• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.93-99
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• 2001

This study aims at finding out pertinent reaction conditions for treating high concentration ammonia contained in N-chemical factory wastewater with decompressed ammonia stripping method that was designed. And it also tries to investigate adsorption capability of removed ammonia to soil. The results from experiments are as follows ; 1. The removal rate of N $H_3$-N of synthetic wastewater was under 85% at pH 10 with decompressed ammonia stripping method. The reaction time in pressure 360 mmHg at pH 11 and 12 was shorter than in 460 mmHg, and the removal rate of N $H_3$-N with decompressed ammonia stripping method at 9$0^{\circ}C$ was 11~15% higher than air stripping 2. The optimum conditions for decompressed ammonia stripping with synthetic sample were shown as pH 12, temperature 9$0^{\circ}C$, internal reaction pressure 460 mmHg and reaction time 50 minutes. These conditions were applied to treat the wastewater containing organic-N 290.5mg/$\ell$, N $H_3$-N 168.9mg/$\ell$, N $O_2$-N 23.2mg/$\ell$, N $O_3$-N 252.4mg/$\ell$, T-N 735mg/$\ell$. Organic-N turned out to be removed 60%, the removal rate of N $H_3$-N IS 94%, T-N is 50%. But N $O_2$-N and N $O_3$-N were increased with 7.8% and 14.9% respectively. 3. The CO $D_{Sr}$ removal rate in decompressed ammonia stripping reaction was 42% and S $O_4$$^{2-}$ was removed 8.2%. It was turned out caused with higher pH and thermolysis. 4. In soil adsorption of ammonia desorbed from the decompressed stripping process of wastewater, the recovery rate was 76% in wet soil.

• Korean Journal of Environmental Biology
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• v.17 no.1
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• pp.117-124
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• 1999

Nutrients removal by water hyacinth, Eichhornia crassipes (Mart.) Solms from nutrient enriched waters and swinery wastewater were evaluated. The contents of nitrogen and phosphorus of dried water hyacinth increased from 1.4 to 3.3% and 0.21 to 0.80% when water hyacinth available N and P in the culture medium were increased from 0.7 to 5.0 mgN/1 and 0.06 o 1.5 mgP/l. respectively. Maximum N and P contents were found to be 4.1 and 0.90%, respectively. The significant relationship was observed between the standing crop of water hyacinth and the biomass yield per unit area and time. Biomass yield increased gradually until standing crop reached 15 kg wet wt./m$^2$, and then rapidly decreased. The high biomass yield of up to 0.5 kg/m$^2$/day was obtained in the range of 7 to 20 kg/m$^2$of standing crop. The potential removal rates of N and P by the water hyacinth during summer were found to be 2,250 to 2,710 mgN/m$^2$/day and 570 to 595 mgP/m$^2$/day, respectively, when 15 kg/m$^2$in standing crop and nutrient concentrations of culture medium were ranged from 1.24 to 6.2 mgP/1 and 3.2 to 32.5 mgN/1, respectively, Inorganic N and P concentrations of swinery wastewater were in the range of 82 to 121 mgN/1 and 22 to 79 mgP/1, respectively. Nitrogen and P removal rates of water hyacinth cultured in swinery wastewater were found to be in the ranges of 2,000 to 2,600 mgN/m$^2$/day and 157 to 254 mgP/m$^2$/day, respectively, at 10 times diluted water of swinery wastewater.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.78-88
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• 1985

Nitrogen fertilizer effectiveness on rice production was studied to evaluate the different forms and sources. Seven kind of nitrogen fertilizers were applied in two levels, 15 and 30 kg per 10a on Jinjubyeo (Japonica type) in silt loam paddy soil of pot cultivation. The results were summerized as follows; 1. pH in soils was decreased with enhancement of ammonium sulfate application in $NH_4-N$, but it was increased with times after nitric-acid application and PH change in soil was not remarkable when $NO_3-N$ with accessory component was applied. 2. $NH_4-N$ contents in soil were the lowest at 2 weeks after application in N 15kg/10a regardless of different sources of nitrogen fertilizer. $NO_3-N$, in N 30kg/10a, was decreased continuously until 4 weeks, while $NH_4-N$, Urea-N were at minimum during 2-3 weeks. 3. Growth of culm length and straw weight applied with AN (Ammonium Nitrate), AS (Ammonium Sulfate) and urea were superior to the form of nitrate. While NA (Nitric Acid), PN (Potassium Nitrate) and CN (Calcium Nitrate) plot of the $NO_3-N$ was the dominant fertilizers for root elongation. 4. Brown rice yields were increased dominantly by $NH_4-N$ application such as AS or AP than $NO_3-N$ pot. But the yields in case of $NO_3-N$ application CN, PN and NA were decreased. 5. N, P, Mg and Mn content of straw ranked the effectiveness of nitrogen forms as $NH_4-N$, Urea-N and $NH_4-N+NO_3-N$, while K, Ca and $SiO_2$ content of straw in $NO_3-N$ fertilizer plot were high while N, P, Mg, Mn, Fe and Mg were low. 6. Increament of nitrogen absorption in straw was stimulated by enhancement of phosphorous absorption and the growth and yield of rice plant were increased. Absorption of N, P, Ca and Mg was decreased by CN application. Absorption of N, P and Mg also was decreased by $NO_3-N$ application and N, P, Mg or Ca content were seemed to simulated the growth and yield of rice plant. 7. $SiO_2$, Zn and Fe contents of the root at harvest stage were higher than those of the straw. N, P, Mg, Mn, Zn and Fe contents were high in $NH_4-N$ and Urea treatment. While K, ca and $SiO_2$ contents, however, were high in $NO_3-N$ treatment.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.439-443
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• 2006

Soil properties of Quercus variabilis forest on Youngha valley at Mt. Worak National Park were studied as a part of Korea National Long-Term Ecological Research. Soil sampling was carried out along the 50 cm soil depth with 10cm intervals at every quarter from May 2005 through July 2006. Fresh soil was used for $NH_4{^+}-N,\;NO_3{^-}-N$, and soil water content determination. Remaining soils were air dried in the shade, and then used for determination of soil pH, T-N, T-P and exchangeable cation. Average soil organic matter in top soil was $8.5{\pm}1.2%$ and decreased with soil depth. Bulk density of top soil was $0.82{\pm}0.07g/cm^3 $and increased with soil depth. Soil organic matter and bulk density showed a negative linear correlation ($R^2=0.8464$). Soil pH in top soil and subsoil was similar. T-N, $NH_4{^+}-N,\;NO_3{^-}-N$ and T-P in top soil were $1.9{\pm}0.5mg/g,\;7.3{\pm}1.0mg/kg,\;2.0{\pm}0.4mg/kg\;and\;0.2{\pm}0.05mg/g$, respectively. $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in top soil were $84.6{\pm}24.4,\;408.8{\pm}137.8\;and\;93.4{\pm}23.0mg/kg$, respectively. They decreased with soil depth. Amounts of organic matter, T-N, $NH_4{^+}-N,\;NO_3{^-}-N$, T-P, $K^+,\;Ca^{2+}\;and\;Mg^{2+}$ in 50 cm soil depth were 250.9, 3.45, 0.025, 0.003, 0.639, 0.181, 0.845 and 0.302 ton $ha^{-1}\;50cm-depth^{-1}$, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.31-39
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• 2017

From July to August 2013, liquid fertilizers produced at 180 liquid manure public resource centers and liquid fertilizer distribution centers were collected. The maturity of liquid fertilizers was measured using the mechanical maturity measurement device. The nutrient contents (nitrogen, phosphorus, and potassium), physicochemical properties, and heavy metal content of 46 liquid fertilizers were investigated in this study. We used a matured liquid fertilizer with a total number of 46, with number of 7 for Gyeonggi-do, 3 for Chungcheongbuk-do, 2 for Chungcheongnam-do, 13 for Jeollabuk-do, 5 for Jeollanam-do, 3 for Gyeongsangbuk-do, 11 for Gyeongsangnam-do, 1 for Daejeon, and 1 for Jeju-do. The physicochemical properties were as follows: pH 8.0, EC 11.6 mS/cm, SS 5,188 mg/L, TKN 847mg/L, ${{NH_4}^+}-N$ 317 mg/L, ${{NO_3}^-}-N$ 170 mg/L, Org-N 360 mg/L, TP 193 mg/L, and TK 2,557 mg/L. The total amount of NPK was 3,596 mg/L. The total amount of N-P-K was as follows: a number of 2 at 1,000-2,000 mg/L (4%), a number of 17 at 2,000-3,000mg/L (37%), a number of 11 at 3,000-4,000mg/L (24%), and a number of 16 at 4,000mg/L or more (35%). Thus, 41% of the mature liquid fertilizers were below the official standard of commercial fertilizer (livestock manure liquid fertilizer) (0.3% of the total amount of N-P-K). Most of the N-P-K total amount showed non-uniform characteristics of low nitrogen and low phosphoric acid due to the potassium concentration. The average heavy metal content in the matured liquid fertilizer was as follows: As, not detected; Cd, 0.01 mg/kg; Hg, not detected; Pb, 0.02 mg/kg; Cr, 0.14 mg/kg; Cu, 6.89 mg/kg; Ni, 0.44 mg/kg; and Zn, 20.70 mg/kg. Thus, the official standard of commercial fertilizer was satisfied in all categories, indicating a safe level.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.685-690
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• 1998

The wetting behavior and the characteristic of spontaneous infiltration of pure Al and Al-(Si)-Mg alloys on {{{{ { {Al }_{ 2} O}_{3 } }} in vacuum argon and nitrogen atmosphere were investigated to find out the spontaneous in-filtration mechanism. The wetting of molten Al and Al alloys on {{{{ { {Al }_{ 2} O}_{3 } }} was only possible in cacuum at-mosphere but the sponataneous infiltration of molten Al-(Si)-Mg alloys was successfully made on {{{{ { {Al }_{ 2} O}_{3 } }} pre-form in nitrogen atmoshpere. The difference of wettability and spontaneous infiltration of molten Al and Al alloys on {{{{ { {Al }_{ 2} O}_{3 } }} were found to be related to formation of the Mg-N compound coated layer on {{{{ { {Al }_{ 2} O}_{3 } }} particles which was believd to increase wettability of molten Al alloys on {{{{ { {Al }_{ 2} O}_{3 }.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.272-276
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• 2005

Food wastewater derived from three-stages methane fermentation system showed high concentrations of sCOD, T-N and $NH_{3}-N$. To treat the organic wastewater, the optimal operating conditions for high efficiency $UV/TiO_{2}$ photocotalytic system have been investigated. In the first process, wastewater was pre-treated with $FeCl_{3}. The optimum pH and concentration for coagulation were 4.0 and 2000 mg/L, respectively. Through this process, 52.6% of $COD_{cr}$ was removed. The second process was $UV/TiO_{2}$ photocatalytic reaction. The optimum conditions for the operation of $UV/TiO_{2}$ photocatalytic system developed in this lab have been studied. In this process, CODcr was removed from 2890 to 184 mg/L and T-N was removed from 2496 to 914 for 24 hours, respectively.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.223-227
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• 2007

This study was carried out to establish the reasonable level of nitrogen (N) fertilization based on soil nitrate nitrogen $(NO_3-N)$ content for cucumber (Cucumis sativus L.) under plastic film house. Cucumber plants were cultivated with standard and free N fertilization in eight soils which had various amount of $NO_3-N$ ranging from 67 to 343 mg/kg. The yield of cucumber was in the range of 1006 to 2369 g/plant depending on the nitrogen supplying capability of soils. The amount of $NO_3-N$ in the soil was negatively correlated with agronomic efficiency (AE) and N use efficiency (NUE). The critical level of soil $NO_3-N$ content for cucumber in N free fertilization was found to be about 260 mg/kg in Cate-Nelson analysis of variance between soil $NO_3-N$ and AE or NUE. Also the same critical soil $NO_3-N$ content was found in the yield and amount of N uptake of cucumber under N free fertilization. A standard N fertilization was required when soil $NO_3-N$ content was below 70 mg/kg. The optimal application rate of N fertilizer for cucumber in the soils containing $NO_3-N$ between 260-70 mg/kg could be recommended by the equation Y=-1.032X+269.2 (Y: N fertilization rate, kg/ha; X : soil $NO_3-N$ content mg/kg).

• Korean Journal of Crystallography
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• v.2 no.1
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• pp.12-16
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• 1991

C18H22N4OS, Mr=342.47, monoclinic, P2₁/c,a=11.802(2), b=31.962(2), c=9.829(2)A, β=100.12(1)˚, V=3694.8A3,F(000)=1472, Z=8, Dx=1.246 Mg m-3, Dm=1.17Mg m-3,λ=0.71073 A, μ=0.15mm-1, T=294 K. final R=0.0856 for 3718 observed reflection (Fo>3σ(Fo)) There are two molecules in an asymmetric unit and a major difference between these molecules is in the C(9)-N(1)-C(6)-C(7) torsion angles [58.8(8)˚and 1(1)˚]. Both molecules have intramolecular N(1)-H(10)'N(3) hydrogen bonds [ 2.613(7) and 2.566(7) A] and assume V-shaped conformation with N(2) atoms at the verices. The two independent molecules are linked by the two N(2)-H(11)'S' hydrogen bonds[3.367(5) A and 3.421(4)A] and the dimergen are held together by van der Waals forces.

• Analytical Science and Technology
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• v.14 no.3
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• pp.238-243
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• 2001

The study was carried out to analysis of the pollutant $COD_{Mn}$, T-N, T-P for water quality proximated to sediment in lake of K river basin. water extracted from sediment showed higher $COD_{Mn}$, T-N, T-P datas than water proximated to sediment. Also, water proximated to sediment and water 5-10cm proximated to sediment showed the following data : $COD_{Mn}$, 1.2~1.9mg/L, T-N, 1.3~6.2mg/L, TP, 0.05~0.26mg/L, respectively. From this results, we have known the fact that the pollution degree of sediment have an effect on the water quality in lake and stream.