• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.119-130
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• 2006

As unialgal cultures to examine the growth kinetics of an algal species, Microcystis aeruginosa was grown in chemostats with nitrogen and phosphorus limitation. The nutrient concentrations of $NH_4\;^+\;and\;PO_4\;^{3-}$ to limit the growth of M, aeruginosa were approximately 200 ${\mu}M$ and 7 ${\mu}M$, respectively. Cell size of the algae decreased towards the $NH_4$-nitrogen limitation under a constant dilution rate, while it increased in the $PO_4$-limitaion. The cell quota of nitrogen under nitrogen-limited conditions was 6.1 ${\mu}mol$ mg $C^{-1}$ and, under nitrogen sufficient conditions, ranged from 9.5 ${\mu}mol$ mg $C^{-1}$ to 12.4 ${\mu}mol$ mg $C^{-1}$. In addition to the cell quota, the half-saturation constants for nitrogen uptake ($K_s$) and the growth rate (${\mu}_m$) was 36 ${\sim}$ 61 ${\mu}M$ and 0.28 ${\sim}$ 0.35 ${\mu}mol$ cell ${\cdot}$ $hr^{-1}$ to show high values in comparison with other algal species. As the limiting concentration, cell quota and uptake rate of M. aeruginosa were higher than those of any other species, the its nitrogen requirement would be great. In the other side, as the half saturation constant ($K_s$) for nitrogen uptake was higher, and the ratios ofmaximum uptake rate ($V_m$) and $K_s$ was relatively low, the species would have the low competitive ability in the low nitrogen concentration in the ambient water. However, the low concentration of nitrogen in the Nakdong River during the Microcystis outbreak would be the inevitable results of the algal blooms. In the lower Parts of the Nakdong River, the nutrient status was coupled with the growth kinetics of the blooming algae to have clear seasonal variations through a year.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.77-93
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• 2000

Field survey on the spatio-temporal distribution of water quality and chlorophyll a concentration, and the environmental factors on the variation of phytoplankton biomass were carried out at the 23 stations for four seasons in the Shiahae, southwestern coast of Korean Peninsula from February to October in 1995. I made an analysis on biological factor as chlorophyll a concentration as well as environmental factors such as water temperature, salinity and nutrients; ammonia, nitrite, nitrate, dissolved inorganic nitrogen, phosphate, N/P ratio, silicate and Si/P ratio. The waters in the Shiahae were not stratified due to the tidal mixing and high velocity of tidal current. And the high productivity in photic layer were supported by high nutrients concentration from freshwater on lands and bottom waters The low depth of transparency in the Shiahae had a bad influence upon primary production and marine biology. In Shiahae had a sufficient nutrients for primary production during a year. Especially dissolved inorganic nitrogen and silicate were high, the other side, phosphate was low. The source of nutrients in summer and silicate supply depend on input of freshwater from lands, the other side, dissolved inorganic nitrogen and phosphate were depend on rather supplied from bottom layer by the mixing and input of seawater from outside than input of freshwater from lands. Phosphate seemed to become a limiting nutrient for the primary production at all area of Shiahae in winter and at the northern parts in other seasons. However, dissolved inorganic nitrogen seemed to do it at the southern parts in other seasons except winter. Silicate didn't become a limiting nutrient for diatoms in Shiahae. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round, it was controlled by the combination of the several environmental factors, especially of nitrogen, phosphorus and the physical factors such as light intensity. [Spatio-temporal distribution, Seasonal fluctuation, Nnutrients, Chlorophyll a, Environmental factors, Nutrient source, Limiting Nutrient, Light, Shiahae] .

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.261-269
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• 2001

The purpose of present study was to introduce a multimetric approach, so called the Index of Biological Integrity (IBI) as a tool for evaluations of water environments. We used 11 metric systems for the IBI to evaluate stream conditions, based on the fish community, and modified 5 original metric attributes suggested by Karr (1981). Overall IBI values in Kap Stream averaged 36 (n = 5) and ranged 17${\sim}$49, indicating a 'fair condition' according to the modified criteria of Karr (1981) and U.S. EPA (1993). However, there were distinct differences in the IBI values among 5 study sites. The IBI values at sites 1, 2, and 3 were 49, 45, and 41, which indicated 'good${\sim}$excellent', 'good', and 'fair' condition, respectively, while values at sites 4 and 5 were 17 and 29, which indicated 'very poor' and 'poor', respectively. The minimum IBI at site 4 was probably due to continuous inputs of wastewater from wastewater disposal plants. The condition at site 4 resulted in predominance of tolerant species (50%), omnivore species (50%), and high abnormalies (43%). In the mean time, the IBI value at site 5, located near 5km downstream from the site 4, increased compared to that of site 4, and this seemed to be a result of recovery of water quality as the polluted water goes downward. We believe that present bioassessment methodology of IBI applied in this study may be used as a key tool to set up specific goals for stream restoration plans and dentify recovery levels of lotic ecosystems after restoration activities(i.e., prevention of point-source pollutant input, restoration of physical habitats, construction of riparian vegetation) as well as a biological measure diagnosing current stream conditions.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.246-254
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• 2017

Microcystin-LR (MC-LR) is one of most abundant microcystins, and is derived from blue-green algae bloom. Advanced oxidation processes (AOPs) are effective process when high concentrations of MC-LR are released into a drinking water treatment system from surface water. In particular, UV-based AOPs such as UV, $UV/H_2O_2$, $UV/O_3$ and $UV/TiO_2$ have been studied for the removal of MC-LR. In this study, UV-LED was applied for the degradation of MC-LR because UV lamps have demonstrated some weaknesses, such as frequent replacements; that generate mercury waste and high heat loss. Degradation efficiencies of the MC-LR (initial conc. = $100{\mu}g/L$) were 30% and 95.9% using LED-L (280 nm, $0.024mW/cm^2$) and LED-H (280 nm, $2.18mW/cm^2$), respectively. Aromatic compounds of natural organic matter changed to aliphatic compounds under the LED-H irradiation by LC-OCD analysis. For application to raw water, the Nak-dong River was sampled during summer when blue-green algae were heavy bloom in 2016. The concentration of extracellular and total MC-LR, geosmin and 2-MIB slightly decreased by increasing the LED-L irradiation; however, the removal of MC-LR by UV-LED (${\lambda}=280nm$) was insufficient. Thus, advanced UV-LED technology or the addition of oxidants with UV-LED is required to obtain better degradation efficiency of MC-LR.

• Korean Journal of Environmental Agriculture
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• v.12 no.1
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• pp.41-49
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• 1993

The Study was conducted to develope the low temperature tolerant methane-producing bacteria(LTTB) and to increase the efficiency of anaerobic fermentation for the treatment of agricultural and livestock wastes at low temperature. The samples were collected from muddy soil, water logged sediment, organic layer and anaerobic sludge at three latitudes, $34.8{\sim}37.4\;^{\circ}N(Korea)$, $41.4\;^{\circ}N(USA)$ and $54.5{\sim}56.9\;^{\circ}N(Canada)$. They were used for determination of the methanogenesis rates for isolation and identification of the LTTB. The methanogenesis rate of smaples at low temperature were higher in the cellulose medium than methanol medium. The methanogenesis rate in the samples of subarctic region were $15{\sim}19$ moles/ml during 30 days at low temperature($8\;^{\circ}C$), whereas not detected in the samples of temperate region. The methanogenesis rate in the enrichment culture of subarctic samples were inhibited by the $40\;{\mu}g/ml$ of streptomycin + vancomycin or ampicillin + oleandomycin which were not effect to the methanogens. An inhabitation of high temperature tolerant methane producing bacteria was identified in the samples of temperate region, whereas that of the LTTB growing at $8{\sim}13^{\circ}C$ was identified in the subarctic region.

• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.109-121
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• 2001

Water environment and freshwater algae were studied in the upstream of the Tamjin River Dam. Among the environmental factors, DO concentration in the Tamjin River ranged from 9.0 mg $O_2/l$ to 9.2 mg $O_2/l$, pH from 7.0 to 7.1 and conductivity from $98{\mu}S/cm$ to $100{\mu}S/cm$. Average concentration of $NH_4$ and $NO_3$ ranged from $40{\mu}g\;N/l$ to $56{\mu}g\;N/l$ and from $489{\mu}g\;N/l$ to $611{\mu}g\;N/l$, respectively. $NO_3$ was more plentiful above 9~15 fold than that of $NH_4$. Average concentrations of soluble reactive phosphorus and soluble reactive silicon were $2{\mu}g\;P/l$ and 1.6 mg Si/l, respectively. Particulaly, Si nutrient increased by heavy rain events during summer season. The ratios of N/P and Si/P ranged from 248 to 261 and from 640 to 740, respectively. It is assumed that P would be limiting nutrient on the freshwater algal growth. Average content of planktonic chlorophyll-a ranged from $5{\mu}g/l$ to $13{\mu}g/l$. Mean contents of chlorophyll-a, phaeo-pigment and ash-free dry matter of periphyton were $50.3mg/m^2$, $11.9mg/m^2$, $11.5g/m^2$ in the main stream and $30.1mg/m^2$, $5.6mg/m^2$, $7.8g/m^2$ in the tributary. By comparison of the epilithon biomass, the main stream was higher with 1.5~2.1 fold than the tributary. The impotant algae were composed of diatom Achnanthes linearis, A. minutissima, Fragilaria crotonensis, Gomphonema gracile, Tabellaria flocculosa and blue-green algae Microcystis aeruginosa. In the relative abundance of the phytoplankton and epilithon, the serial dominance were diatom > green algae > blue-green algae, and diatoms were very abundant in comparison with other algal phylum.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.36-43
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• 1985

This study was conducted to find out the consumptive use of irrigated water for calculation of a duty of water in paddy rice. Tall statured Japonica rice variety is Jinju(late). Short statured Tongil varities-Taebaek(early) and Pungsan(medium) were planted on the experimental farm of kyungpook National University in 1983. The results obtained in this study were as follows : 1. The average temperature of the underwater surface was $27.1^{\circ}C$ and the maximum was recorded at beginning of the August. 2. The evapotranspiration was gradually increased after transplanting and showed the peak from booting to heading stage of rice varieties. The average evapotranspiration through the whole growing period was 8. 43mm/day(Jinju) for tall statured Japonica variety, and 7.78mm/day(Taebaek), 7.71mm/day(Pungsan) for short statured Tongil varieties. 3. The ratio of evapotranspiration to pan-evaporation through the whole growing period was 1.71 for Japonica variety and 1.55 for Tongil varieties. 4. K-value in Blaney & Criddle formula was 1.41 for Japonica variety and 1.30 for Tongil varieties. Coefficient consumptive use of water (Kc-value) was 1.40 for Japonica variety and 1.27 for Tongil varieties. 5. It appeared that the water consumption in the 6, 8 cm pot is more than that of 2, 4 cm pot but the number of panicle of the 6, 8 cm pot is somewhat less than that of 2, 4 cm pot. The deeper water level is the less tiller became. It is consindered that 2 cm pot is more profitable than the others.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.1
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• pp.1-8
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• 2005

We estimated the loadings of nitrogen and phosphorus flowing into Gwangyang Bay front river for monthly interval from April to December of 2003. We analyzed the concentrations of nitrogen and phosphorus in water and estimated the flowing rates of fresh water in 34 rivers. The amounts of water flowing into the Gwdngyang Bay from Sum-Jin River was 51-76％ in the total inflow of the river. The river water over 96％ of discharge was from Sumjin River, Dong River, Ju-Kyo River, Seo River and Shinkyum River. The flowing patterns of nitrogen and phosphorus into Gwangyang Bay were similar to the flowing of river. The nitrogen and phosphorus loadings into the Bay were higher in July and August than in dry seasons. In particular, the concentrations of phosphorus were high in Namshu River, Deukyang River and Kilho River sewage during in dry seasons. The range of DIN and TN loadings from Sumjim River were 46-66％ and 36-64％, respectively. The loading of DIP and TP from Sumjim River were 2-55％ and 12-67％, respectively. These results show that the most efficient control of N. p flow into Gwangyang Bay is to restrain the inflows of N, p from Namshu River, Deukyang River and Kilho River and to restrain the flows of N, p from Dong River, Ju-Kyo River and industrial plant. The DIN/DIP atom ratio in river water was about 18 in July and August, while the ratio was more higher in dry seasons than July and August of rainy seasons. The TN/TP atom ratio in river water was about 7 in rainy seasons, while the ratios were higher than 100 in the other months of dry seasons.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.6
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• pp.590-598
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• 2005

An adequate method to identify chromium separation, Cr(III) and Cr(VI), in water samples were studied by using High Performance Liquid Chromatography(HPLC) coupled with Inductively Coupled Plasma Mass Spectometer(ICP-MS) equipped with Dynamic Reaction Cell(DRC). The characteristic distribution of Cr(III) and Cr(VI) in the raw water taken at the six water intake stations in Seoul, was analyzed by the method developed by the authors. The chromium species separated by HPLC was isocratically conducted by using tetrabutylammonium phosphate monobasic(1.0 mM TBAP), ethylenediaminetetraacetic acid(0.6 mM EDTA) and 2% v/v methanol as the mobile phase. 5% v/v methanol was used as flushing solvent. A reactive ammonia($NH_3$) gas was used to eliminate the potential interference of $ArC^+$. Several Parameters such as solvent ratio, pH, flow rate and sample injection volume were optimized for the successful separation and reproducibility. Although it has been reported thai the separation sensitivity of Cr(III) is superior to that of Cr(VI), the authors observed Cr(VI) was more sensitive than Cr(III) when ammonia($NH_3$) gas was used as the reaction gas. It took less than 3 minutes to analyze chromium species with this method and the estimated detection limits were $0.061\;{\mu}g/L$ for Cr(III) and $0.052\;{\mu}g/L$, for Cr(VI). According to the results from the analysis on chromium species in the raw water of the six intake stations, the concentrations of Cr(III) ranged from 0.048 to $0.064\;{\mu}g/L$(ave. $0.054\;{\mu}g/L$) while that of Cr(VI) ranged from 0.014 to $0.023\;{\mu}g/L$(ave. $0.019\;{\mu}g/L$). Recovery ratio was very high($90.1{\sim}94.1%$). There were two or three times more Cr(III) than Cr(VI) in the raw water.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.772-778
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• 2012

In order to develop the application method of compost manure (CM) and liquid manure (LM) for rice cultivation, experiments were conducted at silty loam paddy field in Gochang, Jeonbuk, a LM applied rate as N%; non-application, chemical fertilizer (CF) 100%, CM 50%+LM 50%, CM 30%+CF 70% and CM 30%+LM 70% as basal and additional fertilizer. $NH_4^+$-N content in paddy soil was higher with CF 100% application than the split application of compost and liquid pig manure fertilizer during the early stage of rice growth. However, there was no significant difference in the later part of rice growth. Amount of $NO_3^-$-N in leachate was decreased in CM 30%+LM 70% and CM 30%+CF 70% split applications compared to CF 100%. Amounts of OM and Avail $P_2O_5$, Exch. cations in soil of experiment after were highest with the split application of CM 50%+LM 50% and CM 30%+LM 70%. Amount of nutrient uptake of plants were no significant difference between the split application plots of CM and LM, but nitrogen utilization rate was 66% in average CM 50%+LM 50% and CM 30%+LM 70% to compared CF 100%. The rice yield of CM 50%+LM 50% was lower (90%) comparing that of CF 100% ($557kg\;10a^{-1}$). But the yield in CM 30%+CF 70% and CM 30%+LM 70% reached 96% in average, which did not show significant difference with that of CF 100%. Accordingly, LM 70% or CF 70% split application after CM 30% application was helpful in enhancing the physicochemical property of soil as well as reducing CF. It could be evaluated that this application in segmentation was better in productivity improvement and soil pollution reduction than the esinultaneous application of LM 100% in terms of split application in times of requirement for plants.