• 환경생물
• /
• 제37권3호
• /
• pp.299-308
• /
• 2019

2012년 8월 1일부터 7일까지 한국 남해 연안의 목포에서 부산에 이르는 37개의 정점에서 채집된 Acartia속 요각류의 공간 분포 양상에 대하여 분석하였다. A. erythraea는 용존산소가 2 mg L^-1 이하인 반 폐쇄적인(가막만, 마산만)만에서 높은 출현 개체수를 보였다. A. sinjiensis는 엽록소-a 농도가 2 ㎍ L^-1 이상인 반 폐쇄적인 만에서 높은 출현 개체수를 보였다. A. ohtsukai는 수온 26℃ 이상, 염분 30 이하일 때 높은 출현 개체수를 보였다. A. hongi, A. hudsonica는 수온이 27℃ 이하, 용존산소 5 mg L^-1 이상인 해역에서 출현하였다. 이러한 결과 환경요인이 여름철 남해 연안에 출현하는 Acartia속 요각류의 공간적 분포에 영향을 미칠 수 있음을 시사하고 있다.

• 한국물환경학회지
• /
• 제38권6호
• /
• pp.282-291
• /
• 2022

Since the efficiency of wastewater treatment using microalgae differs depending on the metabolic characteristics of the species, it is important to understand the characteristics of target algae prior to the application in wastewater treatment. In this study, for the application of Arthrospira platensis to wastewater treatment, which is a filamentous alkaliphilic cyanobacteria, basic species specificity was identified and the possibility of application to wastewater treatment was investigated. As a result of the species specificity investigation, the specific growth rate between pH 7.0 and 11.0 showed the highest value near pH 9 at 0.25/day. The reason for the relatively low growth(0.08/day) at pH 11 was thought to be the CA(carbonic anhydrase) enzyme that is involved in carbon fixation during photosynthesis has the highest activity at pH 8.0 to 9.0, and at pH 11, CA activity was relatively low. In addition, A. platensis showed optimal growth at 400 PPFD(photosynthetic photon flux density) and 30℃, and this means that cyanobacteria such as A. platensis have a larger number of PS-I(photosystem I) than that of PS-II(photosystem II). It was speculated that it was because higher light intensity and temperature were required to sufficiently generate electrons to transfer to PS-I. Regarding the applicability of A. platensis, it was suggested that if a system using the synergistic effect of co-culture of A. platensis and bacteria was developed, a more efficient system would be possible. And different from single cocci, filamentous A. platensis expected to have a positive impact on harvesting, which is very important in the latter part of the wastewater treatment process.

• 한국자기공명학회논문지
• /
• 제9권2호
• /
• pp.138-154
• /
• 2005

Vanadium-incorporated aluminophosphate molecular sieve $VO^{2+}-SAPO-5$ was studied by electron spin resonance (ESR) and electron spin echo modulation (ESEM) spectroscopies to determine the vanadium structure and interaction with various adsorbate molecules. It was found that the main species at low concentration of vanadium is a monomeric vanadium units in square pyramidal or distorted octahedral coordination, both in oxidation state (IV) for the calcined hydrated material and in oxidation state (V) for the calcined material. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. It is suggested as a $VO(H_2O)_3^{2+}$ complex coordinated to two framework oxygen bonded aluminum. When calcined, hydrated $VO^{2+}-}SAPO-5$ is dehydrated at elevated temperature, a species loses its water ligands and transforms to $VO^{2+}$ ions coordinated to two framework oxygens (species B). Species B reduces its intensity, significantly after treatment with $O_2\;at\;600^{\circ}C$ for 5 h, thus suggesting oxidation of $V^{4+}\;to\;V^{5+}$. When dehydrated $VO^{2+}-SAPO-5$ contacts with $D_2O$ at room temperature, the EPR signal of species A is observed. Thus species assumed as a $VO^{2+}(O_f)_2(D_2O)_3$, by considering two framework oxygens. Adsorption of deuterated ethanol, propanol on dehydrated $VO^{2+}_{-}SAPO-5$ result in another new vanadium species E and F, respectively, which are identified as a $VO^{2+}-(CH_3CH_2OD)_3,\;VO^{2+}-(CH_3CH_2CH_2OD)_2$ complex. When deuterated benzene is adsorbed on dehydrated $VO^{2+}-SAPO-5$, another new vanadium species G, identified as a $VO^{2+}-(C_6D_6)$ is observed. Possible coordination geometries of these various complexes are discussed.

• 환경생물
• /
• 제37권4호
• /
• pp.600-606
• /
• 2019

본 연구는 2018년 7월 20일부터 2018년 8월 1일까지 안산시 단원구에 위치한 화랑유원지 오토캠핑장의 집수정에서 연구를 실시하였으며, 조사지점은 기법별로 대조지점, 천적지점, Bti 지점을 선정하였다. 서식처 환경 분석 및 채집된 저서성 대형무척추동물을 대상으로 종조성, 군집분석, 상관성 분석, 유사도 분석을 실시하여 잔물땡땡이, Bti가 저서성 대형무척추동물에 미치는 영향을 파악하였다. 서식처 환경 분석 결과, 수질항목은 지점간 유의한 차이는 없는 것으로 분석되었으며(p>0.05), 하상구조 및 식물군락이 유사하여 서식처 특성에 의한 종조성의 차이는 적을 것으로 판단된다. 조사시간 동안 총 11목 22과 38종 4,818개체가 출현하였으며, 천적지점은 대조지점과 비교적 유사한 종조성을 나타내는 것으로 분석되었다. 반면 Bti 지점은 다른 지점에 비해 단순한 종조성을 나타내었으며, 파리목의 종수 및 개체수가 가장 빈약한 것으로 분석되었다. 군집 분석 결과, 조사기간 동안 Bti 지점에서 불안정한 군집양상을 나타내었으며, 천적지점은 비교적 안정적인 군집양상을 나타내는 것으로 분석되었다. 파리목과 모기유충을 대상으로 수질과의 상관성 분석을 실시한 결과, 파리목과 기온, 수온은 음의 경향성을 나타내었으며, 모기유충과 기온은 -0.610^⁎, 수온은 -0.674^⁎로 유의한 음의 상관성을 나타내는 것으로 분석되었다 출현종을 대상으로 유사도 분석을 실시한 결과, 대조지점과 천적지점은 조사시기별 61.11~73.68%, Bti 지점은 30.77~56.00%의 유사도를 나타내어 천적지점에 비해 대조지점과 유사도가 낮은 것으로 분석되었다. 본 연구는 단기간의 연구 결과로 습지유형 등을 고려하여, 다양한 환경에서 생물학적 모기유충 방제 기법이 저서성 대형무척추동물에게 미치는 영향에 대한 장기적인 연구가 필요할 것으로 판단된다.

• 한국환경과학회지
• /
• 제9권5호
• /
• pp.429-436
• /
• 2000

In order to study on the variational characteristics of water quality and chlorolphyll a concentration the water samples were collected daily or three times a week during the period from April 1990 to November 1991 at Kukdong port located in the northern Kamak bay of Southern Korea I made an analysis on biological factor as chlorophyll a concentration as well as physico-chemical factors such as water temperature salinity sigma-t dissolved oxygen, nutrients (ammonia, nitrite, nitrate, phosphate, and silicate) N/P ratio and chemical oxygen demand. In Northern Kamak bay seasonal variations in physical factors such as water temperature salinity and sigma-t were very marked. On the other hand chemical factors such as nutrients concentration and COD were not so. Chemical factors, in particular silicate were influenced by input of freshwater. And the roles of silicate on the seasonal succession of phytoplankton species composition was very low. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round and it was controlled by the combination of several factors especially of N/P ratio determined by dissolved inorganic nitrogen.

• 청정기술
• /
• 제29권1호
• /
• pp.39-45
• /
• 2023

To investigate the effects of Mg addition at different aging times and temperatures, Cu/MgO/Al₂O₃ catalysts were synthesized for the low-temperature water gas shift (LT-WGS) reaction. The co-precipitation method was employed to prepare the catalysts with a fixed Cu amount of 30 mol% and varied amounts of Mg/Al. Synthesized catalysts were characterized using XRD, BET, and H₂-TPR analysis. Among the prepared catalysts, the highest CO conversion was achieved by the Cu/MgO/Al₂O₃ catalyst (30/40/30 mol%) with a 60 ℃ aging temperature and a 24 h aging time under a CO₂-rich feed gas. Due to it having the lowest reduction temperature and a good dispersion of CuO, the catalyst exhibited around 65% CO conversion with a gas hourly space velocity (GHSV) of 14,089 h-1 at 300 ℃. However, it has been noted that aging temperatures greater or less than 60 ℃ and aging times longer than 24 h had an adverse impact, resulting in a lower surface area and a higher reduction temperature bulk-CuO phase, leading to lower catalytic activity. The main findings of this study confirmed that one of the main factors determining catalytic activity is the ease of reducibility in the absence of bulk-like CuO species. Finally, the long-term test revealed that the catalytic activity and stability remained constant under a high concentration of CO₂ in the feed gas for 19 h with an average CO conversion of 61.83%.

• 한국어류학회지
• /
• 제26권4호
• /
• pp.310-321
• /
• 2014

2007년 12월의 태안 Hebei Spirit 유류 유출지점으로부터 약 10 km 떨어진 액상의 유류 오염 피해를 직접 받은 만리포 조간대 천해역 어류의 종조성 변화를 분석하였다. 어류는 2008년 2월부터 2009년 12월까지 월별로 그믐 사리 간조 때 주야 각 5회씩 지인망으로 채집하였다. 월별 주야간 어류 종조성은 유의한 차이를 보이지 않았다. 2008년에는 총 21종, 1,032마리, 6,544.2 g의 어류가 채집되었고, 2009년에는 31종, 4,206마리, 35,659.6 g의 어류가 채집되었다. 출현한 어류는 소형어이거나 유어들이었으며, 채집량이 많은 어류들은 연안 주거종이었고 계절에 따라 출현하는 회유종은 양적으로 적었다. 출현종 가운데 가숭어 (Chelon haematochelius), 조피볼락 (Sebastes schlegelii), 복섬 (Takifugu niphobles)과 문치가자미(Pleuronectes yokohamae)가 조사 기간 중 우점하였다. 2008년의 월별 채집생물량과 종 다양성지수는 2009년에 비하여 유의하게 낮았다. 2008년 2월에서 6월까지는 일부 주거종들 만이 채집되어 출현종수와 채집량이 낮았고, 5월에 가장 낮았으며 7월 이후 채집량이 증가하였다. 2009년에는 봄에 수온이 상승하며 출현종수와 채집량이 증가하여 하계에 최대값을 보이고 가을에 낮아지는 전형적인 온대 천해 어류 종조성 변화를 보였으며, 오염 피해가 적었던 곳과 비슷한 양상을 보였다. 만리포에서 오염 이후 초기 몇 달간은 천해어류 출현종수와 채집량이 적었던 것은 잔존유류의 영향과 조간대 모래 세척 등의 유류 방제작업에 따른 서식처 교란 때문으로 보인다. 2008년 9월 이후 월별 채집량이 2009년의 같은 달 채집량과 큰 차이가 없어 2008년 9월 이후에는 잔존 유류 영향이 어류 종조성에 미치는 영향은 크지 않은 것으로 추정된다.

• 한국조경학회지
• /
• 제26권3호
• /
• pp.258-266
• /
• 1998

The purpose of this study is to investigate the actual conditions, to find problems, and to present an improvement plan of interior landscape in the subway stationis. Moreoiver, it will presume the possibilties to develop the subway and ways to utilie underground space effectively. The results are summarized as follows A light intensity was recorded 0-100 Lux as the lowest light and 500 Lux below as the highest in 61 subway stations. An average temperature of 12 $^{\circ}C$and an air humidity of 38% were recorded over a 4 month period from January to April, but includes a drastic variaton between -8.5$^{\circ}C$ and 21.5$^{\circ}C$. Soil acidity of pH 7 below and soil moisture of 1-2 wet degree were apeared in subway stations mostly. Plant forms consisted of artificial flower & flower. Plant species were recorded at a total of 54 species and appeared in the order of Araucaria heteropylla, Ophiophogon jaburan, Aspidistra elatior cv. 'Asahi' and Hedera helix. Plant height was, for the most part, below 0.5m. Plant species that was fined of conditions were Palm, Camellia japonica, Araucaria heterophylla as a high plant, dracaena fragrans, dracaena deremensis cv. Wakneckii as a middle plant, and Ophiopogon jaburan, Hedra helix, ytomium falcatum, Aspidistra elatior cv. Asahi as a low plant. It used to water materials such as small pool, small cascade, water cycles and natural materials such as natural rock, small rock, sand, bark and animal materials such as squirrels, birds, goldfish as an object for plants in the subway stations. From these actual conditions, First of all, It must make up physical environments such as light, temperature humidity, soil for plant growth, and is important to chooce suitable indoor plants and draw up systematic management in the subway environments. Also, it change plants frequently and uses variable objects for subway stationi individuatism, Moreover, indoor plants with strong environmental adaptation abities such as shade tolerance, drought tolerance and cold tolerance need to develope variable species possibly. If these improvements occur, utilization and amenity of subway stationis will increase, according to the use of interior landscape.

• 한국수산과학회지
• /
• 제25권4호
• /
• pp.251-264
• /
• 1992

수괴지표성 요각류 및 모악류의 분포, 군집구조 그리고 요인분석으로써 황해 동남 해역에 분포하는 수괴의 시공간적 변동 및 특성을 밝혔다 본 연구에서는 요각류인 Undinula darwini, Lucicutia flavicornis, Pleuromamma gracilis와 모악류인 Sagitta enflata는 난류 외양성 종으로, Euchaeta russelli 와 Euchaeta plana는 난류성이나 내성이 강하여 분포 범위를 넓게 가지는 종으로, Sagitta wassa는 연안성 종으로, Sagitta bedoti는 혼합성 종으로 그리고 Centropages abdominalis는 연안 저온성 종으로 특성 지어졌으며, 이들의 분포로써 수괴를 분석하였다. 2월의 경우, U. darwini, L. flavicornis, P. gracilis, E. russelli, E. plana 그리고 S. enflata가 출현하는 제주도 서방, 수온 $14^{\circ}$ 이상인 해역이 쿠로시오 난류 수괴로, 수온 $10^{\circ}$이하이며, C. abdominalis가 출현하는 진도 이북해역이 황해 냉수괴로 나타났다. E. plana와 E. russelli가 소량 출현하며, 혼합성 종인 S. bedoti가 출현하는 수온 $12-14^{\circ}$인 제주도-진도간 해역은 혼합 수괴인 것으로 나타났다. 8월의 경우, 수온 약층을 경계로 하여 0-20m층과 20m- 저층으로 분리하여 수괴를 분석하였다. 0-20m 층의 경우, E. plana와 E. russelli가 출현하는 대흑산도까지 난류가 미치며, 집괴 분석 및 수괴지표성 종의 분포로써 볼 때 수괴는 연안에서 외양으로 가면서 크게 대별되어졌다. 20m-저층의 경우, 난류성 종인 E. russelli와 E. plana가 출현하며 수온이 $12^{\circ}C$이상인 제주도 서북방 해역이 난류의 영향을 받는 해역으로 나타났으며, 저온성 종인 C. abdominalis가 출현하는 진도 이북 해역이 황해 냉수괴인 것으로 나타났다. 하계 0-20m층의 진도부관 해역 및 20m- 저층의 진도 이북 해역에서 C. abdominalis가 출현하는 것으로 보아 냉수괴가 존재하는 것으로 나타났다.

• 수산해양기술연구
• /
• 제55권3호
• /
• pp.217-232
• /
• 2019

It was turned out by shrimp beam trawl monthly survey from March, 2015 to February, 2016 that different species composition and abundance of the fish assemblages in Sacheon Bay and coastal waters off Namhae, Korea were compared. As a result of monthly measured sea temperature and salinity of Sacheon Bay and coastal waters off Namhae, sea temperature of both areas was changed seasonally; however, differences in sea temperature occurred during certain periods depending on the region. Salinity was generally low in Sacheon Bay affected by fresh water, and both areas was low in summer and high in winter. A total of 73 species representing 37 families were collected in Sacheon Bay. The dominant fish species in terms of numbers and biomass were Liparis tanakae, $23,077inds./km^2$, $332.1kg/km^2$. A total of 91 fish species representing 49 families were collected in coastal waters off Namhae. The dominant fish species in terms of numbers were Leiognathus nuchalis, $139,683inds./km^2$ and biomass were Chelidonichthys spinosus, $1,078.6kg/km^2$. Analysis of dendrogram of the clustering showed that Sacheon Bay and coastal waters off Namhae were distinctive featured (global R = 0.691, p = 0.017). And except of summer season (July-October), there was a distinctive feature seasonally (global R = 0.844, p = 0.001). The fish species that appeared in common in both areas, where fish species caught in Sacheon Bay, an important inner bay,were smaller than those caught in coastal waters off Namhae appeared. It presented that Sacheon Bay plays a more important role in spawning and nursery ground for fisheries resource than coastal waters off Namhae, Korea.