• 한국토양비료학회지
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• 제44권3호
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• pp.387-393
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• 2011

본 연구는 환원증류법을 사용하여 축사, 매립지, 시설재배지 등 높은 수준의 질산태 질소로 오염된 토양의 질산태질소 함량을 정확히 측정하는데 있어서, Devarda's alloy 의 입자 크기가 질산태 질소의 회수율에 미치는 효과와 Devarda's alloy의 처리량과 환원된 질산태 질소의 양과의 상관관계, 고농도의 질산태 질소를 함유한 토양 추출액의 정확한 분석을 위한 적절한 접근방법을 파악하고자 수행되었다. 본 연구에서 시험된 각 Devarda's alloy는 입자 크기의 분포가 서로 달랐으며, 이는 다소 높은 질산태 질소 조건인 1 mg과 2 mg $NO_3$-N에서 서로 다른 질산태 질소 회수율로 반영 되었다. 한편, 고농도의 질산태 질소 조건에서는 모든 Devarda's alloy들이 용액 중 질산태 질소의 함량이 증가할수록 급격히 질산태 질소의 회수율이 감소하는 경향을 보였으나, 시험된 모든 Devarda's alloy들은 예상과 달리, 단위 질량 당 환원된 질산태 질소의 양이 용액중 질산태 질소의 양에 비례하여 감소하는 경향을 보였다. 이상의 연구결과들은 높은 수준의 질산태 질소로 오염된 토양 시료를 안정적으로 분석하기 위해서는 Devarda's alloy의 입자 크기 분포를 감안한 충분한 처리, 그리고 두 수준 이상의 Devarda's alloy를 처리한 후 회수된 질산태 질소량 변화를 살피는 것이 필요하다는 것을 제시한다. 아울러, 본 연구에서 발견된 질산태 질소량의 화학적 비당량성은 앞으로의 연구를 통해 보다 자세히 조사되어야 할 것으로 사료된다.

• 한국대기환경학회지
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• 제14권3호
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• pp.229-236
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• 1998

Visibility is a good indicator of comprehensive alto quality. The prevailing visibility in Seoul is no better than the past although the average concentration of SO2 and TSP (total suspended particulate) has decreased quite significantly in the past decade, owing to the government efforts to reduce the emission. Then, a question arises why visibility has not been improved. In order to answer this question we have investigated which components of air pollutants are most responsible for the visibility degradation in Seoul. Analysis on the visibility vs the aerosol sixte distribution measured by an optical particle counter shows that the particles of the size interval between 0.5mm and 2.5mm are most responsible for the visibility degradation. Among the criteria air Pollutants, NOB concentration is found to be moot responsible, rather than PM10. ton analysis of the particulate collected by a high volume sampler shows that the nitrate component increases more significantly than other ions when visibility becomes very poor. Therefore, we conclude that the major causes of visibility degradation in Seoul are the increase of NOB, nitrates and the particles of the size range between 0.5mm and 2.5mm.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권3호
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• pp.43-51
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• 2020

About 90% of groundwater wells in Jeju Island are reported to be under the threat of contamination by infiltration of the surface pollutants. Most of those wells have improperly grouted annulus which is an empty space between the well and the inner casing. As a remedy to this problem, some of the wells were re-grouted by filling the annulus with cement without lifting an inner casing. In order to evaluate whether this method is appropriate for the geological structure of Jeju Island, two wells (W1 and W2) were selected and this method was applied. The water holding capacity did not decrease while the nitrate levels decreased from 16.8 and 20.2 to 6.8 and 13.8 mg/L in W1 and W2, respectively. The higher nitrate level in W2 is deemed to be influenced by the livestock farms located in the upper area of the well. In addition, transmissivity of the vedose zone was higher in W2 than W1, potentially facilitating the transport of nitrate to the groundwater. The overall result of this study suggests re-grouting of wells for the purpose of protecting water quality of goundwater should take into account geological structure of vadose zone as well as appropriate source control of the contaminants.

• 한국작물학회지
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• 제43권1호
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• pp.23-27
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• 1998

Inhibition of nodule formation and nitrogen fixation by soil nitrogen, primarily nitrate, is well known in legume plants. The present study was undertaken to evaluate the effect of ${NO_3}^-$ on the nodulation, nitrogenase activity, and growth of supernodulating soybean mutant and its wild type. A greenhouse study was conducted to compare two of supernodulating mutants, 'SS2-2' and 'nts 382', with the normal nodulating cultivar 'Sinpaldalkong 2' when grown in a 1-l styroform cup filled with sand, and fertilized with five levels of ${NO_3}^-$ (0, 2, 4, 8, and 12 mM). During the growth period, each plant was supplied two or three times a week with 50 mL of nutrient solution. Supernodulating soybean mutants, SS2-2 and nts 382, showed more nodules and nodule mass, and greater $C_2\;H_2$ activity than the wild type, Sinpaldalkong 2, regardless of the level of exogeneous nitrogen supply. On the other hand, total dry weight of SS2-2 mutant, which was smaller than Sinpaldalkong 2, did not respond to the various ${NO_3}^-$-N levels. This suggested that supernodulating SS2-2 mutant could maintain fairly high total dry weight at the low ${NO_3}^-$-N level, even in the absence of exogeneous ${NO_3}^-$-N in the nutrient solution. From the reduced top growth and high nitrogen fixing ability of supernodulating mutants, it was surmised that supernodulating mutant could potentially protect agricultural environments from pollution through the reduction in nitrogen fertilization as well as maintain fairly high yield with increasing planting density.

• 한국환경농학회지
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• 제14권1호
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• pp.97-108
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• 1995

일본 오끼나와현 궁고도(宮古島)의 지하수에 대해서 질산태질소($NO_3-N$) 농도의 현상을 지역별로 조사하고, 질소안정동위체 자연존재비(${\delta}^{15}N$)의 측정을 병용하여 그 오염원을 추정하였다. 궁고도(宮古島)의 지형, 농업형태, 취락의 존재 등 몇종의 요인을 고려하여, 대표적인 10지점을 선정한후, 매월 1회 지하수를 채취하여, 양이온, 음이온 농도를 측정한 후, 정밀동위체비질량분석계(Finnigan MAT 252)를 이용하여 $NO_3-N$의 ${\delta}^{15}N$ 치(値)를 측정하였다. 질산태질소($NO_3-N$) 농도는 측정 기간 중 평균 $1.4{\sim}11.5mgL^{-1}$의 범위였으며, 월간변동이 큰 것과 적은 것이 있었다. ${\delta}^{15}N$치(値)는 측정기간 중의 평균 +4.3${\sim}$+9.7$%_o$의 범위에 있었으며, 비교적 변동이 적었다. $NO_3-N$ 농도와 ${\delta}^{15}N$치(値)의 분포로부터, 조사 지하수는 Tuga-ga를 포함시켜 4군(群)으로 분류되었다. 각 $NO_3-N$의 기원을 추정하여, 퇴구비 등 축산 폐기물, 분뇨(糞尿) 등 생활하수(生活下水), 화학비료, 토양유기물 등으로부터 유래하는 $NO_3-N$의 복합적 기여에 대하여 고찰하였다. 또한 이 지역에서 사용되어지고 있는 화학비료 중의 질소의 ${\delta}^{15}N$치(値)는 -3.9${\sim}$-1.4$%_o$의 치를 나타냈기 때문에 시비된 비료의 질산화 과정에 있어서 일부가 암모니아로서 휘산되는 것으로 추정되며, 그 결과 지하수 중의 ${\delta}^{15}N$치(値)가 증가되는 것으로 추정하였다.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.350-357
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• 2017

Purpose: In-situ monitoring of water quality is fundamental to most environmental applications. The high cost and long delays of conventional laboratory methods used to determine water quality, including on-site sampling and chemical analysis, have limited their use in efficiently managing water sources while preventing environmental pollution. The objective of this study was to develop an on-site water monitoring system consisting mainly of an Arduino board and a sensor array of multiple ion selective electrodes (ISEs) to measure the concentration of $NO_3$ ions. Methods: The developed system includes a combination of three ISEs, double-junction reference electrode, solution container, sampling system consisting of three pumps and solenoid valves, signal processing circuit, and an Arduino board for data acquisition and system control. Prior to each sample measurement, a two-point normalization method was applied for a sensitivity adjustment followed by an offset adjustment to minimize the potential drift that could occur during continuous measurement and standardize the response of multiple electrodes. To investigate its utility in on-site nitrate monitoring, the prototype was tested in a facility where drinking water was collected from a water supply source. Results: Differences in the electric potentials of the $NO_3$ ISEs between 10 and $100mg{\cdot}L^{-1}$ $NO_3$ concentration levels were nearly constant with negative sensitivities of 58 to 62 mV during the period of sample measurement, which is representative of a stable electrode response. The $NO_3$ concentrations determined by the ISEs were almost comparable to those obtained with standard instruments within 15% relative errors. Conclusions: The use of the developed on-site nitrate monitoring system based on automatic sampling and two-point normalization was feasible for detecting abrupt changes in nitrate concentration at various water supply sites, showing a maximum difference of $4.2mg{\cdot}L^{-1}$ from an actual concentration of $14mg{\cdot}L^{-1}$.

• 미생물학회지
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• 제10권3호
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• pp.97-104
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• 1972

The extent of water pollution was investigated at 4 stations in Kyonggi Bay during the summer seasons in 1970 and 1971. The concentrations of dissolved oxygen, total hardness, ammonia, nitrate, nitrite, phosphate, chemical oxygen demand, salinity, biochemical oxygen demand, coliform bacteria and facel coli were examined together with the measurement of pH and transparency. The relationship between the extent of pollution and the distance from the Inchon Bay also was examined. The concentrations of biochemical oxygen demand, chemical oxygen demand, ammonia, nitrate, nitrite, phosphate, coliform bacteria nad fecal coli were all highest at station 1, and lowest at station 4. Values were somewhat higher at low tide level in general. On the contrary, dissolved oxygen concentration was highest at station 4 and lowest at station 1. The highest and lowest values of biochemical oxygen demand were 10.88 ppm at station 1 and 0.27 ppm at station 4. The chemical oxygen demand concentrations at station 1 and 4 were 1.90 ppm and 0.63 ppm. Ammonia concnetration at station 1 was 0.43 pp, and was nearly 5 times as much as that at station 4. The values were $2.45{\times}10^{-4}$ ppm at station 1, and $6{\times}10^{-4}$ ppm at station 4. Nitrite concnetration at station 1 was $3{\times}10^{-4}$ppm and was the highest, while the lowest was $9.45{\times}10^{-5}$ ppm at station 4. Phosphate value at station 1 too was the highest and was about 4 times as much as that at station 4. Coliform bacteria were most abundant at station 1, and were counted to be 1.$1.7{\times}10^{-5}$cells/ml. At station 4, the number greatly reduced to 8 * 10$^{2}$ cells/ml. The number of fecal coli at station 1 was $2{\times}10^{-4}$ cells/ml. But at station 4, no fecal coli was detected at high tide level. At low tide level, 3 cells/ml were counted at station 4. In all of these, the highest data were obtained at low tide level, while most of the lowest value, at high tide level. Generally, values at statio 1 were 3-5 times as much as those at station 4. Concentration of dissolved oxygen at station 1 was 0.366 mg-atoms/1 and was the lowest. The highest value was 0.420 mg-atoms/1 and was recorded at station 4. The highest at station 4, which certainly were believed to be the result of the dilution by the fresh water of the Han river flowing into the Inchon Bay. As we can see from the data above, the extent of pollution was highest at station 1, the nearest from Inchon harbor, and lowest at station 4, where is the farthest, Station 1 and 2 were proved to be much polluted, but station 3 and 4, not.

• 한국지반환경공학회 논문집
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• 제11권3호
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• pp.5-16
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• 2010

국내 지하수 오염을 감시 관측하기 위하여 1990년대 초부터 2,000개 이상의 지하수수질측정망이 설치 운영중에 있으며, 지하수오염우려가 높은 지점에 설치된 781개소의 1996년부터 2007년까지 연 2회 분석 자료를 활용하여 오염우려지역에서의 지하수 수질 현황과 추세특성을 분석하였다. 건강상 유해물질이 검출된 경우의 평균 농도는 시안, 수은, 페놀, 6가 크롬, 트리클로로에틸렌, 데트라클로로에틸렌, 1.1.1-트리클로로에탄 등에서 생활용 지하수 수질기준을 초과하는 것으로 나타났고, 일반오염물질의 평균 농도는 기준 이하로 나타났으나 이는 상대적으로 비오염지역에 설치된 국가지하수관측정의 수질 보다 농도가 높은 것으로 나타났다. Sen의 방법을 이용하여 토지용도별로 일반오염물질(염소이온농도, 질산성질소, 수소이온농도)과 전기전도도의 추세를 평가한 결과, 도시지역과 공단지역 등에서 수질 악화 비율이 높은 것으로 나타났고, 2000년대 중반에도 수질 악화는 더욱 가속화되는 것으로 평가되었으며, 지역에 따라 수질이 개선되는 지역이 있는 반면 수질악화가 심화되는 등 추세의 편차가 증가되는 것으로 나타났다. 따라서, 계속되는 수질 악화를 방지하기 위해서는 본 연구에서 제시된 수질 악화 추세가 높은 지역에 대해서 보다 세밀한 감시 관측을 수행하고 보다 정밀한 분석을 통하여 개선 대책을 수립, 시행하는 것이 필요된다.

• 한국초지조사료학회지
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• 제22권1호
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• pp.37-44
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• 2002

본 연구는 가축분뇨의 시용수준과 이의 효과를 증진시키기 위한 추가적인 화학비료 시용수준이 사료작물의 생산성과 이에 의한 환경오염에 미치는 영향에 대한 것으로써, lysimeter에서 옥수수에 대한 액상발효우분 시용수준과 추가적인 요소N의 시용수준에 따라 질소의 이용효율과 함께 NO$_3$$^{-}$의 용탈에 의한 환경오염에 미치는 영향을 정확히 규명, 가축분뇨의 자원화는 물론 가축분뇨에 의한 환경오염 방지대책 수립을 하고자 수행하였는데 그 결과는 다음과 같다. 1. 옥수수의 건물수량은 액상발효우분 및 요소 시용수준이 증가함에 따라 비례적으로 증가하였다. 2. 옥수수 중의 전질소 함량은 액상발효우분 및 요소의 시용수준이 증가함에 따라 증가를 하였다. 3. 용탈수 중의 NO$_3$$^{-}$ 함량은 평균 7.58ppm (6.27~9.02ppm)으로 매우 낮았고 시용수준간에도 차이가 거의 없었다. 그러나 강우량이 높은 시기에 NO$_3$￣의 용탈 함량도 증가하였다.

• 한국토양비료학회지
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• 제50권5호
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• pp.345-356
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• 2017

We investigated 52 livestock farming complexes in Gyeong-Gi and Incheon provinces based on low, medium, and high livestock density and groundwater quality. The objective of this study was to evaluate a relationship between nitrate N concentration in groundwater and animal factors, such as livestock density and animal species. 2,200 groundwater samples for 3 years from 2012 to 2014 at Gyeong-Gi and Incheon provinces were collected and analyzed for pH, EC, DO, ORP, temperature, major anions and cations, such as $NO_3-N$, ${HCO_3}^-$, ${PO_4}^-$, ${SO_4}^{2-}$, $Cl^-$, $NH_4-N$, $K^+$, $Na^+$, $Ca^{2+}$, $Mg^{2+}$, T-N, and TOC. Average concentration of total N for generated load density was $23,973g\;day^{-1}\;km^{-2}$ for cattle, $51,551g\;day^{-1}\;km^{-2}$ for pig, and $52,100g\;day^{-1}\;km^{-2}$ for poultry. For animal feeding species, average ratio for generated load over discharge load was 16.1% for cattle, 7.8% for pig, and 7.1% for poultry. Therefore, cattle feeding region is highly vulnerable for water pollution compared to pig and poultry feeding areas. The concentrations of chloride, nitrate, and total N in the groundwater samples were higher at high animal farming regions than other regions. The average concentration of nitrate, and chloride in groundwater samples was $5.0mg\;L^{-1}$, $16.6mg\;L^{-1}$ for low livestock density, $6.9mg\;L^{-1}$, $17.7mg\;L^{-1}$ for medium livestock density and $7.6mg\;L^{-1}$, $22.7mg\;L^{-1}$ for high livestock density and total nitrogen (T-N) was $7.7mg\;L^{-1}$ for low livestock density, $9.4mg\;L^{-1}$ for medium livestock density, $10.7mg\;L^{-1}$ for high livestock density. In conclusion, based on this research, for managing groundwater quality near livestock farming regions, $Ca-(Cl+NO_3)$ group from the Piper diagram is more efficient than using 19 factors for water quality standard.