• Korean Journal of Environmental Biology
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• v.35 no.2
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• pp.143-151
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• 2017

This study illustrates changes in the epilithic diatom assemblages in response to urban climatic conditions. We further assess the impact of abnormal urban climate to the urban stream environment. Epilithic diatoms, water chemical and physical variables were sampled every quarter, and assessed at 3 Oncheon stream sites, for a period of two years(from 2013~2014). The variation of physiochemical properties such as BOD, COD, T-N and T-P, show that the water quality was strongly influenced with long periods of drought and flood disturbance. Epilithic diatom assemblages were separated along the stream sites; however, the physical disturbance from urban drought and stormwater changed the composition of diatom assemblages instead of decreasing the taxonomic richness. Thus, our results suggest that epilithic diatom assemblages are altered in response to urban climatic changes, resulting in variations of stream conditions. Hence, strategies of climate change adaptation are required when considering urban stream environments.

• Membrane and Water Treatment
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• v.9 no.6
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• pp.473-480
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• 2018

The effect of three iron-based adsorbents pre-depositing on ultrafiltration membrane for humic acid (HA) removal and membrane fouling was investigated. The result showed that pre-depositing adsorbents on membrane could not only reduce membrane fouling but also enhance HA removal. The flux was related to the adsorbent dosage and the optimal dosage for pre-deposition was $35.0g/m^2$. The dissolved organic carbon (DOC) removal of HA was 38.3%, 67.3% and 41.1% respectively when pre-deposited $35.0g/m^2$ $FeO_xH_y$, $MnFe_2O_4$ and $Fe_3O_4$ on membrane. Different adsorption effect of adsorbents on HA contributed to increasing of the flux at different level. Zeta potential of three adsorbents all decreased after adsorbed HA. The adsorption capacity of the three adsorbents was $FeO_xH_y$ > $MnFe_2O_4$ > $Fe_3O_4$. Atomic Force Microscopy (AFM) measurement showed the thickness of pre-deposition layers formed by different adsorbents was different. The scanning electron microscope (SEM) detection showed the morphology and compactness of pre-deposition layers formed by different adsorbents was different.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.440-443
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• 2012

도시지역의 도로, 교량 및 주차장과 같은 포장지역은 작은 면적이지만 강우 시 다른 토지이용에 비해 강우 유출량이 높고, 상수원인 하천의 종 및 횡방향으로 존재하기 때문에 직접적인 오염 원인으로 작용하고 있다. 이에 대한 대책으로 최적관리기법(Best Management Practices, BMP) 또는 저영향개발(Low Impact Development, LID)과 같은 관리 방안을 적용하여 강우에 의해 발생되는 강우유출수와 비점오염물질을 동시에 저감하는 방안이 연구되고 있으나, 모델링을 통한 비점오염물질 배출량의 정량화와 저감시설의 성능평가에 대한 연구는 부족한 실정이다. 본 연구에서는 주차장 지역에서 발생하는 비점오염물질의 배출량 모의 가능성을 평가하기 위해 국내 외에서 강우유출수의 모의와 저감시설의 성능평가에 많이 사용되고 있는 MUSIC(Model for Urban Stormwater Improvement Conceptualization) 모형과 SWMM(Storm Water Management Model) 모형을 이용하여 강우유출수 수문 수질 모의를 실시하여 각 모형의 적용성을 평가한 결과, 두 모형 모두 총 유출체적 오차가 ${\pm}6%$ 이내로 수문모의에 대한 적용성이 우수하게 나타났지만, 수질의 경우 SWMM 모형이 MUSIC 모형에 비하여 오염물질의 배출량을 실측치와 가깝게 모의함으로서, 결과적으로 대상지역에 대해 SWMM 모형이 MUSIC 모형에 비해 주차장의 초기우수현상을 더 잘 재현하는 것으로 나타났다.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.768-777
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• 2009

The characteristics of stormwater runoff was examined on distinct types of agricultural and industrial area in Lake Sihwa watershed. During rainfall event, the peak concentrations of SS, $COD_{Mn}$, and TP were observed after 6~11 hours of rainfall in agricultural areas. Whereas, the peak concentrations occurred within the first one hour after rainfall and then the highest concentration of NPS pollutants sharply decreased, showing strong first flush effect in industrial areas. The strong first flush effect of suspended solid was apparent in agricultural areas, while those of organic matters and nutrients were clear in industrial areas. The cumulative load curves for NPS pollutants showed above the $45^{\circ}$ straight line, indicating that first flush effect occurred in industrial areas. The mean SS EMC values of agricultural areas ranged from 60~598 mg/L (Avg. 285 mg/L), it was higher value when compare to other areas. While the mean $COD_{Mn}$, TN, and TP EMCs values of industrial areas were shown the highest values as 67.7 mg/L, 12.1 mg/L and 2.1 mg/L respectively.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.689-696
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• 2009

Unit load approach has been used to estimate the non-point pollutant load in Total Water Pollution Load Management System (TWPLMS). In this study, locally applicable unit loads for road and parking lot were developed based on the measurements of 9 rainfall events from 2007 to 2008 in Yongin city of Gyeongan stream watershed. Observations showed that stormwater runoff began at low precipitation (>1 mm) and peak pollutant concentration occurred at the beginning of the runoff because of impervious nature of the sites. Averaged event mean concentrations (EMCs) of road (parking lot) were estimated as COD 105.36(62.69) mg/L, BOD 15.94(13.20) mg/L, TSS 183.45(66.52) mg/L, T-N 4.63(3.28) mg/L, T-P 0.45(0.39) mg/L. Higher EMCs at the road than parking lot may reflect heavier traffic. Unit loads Estimated from the EMCs and 10 year average rainfall data were COD $331.17kg/km^2{\cdot}day$, BOD $50.20kg/km^2{\cdot}day$, TSS $580.13kg/km^2{\cdot}day$, T-N $14.68kg/km^2{\cdot}day$, T-P $1.43kg/km^2{\cdot}day$ in the road and COD $186.59kg/km^2{\cdot}day$, BOD $39.22kg/km^2{\cdot}day$, TSS $199.15kg/km^2{\cdot}day$, T-N $9.70kg/km^2{\cdot}day$, T-P $1.16kg/km^2{\cdot}day$ in the parking lot. The estimated unit loads are not so comparable to the ones listed in TWPLMS technical guideline and published data that locally developed unit loads should be used to estimate non-point pollutant loads.

• Journal of Korea Water Resources Association
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• v.39 no.7 s.168
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• pp.575-581
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• 2006

This paper presents a systematic approach for the economical design of stormwater quality control systems. For the design of runoff quality control system (RQCS), the rainfall-runoff process requires the local rainfall data recorded continuously. In this study the rainfall probability distribution is assumed to follow an exponential decay function. Applying the exponential decay function, the normalized curves are derived to explain the non-exceedance probability distributions. The optimal curves for the determination of the RQCS size are derived based on the overflow risk. Comparison of the optimal capture volume and peak runoff rate to those computed by an urban rainfall-runoff model(ILLUDAS) demonstrates that the optimal CSOs(Combined Sewer Overflows) curves derived in this study can be utilized for the design of stormwater quality control systems in Korea avoiding an excessive computational effort based on over flow risks.

• Journal of Wetlands Research
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• v.18 no.1
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• pp.10-15
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• 2016

In this research, the environmental effects of rain garden when applied to a stormwater runoff originated from a rooftop were evaluated. The rain garden that was utilized as LID represents less than 1% of the catchment area that it drains. Storm event monitoring was conducted from March 2012 to August 2014 on a total of 19 storm events. In the 19 storm events that was monitored only 32% produced an outflow which has a mean rainfall characteristic of approximately 25 mm. With the application of rain garden, hydrologic improvement was observed as the facility exhibit a delay and reduction in the production of runoff and peak flows as the rainfall progresses. Furthermore, in terms of pollutant reduction, it was observe that the rain garden showed a generally satisfactory performance in reducing pollutants. In addition to this, the rain garden also has additional attributes that adds to the aesthetic appeal of the surrounding environment as well as in the lives of the people. The findings of this research will help in the further improvement and reinforcement of LID designs.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1375-1384
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• 2010

Growth in population and urbanization has progressively increased the loading of pollutants from nonpoint sources as well as point sources. Especially in case of road regions such as city trunk road, national road and highway are rainfall and pollutants runoff intensive landuses since they are impervious and emit a lot of pollutants from vehicle activity. This research was conducted to investigate the nonpoint sources concentration and quantifying stormwater pollutants which are contained in rainfall runoff water. Three different monitoring sites in Jinju and Changwon city were equipped with an automatic rainfall gauge and flow meter for measuring rainfall and the volume of rainfall runoff. In the case of average EMC value, city trunk road was shown the highest value in target water quality items like as BOD, COD, SS, TN and TP. Or the amount of runoff loads by water quality items showed the highest value in city trunk road. And runoff load in city trunk road was 43.8 times high value compared to highway by value of city trunk road $356.7 mg/m^2$, highway $8.150 mg/m^2$, national road $19.99 mg/m^2$ in the case of BOD.

• Journal of Environmental Impact Assessment
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• v.22 no.6
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• pp.557-568
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• 2013

In this study, Calculated the nonpoint sources(NPS) load per unit area about various rainy events in vineyard of Nakdong River basin. NPS monitoring and calculation for NPS load per unit area were estimated from 'Investigation method of precipitation discharge(National Institute of Environmental Research, 2007)'. The evaluation of applicability for NPS load per unit by compared with prior research data and Total Maximum Daily Load(TMDL) data. Five target areas were each $2000m^2$, $1800m^2$, $1943m^2$, $2484m^2$, $864m^2$ and located in Gyeongsangbukdo Gyeongju, Gyeongsangbukdo Sangju, Gyeongsangnamdo Hapcheon in Korea. Since fruits were the only crop on the target area, the characteristics of stormwater discharge at survey sites could be evaluated independently. A total of 115 rainfall events in the Orchard area during five years(2008-2012) was surveyed, and 38 of them became stormwater discharge. In the Nakdong River watershed, average of event mean concentrations(EMCs) in Orchard area for biochemical oxyzen demand(BOD), Chemical oxyzen demand(COD), total nitrogen(T-N), total phosphorus(T-P) were 2.0mg/L, 10.1mg/L, 3.195mg/L, 0.578mg/L, respectively. NPS load per unit area in Orchard area showed BOD : $2.0kg/km^2{\cdot}day$, COD : $10.2kg/km^2{\cdot}day$, T-N : $3.220kg/km^2{\cdot}day$, T-P : $0.606kg/km^2{\cdot}day$.

• Journal of Environmental Science International
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• v.20 no.3
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• pp.361-372
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• 2011

This study analyzed the characteristics of stormwater runoff by rainfall type in orchard areas for two years. Effluents were monitored to calculate the EMCs and runoff loads of each pollutant. The runoff characteristics for nonpoint sources from vineyards were also inspected based on independent variables that affect runoff such as rainfall and rainfall intensity. The average runoff loads of each pollutant from vineyard_A and vineyard_B were found as follows: BOD 39.13 mg/$m^2$, COD 112.13 mg/$m^2$, TOC 54.98 mg/$m^2$, SS 1,681.8 mg/$m^2$, TN 18.29 mg/$m^2$, and TP 4.06 mg/$m^2$, which indicates that the COD's runoff load was especially high. The average EMCs from vineyard_A and vineyard_B, which represents the quality of rainfall effluent, were also analyzed: BOD 3.5 mg/L, COD 11.5 mg/L, TOC 5.2 mg/L, SS 211.7 mg/L, TN 1.774 mg/L, and TP 0.324 mg/L. This suggested that the COD, as an indicator of organic pollutants, is high in terms of EMCs as well. As rainfall increased, the EMCs of BOD, COD, TOC and SS kept turning upward. At a point, however, the high rainfall brought about dilution effects and began to push down the EMCs. Higher rainfall intensities led to the increase in the EMCs that displays the convergence of rainfall. Low rainfall intensities also raised pollutant concentrations, although the concentrations themselves were slightly different among pollutants.