• Applied Biological Chemistry
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• v.19 no.4
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• pp.189-201
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• 1976

In an effort to develop a microbial in secticide, B. thdringiensis var. thuringiensis was cultured in the medium composed of cocoon-cooked water from a filature. The results obtained are summarized as followss : (1) Bacillus thuringiensis is a bacterium producing a ${\delta}-endotoxin$ especially toxic to lepidopterous insects and a thermostable exotoxin harmful to dipterous insects. (2) With a view to utilizing the cocoon-cooked water discarded from the filature, as a nutrient source in the B. thuingiensis culture, it was analyzed to contain large amounts of various minerals and protein (7.5 mg/ml) believed to be extracted from the pupae. (3) A large amount of the ${\delta}-endotoxin$ can be obtained most cheeply by using cocoon-cooked water instead of distilled water in preparing GYS and citrate salts media. (4) The largest amount of a mixture of the vegetative cells, spores, and crystals was obtained by addition of 8 gr/l of glucose to the GYS medium. (5) The growth of the bacterium was far better, when leucine, isoleucine, and valine were added all together to the citrate salts medium to the concentration of $1.25{\times}10^{-3}M$. (6) The best growth was observed by addition of Na-glutamate to the citrate salts medium to the concentration of $2.5{\times}10^{-3}M$. (7) The optimal culture time ranged from 9 to 15 days. (8) The highest mortality was shown in Pieris rapae Linne with a pH of the total body extract of 8.4, whereas Dendrolimus spectabilis Butler and Bombyx mori Linne with lower pH's were less susceptible to the ${\delta}-endotoxin$. (9) The presence of the thermo stable exotoxin was confirmed by the fact that the supernatant of the culture was very toxic to the Drosophila melanogaster tested.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.521-527
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• 1999

To investigate the variations of environmental and microbial populations in six stations at water region of Gangjin Bay, nutritive salts, water temperature, COD, DO, pH, heterotrophic bacteria, fungi and facal coliform bacteria were analysed four imes from February to November, 1998. These data were subjected to simple statistics, correlation analysis and principal factor analysis. Ecosystem of Gangiin Bay was regulated by 2∼4 factors during four seasons. We estimated that it was mainly influenced by inflow of fresh water, nutrient salts, suspended solids, salinity and variation of water temperature. These results suggested that influences of environmental factor of Gangiin Bay was relatively less than those of other bays.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1147-1151
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• 2007

Biodegradation of endocrine-disrupting bisphenol A was investigated with several white rot fungi (Irpex lacteus, Trametes versicolor, Ganoderma lucidum, Polyporellus brumalis, Pleurotus eryngii, Schizophyllum commune) isolated in Korea and two transformants of T. versicolor (strains MrP 1 and MrP 13). I. lacteus degraded 99.4% of 50 mg/l bisphenol A in 3 h incubation and 100% in 12 h incubation. which was the highest degradation rate among the fungal strains tested. T. versicolor degraded 98.2% of 50 mg/l bisphenol A in 12 h incubation. Unexpectedly, the transformant of the Mn-repressed peroxidase gene of T. versicolor, strain MrP 1, degraded 76.5% of 50 mg/l bisphenol A in 12 h incubation, which was a lower degradation rate than wild-type T. versicolor. The removal of bisphenol A by I. lacteus occurred mainly by biodegradation rather than adsorption. Optimum carbon sources for biodegradation of bisphenol A by I. lacteus were glucose and starch, and optimum nitrogen sources were yeast extract and tryptone in a minimal salts medium; however, bisphenol A degradation was higher in nutrient-rich YMG medium than that in a minimal salts medium. The initial degradation of endocrine disruptors was accompanied by the activities of manganese peroxidase and laccase in the culture of I. lacteus.

• Clean Technology
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• v.21 no.4
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• pp.257-264
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• 2015

Conventional physicochemical technologies for algae growth inhibition have economical and environmental pollution problems. This study attempted to overcome the problems by nature-friendly biological inhibition technology using fibrous carrier. The experimental results showed that the most effective carrier material, polyester, exhibited the highest biofilm thickness. The removal efficiency for nutrient salts, such as nitrogen and phosphorous, and algae growth inhibition of polyester carrier was 14.59%, 6.36%, and 77%, respectively, which is higher than for control group. These result indicate that the polyester carrier is available in eutrophic lake.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.376-385
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• 2008

Twenty lactating crossbred cows yielding 10 to 15 litres of milk daily during mid lactation were selected and divided into four groups of five animals to assess the effect of feeding calcium soaps of palm oil fatty acids (bypass fat) on milk yield, milk composition and nutrient utilization in lactating crossbred cows. The animals in groups 1 (control), 2, 3 and 4 were fed concentrate mixture containing 0 (no bypass fat), 2, 4 and 6% bypass fat, respectively. The average daily dry matter consumption in the various groups ranged from 13.1 to 13.6 kg and showed no significant difference among treatment groups. There was no significant difference among different groups in digestibility of DM, OM, CP and CF, however, ether extract digestibility in cows of groups 2 and 4 was significantly (p<0.05) higher than the control group. The average milk yields of the cows in group 3 (4% bypass fat) showed a significantly (p<0.05) higher value than cows of groups 1 and 2. Similarly, a significant (p<0.05) increase in fat yield, 4% FCM yield and SNF yield was observed for the cows in group 3 (4% bypass fat). The milk composition in terms of total solids, fat, lactose, protein, solids-not-fat and ash percentage showed a varying response and bypass fat feeding did not have any effect on milk composition of cows in different groups. The gross and net energetic efficiency of milk production ranged from 23.6 to 27.5% and 37.1 to 44.4%, respectively, and showed no significant difference among different treatment groups. The gross and net efficiency of nitrogen utilization for milk production ranged from 24.0 to 28.7% and 37.2 to 43.5%, respectively, and no significant difference was noted among different treatment groups. The supplementation with calcium salts of palm oil fatty acid reduced the proportion of caproic, caprylic and capric acids and significantly (p<0.01) increased the concentration of palmitic, oleic, stearic, linoleic and linolenic acids in milk fat with increase in level of bypass fat supplementation. It was concluded that incorporation of calcium salts of palm oil fatty acids at a 4% level in the concentrate mixture of lactating crossbred cows improved the milk production and milk quality in terms of polyunsaturated fatty acids without affecting the digestibility of nutrients.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.1
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• pp.89-102
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• 2021

Soils in agricultural lands contain large amount of organic matter and nutrients due to the injected fertilizers and manure. During heavy rain, surface water and base runoff pollutants flows into a nearby stream or lake with eroded soil from agricultural lands. On the other hands, agricultural lands near the lake are inundated due to the increase of the water level in the lake, leading to organic matter and nutrient release from the inundated soil. In this study, releasing rates of nutrient salts and organic substances were analyzed for the soil in the agricultural land, where cultivation activities has been carried out and periodically flooded, to account for the possibility of contamination from the inundated agricultural land in reservoir areas The experiment results have shown that COD was released from the soil in anaerobic conditions, and T-P was released in both anaerobic and aerobic conditions. However, in the case of T-N, it was found that the runoff by soil was not made before the rainfall occurred, and when the soil was impound due to rainfall, the elution occurred under the aerobic conditions. Through the results of this study, it was possible to account for the effect of flooded agricultural lands on the water quality in the lake, and this could be reflected in an efficient agricultural non-point pollution management policy. In order to determine the precise releasing rate for each agricultural land, it is believed that the leaching experiment for paddy fields and grasslands are needed.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.247-251
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• 2000

This study was conducted to investigate tissue nutrient contents and salt accumulation in plastic house soils cultivating lily, rose and carnation. The soil tested had high total salts, available phosphate and exchangeable potassium. The soil cultivating rose had highest salt concentvation followed by chose of carnation and lily. Tissue nutrient contents of lily were higher than chose of carnation and rose. In comparison among cultivars, the nutrient contents were as follows; 'Snow Qeen'>'Le Reve'>'Casa Blanca' in lily; 'Marina'>'Super star'>'Mary Devor'>'Madelon' in carnation; and 'Cocktail'> 'Marina'>'Maderon' in rose. The range of the nutrient contents were: T-N: $1.66\;{\sim}2.35%$, K: $1.73{\sim}2.23%$, Zn: $2.13{\sim}6.43\;mg/kg$, Cu: $3.79{\sim}13.89\;mg/kg$ in carnation; T-N: $0.79{\sim}1.65%$, P: $0.18{\sim}0.44%$, Ca: $0.59{\sim}1.26%$, Mg: $0.21{\sim}0.46%$, Zn: $23.65{\sim}90.30\;mg/kg$, Cu: $0.99{\sim}4.62\;mg/kg$ in lily; and T-N: $0.75{\sim}1.62%$, P: $0.17{\sim}0.30%$, K: $1.60{\sim}2.91%$, Ca: $0.64{\sim}0.94%$, Zn: $24.57{\sim}48.31\;mg/kg$, Cu: $3.10{\sim}9.08\;mg/kg$ in rose. The amount of nutrients uptake per plant was high in order of: K > T-N > Ca > Mg in lily; and T-N > K > Ca > P > Mg in rose.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.196-202
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• 2005

This research was conducted to determine the amount of water absorbed by a polyacrylamide hydrogel such as Stocksorb C (STSB), effect of salts on inhibition in hydration of STSB, and the hydrogel effects on changes of nutrient concentration in external solution. Absorption of deionized water by STSB reached a maximum of 180 $mL{\cdot}g^{-1}$. Monovalent soluble salts such as $KH_2PO_4,\;KNO_3$, and $(NH_4)_2SO_4$ reduced absorption of the hydrogel, but the degrees of inhibition in absorption were similar in three kinds of salts. Twenty milliequivalents per liter of $Ca_{2+}\;or\;Mg_{2+}$ reduced water absorption of STSB to $14\%$ compared to those of deionized water. Solution absorption was consistently lower in the presence of divalent cations than in the presence of the monovalent cations. But the absorption was unaffected by the uncharged salt such as urea in all concentrations tested. The final $K^+\;and\;NH_4^+-N$ concentrations of the solution remaining after absorption by STSB was higher than those of the initial solution. The soaking of STSB to full strength of Hoagland solution resulted in increase of $NO_3^--N,\;H_2PO_4^-\;and\;SO_4^{2-}$ concentrations in external solution compared to initial solution, reaching 5,300, 250 and 1,500 $mL{\cdot}g^{-1}$, respectively, at 24 hrs after soaking.

• Journal of Environmental Science International
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• v.15 no.6
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• pp.571-577
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• 2006

This study make a comparison between the phosphorus removal performance of FNR(Ferrous Nutrient Removal) process and A/O process by the laboratory experiments. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. Iron precipitation reactor on the electrochemical behaviors of phosphorus in the iron bed. The phosphorus removal in FNR process was more than A/O process. Iron salts produced by iron electrolysis might help to remove COD and nitrogen. And the demanded longer SRT is the more removes the removes COD, nitrogen, and phosphorus. Also, FNR process of sludge quantity more reduce than A/O process to input cohesive agents.

• Journal of Environmental Health Sciences
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• v.17 no.2
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• pp.35-40
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• 1991

This study was performed to investigate the contamination degree of effluent from the sewage purification system and septic tank. The 711 samples, were collected from the large size tank located in Seoul from Mar. to June 1991. The results were as follows 1. The pH values of effluent were largely neutral of 6.96 in sewage and 7.43 in septic tank. 2. The average concentration of BOD was 48.18 mg/l in sewage and 127.0 rng/l in septic tank. 3. The average concentration of SS was 40.8mg/l in sewage and 90.5rng/l in septic tank. 4. In the analysis of nutrient salts, the average concentration of NH$_{3}$-N was 31.62mg/l in sewage and 88.79 mg/l in septic tank. 5. In the analysis of correlation among items, BOD, SS, NH$_{3}$-N and PO$_{4}$-P were higly correlated beween items. 6. As a results of above analysis, it is considered as desirable evaluation method of effluent not through the only item but through the integrated items.