• The Korean Journal of Mycology
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• v.28 no.2
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• pp.93-96
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• 2000

To investigate the effect of inorganic nutrient supplement in oyster mushroom (Pleurotus ostreatus), we have conducted some study on cultural and growth characteristics of fruitbody formation and chemical composition of media and fruitbody. When supplemented with slow releasing fertilizer, contamination rate was not different from non-supplemented medium, days for incubation time and first pinhead were faster than non supplemented medium. And fruitbody yield and biological efficiency were increased $10{\sim}28%,\;7{\sim}20%$ respectively, but biological efficiency was decreased when increased supplement ratio. The chemical compositions (total carbon, total nitrogen, ammonia nitrogen, nitrate nitrogen, potassium and phosphate) of slow releasing fertilizer supple mented medium and fruitbody were compared with non-supplemented.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.237-243
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• 2011

As the effluent quality standard of the municipal wastewater treatment plant (MWTP) has been strengthened, the treatment of the recycle water containing high concentration of ammonium nitrogen has been considered as one of retrofit methods for upgrading the exising MWTPs. In this study, nitritation, economic nitrogen removal process, was induced by laboratory-scale reactor at the $35^{\circ}C$, $20^{\circ}C$, and $10^{\circ}C$ temperature conditions using anaerobic digester supernatant. The stable nitritation was achieved over $20^{\circ}C$, but nitrification was induced at $10^{\circ}C$. It means that the nitritation was affected by SRT and temperature. SRT, demanded for nitritation, is changed according to the temperature. Therefore, it is considered that SRT and temperature are important factors in nitritation. Also, it is approved that inducing the ammonium nitrogen removal and the nitritation are more beneficial over $20^{\circ}C$. The conclusion of this study can be used for the important basic reference when nitritation process is applied for MWTPs.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.62-67
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• 2016

In this study, a pellet-type adsorbent was prepared by using the water-treatment sludge as a raw material, and its physical and chemical properties were analyzed through $N_2$-adsorption, XRD, XRF, and $NH_3$-TPD measurements. Adsorption performance for gaseous ammonia and formaldehyde was compared between the pellet-type adsorbents prepared from water-treatment sludge and the impregnated activated carbon. Although the surface area and pore volume of the pellet-type adsorbent produced from water-treatment sludge were much smaller than those of the impregnated activated carbon, the pellet-type adsorbent produced from water-treatment sludge could adsorb ammonia gas even more than that of using the impregnated activated carbon. The pellet-type adsorbent prepared from water-treatment sludge showed a superior adsorption capacity for ammonia which can be explained by chemical adsorption ascribed to the higher amount of acid sites on the pellet-type adsorbent prepared from water-treatment sludge. In the case of formaldehyde adsorption, the impregnated activated carbon was far superior to the adsorbent made from the water-treatment sludge, which can be attributed to the increased surface area of the impregnated activated carbon.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.329-338
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• 2009

Emission of ammonia to the atmosphere are considered a threat to the environment. The application of livestock manure and compost contributes significantly to the emission of ammonia from agriculture. The reduction in NH3 losses from field-applied manure and compost would be a good strategy to reduce national $NH_3$ emission. In this study, various application techniques of liquid manure and compost were compared to evaluate their potential for reducing $NH_3$ emission. In compost application, the reductions in $NH_3$ emission were 70 and 15% for immediately rotary after application (IRA) and rotary at 3-day after application (RA-3d) in comparison with surface application (SA). Total ammonia emissions for 13 days, expressed as % ammonia-N applied in compost, were 42, 35.7, and 12.7% for SA, RA-3d, and IRA treatments, respectively. Mean reductions in NH3 emission from application of liquid pig manure were 26 and 50% for rotary harrow after surface broadcast application in spring and fall, respectively, in comparison with surface broadcast application. Ammonia emission rate was decreased with increasing water content in soil due to dilution effect, but this reduction only was temporary up to 12 hours after application and cumulative $NH_3$ emission was increased with increasing water content in soil. However, the delay would be beneficial because it allows time for rotary hallow of the applied liquid pig manure. Therefor, ammonia emission can be reduced by immediately incorporation of liquid manure and compost after surface application.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.268-273
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• 1998

Changes of chemical component and losses of chemical fertilizer by infiltration water from 0.5ha of paddy field in Chinan area of Chonbuk province during the rice cultivation were investigated. The infiltration water samples were collected in a ceramic porous cup which was a buried at the 30, 50, 70, 90㎝ of soil depth. pH of infiltration water ranged $6.64{\sim}7.90$ and EC showed $324{\sim}647{\mu}$S/cm. The content of total-N, $NH_4-N$ and $NO_3-N$ were $0.58{\sim}14.59$, $0.05{\sim}4.25$, and $0.15{\sim}7.71mg/L$ respectively. The content of total-P and ortho-P were $0.009{\sim}0.077mg/L$ and $0{\sim}0.029mg/L$ The content of $Ca^{++}$, $Mg^{++}$, $Na^{+}$ and $K^{+}$ showed $0.88{\sim}4.78$, $0.22{\sim}1.04$, $0.17{\sim}0.98$, and $0.84{\sim}3.19㎎/L$. These all at the first transplanting are higher than that of other periods. The content of $SO_4^{2-}$ showed $3.92{\sim}18.72mg/L$ and decreased with a soil depth. However $Cl^-$ of infiltration water ranged $9.03{\sim}19.97mg/L$ and no difference with a soil depth. When infiltrated $2,416.5m^{3}$ of an infiltration water from 0.5ha of paddy field during the rice cultivation, losses of chemical components were 20.34㎏/㏊ of total-N, 3.54㎏/㏊ of $NH_4-N$, 10.44㎏/㏊ of $NO_3-N$, 0.16㎏/㏊ of total-P and 0.028㎏/㏊ of ortho-P. Also $Ca^{++}$, $Mg^{++}$, $Na^+$, $K^+$, $SO_4^{2-}$ and $Cl^-$ were lost 10.24, 2.84, 2.84, 7.22, 50.04 and 62.20㎏/㏊ respectively. There were lost by infiltration water 9.35% of nitrogen, 0.59% of phosphorous and 22.79% of potassium in applied chemical fertilizer.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.1-6
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• 2022

Urea is one of the most common nitrogen fertilizer, but nitrogen use efficiency by crop is low because of rapid hydrolysis of urea and loss of nitrogen in environments. Therefore, it is important to control the nitrogen release from nitrogen fertilizers. In this study, pyroligneous acid (PA) was used as a mean to inhibit urease in soil and prevent excessive nitrogen release from urea. Active ingredient in PA (AI) inhibited ammonification of urea in soil by reducing extracted ammonium nitrogen at 79.7% compared to the soil without PA. In order to evaluate the effect of PA on fertilization efficiency of urea, Chinese cabbage (Brassica campestris var. Pekinensis) was cultivated in soil treated with urea and PA both in pot and field. For PA treatment, half amount of urea was used compared to the amount of urea conventionally applied to Chinese cabbage. The PA treatment with half amount of urea resulted in similar Chinese cabbage biomass to the conventional urea application. Nitrogen concentration in Chinese cabbage was less in PA treatment indicating that Chinse cabbage effectively used nitrogen. Consequently, fertilization of urea with PA will reduce amount of fertilizer and frequency of application.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.356-362
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• 1995

This experiment was carried out to investigate the effects on the seasonal population change of microflora of long-term application of organic matters in Fluvio-Alluvial plain of Jeonbug series. As organic matters, rice straw and compost of 5 and 10ton/ha, which were applied with the different nitrogen fertilizer level of 0, 150kg/ha into the soil 15cm deep, respectively. A number of total aerobic bacteria were gradually increased from just after water-logging before rice transplanting to pancle formations stage, afterthat decreased at harvest. The other side, a number of actinomycetes, fungi and cellulose-decomposers were slightly fluctuated until panicle formation stage and increased at havesting stage. In general, microorganism numbers were higher in organic matter with long-term nitrogen fertilizer applied plot, while cellulose-decomposers were higher in only organic matter applied plot. The microorganisms of ammonia-oxidizing, nitrate-reducing and nitrite-oxidizing, and denitrifying bacteria showed the maximum number at harvest stage, at panicle formation stage and at early tillering stage, respectively, while that of ammonifying bacteria were variable if nitrogen fertilizer applied or not at the respective periods in nitrogen cycle under water-logging. These bacteria were numerous in the organic matter plots combined with nitrogen fertilizer, especially, denitrifying bacteria in rice straw, others no difference.

• Journal of Aquaculture
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• v.16 no.1
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• pp.15-23
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• 2003

We have investigated water quality of the coastal saline groundwaters utilized for fish farms in Jeju Island. The water quality investigation included the spatial observations for 75 fish farms during March-May, 1994 and the hi-monthly observations for both coastal saline groundwaters and seawaters at four fish farms from August 1994 to December 1995. Water temperature of the saline groundwaters ranged from 16 to 18$^{\circ}C$ over the study period. Salinity of the saline groundwaters varied between 20.60 ppt and 34.02 ppt, slightly lower than that of the coastal seawaters(26.47~34.53 ppt). This salinity variation must be associated with local precipitation conditions in Jeju Island. The oxygen saturation for most saline groundwater samples was lower than 80%, ranging from 24.7 to 89.8%. The COD and pH values for the saline groundwaters were similar to those for the coastal seawaters. The concentrations of DIP for the saline groundwaters varied between 0.021 mg/L and 0.121 mg/ L, and seasonal variation of DIP in the saline groundwater ranged from 0.014 to 0.077 mg/L, which were higher than that of the coastal seawaters(0.000~0.015 mg/L). Nitrate in the saline groundwaters accounted for more than 90% of the DIM. The maximum concentrations of ammonia, nitrite, nitrate and DIN in the saline groundwaters were 0.085, 0.012, 2.294 and 2.309 mg/L, respectively. These concentrations of the saline groundwaters were considerably lower than those affected culture organisms. Overall, the saline groundwaters utilized for fish farms in Jeju Island appear to maintain good waterquality for fish farms.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.20-26
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• 2006

This study investigated on the conversion of nitrogen component in ammonia gas to control fuel-NOx. Control conditions were found to suppress the production of NOx in the catalytic combustion of the gasified fuels. Also, the results would provide the basis of the theoretical study on fuel-NOx generation mechanism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.743-746
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• 2007

본 연구에서는 LCD, 이미지 센서 등의 개별 소자인 비정질 실리콘 박막 트랜지스터에서 게이트 유전층 및 절연층으로 사용되는 비정질 질화 실리콘 박막을 사일렌$(SiH_4)$ 및 암모니아가스를 사용해서 PECVD(Plasma Enhanced Chemical Vapor Deposition) 진공 증착장비로 최적의 비정질질화실리콘 박막 증착 조건을 확립한다. 먼저 반응실의 진공도, rf 전력 , $SiH_4$ 및 질소 그리고 암모니아가스의 flow rate를 변화시키면서 형성된 박막의 특성을 조사한다. 계속해서 다른 변수를 고정시킨 상태에서 rf 전력을 변화시키고 다음에는 반응실의 진공도 등을 변화시켜 최적의 증착조건을 확립한다. 이렇게 확립된 증착조건을 사용하여 비정질질화실리콘박막을 제작하여 특성을 측정한결과 우수한 성능을 나타냈음을 확인하였다.