• 한국해양환경ㆍ에너지학회지
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• 제17권2호
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• pp.90-103
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• 2014

2011년 9월에 동해의 수괴 분포와 용존 무기 및 유기 영양염의 분포 특성을 파악하였다. 수온, 염분, 용존산소의 분포를 통하여 연구해역의 수괴 기원은 WM(water mass)-I, WM-II, WM-III, WM-IV 등 4개의 대표적인 수괴로 구분되었으며, 그 성격은 각각 대마난류표층수, 대마난류중층수, 북한한류수, 동해고유수와 유사하였다. 용존 영양염의 경우, 용존 무기 질소(DIN; dissolved inorganic nitrogen)와 용존 무기 인(DIP; dissolved inorganic phosphorus)은 WM-IV에서 가장 높았으며, WM-III, WM-II, WM-I 순으로 나타났다. 반면에 용존 유기 질소(DON; dissolved organic nitrogen)와 용존 유기 인(DOP; dissolved organic phosphorus)은 무기 영양염과 상반되는 분포를 보였다. 연구해역에서 수괴 전체에 대한 DIN : DIP 비는 약 15.8로 Redfield ratio(16)에 근접한 수치를 보이고 있으나, 혼합층의 경우 5.3으로 무기질소가 식물플랑크톤 성장의 제한 요인으로 작용할 수 있는 것으로 보였다. 하지만 무기 질소가 제한된 혼합층에서 DON은 용존 총 질소(DTN; dissolved total nitrogen) 중 약 70%를 구성하였다. 따라서 풍부한 DON은 동해에서 식물플랑크톤의 성장을 위한 중요한 영양염 공급원으로 판단된다.

• 해양환경안전학회지
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• 제22권1호
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• pp.42-51
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• 2016

2014년 9월 동해 남서해역의 용존 영양염 분포 및 식물플랑크톤 군집구조와 우점종의 질소 화합물에 대한 이용성을 파악하였다. 용존 무기 질소(dissolved inorganic nitrogen; DIN)와 용존 무기 인(dissolved inorganic phosphorus; DIP)은 표층에서 낮고, 수심이 깊어짐에 따라 증가하였다. 반면에 용존 유기 질소(dissolved organic nitrogen; DON)와 용존 유기 인의 경우 무기태 영양염과 상반되는 분포를 보였다. DIN:DIP 비는 전체 수괴에서 약 20으로 Redfield ratio (16)보다 다소 높게 나타났지만, 혼합층의 경우 2로 식물플랑크톤의 생장에 대해 무기 질소가 제한요인으로 작용할 수 있는 것으로 보였다. 특히, 무기 질소가 제한된 혼합층에서 DON은 용존 총 질소(dissolved total nitrogen; DTN) 중 88 %를 차지하였다. 우점종 Chaetoceros debilis와 Prorocentrum minimum은 DIN 이외에 요소와 아미노산과 같은 다양한 DON을 이용하여 생장하였다. 따라서 식물플랑크톤의 DON 이용능력은 DIN이 제한된 동해에서 중요한 생존전략으로 작용할 것이다.

• 대한환경공학회지
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• 제33권7호
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• pp.481-484
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• 2011

염소 소독시 유기성 클로라민 생성에 대한 대부분의 연구가 모델 화합물질(예, 아미노산)을 사용한 연구결과로, 실제 자연상태에서 발생된 용존유기질소(DON)에 의한 유기성 클로라민 생성에 적용할 수 없다. 본 연구는 지표수에서 추출된 16개 천연유기물질(NOM)을 사용하여 염소 소독시 DON이 유기성 클로라민 생성에 미치는 영향을 조사하였다. 크게 염소 주입량과 반응시간, 그리고 DON 분자량이 유기성 클로라민 생성에 미치는 영향에 대해 살펴보았다. 염소 주입량을 변화시킨 시험결과, 소비된 염소량 1 mg당 0.25 mg이 유기성 클로라민으로 전환되었다. DON은 염소와 반응하여 10분 이내에 빠르게 유기성 클로라민을 생성하였고, 그 후 계속해서 분해(가수분해, 산화)되었다. 반응시간 10분과 24시간의 유기성 클로라민 평균값은 각각 0.78과 $0.16mg-Cl_2/mg-DON$이었다. NOM의 DOC/DON 비율이 낮을수록, 즉 NOM내 DON의 함량비가 높을수록 유기성 클로라민 생성율이 높았다. 10,000 Da 분획시험 결과, DON의 분자량은 유기성 클로라민의 생성에 큰 영향을 미치지 않았다.

• 한국환경과학회지
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• 제17권11호
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• pp.1265-1271
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• 2008

Aerated submerged bio-film (ASBF) pilot plant has been developed. The presented studies optimized an inexpensive method of enhanced wastewater treatment. The objectives of this research were to describe pilot scale experiments for efficient removal of dissolved organic and nitrogen compounds by using ASBF reactor in plug-flow reactor (PFR) and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophs and autotrophs in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. This direct gas-phase contact should increase the oxygen transfer rate into the bio-film, as well as increase the micro-climate mixing of water, nutrients, and waste products into and out of the bio-film. This research also investigated the efficiency of dissolved organic matter and ammonia nitrogen removals in the ASBF. As it was anticipated, nitrification activity was highest during periods when the flow rate was lower, but it seemed to decline during times when the flow rate was highest. And ammonia nitrogen removal rates were more sensitive than dissolved organic matter removal rates when flow rates exceeded 2.2 L/min.

• Ocean and Polar Research
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• 제45권3호
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• pp.103-111
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• 2023

To evaluate the impact of effluents from land-based fish farms on the coastal ocean of Wando, Korea, we analyzed inorganic nutrients, particulate organic carbon (POC), dissolved organic carbon (DOC), and colored dissolved organic matter (CDOM) in the effluent and influent of land-based fish farms during the summer (July) of 2021. The average concentrations of nutrients (Dissolved inorganic nitrogen, phosphorus, and silicate; DIN, DIP, and DSi, respectively) in the effluents of this study area were 17±3.7 μM, 1.4±0.7 μM, and 14±1.6 μM, respectively. The average concentrations of POC and DOC were 37±22 μM and 81±13 μM, respectively, with POC accounting for about 30% for total organic carbon in effluents. The Reduced Dissolved Inorganic Nitrogen/Total Dissolved Inorganic Nitrogen ratio (0.7), potential short-period index, indicates that the discharge of nutrients excreted by the fish and unconsumed feed into coastal water results in such nutrients being deposited and accumulated in the sediment. Subsequently, this continuous accumulation triggers the release of ammonium ions during organic matter decomposition, and the ammonium-enriched waters that encroach on fish farms as influent seem to be due to the diffusion of high concentrations of ammonium from bottom sediment. Furthermore, we used fluorescence indices to examine the characteristics of organic matter sources, obtaining mean values of 1.54±0.19, 1.06±0.06, and 1.56±0.06 for the humification index, biological index, and fluorescence index, respectively, in the effluent. These results indicate that the organic matters had an autochthonous origin that resulted from microbial decomposition, and such organic matters were rapidly generated and removed by biological activity, likely supplied from the sediment. Our results suggest that the effluent from land-based fish farms could be a potential source of deoxygenation occurrence in coastal areas.

• Journal of Ecology and Environment
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• 제30권3호
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• pp.209-223
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• 2007

Twenty-four wetlands located in Higashi-Hiroshima City in West Japan were selected for this study in order to investigate both the relationship between aquatic plant composition and environmental conditions; and the relationship between changing land use patterns in the catchments and the concentration of different forms of nitrogen in the wetlands. The dominant and subdominant species which comprised the principal vegetation were determined based on a vegetation census conducted in each wetland during the growing season from June to August, 2006. The seasonal variations of water quality factors (pH, electrical conductivity, turbidity, dissolved oxygen, total dissolved solid, and temperature) and different forms of nitrogen such as nitrite, nitrate, ammonium, total nitrogen, dissolved organic nitrogen and dissolved inorganic nitrogen concentrations were analyzed as important indicators of water quality for the surface water of the wetlands. The surveyed wetlands were classified into three types (non-disturbed wetlands, moderately-disturbed wetlands and highly-disturbed wetlands), based on the degree of human disturbance to their catchment areas. An analysis of variance indicated that there was a significant difference among the wetland groups in the annual mean values of electrical conductivity, total dissolved solids, total nitrogen, nitrite, dissolved inorganic nitrogen and dissolved organic nitrogen. Classification of the wetlands into three groups has revealed a pattern of changes in the composition of plant species in the wetlands and a pattern of changes in nitrogen concentrations. A majority of the non-disturbed wetlands were characterized by Brasenia schrebi and Trapa bispinosa as dominant; with Potamogeton fryeri and Iris pesudacorus as sub-dominant species. For most of the moderately-disturbed wetlands, Brasenia schrebi were shown to be a dominant species; Elocheriss kuriguwai and Phragmites australis were observed as sub-dominant species. For a majority of the highly-disturbed wetlands, Typha latifolia and T. angustifolia were observed as dominant species, and Nymphea tetragona as the sub-dominant species in the study area. An analysis of land use and water quality factors indicated that forest area played a considerable role in reducing the concentration of nutrients, and can act as a sink for surface/subsurface nutrient inputs flowing into wetland water, anchor the soil, and lower erosion rates into wetlands.

• 한국해양환경ㆍ에너지학회지
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• 제16권1호
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• pp.25-35
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• 2013

실내실험과 현장관측을 통해서 용존태무기질소(dissolved inorganic nitrogen; DIN) 제한 하에서 유독와편모조류 Alexandrium tamarense와 A. catenella의 생존과 우점화 전략을 살펴보았다. 현장관측결과 마산만에서 Alexandrium 속이 출현하는 기간동안 DIN이 식물플랑크톤의 성장 제한영양염으로 나타났다. 성장동력학 실험으로부터 도출된 질산염의 Ks값은 현장에서 우점하는 규조류보다 A. tamarense와 A. catenella가 높아, 영양염 경쟁에 있어 불리한 위치에 있는 것으로 나타났다. 하지만 A. tamarense와 A. catenella는 DIN 제한하에서 요소나 아미노산과 같은 용존유기질소 (dissolved organic nitrogen; DON) 화합물을 성장에 이용하였다. 따라서 마산만과 같이 Alexandrium 속이 출현하는 봄~여름까지 DIN이 제한영양염으로 작용하는 환경에서 DON의 흡수능력은 이들 종이 성장을 유지하는데 큰 역할을 할 뿐만 아니라 종의 우점과정 및 종간 경쟁에서도 중요한 영향을 줄 것으로 보인다.

• Ocean and Polar Research
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• 제39권1호
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• pp.35-43
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• 2017

Concentrations of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), dissolved organic phosphate (DOP), and colored dissolved organic matter (CDOM) were measured in the coastal sea off inland aqua farms in northeastern Jeju Island in summer 2015. The highest concentrations of DOC, DON, and DOP were revealed in the surface water off Hado-ri where the lowest salinity conditions prevailed (31.6). The concentrations of DOC, DON, and DOP in the surface water were lower in the inner stations (SH1-1, 1-2, and 1-3) near the aqua farms of the Haengwon-ri than in the outer stations. The concentrations of DOC, DON, and DOP negatively correlated with salinity. These results indicate that the contribution of dissolved organic matter (DOM) from the aqua farms seems to be not significant. On the other hand, the higher concentrations of DON and DOP in the inner stations of Hado-ri (HD 1-1) seem to be attributed to excrement of migrating birds. The three components of CDOM (T, M, and C peaks) showed no relationship with salinity, perhaps due to various in situ productions by marine organisms and decomposition by ultraviolet radiation. The observed lower C:M ratio, an indicator of terrestrial source, and the higher biological index (BIX) of CDOM in the station off Hado-ri indicate that DOM is produced mainly by biological activity. Based on the higher humification index (HIX) of CDOM and the higher DOC:DON ratio off Haengwon-ri, refractory DOM in the inland aqua farms is likely transported to the coastal sea.

• 한국해양학회지:바다
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• 제19권4호
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• pp.232-242
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• 2014

본 연구는 유해 와편모조류 Cochlodinium polykrikoides와 규조류 Skeletonema sp.의 용존 유기 영양염에 대한 이용 및 흡수능력을 통해서 종간 경쟁관계를 파악하였다. C. polykrikoides와 Skeletonema sp.는 용존 무기 질소와 무기인 이외에 다양한 용존 유기 질소와 유기 인을 이용하여 성장하였다. 이는 용존 무기 질소 또는 무기 인이 제한 영양염으로 작용하는 환경에서 중요한 생존전략으로 작용할 것이다. Urea와 glycerophospahte(glycero-P)의 흡수동력학 실험으로부터 도출된 반포화상수(Ks) 값은 C. polykrikoides가 Skeletonema sp.에 비해서 낮은 값을 보였다. 이는 Skeletonema sp.가 C. polykrikoides에 비해서 urea와 glycero-P와 같은 유기 영양염에 대한 친화성이 높음을 의미한다. 하지만 Skeletonema sp.가 유기 영양염에 대한 친화성이 높을지라도 C. polykrikoides가 ${\alpha}$ (${\rho}_{max}/Ks$) 값이 높아, 저농도의 영양염 조건(

• 한국물환경학회지
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• 제30권5호
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• pp.503-511
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• 2014

The temporal and spatial analyses of total nitrogen (TN) fractionation were conducted in order to understand 1) total nitrogen components in streams and 2) their patterns in rainy and dry seasons. The result showed that the concentration of nitrogen components in stream water was lower in non-urban area and getting higher in urban area. Dissolved total nitrogen (DTN) was 95~97.7% of total nitrogen in streams, and the proportion of dissolved organic nitrogen (DON) and ammonia nitrogen ($NH_3-N$) was higher with increasing urban area. The concentration of total nitrogen and nitrate nitrogen ($NO_3-N$) were highest in winter among four seasons. The result was showed that concentration of $NH_3-N$ was same variation as concentrations of TN and $NO_3-N$ in urban-rural complex and urban areas, except rural areas. During rainy season, concentrations of particulate organic nitrogen (PON) and $NH_3-N$ increased in rural areas and decreased in both urban-rural complex and urban areas. Correlation between total nitrogen components and land uses was positively correlated with site > paddy, and negatively correlated with forest. The variation of total nitrogen concentration was determined by $NO_3-N$ in non-urban areas, by $NO_3-N$ and $NH_3-N$ in urban-rural complex and by $NH_3-N$ in the urban areas.