Conclusively, it is necessary to expand the application of the freshwater movement method and manage the ignition loss to raise PA's usability.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.97-108
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• 2005

Samples of water, soil, and sediment were taken from 10 streams near Andong, Korea in May 2004. To assess the degree of environmental pollution of each stream, chemical pollutants such as total notrogen (T-N), total phosphorus (T-P), chemical oxygen demand (COD), heavy metals, organophosphorus pesticides, organochlorine pesticides, and dioxin-like PCB congeners were analyzed by standard process tests or U.S. EPA methods. In addition, biomarkers originated from insect immune systems of beet armyworm, Spodoptera exigua, were used to analysis of the environmental samples. Except Waya-chun stream showing T-N content of 9.12 mg/L, most streams were contaminated with relatively low levels of overall pollutants in terms of T-N, T-P, and COD, compared to their acceptable environmental levels designated by the Ministry of Environment. Contents of Pb and Cd in samples of each stream were much lower than environmentally permissible levels. However, several times higherconcentrations of Pb and Cd were found in locations at Mi-chun, Kilan-chun, and Hyunha-chun streams, in comparison with other streams. Diazinon, parathion, and phenthoate compounds among organophosphorus pesticides were detected as concentrations of 0.19, 0.40, and $1.13\;{\mu}g/g$, respectively, from soil sample collected in the vicinity of Mi-chun stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners, known as endocrine disrupting chemicals, selected in this study were not found above the limit of detection. Biomarker analyses using insect immune responses indicated that Waya-chun stream was suspected as exposure to environmental pollutants. Limitation and compensation of both environmental analysis techniques are discussed.

• Journal of Environmental Science International
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• v.3 no.2
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• pp.101-109
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• 1994

Chlorinated water in swimming pools contains chloroform at elevated levels compared to chlorinated drinking water Chloroform levels in four indoor swimming pools(swimming pools A, B and C in a city of Korea and swimming pool D in a city of New Jersey in the United States) were examined. The chloroform levels in the water of swimming pool C (city-managed) weve shown to be significantly(p=0.0001) different from those of private swimming pools A and B: the mean chloroform levels in the pools A, B, and C are 22.8, 17.8, and 31.1 $\mu\textrm{g}$/l, respectively. Furthermore, all of these chloroform levels are significantly(P=0.0001) different from those of New Jersey: chloroform concentration of the Korean pools ranged from 10.9 $\mu\textrm{g}$.l to 47.9 $\mu\textrm{g}$/l with a mean of 23.2 $\mu\textrm{g}$/l, while it ranged from 27 $\mu\textrm{g}$/l to 96$\mu\textrm{g}$/l with a mean of 64.4 $\mu\textrm{g}$/l in the New Jersey pool. The disinfection processes would cause part of this difference since the swimming pools in Korea applied both chlorination and ozonation method, while the swimming pool in New Jersey used chlorination method only. It was implied that swimming parameters inconsistently vary, resulting in fluctuation of and no constant accumulation of chloroform in the water with the change of time for the day. A regression analysis showed no relationships between sampling time and chloroform concentrations for the sampling day in the swimming pools of Korea. A F-test indicated no significant difference of chloroform concentrations in the morning and afternoon samples collected in the swimming pools. Ingestion dose was estimated to be 0.58$\mu\textrm{g}$ from an hour swimming in a city of Korea, taking into accounting an average of 23.2 $\mu\textrm{g}$/l in swimming pools in the city In extreme situation, the ingestion dose was estimated to be 12.0 $\mu\textrm{g}$ from an hour swimming in a city of Korea.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.524-533
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• 2008

Industrial wastewater generated in the electroplating and metal finishing industries typically contain toxic free and complex metal cyanide with various heavy metals. Alkaline chlorination, the normal treatment method destroys only free cyanide, not complex metal cyanide. A novel treatment method has been developed which destroys both free and complex metal cyanide as compared with Practical Plant(I). Prior to the removal of complex metal cyanide by Fe/Zn coprecipitation and removal of others(Cu, Ni), Chromium is reduced from the hexavalent to the trivalent form by Sodium bisulfite(NaHSO$_3$), followed by alkaline-chlorination for the cyanide destruction. The maximum removal efficiency of chromium by reduction was found to be 99.92% under pH 2.0, ORP 250 mV for 0.5 hours. The removal efficiency of complex metal cyanide was max. 98.24%(residual CN: 4.50 mg/L) in pH 9.5, 240 rpm with 3.0 $\times$ 10$^{-4}$ mol of FeSO$_4$/ZnCl$_2$ for 0.5 hours. The removal efficiency of Cu, Ni using both hydroxide and sulfide precipitation was found to be max. 99.9% as Cu in 3.0 mol of Na$_2$S and 93.86% as Ni in 4.0 mol of Na$_2$S under pH 9.0$\sim$10.0, 240 rpm for 0.5 hours. The concentration of residual CN by alkaline-chlorination was 0.21 mg/L(removal efficiencies: 95.33%) under the following conditions; 1st Oxidation : pH 10.0, ORP 350 mV, reaction time 0.5 hours, 2nd Oxidation : pH 8.0, ORP 650 mV, reaction time 0.5 hours. It is important to note that the removal of free and complex metal cyanide from the electroplating wastewater should be employed by chromium reduction, Fe/Zn coprecipitation and, sulfide precipitation, followed by alkaline-chlorination for the Korean permissible limit of wastewater discharge, where the better results could be found as compared to the preceding paper as indicated in practical treatment(I).

• Analytical Science and Technology
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• v.13 no.1
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• pp.55-65
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• 2000

In this study, we collected the tap water that treated from water plant in Seoul, Incheon, Taejon, Kwangju, Taeku and Pusan and supplied each house. The sampling period was June and September, 1997. The concentration of THMs formed by chlorination in drinking water was determined with the purge and trap method with GC/MSD recommended by the us EPA 542.2 method. Chloroform is the most of THMs (47.43%~93.11%) and the content order is bromodichloromethane > chlorodibromomethane > bromoform. In Incheon, Taejon, Kwangju, Taeku and Pusan, the content of bromodichloromethane, chlorodibromomethane and bromoform was higher than Seoul. But, in June and September, the concentration of THMs in six cities is not over Korea Drinking Water Regulation $100{\mu}g/L$. The calculated human exposure for each substances were chloroform $6.14{\times}10^{-4}mg/kg/day$, bromodichloromethane $1.01{\times}10^{-4}mg/kg/day$, chlorodibromomethane $0.29{\times}10^{-4}mg/kg/day$, bromoform $0.01{\times}10^{-4}mg/kg/day$ and THMs $7.98{\times}10^{-4}mg/kg/day$.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.25-31
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• 1996

Transgenic tobacco plants expressing calmodulin derivative($lys{\rightarrow}ile$ 115 calmodulin) and hygromycin resistance genes or hygromycin resistance gene alone(control) were generated by Agrobacterium-mediated DNA transfer. Seeds obtained from the transgenic plants($F_o$) were tested for resistance to hygromycin and the expected 3 : 1 ratio was observed. The expression of calmodulin derivative in the tobacco plants was identified by a combined method of Western blot and Chemiluminescence. The effects of surface sterilizers on the germiation of seeds from transgenic tobacco plants were tested in Murashige and Skoog agar medium. Seeds obtained from transgenic tobacoo plants expressing the calmodulin derivative showed no fungi contamination with normal germination by treating with sterilized water alone or sodium hypochlorite(2% effective chlorine). In contrast, seeds from the control transgenic tobacco plants showed severe contamination with fungi by treating with sterilized water alone and showed no contamination with normal germination by treating with sodium hypochlorite(2% chlorine). The effects of calcium concentration on the germination of seeds from transgenic tobacco plants were tested in Murashige and Skoog agar medium. Seeds obtained from transgenic tobacco plants expressing the calmodulin derivative showed better germination frequency than that of the control transgenic tobacco seeds in the medium containing 30 mM $CaCl_2$. The data raise the possibility that the expression of calmodulin derivative gene in tobacco plants could increase adaptability of the seeds to environmental stresses.