• 상하수도학회지
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• 제14권2호
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• pp.181-195
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• 2000

The effect of the intercepting ratios on the water quality improvement was simulated by using Finite Segment Method in a urban river where intercepting sewer under the ground and constructing sewage treatment plant are now being proceeded. To simulate variations of the water quality caused by river flows, rating curve at each gaging station was derived from measurements. Water quality data were from the exiting observations at each key stations from 1990 to 1998, for 1999 and 2000 data we measured in creek and drainage ditch in addition to observation stations. It revealed that increasing the intercepting ratios improved the water quality.

• 한국관개배수논문집
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• 제21권1호
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• pp.55-63
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• 2014

A sedimentation basin for agricultural water quality improvement was researched to analyze the water quality purification characteristics. The sedimentation basin constructed at the inlet of Gamdon reservoir in Muan-gun, Jeollanam-do was selected as the research field of this study. The surface area of the sedimentation basin is $34,000m^2$, volume is $122,000m^3$, and hydraulic retention time is 0.3hr~7.3day. The average influent loading of SS was 156.6kg-SS/d, and the effluent loading was 67.5kg-SS/d with the average removal rate of 56.9%. The average influent loadings of BOD and COD were 33.0kg-BOD/d and 60.3kg-COD/d respectively, and the effluent loadings were 26.4kg-BOD/d and 48.6kg-COD/d with the average removal rate of 20.1% and 19.3% respectively. Therefore, the results of this study show that a sedimentation basin can purify SS and organic matters. The average influent loadings of T-N and T-P were 28.7kg-TN/d and 2.97kg-TP/d respectively, and the effluent loadings were 16.3kg-TN/d and 1.41kg-TP/d with the average removal rate of 43.0% and 52.6% respectively. In conclusion, the overall results of this study show that a sedimentation basin is a feasible alternative to purify organic matters and nutrients.

• 환경위생공학
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• 제21권3호
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• pp.61-72
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• 2006

This study was carried out for verification of efficiency of seawater exchange breakwater which was installed in joomoongin harbor for the first time in our country. The joomoongin harbor, where seawater exchange breakwater has been constructed, shows typical for fishery and tourist port city specifics of greatest pollutants discharge volume in spring and summer, when tourist inflow and fishery activity is most vigorous. On the East Sea seawater flux through seawater exchange breakwater for the smallest waves (up to 0.5 m) was found out to be $1,526-3,052m^3/day$. After construction of seawater exchange breakwater, Zone 1 and Zone 2 of stagnant water inside the port were found to be a lot improved. Zone 3, adjacent to outport area, was found to be lower comparing with Zone 1 and Zone 2. The results of statistical analysis show that comparing with water quality improvement effect before and after seawater exchange, water quality after installation of seawater exchange breakwater became much better, primarily because of physical change around the harbour.

• 유통과학연구
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• 제19권4호
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• pp.53-60
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• 2021

Purpose: This study focuses on exploring ways to improve the distribution method of shrimp farming so that it is eco-friendly and increases the distribution of shrimp. Research design, data and methodology: The experimental device installed in a biofloc shrimp culture in one area tested 10 times. Complex odor, concentration of H2S, water quality improvement effected by decomposition of organic substances, and degree of microbial activation measured. The data of the experimental results verified using the T-test technique, and the p value was determined based on the significance probability of 0.05. Results: This experimental device was effective in reducing odor and hydrogen sulfide in shrimp farms. With the improvement of water quality, dissolved oxygen increased due to the microbubble and cavitation action of air ejector and ultrasonic waves. In addition, the cultured microorganisms in the cultured water treated by the experimental device were remarkably proliferated compared to the raw water. Conclusions: The biofloc distribution method has a significant effect on improving water quality and reducing odor substances and will become a new eco-friendly and efficient distribution method for shrimp farming in the future.

• 한국환경복원기술학회지
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• 제16권5호
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• pp.1-17
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• 2013

We researched the fauna restoration of 5 urban streams in Ulsan established as ecological streams by improving water quality and river environment. The fauna inhabitation were compared according to the conditions of geometrical feature such as river width, low-water channel width, ect and water quality, water volumn, inland and forceland. The Mugeo cheon has clearly shown the fauna restoration effects resulting from supplying sustainable maintenance water and wastewater treatments. In the Yaksa cheon, on the other hand, the restoration effects were low due to the inflow of wastewater and sledges in some part of stream ever though the improvement of water quality. The Yeocheon cheon was found to have disadvantage on the ecological inhabitations due to supplying the maintenance water with highly concentrated salinity. The fauna restoration effect of the Meongjeong cheon was low due to the inflow of wastewater to the down stream. Therefore by supplying the maintenance water and improving the connection to the Taehwa river at the estuary, better restoration effects could be observed. In the Cheokgwa cheon, which is almost a natural river, the ecological integrity of the fauna population has been maintained quite well. It was concluded that the project to transform urban streams into ecological streams should focus on not only keeping water volume and quality but also maintaining favorable conditions for the migration and settlement of animal species close to the natural state.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.645-650
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• 1999

Three floating islands have been constructed for water quality improvement for a polluted irrigation reservoir. Phragmites australis was considered as the suitable aquatic macrophyte of the floating island. From April to August in 1999, the net primary productivity of Phragmites australis was 3,530gDM/㎡. Uptake rates of nitrogen and phoshorous by Phragmites australis planted in the floating island could be estimated to 10.2kg/d/ha and 0.8kg/d/ha, respectively. The floating islands worked well as a habitat of fish and prawns. Therefore, the floating islands could be evaluated a good measure ofwater quality improvement for irrigation reservoir.

• 한국농공학회지
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• 제42권1호
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• pp.73-82
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• 2000

Large quantitive of polllutants are washed into reservoirs during storm events. These polllutants contribute to eutrophication, such as algal blooms and fish kills. This study was conducted for the purpose of assessing the pollutant removal possibilities of sedimentation pool formed by deep dredging of a reservoir inlet. Water quality data were collected in the Masan reservoir, whose inlet has been dredged deep like sedimentation pool. The average concentration of chemical oxygen demand(COD) , toatal nitrogen(T-N) and total phosphrous(T-P) in the deep dredged area were 8.7 ~20.5mg/ι (T-N), 0.17~0.84mg/ι(T-P), which were 4.9%(COD), 29.0%(T-N) and 44.8%(T-P) higher than those of middle part of the reservior. The texture of sediment in the dredged area was silty loam, while that of the middle part was sandy clay loam. Organic matter contents, T-N and T-P of the bottom soil in the dredge area showed higher values than the middle part of the reservoirs. From these results, it was considered thedeep dredged area in the inlet of reservoir might play a key role to settle pollutant particulate. Based on the result of water quality analysis, deep dredging of the reservoir inlet could be assessed to reduce T-N and T-P of the reservoir about 6.5% , 8.3%, respectively. However, the effect of the sedimentation pool would be raised if the settled particles were taken into account in assessing water quality improvement for the reservoir. Accordingly, dredging of a reservoir inlet to make a shape of sedimentation pool is recommended for water quality improvement of reservoir in the stage of dredging plan.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1182-1183
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• 2005

• 한국물환경학회지
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• 제25권6호
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• pp.972-978
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• 2009

This study modifies the present total maximum daily load (TMDL) system of Ministry of Environment and applies to the Anyangcheon watershed. Hydrologic Simulation Program-FORTRAN (HSPF) model is used to simulate both runoff and non-point source pollution, simultaneously, instead of QUAL2E. The drought flow (355th daily flow) is proposed for the target water quantity since it is easier to satisfy low flow (275th daily flow) for the target water quality than drought flow. The increase of discharge is more than the increase of pollutant load except for the period under low flow. The measured unit loads for non-point source are used to consider the regional runoff characteristics. The measured water quantity and quality data are used since the ministry of environment supports only water quality. This analysis results show some reasons for the improvement of the present TMDL system of Korea.

• 상하수도학회지
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• 제21권1호
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• pp.131-138
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• 2007

A rainwater utilization facility consists of its catchment area, treatment facility, storage tank, supply facility and pipes in general. The rainwater storage tank which occupies the largest area of the facility has been usually considered quantitatively for determining the storage capacity. Hence, there is little information on water quality improvement by sedimentation in a rainwater storage tank in operation. In this study, we measured the rainwater quality in a rainwater storage tank in operation during late spring and summer, and showed water quality improvement of turbidity removal of 25~46% by sedimentation in a rainwater storage tank under a fixed water level without inflow and outflow after runoff ceased. It is necessary to have a considerable distance between the inlet and outlet of the tank and, if possible, it is recommended that the design should allow for an effective water depth of over 3 m and supply rainwater near the water surface. The operation method which increases the retention time by stopping rainwater supply for insuring low turbidity is recommended when the turbidity of rainwater runoff is high. And also more efficient operation and maintenance of the rainwater utilization facility is expected through the tailored design and operation of the facility considering particle removal and behavior.