• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.943-951
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• 2006

Spatial distribution of water pollution in the Gap Stream was investigated from October to November, 2005. Sampling was conducted three times including effluents discharged from a wastewater treatment plant (WWTP) and a dam reservoir during the low-flow period. As a typical urban stream, total nitrogen and inorganic nitrogen concentrations increased toward downstream. Ammonia concentration was the highest in the treated water of the wastewater treatment plant and the lowest nitrate concentration was found in the effluent of the dam reservoir. A part of soluble reactive phosphorous (SRP) in total phosphorous was 22~54% in the upstream reach of WWTP in the Gap Stream whereas 68~73% in the downstream reach. Mean chlorophyll-a concentration ranged from 1.6 to $11.0{\mu}g/L$ and it tends to increase toward downstream except for WWTP effluent. As expected, untreated wastewater and WWTP effluent were suggested as the major sources of water pollution in the Gap Stream. In this study, the water pollution of the Gap Stream is a significant undergoing typical eutrophication, caused by excessive phosphorus and nitrogen nutrients from WWTP located in the watershed. As a result, the critical factor for the water pollution was evaluated to dissolved inorganic nitrogen and phosphorus nutrients. Particularly, SRP is a most important for the eutrophication. It suggest that may occur in the most urban streams of Korean peninsula. Therefore, because the necessity of water pollution management in the urban stream, inorganic N and P nutrients should be included as an essential component of water quality criteria in the advanced water quality project of Korean Government by enforcing of water quality assessment and total maximum daily loads (TMDLs).

• Journal of Environmental Science International
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• v.28 no.1
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• pp.37-54
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• 2019

The groundwater quality through livestock excreta survey based on "Act of the management and use of livestock excreta" was investigated by selecting sampling sites within 1 km of the farmland without considering hydrogeological units. However, these sites can be affected by various pollution sources such as chemical fertilizers and livestock excretions. Additionally, the effects of pollution sources on groundwater quality in the sites cannot be clearly distinguished from naturally occurring backgrounds. In this study, a method was developed to select the sampling sites for groundwater quality through livestock excreta survey in order to understand the effects of pollution sources especially livestock excreta. First, the concentrations of nitrate within the radius of 200 m, 300 m, 500 m and 750 m, respectively, from the farms regarded as pollution sources in hydrogeological units were compared in 2016-2017. All the nitrate concentrations at 200 - 500 m from the farms exceeded a background concentration, 13.3 mg/L. Those at 750 m and the background concentrations measured by the Ministry of Environment were comparable. Therefore, the appropriate radius was suggested as 500 m for livestock excretions survey. In this study, the areas within 500 m from the farms could be considered under the influence of livestock excretions, while those beyond 500 from the pollution sources as background in hydrogeological units. The developed method was validated by applying it to the sites selected based on both administrative divisions and watersheds for livestock excretion survey. The average densities for the developed method were 0.82 and 0.39 points/km2, respectively, which were considered as appropriate levels according to those of the European Environmental Agency.

• Journal of the Mineralogical Society of Korea
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• v.17 no.2
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• pp.147-155
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• 2004

Anion adsorption properties of organobentonites modified by two cationic polymers, hexadecyltrimmethylammonium (HDTMA) and cetylpyridinum (CP), were investigated. The organobentonites showed the significant expansion of basal spacing to 42.0 $\AA$ at room temperature. The adsorption experiments were conducted for the 0.2 g of organobentonites with 40 mL solutions of various concentrations of anions such as nitrate, sulfate and phosphate. As a result, the organobentonites showed excellent adsorption capacities for those anions whereas untreated bentonite showed very low adsorption capacity. Adsorption rate of HDTMA-bentonite was about 90% for 100 mg/L solutions of nitrate and phosphate, and that of CP-bentonite was 97% for 100 mg/L solution of nitrate. Adsorption behaviors were slightly different for the different organobentonites and anions. Both organobentonites showed relatively higher adsorption rate for nitrate and phosphate than sulfate. Therefore, these organobentonites showing high anion adsorption capacities can be used far the removal of deleterious anions in the treatment of environmental pollution.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.121-122
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• 2002

PAN (Peroxyacetyl Nitrate)은 오존과 함께 대도시 광화학오염의 주요 원인물질로 알려져 있고 대기 중 NOx와 VOCs가 PAN의 생성에 복잡한 반응 경로를 통해 영향을 줄 뿐 만 아니라 원거리 이동을 통하여 비교적 청정지역에 주요한 NOx 공급원으로 알려져 있다. 하지만 PAN은 대기 중 농도가 작고 비교적 낮은 온도에서도 쉽게 열분해 되기 때문에 관측이 어려운 물질이다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.65-66
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• 1999

도시지역의 시정변화는 일정한 경향성을 지니는 일부 오염물질들의 배출에 의해 지배적인 영향을 받는 것으로 보고되고 있다. Sulfate, nitrate는 대기중의 상대습도와 밀접한 관계를 지니고 있어서, 일일주기로 증감하는 수증기와의 반응에 의하여 입자의 크기가 성장ㆍ감소하여 대상물체의 이미지 형성광(image forming light)을 산란시킴으로써 관측자의 시야 경로부터 빛을 이탈시키는 현상을 나타낸다.(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.05a
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• pp.131-132
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.380-381
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• 2003

환경 중의 방향족 탄화수소 화합물은 발암의 가능성으로 인하여 중요한 관심의 대상이 되고 있다(Kourtidis et al, 2002; Volkamer et al, 1998; Etzkorn et al, 1999). 방향족 탄화수소는 화석연료와 같은 유기물질의 불완전 연소로부터 형성되는 인위적 오염물질로 간주된다. 도시지역에서 발견되는 방향족 탄화수소는 자동차의 배기가스 등으로부터 주로 발생한다. 이들은 광화학 반응을 통해 오존, PAN(Peroxyacetyl nitrate) 등을 생성하고. OH 라디칼과의 반응을 통해 소멸되는 것으로 알려져 있다(Kourtidis et al., 2002; Volkamer et al., 1998). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.293-294
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• 2003

동북아시아 지역은 대기오염물질의 배출량이 증가하고 있는 실정이며, 특히 중국은 이 지역의 SOx와 NOx 배출량의 많은 부분을 차지하고 있다. 또한 이 지역은 입자 중 토양 성분의 농도가 높고, 토양 입자의 이동이 활발하다 주로 중국 동해안에 집중되어 있는 배출원에서 배출된 산성 대기오염물질과 토양성분의 입자가 장거리 이동을 통하여 배출지 이외의 지역을 전달될 가능성이 있는데, 이러한 장거리 이동 중에 SOx와 NOx 등의 기체상 산성물질은 SO$_4$$^{2-}$ 와 NO$_3$$^{-}$등의 입자상 산성 물질로 변환하여 침적될 수 있다. (중략)

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.513-518
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• 2000

It has been acknowledged that fertilizer, natural soil nitrogen and animal waste, municipal waste have different mass ratio of nitrogen which is presented as a symbol of $\delta^{15}$N. and that the values of $\delta^{15}$N for fertilizer and natural soil nitrogen and animal waste are placed less than +5$\textperthousand$ and higher than +10$\textperthousand$, respectively. thus, Nitrogen pollution sources and contribution can be interpreted in watershed through $\delta^{15}$N analysis and then, analysis is performed with Kjeldhl-Dumas method. In this study, The values of $\delta^{15}$N are between +1.46$\textperthousand$ and +8.97$\textperthousand$, and the nitrate concentration is placed less than 3.31mg/L and higher than 0.19mg/L, respectively. Thus, this watershed is noncontamination area at the present time. But as a result of $\delta^{15}$N, contribution of natural soil nitrogen be discovered in this watershed, presently.

• Journal of Ecology and Environment
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• v.38 no.2
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• pp.145-156
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• 2015

This study was based on water quality data of the Lake Doam watershed, monitored from 2010 to 2013 at eight different sites with multiple physiochemical parameters. The dataset was divided into two sub-datasets, namely, non-rainy and rainy. Principal component analysis (PCA) and factor analysis (FA) techniques were applied to evaluate seasonal correlations of water quality parameters and extract the most significant parameters influencing stream water quality. The first five principal components identified by PCA techniques explained greater than 80% of the total variance for both datasets. PCA and FA results indicated that total nitrogen, nitrate nitrogen, total phosphorus, and dissolved inorganic phosphorus were the most significant parameters under the non-rainy condition. This indicates that organic and inorganic pollutants loads in the streams can be related to discharges from point sources (domestic discharges) and non-point sources (agriculture, forest) of pollution. During the rainy period, turbidity, suspended solids, nitrate nitrogen, and dissolved inorganic phosphorus were identified as the most significant parameters. Physical parameters, suspended solids, and turbidity, are related to soil erosion and runoff from the basin. Organic and inorganic pollutants during the rainy period can be linked to decayed matters, manure, and inorganic fertilizers used in farming. Thus, the results of this study suggest that principal component analysis techniques are useful for analysis and interpretation of data and identification of pollution factors, which are valuable for understanding seasonal variations in water quality for effective management.