• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.6
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• pp.145-159
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• 2010

A Sustainable Structured wetland Biotop (SSB) system was planned, designed, and finally constructed, and maintained in the An-teo Reservoir ecological park, which is the habitat of the endangered Gold-spotted Pond Frog. The system purifies polluted water of An-teo Reservoir which flows from up to bottom within the system. Water was sampled once a month at the inlet and at the outlet from December, 2009 to August, 2010. BOD5, SS, T-N and T-P were analyzed. Average influent and effluent BOD5 concentration was 2.9 and 1.0 mg/L, respectively, and BOD5 removal was 67%. SS concentration of influent and effluent averaged 18.1 mg/L and 2.5 mg/L, respectively, and SS abatement amounted to 86%. Average influent and effluent T-N concentration was 0.426 mg/L and 0.147 mg/L, respectively, and T-N retention was 66%. T-P concentration of influent and effluent averaged 0.071 mg/L and 0.022 mg/L, respectively, and T-P removal amounted to 68%. Plant and frog species of the system were monitored during the period. Amphibia and reptiles provided 7 species and 4 families including the Endangered Gold-Spotted Pond Frog (Rana chosenica ) which also lives in the system. Twenty-six plant species were naturally introduced into the system, however, they didn't make up a significant portion of the plant populations compared with the planted species. The endangered plants, Bladderwort (Utricularia vulgaris var. japonica ) and Euryale ferox were observed in An-teo Reservoir as well as in the system.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.6
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• pp.673-682
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• 2016

In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on "Water Quality Monitoring Networks" in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.

• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.123-130
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• 2002

Bench scale experiments were carried out with two biological nutrient removal(BNR) units, A/O and $A^2O$ processes, to investigate the behavior of phosphorus in the system and to compare the characteristics of phosphorus removal in two BNR processes. To achieve this goal, COD/T-P and COD/TKN ratios of the influent was varied in the range of 23~64 and 5~24, respectively. In A/O process, influent COD/T-P ratio should be kept higher than 44mg/L to meet the final effluent T-P concentration lower than 1mg/L and in $A^2/O$ process, influent COD/T-P and COD/TKN ratios higher than 56 and 10, respectively, were required for good phosphorus release and uptake with no influence of nitrate nitrogen in return sludge. At this conditions, the rate of phosphorus release in the anaerobic basin should be kept higher than 0.1 kg S-P/kg MLVSS d In A/O process, the phosphorus content of anaerobic and aerobic sludges was increased as SRT of total system was becoming longer resulting in decreasing the difference of phosphorus content between two sludges while phosphorus release in anaerobic basin and phosphorus uptake in aerobic basin was not incident. In $A^2/O$ process, the phosphorus content of anaerobic and aerobic sludges were not increased with higher SRT of total system due to the relatively high nitrate concentration in return sludge. However, the difference of phosphorus content between anaerobic and aerobic sludges was incident when phosphorus release and uptake was observed.

• Journal of Environmental Health Sciences
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• v.7 no.1
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• pp.1-7
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• 1981

During 20 days from November 4 to 28, 1980, the quantities of grease and oil, BOD (biological oxygen demand), COD (chemical oxygen demand), SS (suspended solid) were measured at Grit Chamber, Primary Sedimentation Tank, Secondary Sedimentation Tank in Chung Gye Chun sewage treatment plant. The results were as follows. 1. The average of grease and oil quantities were 251mg/l at Grit Chamber, 185mg/l at Primary Sedimentation Tank, 47mg/l at Secondary Sedimentation Tank. 2. In the secondary treatment for the removal of grease and oil, the removed quantities of grease and oil were increased according to increasing the quantities of influent grease and oil. The regression equation were as follows G.O.removed=0.731 G.O. influent+3.235 (r=0.887) 3. The average of grease and oil removal rate was 76.4% and the standard deviation of grease and oil removal rate daily was 10.6%. 4. G.O. (grease and oil) and BOD, COD, SS showed significant correlationship at Grit Chamber, Primary Sedimentation Tank, Secondary Sedimentation Tank. (P<0.05). 5. In the secondary treatment, effluent grease & oil and other parameters were analyzed by means of Stepwise multiple regression. Multple regression equation for estimates of effluent grease and oil were as follows. $GO_E=-9.1637+2.0380 SS_E+0.068 SS_I$ (r=0.778) 6. The correlative parameters for the effluent grease and oil seem to be the influent SS and the effluent SS. 7. It was estimated that the removal of grease and oil would be improved by means of improvement of suspended solids removal efficiency but it is necessary to inquire further into the study.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.4
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• pp.35-44
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• 1999

In this study, it was attempted to remove nitrate and carbon in a single-stage reactor using acetate as substrate. Hybrid type upflow sludge baffled filter reactor was adopted using anaerobic sludge. Sludge bed in the bottom of reactor was intended to remove carbon and nitrate by denitrification and methanogenesis. And floating media in the upper part of reactor were intended to remove remaining carbon which was not removed due to the inhibition of nitrogen oxide on methane producing bacteria. The reactor removed over 96% of COD and most of nitrate with volumetric loading rate of $4.0kgCOD/m^3{\cdot}day$, hydraulic retention time of 24hr, 4,000mgCOD/L, and $266mgNO_3-N/L$. Nitrate in anaerobic sludge was converted to nitrogen gas(denitrification) or ammonia (ammonification) according to pH of influent, COD removal efficiency was easily affected by the change of volumetric loading rates and nitrate concentration. And when influent pH was about 4.7, most nitrate changed to ammonia while when influent pH was about 6.8~7.0, most nitrate denitrified independent of $COD/NO_3-N$ ratio. Most granules were gray and a few were black. In gray-colored granule, black inner side was covered with gray substance and SEM illustrated Methanoccoci type microorganisms which were compact spherical shape. Anaerobic filter removed residual COD effectively which was left in sludge bed due to the inhibition of nitrogen oxide.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.180-184
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• 2016

In this study, we evaluated complex media with influent sewage water (ISW) to isolate novel taxa of bacteria. It was possible to cultivate 13 genera using the complex media with ISW. Additionally, more diverse genera were identified at 37℃ than at 25℃, using the complex media with ISW. Total 12 strains of 179 bacterial isolates were shared less than 97% 16S rRNA gene sequence similarities with any known species. These isolates could be assigned to genera Tessaracoccus, Paracoccus, or Candidimonas (or Paralcaligenes).

• Journal of Environmental Health Sciences
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• v.30 no.1
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• pp.50-58
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• 2004

The present study was designed to evaluate primary production organic matter in basin of lake around by execution of total maximum daily loading. BOD influent loading of Uiam lake was 2,819 kg/day, which was less then 28.3 percent, total effuluent loading as 3,619 kg/day, in comparision with BOD, total nitrogen influent loading was 4,681 kg/day, which was less then 10.0 percent, total effuluent loading as 5,150 kg/day. But in case of total phosphors influent loading was 73.3 kg/day, which was more then 34.2 percent, total run off loading as 48.3 kg/day. The result of survey reduction plan of primary production organic matter in basin of lake around which objectives of abstract is as follows. First plan was reduction of primary production organic matter by moving the outlet of municipal wastewater treatment center from present place to lake downstream. Secondary plan was improvement by diffusion type of outlet municipal wastewater treatment center. The third plan was reduction of environmental impact by passing and storing of municipal wastewater. Finally plan was decline water surface level which was present hydrouric retention time was reduction from 7.6 day to 6.0 day per meter.

• Journal of Environmental Science International
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• v.27 no.6
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• pp.447-456
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• 2018

In this research, the target process was a modified type of a conventional aeration tank with four different influent feeding points and alternated aeration to obtain nitrogen removal. For more accurate switching of influent feeding, the process was operated under a designed control strategy based on monitoring of $NH_4-N$ and $NO_X-N$ concentrations in the tank. However, the strategy did have some limitations. For example, it was not sensitive to detecting the end of each reaction when losing the balance between nitrification and denitrification of each opposite part of biological tank. To overcome the limitations of the existing control strategy, a diagnosis-based control strategy was suggested in this research using the diagnosis results classified as normal (N), ammonia accumulation (AA) and nitrate accumulation (NA). Using the pre-designed rules for control actions, the aeration and volume of the aerated part of the reactor could be increased or decreased at a fixed mode time. In simulations of the suggested diagnosis-based control strategy, the $NH_4-N$ and $NO_X-N$ removal rates in the reactor were maintained at higher levels than those of the existing control strategy.

• Journal of fish pathology
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• v.28 no.3
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• pp.125-131
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• 2015

This study was performed to determine the disinfection efficacy of influent seawater by application of mechanical filtration and UV disinfection system (MFUVDS) in decreasing disease outbreak of juvenile olive flounder (Paralichthys olivaceus). Bacterial disinfection rate of influent seawater following the MFUVDS application was 99.27%. Mortalities of the juvenile reared for 4 months were 20~30% lower than those of the control (25.8%~34.9%).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.2
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• pp.73-78
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• 2007

The suitability of a flexible fiber filter for removing suspended solid (SS) in a recirculating aquaculture system was evaluated. This study focused on variation in the performance with a change in filtering time, influent water quality, and filtering mode duration. The particle distribution diagram of the filter effluent showed that the number of particles bigger than $5-8{\mu}m$ decreased dramatically, and the removal efficiency exceeded 80%. Although the removal efficiencies of SS and chemical oxygen demand (COD) were dependent on the quality of the influent, the SS and COD concentrations of the effluent were not affected by the influent concentrations. This was despite the deterioration if water quality after feeding in the rearing tank. The performance of the filter was not affected by the filtering mode duration, feeding conditions, or filtering time. The SS concentration and turbidity of the recirculating-type rearing tank were 30% and 50% lower, respectively, than of the a non-recirculating-type rearing tank under the same operating conditions. The flexible fiber filter was applicable to a recirculating aquaculture system that uses plenty of seawater, based on its low filtering resistance $(2kg_f/cm^2)$, high flux $(330m^3/m^2/hr)$, and high fine particle removal efficiency (80%, $5-8{\mu}m$).