• Journal of Environmental Science International
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• v.25 no.7
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• pp.937-950
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• 2016

Algal blooming in 4 major rivers introduces substantial impacts to water front activity. Concentrations of algae are increasing at major points along the Geum River. Ecosystem food webs can be affected by algal blooming because blue-green algae release toxic materials. Even though there have been many studies on blue-green algae, its causality to environmental factors has not been completely determined yet. This study analyzed the exclusive correlation between various hydrometeorological, water quality, and hydrologic variables and the cell number of cyanobacteria to understand causality of blue-green algae in the Geum River. A prewhitening process was introduced to remove the autocorrelation structure and periodicity, which is useful to evaluate the effective relationship between two time series.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.376-383
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• 2016

In this paper, the blue-green algae monitoring program of applying IoT(Internet of things) technologies is designed and implemented that can check out the status of the river's water quality in real time. The proposed system is to extract the image data from the camera of raspberry pi by an wireless network, and it is analyzed through the HSV color model. We measure the temperature using a DS18B20 1-wire temperature sensor. The extracted information of image data and temperature is then analyzed in C and Python programs for use with Raspberry Pi. The XML data in PHP program is made from the analyzed information and provides Web services. It also allows to refer the XML data using mobile devices.

• Korean Journal of Pharmacognosy
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• v.31 no.2
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• pp.252-255
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• 2000

In order to screen new radical scavenging principle which is expected to be antiaging drug lead, we have investigated 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the marine microalgae, greenalgae(10 speices), diatom (10 speices) and blue-green algae (10 speices). The significant activities$(IC_{50}:\;<100\;{mu}g/ml)$ were observed in 4 species of green algae (MA002, 006, 009, 010), 1 species of diatom (MA015) and 5 species of blue-green algae (MA017, 018, 019, 024, 025). Within the scope of family tested, MA009 $(IC_{50}:\;=78\;{mu}g/ml)$, MA015 $(IC_{50}:\;=38\;{mu}g/ml)$ and MA019 $(IC_{50}:\;=41\;{mu}g/ml)$ displayed the most significant activity. Among the marine microalgae tested at family level, cyanophycean blue-green algae was shown to be the most active family on screening of new bioactive compounds.

• Journal of Environmental Science International
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• v.18 no.3
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• pp.289-298
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• 2009

The blue-green algae which caused odor problem in the tap water are difficult to precipitate in sedimentation basin and clogged the filter void rapidly. The studies of this paper were not only oxidation, coagulation and sedimentation processes for effectively removing blue-green algae but yellow clay and polyamine for verification as coagulants aids. The results of this research are summarized as follows: Higher ozone dose(C) and longer contact time(T) were needed for a high degree of removing blue-green algae efficiency. the removal rate of blue-green algae was proportional to the $C\times T$ value. The removal percent of chlorophyll-a by sedimentation and filter without pre-ozonation was about 75% but 1 mg/L pre-ozonation could increase the removal percent of chlorophyll-a to 99% and more pre-ozonation could remove completely. Though the removal efficiency of turbidity could increased by high dose of chlorination, the dissolved organic carbon was increased. More chlorine dose from 4 to 10 mg/L dissolved organic carbon was decreased. Using yellow clay as coagulant aids increased density of floc so the settling velocity of floc become rising but polyamine could not increase settling velocity of floc though it could formated large floc.

• ALGAE
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• v.19 no.3
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• pp.227-234
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• 2004

A study on the dynamics of phytoplankton community and the physico-chemical environmental factors was performed biweekly from April 1998 to March 1999 in Youngchun Dam. A total 72 phytoplankton taxa was identified and dominant taxa were blue-green algae and diatoms. The highest value of phytoplankton standing crop (24,826cells·ml$^{-1}$) was observed in September 7, 1998, the blooming period of blue-green algae Phormidium sp., while the lowest (318cells·ml$^{-1}$) was measured in June 18, 1999. The phytoplankton communities were dominated by blue-green algae of Anabaena planktonica, Microcystis aeruginosa and Phormidium sp. during the summer and autumn periods and were dominated by diatoms of Synedra acus and Aulacoseira spp. during the spring and winter periods. Secchi disc transparency, chlorophyll-a, total nitrogen, total phosphorus and silicate concentration were varied in the ranges of 0.4-2.5 m, 2.4-32.2mg·m$^{-1}$, 0.845-2.352mg·l$^{-1}$, 0.005-0.093mg·l$^{-1}$, 0.2-15.7mg·l$^{-1}$, respectively. The trophic status of Youngchun Dam were estimated eutrophic according to Lake Trophic States Index (LTSI).

• Journal of Korean Society of Environmental Engineers
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• v.35 no.4
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• pp.289-293
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• 2013

The changes of phytoplankton community in downstream of the Nakdong River from 2002 to 2012 was investigated. Phytoplankton biomass (chlorophyll-a concentration) was gradually increased, but dominant species cell number was gradually decreased. In changes of percentage of dominant species cell number from 2002 to 2012, Diatoms was gradually decreased, but blue-green algae was gradually increased. In changes of annual percentage of dominant period, Diatoms showed high percentage from November to May, and dominant period (%) of diatoms was 56%~74% from June to September, also dominant period of diatoms was about 300 days every year. Percentage of dominant species cell number and dominant period of blue-green algae was 68%~94% and 26%~ 36% from June to September, respectively. And green-algae showed low percentage from April to September. In the transition patterns of diatoms and blue-green algae, Stephanodiscus spp. was the highest dominant species, from December to May, and Aulacoseira spp. and Fragilaria spp. were showed high dominant percentage from May to October. In the case of blue-green algae, Microcystis spp. was the highest dominant species, from May to November, also in the case of green algae, Actinastrum spp., Pediastrum spp., Micractinium spp. and Pandorina spp. were dominant species from April to September.

• Journal of Environmental Science International
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• v.24 no.4
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• pp.541-547
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• 2015

Formation of disinfection by-products (DBPs) including trihalomethans (THMs) and haloacetic acids (HAAs) from chlorination of six different species (Chlorella vulgaris, Scenedesmus sp., Anabaena cylindrical, Microcystis aeruginosa, Asterionella formosa and Aulacoseira sp.) of algal extracellular organic matter (EOM). The EOM characteristics evaluation of six algal species reaching at the stationary phase in the growth curve showed most of its SUVA254 showed below 1 and this means hydrophilic organic matter is much higher than hydrophobic organic matter. Chloroform formation potential (CFFP), dichloroacetic acid formation potential (DCAAFP) and trichloroacetic acid formation potential (TCAAFP) were mainly composed of THMFP and HAAFP in the EOM of various algal species. In the case of THMFP/DOC and HAAFP/DOC values, EOM of blue-green algae has appeared highest and EOM of green algae and diatom in order. THMFP/DOC was higher than HAAFP/DOC in EOM of blue-green algae. In comparison of formation potential by unit DOC composed of HAAFP in algal species EOM, DCAAFP/DOC was 1.5 times to 7.5 time higher than TCAAFP/DOC in the EOM of blue-green algae, while DCAAFP/DOC was found to be relatively high compared to TCAAFP/DOC in the EOM of green algae and diatom.

• The Journal of Natural Sciences
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• v.6 no.1
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• pp.5-39
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• 1993

The Blue-green algae collected from whole coasts of Korea were investigated morphotaxonomically in order to list up Korean marine Cyanophyta and clarify their taxnomic position. As a result, 36 species, 20 genus, 6 families belonging to 3 orders were identified. Among these, 14 species were recorded for the first time in Korea. They are Chroococcus minutus (K$\"{u}$tzing) N$\"{a}$geli, Merismopedia punctata Meyen, Microcystis ichtyoblabe K$\"{u}$zing, Dermocarpa leibleiniae (Reinsch) Born. et Thur., Hydrocoleum confluens (Setchell et Gardner) Drouet, Lyngbya sordida (Zanard.) Gomont, Phormidium forveolarum (Mont.) Gomont, Phormidium hansgieri Schmidle, Skujaella hildebrandtii (Gomont.) de Toni, Sphaeronema lithophila (Ercegovic) Umezaki, Spirulina tenerrima K$\"{u}$tzing, Hormothamnion enteromorphoides Grunow, Michrochaete aeruginea Batters, Michrochaete grisea Thuret ex Born. et flah.. Using the phase contrast microscope and the Nomarski interference micrope, we made photomicrographs of minute blue green algae. The cellular inclusions especially PHB(poly-$\SS$-hydroxy-butyrate) granules of the blue-green algae identified were investigated. The species clearly characteriged to have PHB granule were Lyngbya confervoides, L. semiplena, Phormidium corium, Sirocoleum kurzii, Hormothamnion enteromorphoides and Calothrix crustacea. These result would be fundamental data for estabilishing phylogenetic system of blue-green algae based on physio-biochemical characteristics in future.

• 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.

• ALGAE
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• v.18 no.2
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• pp.135-143
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• 2003

The seasonal dynamics of phytoplankton and trophic state were evaluated weekly at three sites in the Lake Unmoon from May to November 2001. The seasonal succession pattern of phytoplankton community in the Lake Unmoon showed that the dominant species were; i) diatoms during the late spring, ii) dinoflagellates in June, iii) blue green algae, diatoms and dinoflagellates in July, iv) green algae and blue green algae in August, v) blue green algae in September and early November, and vi) diatoms in November. Members of Microcystis were dominant from middle August to late October and members of Aulocoseira appeared as important species in autumn in the Lake Unmoon. The concentration of chlorophyll-a ranged from 2.4 to 23.0 mg ${\cdot}m^{-3}$ (average: 8.6 mg ${\cdot}m^{-3}$) during the study period. Concentrations of total phosphorus were high during the period from July to November with the maximum of 0.028 mg ${\cdot} l^{-1}$. The average N/P ratio was 121, indicating that concentrations of phosphorus may determine the high algal biomass in the Lake Unmoon. Concentrations of silicate were higher in the Lake Unmoon (average value: 10.016 mg ${\cdot}$ l-) than in other lakes (average values: 1.074-4.408 mg ${\cdot}$ l-), suggesting high potential of diatom growth. The average trophic state index in the Lake Unmoon was 52, which was close to eutrophic state, and the trophic state trend was increasing steadily since 1999.