• Journal of The Korean Society of Grassland and Forage Science
• /
• v.22 no.2
• /
• pp.123-130
• /
• 2002

A field experiment was carried out to determine the effect of application level of animal manure on the nitrate nitrogen concentration, sugar content and animal intake of forage sorghum $\times$ sudangrass hybrid (Sorghum bicolor (L.) Moench, cv. Pionee. 988) in 1995. The application amount of animal manure were 50, 100 and 150MT in cattle manure, 20, 40 and 80MT in swine manure, and 10, 20 and 40MT/ha in poultry manure. Non-application plot(control) was involved. The nitrate nitrogen concentration was increased with increasing of application level of animal manure(P<0.05). Average nitrate nitrogen concentration was 397, 512, and 609mg/kg at low, medium and high application level of animal manure. The nitrate nitrogen concentration by plant height was 438mg/kg at 50~60m of plant height, 454mg at 100~120cm, and 418mg at 200~220cm. The nitrate nitrogen concentration of stems was 376mg, and significantly higher than that(135mg) of leaves(P<0.05) regardless of animal manure type, and lower parts of stems and leaves were significantly higher than those of upper parts of plants(P<0.05). Average nitrate nitrogen concentration of leaves was 151mg at lower, and 58mg at upper parts of plants, and the concentration of stems was 357mg at lower, 511mg at middle, and 610mg at upper parts of plants. The sugar contents of sorghum $\times$ sudangrass hybrid was decreased with increasing of application level of animal manure(P<0.05). Average sugar content was 4.9, 4.4, and 4.3。 at low, medium and high application level of animal manure. The sugar content by plant height was 3.9。 at 50~60 and 100~120cm of plant height, and 6.1。 at 200~220cm of plant height. Animal intake of sorghum $\times$ sudangrass hybrid was decreased greatly with increasing of application level of animal manure. Average intake was 73.9, 55.7, and 52.3% at low, medium and high application level of animal manure. The intake by animal manure type was 73.7% in cattle, 59.7% in swine and 62.5% in poultry manure.

• Analytical Science and Technology
• /
• v.35 no.2
• /
• pp.41-52
• /
• 2022

The leaching of nitrate from soil increases the concentration of elements, such as nitrogen, phosphorus, and potassium, in water, causing eutrophication. In this study, the feasibility of using clinoptilolite as an ion-exchange material to reduce nitrate leaching in soil was investigated. Soil samples were collected from three soil depths (0 - 30, 30 - 90, and 90 - 120 cm), and their sorption capacity was determined using batch experiments. The effects of contact time, initial concentration, adsorbent dosage, pH, and temperature on the removal of NO₃^- were investigated. The results showed that an initial concentration of 25 mg L^-1, a contact time of 120 min, an adsorbent dosage of 5.0 g/100 mL, a pH of 3, and a temperature of 30 ℃ are favorable conditions. The kinetic results corresponded well with a pseudo-second-order rate equation. Intra-particle diffusion also played a significant role in the initial stage of the adsorption process. Thermodynamic studies revealed that the adsorption process is spontaneous, random, and endothermic. The results suggest that a modification of clinoptilolite effectively reduces the leaching of nitrate in soil.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.9
• /
• pp.654-659
• /
• 2013

This study was conducted to identify an optimal ratio of carbon to nitrogen (C/N ratio) for denitrification of nitrate using molasses as an external carbon source. A series of batch and column tests was conducted using an indigenous bacterium Pseudomonas sp. KY1 isolated from a nitrate-contaminated soil. For the initial nitrate-nitrogen concentration of 100 mg-N/L, batch test results indicated that C/N ratio of 3/1 was the optimal ratio with a relatively high pseudo-first-order reaction constant of $0.0263hr^{-1}$. At C/N ratio of 3/1, more than 80% of nitrate-nitrogen concentration of 100 mg-N/L was removed in 100 hrs. Results of column tests with a flow velocity of 0.3 mL/min also indicated that the C/N ratio of 3/1 was optimal for denitrification with minimizing remaining molasses concentrations. After 172 hrs of column operation (35 pore volumes) with an influent nitrate-nitrogen concentration of 100 mg-N/L, the effluent met the drinking water standard (i.e., 10 mg $NO_3$-N/L).

• Journal of Animal Science and Technology
• /
• v.47 no.3
• /
• pp.481-490
• /
• 2005

Nitrate contamination in water system is a critical environmental problem caused by excessive application of chemical fertilizer and concentration of livestock. In order to prevent further contamination, therefore, it is necessary to understand the origin of nitrate in nitrogen loading sources and manage the very source of contamination. The objective of this study was to examine the nitrate contamination sources in different agricultural system by using nitrogen isotope ratios. Groundwater and runoff water samples were collected on a monthly basis from February 2003 to November 2003 and analyzed for nitrogen isotopes. The nitrate concentrations of groundwater in livestock fanning area were higher than those in conventional and organic fanning area and exceeded the national drinking water standard of 10mg N/ l. The ${\delta}^{15}N$ranges of chemical fertilizer and animal manure were - 3.7${\sim}$+2.3$\textperthousand$ and +12.5${\sim}$26.7$\textperthousand$, respectively. The higher ${\delta}^{15}N$ of animal manure than those of chemical fertilizer reflected isotope fractionation and volatilization of '''N. The different agricultural systems and corresponding average nitrate concentrations and ${\delta}^{15}N$ values were: conventional farming, 5.47mg/e, 8.3$\textperthousand$; organic fanning, 5.88mg/e, 10.1$\textperthousand$; crop-livestock farming, 12.5mg/e, 17.7%0. These data indicated that whether conventional or organic agriculture effected groundwater and runoff water quality. In conclusions, relationship between nitrate concentrations and ${\delta}^{15}N$ value could be used to make a distinction between nitrate derived from chemical fertilizer and from animal manure. Additional investigation is required to monitor long-term impact on water quality in accordance with agricultural systems.

• Korean Chemical Engineering Research
• /
• v.45 no.2
• /
• pp.190-196
• /
• 2007

This study examined the nitrate removal efficiency which uses an electrowinning, and also analyzed the nitrate removal efficiency under a variety of operating conditions such as nitrate concentrations, pH, current densities, electrodes, reducing agents in order to determine optimal conditions. In addition, the multi-step electro-chemical process test has been also analyzed. During the electrowinning, the identical Zn-Zn and Pt-Ti electrodes in the insoluble oxidation electrode(Pt) has shown the highest nitrate removal efficiency in the 100 mg $NO_3^{-}$ -N/L concentration. In the concentration of 150 mg $NO_3^{-}$ -N/L, the efficiency of the Zn-Zn electrode were 70~85%, and that of Pt-Ti electrode were 40~50% without any change of pH. In the high concentration of 500 and 1,000 mg $NO_3^{-}$ -N/L, the higher the concentration, the more decrease of its nitrate removal efficiency decreased. However, the energy consumed for nitrogen removal increased when the nitrate concentration was high. As a result of the multi-step electro-chemical process test, We chose the Test 4. Because the first, most of the zinc consumed from 1 step was recovered from over the 2 step. The second, amount of consumption anode decreased with insoluble anode Pt from over the 2 step. And the third, Zn cathode increased the possibility of reusing Zn deposited. In view of the results so far achieved, the multi-step electro-chemical process would be applied to treat nitrogen involved in metal finishing wastewater.

• Korean Journal of Veterinary Service
• /
• v.22 no.4
• /
• pp.357-361
• /
• 1999

The most harmful nitrogenous compounds in fish-breeding place using are ammonia and nitrate. Excessively high total nitrogen concentration is the signal of unbalance for breeding fishes in seawater and may result overfeeding or overstocking without seawater treatment system. The failure of elimination for the organic ingredients or nitrogen compounds can also cause the consequence of inadequate oxygen concentration in seawater, either. The study shows the effect of biofilter and W disinfector of seawater in the fish- breeding place. In the results, these tools had ammonia, nitrite, nitrate and decreased 71.8%, 27.6% and 1%, respectively, and the total number of microorganisms decreased up to 81.9%.

• Journal of the Korean Society of Safety
• /
• v.5 no.2
• /
• pp.40-49
• /
• 1990

For the determination of polluant NOx in ambient air, nitrate ion-selective electrode(ISE) was made. To comparison of NOx in each method, the nitrate-ISE, NEBA, Orion electrode were used to determinee NOx in ambient air. In this work, the concentration of NOx in ambient air was average 0.06ppm. The results were good agreement with those obtained by each method within a relative error of 3％, Absorbing efficiency of nitrogen oxides in ambient air was good for Alkali solution. The determination of nitrogen oxides in ambient air using the Aliquat 336N-PVC membrane electrode was one of the useful method. The best characteristics of the Aliquat 336N-PVC me,mbrane electrode were obtained with the ion-exchanger concentration level of 6.5-9.1 percent by weight. The optimal membrane composition, was 9.09wt.％ of ion-exchanger, 30.95wt.％ of PVC, 60.6wt.％ of plasticizer (DBP), and 0.5mm of thickness. Under the above condition, the electrode approached the Nernstian slope most closely, and the linear response ranges produced the best results.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.553-556
• /
• 2000

Possibility of biological nitrogen treatment was tested in wastewaters with low C/N ratio. Chlorella kessleri was inoculated at $10^6\;cell/mL$ of initial density in two different artificial wastewaters: one that contained glucose for organic carbon source and the other without carbon source. Nitrate could be successfully reduced below 10 mg $NO_3/mL$ from initial nitrate concentration of 560 mg $NO_3/mL$ in 10 days even in the wastewater without carbon source, This 98% removal of nitrate without extra organic carbon source lights up the future of biological wastewater treatment, where the insufficient ability of nitrogen removal is a major problem.

• Journal of Plant Biology
• /
• v.29 no.3
• /
• pp.145-156
• /
• 1986

The excretion of ammonia and glutamine synthetase activities were measured in aposymbiotic Paramecium and symbiotic Paramecium. The uptake of nitrate and ammonia, and specific enzyme activities of nitrate reductase, glutamate dehydrogenase and glutamine synthetase were investigated in symbiotic Chlorella from Paramecium bursaria and Chlorella ellipsoidea. The ammonia concentration in the culture media of aposymbiotic Paramecium was increased according to the growth of the Paramecium but it was not changed in symbiotic Paramecium. Nitrate, the major nitrogen source, was taken up at a rate of 0.635 nmol/ 106 Chlorella/hr in Chlorella ellipsoidea. Most of ammonia was assimilated to glutamine by glutamine synthetase, of which acitivty was 1,467 $\mu$mol/mg protein/min in Chlorella elliposidea. Contrary to Chlorella ellipsoidea, ammonia and glutamine transported from the Paramecium were the nitrogen source of symbiotic Chlorella and ammonia was taken up at a rate of 3.854 nmo./106 Chlorella/hr into synmbiotic Chlorella. Most of ammonia were assimilated to glutamate by glutamate dehydrogenase in symbiotic Chlorella. The glutamate dehydrogenase (GDH/NADH) activity was 0.851 $\mu$mol/mg protein/min.

• Journal of Soil and Groundwater Environment
• /
• v.27 no.3
• /
• pp.1-10
• /
• 2022

Most wells developed in Jeju island before the enactment of the Groundwater Management Ordinance in 2002 are vulnerable to aquifer contamination due to inflow of upper groundwater having the high concentration of nitrate nitrogen, likely due to incomplete grouting in upper section of the wells. Although these wells require entire reinstallation, it is often necessary to rehabilitate the existing wells due to various constraints. Therefore, to identified the inflow section of contaminants, the thermal level sensor (TLS) technique was firstly applied for three wells, which enables to monitor temperature variations in every 50 cm depth. Then, the grouting material was injected to the upper section to prevent the inflow of upper contaminated groundwater into the entire aquifer. By applying TLS technique, it was found that the temperature deviations in the upper groundwater inflow section decreased sharply. Moreover, both the change in the concentration of nitrate nitrogen in the rainy/dry seasons and the average concentrations were found to decrease rapidly after grouting material injection. Consequently, the application of TLS proposed in the study turned out to be appropriate to prevent aquifer contamination.