• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.2
• /
• pp.139-145
• /
• 1986

In order to study the influence of nitrate reduction to ionic balance in tissue of tobacco plant, differneces in amounts of those cations and anions were determined and these balances were compared with contents of organic acids and activities of nitrate reductase, while they were fertilized with different nitrogen sources ($NO_3-N$, $NH_4-N$, $NO_3+NH_4-N$) in water culture. The results of studies are summerized as follows; 1. Total uptake of inorganic cations was the highest in nitrate-fed plants, whereas that of inorganic anions showed the highest level in the plants grown with the mixture ($NO_3+NH_4$). The amounts of inorganic cations and anions were comparable in two treatments containing $NH_4-N$, but in plants treated with nitrate only had much higher level of inorganic cations than others. 2. Deficiency in the amount of inorganic anions in nitrate-fed plants was balanced with organic acids, dominantly with malic acid among them. But another two $NH_4-N$ fed plant sustained equilibrium between inorganic cations and anions. 3. Reduction of nitrate was raised in tissues of nitrate-fed plants. By the results of nitrate reduction, cations maintained equilibrium with nitrate ion were let loose. The replacement of inorganic anions with organic anions could be a compensation process for the loss of uptaken nitrate ions which must be reduced to be incorporated into organic N compounds.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.2
• /
• pp.132-138
• /
• 2005

Objective of this research was to evaluate the fate of nitrogen and phosphorous in hydroponic waste solution from the plastic film house cultivation applied to the upland soil by column leaching and field experiment. The pH and EC of leachate were decreased by the reaction with the upland soil in the column leaching experiment. The EC and concentrations of $H^+,\;K^+,\;and\;{NH_4}^+$ of leachate were decreased as the column length (soil depth) was increased. But these were increased as the amounts of the hydroponic waste solution were increased field experiment growing red pepper (Capsicum annum L.) to monitor the nutrients movement using ion exchange resin capsule demonstrated that the nutrient concentration of soil solution was increased in the orders of $PO_4-P. Nitrate concentration of resin capsule inserted into the soil was relatively higher than other nutrients $(NH_4-N\;and\;PO_4-P)$ at the 45 cm of soil depth. The overall results demonstrated that the hydroponic waste solution could be recycled as plant nutrients to enhance fertility of soils. But nitrate leaching was a major factor for safe use of the hydroponic waste solution in soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.561-564
• /
• 2003

강변여과수 개발 예정지역인 함안군 칠서지역의 수질특성을 알아보기 위해 2003년 4월과 2003년 8월 2회에 걸쳐 강변여과수 양수정, 관측정, 주변지역 지하수 및 낙동강 원수 등 총 38개의 물시료를 채수하여 분석하였다. 용존 이온 분석 결과 연구 지역 지하수의 경우는 Ca-HCO$_3$ 유형 또는 Ca-Cl 유형에 속하며, 조사 지점에 따라 충적층 및 암반 지하수의 특징이 확연히 구분되었다. 조사된 지하수의 경우, 질산성질소와 철, 망간의 농도가 다른 성분에 비해 상대적으로 높은 것으로 나타났으며, 그 외의 중금속의 오염은 미미한 것으로 나타난다. 낙동강 원수의 경우 질산성 질소, 철, 망간은 지하수에 비해 낮은 것으로 나타났으나, 조류의 영향으로 매우 높은 pH 값을 보여주었다. 채수된 전체 시료의 분석 결과, 질산성질소(39.1%), 철(13%), 망간(39.1%)이 주로 먹는 물 수질기준을 초과하는 항목으로 나타났다.

• Resources Recycling
• /
• v.4 no.1
• /
• pp.46-51
• /
• 1995

After removal of mercury in the silver oxide batteries with the distillation process, the leaching of valuable metals from the residue was studied. The distilled residue was reacted with the various HNO, concentration, reactlon temperature, readion time and pulp density. It was found that the optimum condition for leachmg was 2N HNO,, 40-60% reaction temperature, 6 hours reaction tlme and 10g/200ml pulp density. More than 99% of silver and zinc were dissolved in this process while less than 50% of iron and nickel were leached

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1612-1614
• /
• 2002

본 논문에서는 엑시머 레이저 조사에 의한 이온 농도의 분포 변화를 알아보기 위해 붕소 이온이 선택적으로 주입된 비정질 실리콘 박막 위에 XeCl (${\lambda}$=308nm) 엑시머 레이저를 조사하여 붕소이온의 수평 확산 현상을 관찰하였다. 도핑 농도의 분포를 알아보기 위해 불산/질산 용액에 의한 고농도 도핑 영역의 습식 식각을 이용하여 약 $10^{18}/cm^3$ 이하의 붕소이온을 가지는 실리콘 박막의 형태를 전자주사 현미경을 이용해서 관찰하였다. 실험 결과, $200mJ/cm^2$의 레이저 에너지가 조사될 경우, 약 100nm의 수평 확산이 일어났음을 확인 할 수 있었다.

• Korean Journal of Soil Science and Fertilizer
• /
• v.38 no.1
• /
• pp.32-37
• /
• 2005

The procedure of soil sampling for on-farm quick test of soil nitrate is very important to improve practical application without weighing or drying soil. To improve application of test strip reflectometer as a quick on-farm analytical procedure for the estimation of soil nitrate concentration, three sampling methods such as gravimetric sampling (GS), particle density sampling (PDS) and bulk density sampling (BDS) for on-farm analytical procedure were investigated with twelve soils of 45 to $281mg\;kg^{-1}$ nitrate nitrogen concentration. The nitrate nitrogen concentrations measured from different soils were compared with two analytical methods, ion electrode method as a standard laboratory analysis (SLA) and test strip reflectometer at three moisture conditions, viz. air dried soil, 20 and 40% of maximum water holding capacity (MWHC). Nitrate nitrogen concentration measured by test strip reflectometer was significantly correlated with that of SLA, and the coefficients of variation (CV) were in the range of 3.5 to 10.9%. These CV values less than 10.9% were thought to be acceptable for the measurement of soil nitrate as an on-farm real time analytical procedure. The nitrate nitrogen concentration by BDS for test strip reflectometer as well as ion electrode method was more similar to that of SLA compared with those by GS and PDS especially in case of moist soils. This result suggests that the BDS is more useful than GS and PDS in case of on-farm analytical procedure of soil nitrate for moist soils. Further the practical measurement by BDS could be improved by substituting the bottle cap with a larger container.

• Resources Recycling
• /
• v.9 no.4
• /
• pp.37-43
• /
• 2000

Leaching of $LiCoO_2$ as a cathodic active materials for recovering Li and Co from spent lithium ion battery was investigated in terms of reaction variables. At the optimum condition determined in the previous work, Li and Co in a $H_2SO_4$ and $HNO_3$ solution were dissolved 70~80% and 40%, respectively. Li and Co were leached over 95% with the addition of a reductant such as $Na_2S_2O_3$ or $H_2O_2$. This behavior is probably due to the reduction of $Co^{3+}$ to $Co^{2+}$. Leaching of $LiCoCo_2$ powder obtained by calcination of an electrode materials from spent batteries was also carried out. Leaching efficiency of Li and Co were over 99% at the optimum condition with $H_2O_2$ addition of 1.7 vol.%. It seems to be due to the activation of $LiCoO_2$ by repeated charging and discharging or an imperfect crystal structure by deintercalation of Li.

• 한국환경농학회:학술대회논문집
• /
• 2009.07a
• /
• pp.350-351
• /
• 2009

• Journal of Marine Life Science
• /
• v.8 no.2
• /
• pp.150-159
• /
• 2023

To determine the toxic effects of the mirror carp, Cyprinus carpio nudus on waterborne nitric acid exposure, they were exposed to waterborne nitric acid at 0, 4, 20, 100, 500, and 2,500 mg NO₃^-/L for 96 h. The semi-lethal concentration (LC₅₀) of the scented fish by 96 hours of acute exposure to nitric acid was 1,433.54 mg NO₃^-/L. The physiological changes of waterborne nitric acid exposure on mirror carp were evaluated through hematologic properties, and RBC count showed a significantly decreased (p < 0.05). The change in the ion control ability of the mirror carp according to exposure to waterborne nitric acid was evaluated through the plasma inorganic component, and calcium and magnesium were significantly decreased (p < 0.05) in the plasma inorganic component. The health and stress status of the mirror carp due to exposure to waterborne nitric acid were evaluated through plasma organic ingredients, and the plasma organic component glucose showed a significantly increase (p < 0.05). Changes in liver damage and enzyme activity due to waterborne nitric acid exposure were evaluated through plasma enzyme components, the enzymatic activities of plasma AST, ALT, and ALP were significantly decreased (p < 0.05) in high levels of waterborne nitric acid exposure. The results of the present study suggest that waterborne nitric acid exposure to C. carpio nudus can toxicly affect survival, hematologic properties, and plasma components.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.6
• /
• pp.2904-2912
• /
• 2011

Water qualities in the decentralized water treatment plants do not frequently satisfy the water standard limit, in particular, fluoride and nitrate are notorious for the poor removal. In this study, an electro-adsorption equipped with carbon nonotube (CNT) electrodes were carried out to effectively remove the nitrate and fluoride in the decentralized water treatment plants. Two types of CNT electrodes, coating and sintering electrodes were applied. Coating electrodes were made based on different kinds of binder and sintering electrodes were made based on different sintering temperature. Removal of fluoride and nitrate when the coated electrodes with organic binder were used for electro-adsorption were 46 and 99.9% respectively, which were better performances than the coated electrodes with inorganic binder were used. On the other hand, removal of fluoride and nitrate when the electrodes sintered at higher temperature ($1,000^{\circ}C$) were 77 and 87% respectively, which were better performances than the electrodes sintered at lower temperature ($850^{\circ}C$). As a consequences, the electro-adsorption equipped with a CNT electrodes could be an potential alternative process for the removal of fluoride and nitrate in a decentralized water treatment plants if proper current density and contact time were applied.