• Journal of Environmental Science International
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• v.15 no.10
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• pp.935-943
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• 2006

This study focuses on analyzing the inflow characteristic of contaminants of city water that flows into a main water system like a reservoir, and intends to provide basic data which can be efficiently reflected on water quality management policy and decision making of a reservoir. The conclusion obtained from the analysis of the inflow of a main water system by analyzing the inflow property of city water contaminants is as follows. In the case of Chungju-cheon stream which is the city water, pollution load from the basic outflow is low when it rains, and with high load of basic outflow during the dry season, due to the discharge of pollutants from the city, the quality of water becomes worse. In the case of Chungju-cheon stream, average BOD is $4.53mg/{\ell}$ when it rains, and the contaminants increase and flow in about 7.8% compared to the average BOD during the average droughty season. The average SS concentration in water is $798.67mg/{\ell}$ and increased 97.2% compared to the average droughty season.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.196-208
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• 2015

This study analyzed the characteristics of sewer flow and its water quality, and investigated changes in the characteristics in three areas where the sewer rehabilitation projects have been carried out. In S1 area, the patterns of the flow became regular and the range of the fluctuation decreased after the sewer rehabilitation. The flow and its BOD concentration increased. The infiltration/inflow and exfiltration showed clear distinction before and after the sewer rehabilitation in this area. In S2 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased considerably after the sewer rehabilitation. Big decrement in stormwater inflow but small in exfiltration appeared in this area. In S3 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased in a small rate in this area.

• Journal of Korean Society of Water and Wastewater
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• v.9 no.4
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• pp.73-86
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• 1995

The propriety of the numerical model application was examined on Paldang resevoir and its inflow tributaries located in the center of the Korean peninsula and the long term water quality forecast of the oxygen profile was carried out in this syduy. The input data of the model was the capacity of the reservoir, catchment area, percolation, diffusion rate, vertical mixing rate, dissolution rate from the bottom of the reservoir, outflow of the resevoir, water quality measurement and meteorology data of the drainage basin, and the output result was the annual estimation value of the dissolved oxygen concentration and the biochemical oxygen demand. The modeling method is based on the measured or calculated boundary condition dividing the water area into several blocks from the macorscopic aspect and considering the mass balance in these blocks. As the result of the water quality forecast, it was expected that the water quality in Northern Han River and Paldang reservoir would maintain the recent level, but that the water quality in the Southern Han River and its inflow tributary would worsen below the grade 4 of the life environmental standard from around 2000 owing to the decrease of DO concentration and the increase of BOD concentration.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.115-123
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• 2000

The dynamics of water quality and phytoplankton population had examined by monthly sampling from the upper to the lower part of watergate in an artificial Shihwa Reservoir in which situated near newly cities and incustrial complex on the west coast of Korea from January 1997 to December 1998. Among environmental factors, yearly average concentration of chl-a, TN and TP seemed to eutrophic or hypertrophic conditions that ranged 146.4~245.8 $\mu\textrm{g}$/$\ell$, 1.6~2.7 mg N/$\ell$, 258~448 $\mu\textrm{g}$ P/$\ell$, 26.9~80.7 $\mu\textrm{g}$/$\ell$, 1.0~2.4 mgN/$\ell$ and 74~239 $\mu\textrm{g}$P/$\ell$ respectively. Water quality was extremely deteriorated to consistently accumulation into inner reservoir by load of pollutants from autochthonous and allochthonous until early July 1997 after embankment. Water pollution of Shihwa Reservoir was remarkble on the biological condition with largely persistent bloom of phytoplankton and increase rate of standing crops was 2.4/yr. The development trend of phytoplankton in water ecosystem were closely related to increse and decrease of physico-chemical factors and those scale seemed to control by nutrient contents. Inflow of seawater into reservoir to object of repair of water quality. As to see dominant species, composition of those composed to mostly freshwater algae before inflow of seawater such as Selenastrum capricornutum of green algae, cyclotella atomus, C. meneghiniana of diatom and Microcystis spp. of blue-green algae and the other hand brackish algae were dominated after inflow of seawater such as Chaetoceros dicipiens, Skeletonema costatum of diatom, Dinophysis acuminata, Gymnodinium mikimotoi, G. sanguineum, Gyrodinium spirale, Prorocentrum minmum of dinoflagellate and Eutreptiella gymnastica of euglenoid. Moreover, small flagellates including Chroomonas spp. of cryptomonad were abundant throughout the year. The cause of water deterioration during fill of the freshwater were complexly supported with extra and intra parameters. The variation pattern of phytoplankton were related to water temperature and salinity by inflow of seawater based to plentiful nutrients. The dynamics of phytoplankton were assessed to ecosystem that clearly condition of dominant by unique or a few angel species seasonally.

• Journal of Environmental Health Sciences
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• v.12 no.2
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• pp.27-37
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• 1986

This study was carried out to investigate inflow stream of Chungju intake reservoir and in catchment area, run-off loading amount, distribution of Nitrogen and phosphorus, N/P ratio, correlationship between T-N and chlorophyll a, correlationship between T-P and chlorophyll a, and study of trophic state. Field survey was carried out from June to August, 1985, for the purpose of finding out the nitrogen and phosphorus concentration in Chungju intake reservoir.

• KCID journal
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• v.7 no.1
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• pp.8-18
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• 2000

The variations of water quality due to inflow of sea water by gate operation were observed in Sihwa Lake. The distributions and concentration of salinity, temperature, dissolved oxygen, nutrient were investigated from Feb. 1997 to Jul. 1998. The salinity

• Journal of Environmental Science International
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• v.10 no.1
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• pp.59-64
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• 2001

The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of $SO_2$and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ration which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20-60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. The organic\`s removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.

• Plant Journal
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• v.15 no.1
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• pp.38-44
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• 2019

This research is an experimental investigation to find the desirable pH of slurry in the desulfurization absorber for a 1000 ㎿ coal fired power plant, operating in compliance with the Air Environmental Conservation Act and the plant's internal regulations. In case the average sulfur dioxide concentration in inflow flue gas, ${\bar{C\;in}}$ [ppm] changed to 500 ppm, 550 ppm, 600 ppm and 635 ppm after fixing inflow flue gas flow rate, generator output, pressure drop in the absorber, and oxidation air flow rate, the desirable pH of the slurry in the absorber, was 5.0, 5.2, 5.3 and 5.4. Thus, it is recommended that the desirable pH of slurry is calculated using the correlation equation, $RpH=0.0018{\times}{\bar{C\;in}}+4,2031$ when the average sulfur dioxide concentration in the inflow flue gas is in the range of 500 ppm to 635 ppm.

• Korean Journal of Ecology and Environment
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• v.35 no.4 s.100
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• pp.285-294
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• 2002

The purpose of this study was to evaluate the relationships between purification characteristics and hydraulic conditions, and to clarify the basic and essential factors required to be considered in the construction and management of artificial wetland system for the improvement of reservoir water quality. The artificial wetland system was composed of a pumping station and six sequential plants beds with five species of macrophytes: Oenanthe javanica, Acorus calamus, Zizania latifolia, Typha angustifolia, and Phragmites australis. The system was operated on free surface-flow system, and operation conditions were $3,444-4,156\; m^3/d$ of inflow rate, 0.5-2.0 hr of HRT, 0.1-0.2 m of water depth, 6.0-9.4 m/d of hydraulic loading, and relatively low nutrients concentration (0.224-2.462 mgN/L, 0.145-0.164 mgP/L) of inflow water. The mean purification efficiencies of TN ranged from 12.1% to 14.3% by showing the highest efficiency at the Phragmites australis bed, and these of TP were 6.3-9.5% by showing the similar ranges of efficiencies among all species. The mean purification efficiencies of SS and Chl-A ranged from 17.4% to 38.5% and from 12.0% to 20.2%, respectively, and the Oenanthe javanica bed showed the highest efficiency with higher concentration of influent than others. The mean purification amount per day of each pollutant were $9.8-4.1\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in BOD, $1.299-2.343\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in TN, $0.085-1.821\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in TP, $17.9-111.6\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in SS and $0.011-0.094\;g{\cdot}m^{-2}{\cdot}d^{-1}$ in Chl-a. The purification amount per day of TN revealed the hi링hest level at the Zizania latifolia bed, and TP showed at the Acrous calamus bed. SS and Chl-a, as particulate materials, revealed the highest purification amount per day at the Oenanthe javanica bed that was high on the whole parameters. It was estimated that the purification amount per day was increased with the high concentration of influent and shoot density of macrophytes, as was shown in the purification efficiency. Correlation coefficients between purification efficiencies and hydraulic conditions (HRT and inflow rate) were 0.016-0.731 of $R^2$ in terms of HRT, and 0.015-0.868 of $R^2$ daily inflow rate. Correlation coefficients of purification amounts per day with hydraulic conditions were 0.173-0.763 of Ra in terms of HRT, and 0.209-0.770 daily inflow rate. Among the correlation coefficients between purification efficiency and hydraulic condition, the percentages of over 0.5 range of $R^2$ were 20% in HRT and in daily inflow rate. However, the percentages of over 0.5 range of correlation coefficients ($R^2$) between purification amount per day and hydraulic conditions were 53% in HRT and 73% in daily inflow rate. The relationships between purificationamount per day and hydraulic condition were more significant than those of purifi-cation efficiency. In this study, high hydraulic conditions (HRT and inflow rate) are not likely to affect significantly the purification efficiency of nutrient. Therefore, the emphasis should be on the purification amounts per day with high hydraulicloadings (HRT and inflow rate) for the improvement of eutrophic reservoir withrelatively low nutrients concentration and large quantity to be treated.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.6
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• pp.30-36
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• 2002

A 0.19 hectare natural-type wetland for stream water treatment demonstration was constructed and planted with cattails from April 2001 to May 2001. Part of its bottom surfaces adjacent to levees have a variety of slope of 1 : 4~1 : 15. Two small open water areas were installed, in which emergent plants could not grow. Removal of nutrients from stream waters was a major objective of the wetland. Waters of Sinyang Stream flowing into Kohung Estuarine Lake were pumped and funneled into the wetland. The lake had been formed by a salt marsh reclamation project and was located southern coastal region of Korean Peninsula. Volumes and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged $120.4m^3/day$ and $112.1m^3/day$, respectively. Hydraulic retention time was about 3.1 days. Average total phosphorous concentration of influent and effluent was $0.19mg/{\ell}$ and $0.075mg/{\ell}$, respectively. Total phosphorous loading rate of inflow and outflow averaged $12.05mg\;m^{-2}\;day^{-1}$ and $4.44mg\;m^{-2}\;day^{-1}$, respectively. Average total phosphorous removal rate in the wetland was $7.61mg\;m^{-2}\;day^{-1}$. Seasonal changes of phosphorous retention rates were observed. The wetland acted as effective phosphorous sinks in the initial stage of the constructed wetland.