• Korean Journal of Construction Engineering and Management
• /
• v.16 no.3
• /
• pp.49-58
• /
• 2015

In order to determine how much a new green building reduce the environmental impacts, it is necessary to establish the reference target for comparison. Therefore, this study aims to establish the reference target by evaluating the environmental impacts of existing buildings. To ensure this end, this study evaluated the environmental impacts(Global warming potential, ozone layer depletion potential, acidification potential, eutrophication potential, photochemical ozone creation potential, and abiotic depletion potential) of 17 existing elementary school buildings, which are located in Seoul, Busan, Daegu, and Gwangju, by using the hybrid LCA model. As a result, the environmental impacts of the case buildings were clearly distinguished in different regions. Therefore, this study presented the reference targets which are appropriate to each region. For example, the reference targets for global warming potential, which can be used in Seoul, Busan, Daegu, and Gwangju, are 3.76E+03, 1.90E+03, 2.63E+03, $2.81E+03kg-CO_2\;eq./m^2$, respectively. The presented reference targets are expected to be useful for understanding how much environmental impacts can be reduced when a new green school building is constructed.

• Journal of Power System Engineering
• /
• v.19 no.2
• /
• pp.84-89
• /
• 2015

The occurrence of algae caused by eutrophication of fresh water is a pollution source to destroy the aquatic environment. When the high voltage electric field is applied in the water, When a high voltage is applied to the electric field in the water, the algae can be broken the balance of cell membranes, and is dead. In this paper, we develop a water quality improvement system for generating an electric field having a higher energy than the zeta potential when a high voltage is applied to 4,000V. To ensure the mobility of the water quality improvement system, we designed the PV generation system using the optimal size technique that is based on the model of power lack ratio. By evaluating the output characteristics of the water quality improvement system, power generation characteristics of the PV generation system, and battery charging characteristics, we can show that the proposed system can be applicable to the water quality improvement system inhibiting the growth rate of the algae in the fresh water.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.3
• /
• pp.270-276
• /
• 2014

Seasonal characteristics of water and sediment qualities and potential effects of the freshwater discharge from a small tide embankment interior in a coastal area in Goheung county were investigated from May to September in 2012. Chemical oxygen demand values (COD) were mostly higher than 2 mg/L in summer ebb tide, which exceed the standard value of water quality criteria II of acceptable level for aquaculture activities. Nitrogen and phosphorus were found as the limiting nutrients for algae growth in summer and fall and in spring, respectively. Nitrogen was the limiting nutrient for diatom growth in the whole studied period. The sudden high values of COD, ammonia, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) were found in water sample collected from station 5 which located in front of the tide embankment sluice gate during spring ebb tide. The freshwater discharge form the tide embankment interior maybe affected the survey areas during a short time interval. Mean values of eutrophication index of the surveyed coastal region in spring, summer and fall were all bigger than 1. Water quality was mostly considered at level II which acceptable for aquaculture activities. Sediment quality in this study was generally in the range of standard for fisheries environment.

• Journal of Environmental Science International
• /
• v.8 no.1
• /
• pp.75-81
• /
• 1999

In recent years increasing production and disposal of wastewater have caused an accelerated eutrophication of receiving waters. Therefore, in order to alleviate the detrimental impact of wastewater discharge, there is an increasing demand for removing the main nutrients, nitrogen and phosphorus, as well as the organic content of the waste water prior to disposal. This is effectively achieved by extended conventional treatment technology. However, the working expenses and energy requirements of such advanced treatment systems are rather high. So in a sparsely populated rural community is required development of wastewater treatment system combined with the regional characteristics. In this study, the systems are planted with Reeds and Amaryllis In A.C and estimated purification potential of system. The results obtained are as follows. BOD removal rate is 20% in the early stage, the last removal rate is 35% in A.C process and is 65% in Amaryllis+A.C process and is 50% in Reed+A.C process. T-N removal rate by Amaryllis is average 2.6g/$m^3$ㆍd, T-N removal rate by Reed is average 1.76g/$m^3$ㆍd. T-P removal rate by Amaryllis is average 0.27g/$m^3$ㆍd, T-P removal rate by Reed is average 0.25g/$m^3$ㆍd. BOD removal rate constant with retention time is 1.4494(1/d), T-N removal rate constant is 0.5428(1/d), T-P removal rate constant is 0.5287(1/d).

• Journal of Environmental Health Sciences
• /
• v.9 no.1
• /
• pp.49-62
• /
• 1983

Evaluation of water quality of Yeong San river and Seomjin river by using of newly simplified MBOD method was performed. Of course, thought that there is some differences between nutrient demands of heterotrophic bacteria and those of Algae which obtain it by photosynthesis, but it has little influence on evaluation of Algae Growth potential. The result of this study were as follows: 1) In both river, the value of Chemical analysis and MBOD method of inorganic salts reveals as nearly same result. 2) Though organic pollution of Seomjin river is less than that of Yeongsan but inorganic contamination is somewhat advanced BOD 2.8 ppm. and MBOD 340 ppm. in Seomjin river but BOD 22 ppm. and MBOD 480 ppm. in Yeongsan river. 3) Both river have tendency to reveal higher Nitrogen value is MBOD=MBOD -P

• Journal of Environmental Science International
• /
• v.21 no.8
• /
• pp.989-996
• /
• 2012

Nitrate contamination of water environments can create serious problems such as eutrophication of rivers. Conventional biological processes for nitrate removal by heterotrophic denitrification often need additional organic substrates as carbon sources and electron donors. We tried to accelerate biological denitrification by using bioelectrochemical reactor (BER) in which electrode works as an electron donor. Denitrification activity of 8 environmental samples from various sediments, soils, groundwaters, and sludges were tested to establish an efficient enrichment culture for BER. The established enrichment culture from a soil sample showed stable denitrification activity without any nitrite accumulation. Microbial community analysis by using PCR-DGGE method revealed that dominant denitrifiers in the enrichment culture were Pantoea sp., Cronobacter sakazakii, and Castellaniella defragrans. Denitrification rate ($0.08kg/m^3{\cdot}day$) of the enrichment culture in BER with electrode poised at -0.5 V (vs Ag/AgCl) was higher than that ($2.1{\times}10^{-2}kg/m^3{\cdot}day$) of BER without any poised potential. This results suggested that biological denitrification would be improved by supplying potential throughout electrode in BER. Further research using BER without any organic substrate addition is needed to apply this system for bioremediation of water and wastewater contaminated by nitrate.

• Journal of Environmental Health Sciences
• /
• v.23 no.1
• /
• pp.18-27
• /
• 1997

The isolation, morphological study and growth characteristics of the algae were investigated from Lake Chuam. The isolated algae were applied the Agal Growth Potential test. The method of isolation and purification of the algae were used to Agar plating(AP), nutrient enrichment(NE), dilution(DI) and micro capillary technique(MC). Total isolated algae were 21 species. They were composed of Cyanophyceae, Dinophyceae, Bacillariophyceae, Euglenophyceae and Chlorophyceae. The numbers of algal strain by isolation technique were highest in dilution(21 species), and those of the rests were showed in order of NE > MC > AP. The sizes of isolated Selenastrum and Scenedesmus were $1.8\pm 1.4 \mu m$, $3.3\pm 0.9 \mu m$ in diameter and $6.4\pm 2.3 \mu m$, $13.6\pm 1.9 \mu m$ in length respectively. The morphology of isolated algae and NIES-collection strain was very similar each other, but the size was smaller isolated algae than that of NIES-collection. The optimum culture condition of isolated Selenastrum and Scenedesmus was about 30$\circ$C(25$\circ$C-35$\circ$C) in temperature and the maximum growth was appeared between 7,000 lux and 8,000 lux in the light intensity. The comparison of $\mu$(specific growth rate) on the concentration of nutrients such as nitrate and phosphate, isolated Selenastrum was appeared maximum it at 1.0 mg $NO_3-N/l$ but NIES-collection strain was showed 95% of maximum it at same nitrate concentration. Maximum g of isolated algae and NIES-collection strain in Scenedesmus onto nitrate concentration were very similar with the result of selenastrum. The specific growth rates of isolated algae and NIES-collection strain on the gradient concentration of phosphate were showed 0.72/day and 0.70/day at 0.02 mg $PO_4-P/l$ in Selenastrum but those of Scenedesmus were appeared 0.61/day and 0.57/day at same concentration $PO_4-P$.

• Journal of the Korean Magnetic Resonance Society
• /
• v.19 no.2
• /
• pp.67-73
• /
• 2015

The microcystin is a cyclic heptapeptide from metabolites of cyanobacteria in the genera mycrocystis, anabaeba as a result of eutrophication. It has been known that microcystin-LR is a potent inhibitor of the catalytic subunits of protein phosphatase-1 (PP-1) as well as powerful tumor promoter. The active site of microcystin actually has two metal ions $Fe^{2+}/Zn^{2+}$ close to the nucleophilic portion of PP-1-microcystin complex. We report the isolation and purification of this microcystin-LR from cyanobacteria (blue-green algae) obtained from Daechung Dam in Chung-cheong Do, Korea. Microcystin-LR was extracted from solid-phase extraction (SPE) sample preparation using a CN cartridge. The cyanobacteria extract was purified to obtain microcystin-LR by HPLC method and identified by LC/MS. The detail structural studies that can elucidate the possible role of monovalent and divalent metal ions in PP-1-microcystin complexation were carried out by utilizing molecular dynamics. Conformational changes in metal binding for ligands were monitored by molecular dynamic computation and potential of mean force (PMF) using the method of the free energy perturbation. The microcystin-metal binding PMF simulation results exhibit that microcystin can have very stable binding free energy of -10.95 kcal/mol by adopting the $Mg^{2+}$ ion at broad geometrical distribution of $0.5{\sim}4.5{\AA}$, and show that the $K^+$ ion can form a stable metal complex rather than other monovalent alkali metal ions.

• Korean Journal of Ecology and Environment
• /
• v.50 no.1
• /
• pp.79-95
• /
• 2017

Euiam and Paldang Reservoirs have often been facing water quality problems, such as eutrophication, algal blooms and off-flavors by treated wastewater effluent (TWE) in the North-Han and the Han River basins, but little is examined on the direct biological effect of TWE. This study tested algal growth potential (AGP) of four TWEs discharged into Euiam and Paldang Reservoirs to evaluate water fertility in September 2014 and March and September 2015. Test alga was used Anabaena circinalis isolated from Paldang Reservoir. Mean concentration of T-N and T-P in TWEs was $3,956.7{\mu}g\;N\;L^{-1}$ and $50.8{\mu}g\;P\;L^{-1}$, and the proportion of $NO_3-N$ and $PO_4-P$ to the total fraction was 72.1% and 40.8%, respectively. Both N and P were high in TWEs, but much higher N than P concentration indicates strong P-limitation. As a consequence, the maximum AGP was determined by $PO_4-P$ concentration (r=0.998, p<0.01). Mean AGP value was $15.4mg\;dw\;L^{-1}$ among four effluents indicating its eutrophic condition. Due to the establishment of tertiary (advanced T-P) treatment method in the studied plants recently, P concentration was significantly decreased in TWEs compared to the years prior to 2012. However, P concentration seems to be still high enough to cause eutrophication and algal blooms. Therefore, wastewater treatment to P-free level needs to be considered if effluents are directly discharged into the drinking water resources.

• Korean Journal of Environmental Agriculture
• /
• v.33 no.4
• /
• pp.314-320
• /
• 2014

BACKGROUND: Run off from agricultural sites contaminates water bodies with nitrogen which is toxic and causes eutrophication when excessively accumulated. Hence, the interest in monitoring nitrogen toxicity in aquatic environment has been continuously increasing. METHODS AND RESULTS: To detect a real time toxicity of various nitrogen compounds, we applied biomonitoring method (biosensor) based on sulfur-oxidizing bacteria (SOB). The toxicity biomonitoring test was conducted in semi-continuous mode in a reactor filled with sulfur particles (2~4 mm diameter) under aerobic condition. Relative toxicity was simply determined by measuring the change in electrical conductivity (EC). Various nitrogenous compounds at different concentrations were evaluated as a potential toxic substance. Nitrite was found to be very toxic to SOB with a 90% inhibition even when the concentration as low as 3 mg/L. However, nitrate and ammonia have any inhibitory effect on SOB's activity. CONCLUSION: The biosensor based on SOB responded sensitively to nitrite even at substantially low concentrations. Therefore, it can be used as a reliable biological alarm system for rapid detection of contaminants due to its simplicity and sensitive nature.