• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.100-109
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• 2006

This study evaluated the effects of water velocity, substrates, and phosphorus concentrations on the growth of filamentous periphytic algae (FPA) in the two types of artificial channel systems using treated wastewater. Controlled parameters included 5 ${\sim}$ 15 cm $s^{-1}$ for the water velocity; 10 and 20 mm wire meshes, natural fiber net, gravel and tile for the substrates: and 0.05 ${\sim}$ 1.0 mgP $L^{-1}$ for the P concentration. Algal growth rate of FPA was compared using both chi. a and dry weight change with time. Under the controlled water velocity range, the growth of FPA increased with the velocity, but the maximum growth rate was shown in the velocity of 10 cm $s^{-1}$. The substrate that showed the maximum growth of FPA differed between the artificial channel and indoor channel, due to the influence of suspended matters which caused the clogging of the meshed substrates. Under the controled range of P concentration, the growth rates of all three FPA species (Spirogyra turfosa, Oedogonium fovelatum, Rhizoclonium riparium) increased with the P increase, but they showed the differential growth rates among different P concentrations. The results of this study suggest that under the circumstance having an large amount of nutrients FPA develop the biomass rapidly and that even a little increase over the threshold velocity causes the detachment of filamentous periphytic algae. Thus, FPA dynamics in eutrophic streams, such as those receiving treated wastewater, seem to be sensitive to the water velocity. On the other hand, detached algal filaments could deteriorate water quality and ecosystem function in receiving streams or down-stream, and thus they need to be recognized as an important factor in water quality management in eutrophic streams.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.79.1-79.1
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• 1999

• KCID journal
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• v.13 no.1
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• pp.118-126
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• 2006

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.335-351
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• 1992

The identification of green algae which were collected from paddy rice fields of the whole nation was conducted in 1991, and also the reproduction processes of three important green algae were investigated. The green algae identified were 46 species in 16 families including 4 species in the Volvocaceae, 4 species in the Palmellaceae, 3 species in the Ulotrichaceae, 3 species in the Oocystaceae and 6 species in the Scenedesmaceae. It was recognized that the algae which have caused a large injury to the flooded direct-seeded rice in Seosan reclaimed saline land was the genus Cladophora. The green water blooms on paddy water were induced mostly by the concentrated populations of suspended green algae such as the genera, Chlamydomonas and Stichococcus. A rapid propagation of Hydrodictyon was resulted from the asexual reproduction forming autocolony in each mother cell. The sexual and asexual reproduction processes of Oedogonium and the sexual reproduction process of Spirogyra were observed.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.350-357
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• 2014

Harmful Algal Bloom Alert System (HABAS) for drinking water supply is require to fast and accurate count as system monitoring of cyanobacterium occurrence and inducing a response action. We measured correlation between colony size and cell number including genus Anabaena, Aphanizomenon, Microcystis, Oscillatoria which are targeted at HABAS, deducted from standard formula, and suggested calculation method from colony size to the number of cell. We collected cyanobacteria samples at Han River (Paldang reservoir), Nakdong River (Dalseong weir, Changnyeonghaman weir) and Geum River (Gobok reservoir) from August to October, 2013. Also, we studied correlation between colony size and cell number, and calculated regression equation. As a result of correlation of harmful cyanobacteria by genus, Anabaena spp. and Aphanizomenon spp. having trichome showed high correlation coefficients more than 0.93 and Microcystis spp. having colony showed correlation coefficient of 0.76. As a result of correlation of harmful cyanobacteria by species, Anabaena crassa, Aphanizomenon flos-aquae, A. issatschenkoi, Oscillatoria curviceps, O. mougeotii having trichome showed high correlation coefficients from 0.89 to 0.96, and Microcystis aeruginosa, M. wessenbergii, M. viridis having colony showed correlation coefficients from 0.76 to 0.88. Compared with other genus Microcystis relatively showed low correlation because even species and colony size are the same, cell density and cell size are different from Microcystis strains. In this study, using calculated regression might be fast and simple method of cell counting. From now on, we need to secure additional samples, and make a decision to study about other species.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1698-1702
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• 2009

효과적인 저수지 수질관리를 위해서는 신뢰도 높은 수리 및 수질모델이 필요하며, 이러한 모델의 성능은 다양한 수문사상에 대하여 적용함으로써 검증할 수 있다. CE-QUAL-W2 모델(이후 W2)은 횡방향 평균 2차원 수리 수질 해석 모델로써 수체의 길이에 비해 폭이 상대적으로 좁고 수심이 깊은 우리나라 대부분의 저수지 지형에 적합한 모델이다. 본 연구의 목적은 기존 연구에서 가뭄년인 2001년과 평수년인 2004년 수문사상에 대하여 보정한 대청호 W2 부영양화모델을 최근 평수년인 2006년과 가뭄년인 2008년을 대상으로 검증하는데 있다. 모델의 검증은 물수지, 수온성층 구조 변화, 부영양화 해석에 중점을 두었으며, 실측자료와 모의결과의 적합성 비교 평가는 결정계수값$(R^2)$, AME(absolute mean error)와 RMSE(root mean square error)를 이용하였다. 저수지 물수지의 적합성을 검증하기 위하여 모의수위와 실측수위를 비교한 결과, $R^2$값이 2006년과 2008년에 각각 0.9945, 0.9972로 나타나 신뢰도가 높은 것으로 확인되었다. 계절별 성층구조 변화 모의 성능을 검증하기 위해 회남수역과 댐 앞 지점에서 수심별 수온의 모의값과 실측값을 비교하였다. 2006년의 경우 모델은 홍수기 동안 안정적으로 수온 성층현상을 모의하였으나, 댐 앞 지점에서 수온 약층이 형성된 구간에서 실측값과 다소 편차를 보였으며, 오차크기는 AME가 $0.561\sim2.088^{\circ}C$, RMSE는 $0.797\sim2.762^{\circ}C$범위였다. 반면, 가뭄년인 2008년에는 전 기간에 걸쳐 모두 안정적으로 저수지 수온 성층현상을 모의하였으며, 오차크기는 AME $0.413\sim1.162^{\circ}C$, RMSE $0.546\sim1.415^{\circ}C$ 범위였다. 조류의 생산성이 높은 표층에서 T-N, T-P 및 Chl-a 농도 모의결과를 장계교, 대정리, 회남대교, 댐 앞, 추동취수탑 및 문의취수탑에서 시계열로 실측값과 비교 검증한 결과, T-N과 T-P는 2006년과 2008년 모두 모든 비교 지점에서 모의값과 실측값의 시계열 변동이 매우 잘 일치하였으며, 홍수기 이외 기간에는 큰 변동 폭을 보이지 않았다. 그러나 기존 연구에서 확인된 바와 같이 7월 이후부터 T-P 모의값이 실측값을 과대 산정하는 경향을 보였는데, 그 원인은 산소 결핍상태에서 저니층에서 용출되는 철(Fe) 또는 망간(Mn)과 같은 이온 성분이 인과 흡착하여 침전되는 기작이 모의과정에 적절히 반영되지 않은 것이 원인으로 판단된다. 조류(Chl-a)농도의 경우, 2006년과 2008년에 모든 지점에서 모델은 조류의 발생과 시계열 변화를 적절히 모의하였으나, 2008년 1월부터 8월까지 댐 앞과 추동 및 문의취수탑에서는 모의값이 실측값을 과대 산정하는 경향을 보였다. 이는 해마다 그리고 계절별로 우점하는 조류 종이 상이한 반면, 모델에서는 이에 대한 매개변수를 적절히 고려하지 못한 것이 원인으로 판단된다.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.655-660
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• 2005

This study was carried out to evaluate of water purification in oxidation pond with filamentous algae mat. It is the water treatment process in the small rural streams to remove the organic materials and nutrients. We used the filamentous algae mat(FAM) which selectively predominate the filamentous algae to prevent the additional contamination by algae outflow. The removal efficiencies of COD, SS, T-N and T-P in Oxidation Pond with Filamentous Algae Mat were -2.5%, 84.7%, 63.9% and 89.2%, respectively. The removal efficiencies of T-N and T-P which are nutrients index were high. Results of this study would help us to determine the possibility of using the water treatment on the contaminated small rural streams.

• Journal of Korea Water Resources Association
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• v.47 no.12
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• pp.1135-1143
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• 2014

This study was carry out to evaluate of water purification in oxidation pond with filamentous algae mat. It is the water treatment process in the small rural streams to remove the organic materials and nutrients. We used the filamentous algae mat (FAM) which selectively predominate the filamentous algae to prevent the additional contamination by algae outflow, and we conducted a experiment on the water treatment process using the aquatic plants such as Eichhornia crassipes. The removal efficiencies (%) of water quality parameters were SS 80.9%, COD 74.6%, TN 76.8%, TP 84.4%, DTN 93.8% and DTP 98.3%, respectively. Temperature, a effect factor, was $21.8{\pm}5.9^{\circ}C$ during the operating period, according to temperature had no effect on the removal efficiencies of pollutants. Hydraulic retention time (HRT) strongly correlated with removal efficiencies (%) of SS and TP having r=0.414 (p<0.005), r=0.446 (p<0.005), respectively, and when HRT was 5day had highly removal efficiency (%) in SS and TP. TN and TP removal efficiency increased with ratio decreasing in both COD/TN and COD/TP of Influent.

• Korean Journal of Poultry Science
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• v.30 no.1
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• pp.55-59
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• 2003

A necrotizing skeletal myopathy was diagnosed in three flocks of 30,000 thirty-eight-week-old layer breeder chickens. The mortality attributed to the myopathy was 17.7%, 12.3% and 21.1% in flock A, B and C, respectively. Clinically, chickens were showed depression, anorexia, posterior paresis, inability to rise, incoordination, reluctance to move, and leg trembling and weakness. The most striking findings at necropsy was pale streaking in the muscles of the thighs and legs. Microscopic lesions included myofiber degeneration and necrosis with massive cellular proliferation interpreted as sarcolemmal nuclei proliferation. Plasma creatine kinase, asparte aminotransferase and akaline phosphatase were markedly elevated. In conclusion, author suggested that submitted chickens were affected by ionophores poisoning.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.166-172
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• 1992

The identification on blue-queen algae which were collected from paddy rice fields of the whole nation was carried out in 1991. The blue-green algae identified were 20 species in 5 families including 7 species in the Chroococcaceae. 1 species in the Chamaesiphonaceae. 1 species in the Pleurocapsaceae, 6 species in the Nostocaeae and 5 species in the Oscillatoriaceae. Among the blue-green algae, 6 species in 4 genera including Cylindrospernum, Anabaenopsis, Anabaena and Nostoc were characterized by heterocysts concerning with nitrogen fixation capacity. A concentrated population of Oscillatoria spp. induced soil flakes with blue tint in paddy rice fields. The genera. Spirulina and Oscillatoria, showed their specific motility.