• Korean Journal of Construction Engineering and Management
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• v.17 no.1
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• pp.40-47
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• 2016

Recently, the demand of sewage treatment facilities have increased by growing the population growth of city and industrialization. However, most of public sewage treatment facilities lack the preparations of design criteria by increasing sewage water amount in the future. In order to respond to this situation, the government has consistently promoted the sewage treatment construction project. This study conducted a survey targeting residents and sewage treatment facilities, civil engineering a VE project professionals for effectively operating the sewage treatment facilities and improving its value to be built in the future. Based on this survey, this study will introduce the list of performance measurements which can not only save cost but also reflect opinion of users and residents. In addition, using Multi-Level Performance Measurement and AHP analyzed the weights of performance measurement which is more objective than existing things for applying efficient VE process

• Korean Journal of Microbiology
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• v.46 no.1
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• pp.38-45
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• 2010

The study performed to identify the type of ESBL against strains which are producing extendedspectrum ${\beta}$-lactamases and isolated from sewage in Suyeong sewage disposal plant, Busan Environmental Corporation. By the standard activated sludge method, Suyeong sewage disposal plant purify living and lavatory sewage gathering from the northeast Busan and the facility purify total 550,000 tons of living sewage disposal a day. 14 strains were isolated by double disk synergy test and the third generation cepha-antibiotics test. Indole, methyl-red, Voges-Proskauer, Simmon's citrate, decarboxylasedihydrolase and sugar-fermentation tests identified as Klebsiella pneumoniae (n=4) and Escherichia coli (n=10). Plasmid-mediated transmission test against isolated 14 strains proved 11 strains transmitted resistance to recipient E. coli J53 (sodium $azide^R$, $ceftazidime^S$). 9 strains of conjugant were expressed ESBL genes transferred from parental strain but 2 conjugants did not expressed. The type of ESBL from each strain was determined by isoelectric focusing points, DNA and amino acids sequencing. The results indicated that the types of ESBL transmitted to recipient E. coli J53 were TEM-1, the parental TEM type and SHV-12 type.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.464-469
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• 2007

환경개선용수의 비용 부담방법과 부담주체를 결정하는 것은 환경개선용수의 효율적 이용과 관리의 핵심적인 요소이다. 환경개선용수의 비용부담 방법은 공공부담, 수익자부담 및 원인자부담이 있다. 그런데, 비용부담 방법은 환경개선용수의 공급에 대한 댓가를 어떠한 형태로 지불받을 것인가? 환경개선용수의 수익자는 누구인가? 그리고 환경개선용수를 어떤 시각에서 바라 볼 것인지에 따라 달라지게 된다. 즉, 환경개선용수가 순수한 공공재로서 당연히 국가가 제공하여야 하는 기본 서비스인지 아니면 일반 재화나 서비스와 같이 수익자 부담원칙에 의거 수요자가 부담해야 하는지, 또는 공공재와 사적재의 양면성을 고려해 공공부담과 수익자부담을 같이 고려하는 형태가 바람직한 지에 대한 검토를 필요로 한다. 아울러, 환경개선용수의 수익자를 설정하는 문제에 있어서는 수요자가 특정한 목적을 위해 물을 사용하는 특정 사업자인지, 아니면 공익적인 측면에서 불특정 다수를 대신하여 환경개선용수를 수요하는 수요자인지에 따라 수익자가 달라지기 때문에 이에 대한 구분도 필요하다. 환경개선용수의 부담방법을 정할 때 수원(水源)을 기준으로 판단하여야 한다. 환경개선용수의 수원으로는 다목적댐, 하수처리장, 빗물, 농업용 저수지, 지하수 및 기타 하천수로 구분할 수 있다. 아울러 비용부담 범위가 물에 대한 부담에 한정하는지 아니면 환경개선용수를 수익지까지 공급하기 위한 공급시설에 대한 부담인지도 명확히 할 필요가 있다. 환경개선용수는 생활 공업용수 등과 같이 하천수를 특정 용도에 사용하는 것이기 때문에 특정 이용자가 국가에 하천수 사용허가를 얻어 이용하는 것으로 수익자가 비용을 부담하는 것을 원칙으로 하는 것이 가장 바람직하다. 왜냐하면 환경개선용수의 확보가 하천관리청의 의무가 되는 경우에는 하천의 물이 공유재산화 됨으로써 나타나는 '공유재산의 비극'(Tragedy of the Commons)을 초래하기 때문이다. 다만, 비용부담의 정도에 있어서는 다른 요인이 고려될 필요가 있다. 원칙적으로 하천의 자연적 기능을 유지하는데 필요한 유량은 하천관리청의 의무이므로 공공부담으로 하고 인위적 기능을 유지하는데 필요한 유량은 수익자 또는 원인자부담이 바람직하다. 이러한 기본 원칙에 따르면, 환경개선용수는 수익자부담 또는 원인자부담이 주(主)원칙이고 공공부담은 부(副)원칙이다. 본 연구는 환경개선용수의 확보 및 공급에 따른 비용부담 원칙에 대한 기준을 제시한다.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.11-18
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• 2010

The contamination of a suite of heavy metals were evaluated in water and sediments of urban stream, Tancheon down the stream. Tancheon is a urban stream which goes all the way across the urban area where various pollution sources are present. The sixteen study sites from seven different areas were designated down the stream. The heavy metal levels of the streams were detected in the order of Zn>Cu>Ni>Pb>Cd>Cr>Sb. There was a difference in the relative order of the concentration ranking in lake sediments. There is a trend that the heavy metal levels are higher at the sites where the construction causes inflow of soil particles to stream. Toxicity tests using pore-water in sediments were conducted for samples collected in some study sites, and pore-water in one site was proven to be toxic to Japanes medaka (Oryzias latipes). The reason may be the fecal pollution rather than heavy metal effect. Strong odor was detected in the sediment whose pore-water samples showed ecotoxicity. We did not observed the increasing concentration of heavy metals down to stream since the soil texture varied in the stream area of our study. Further study is needed to find quantitative relations between the level of contamination and its eco-effect.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.197-201
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• 2011

공공수역의 수질개선을 위해 그동안 하 폐수 처리장 등 친환경시초시설의 건설과 하수관거의 확충으로 점오염을 통제해왔으나, 여전히 하천, 호소, 연안의 수질은 목표 수준까지 개선되지 않고 있으며, 점오염원 삭감에 따라 상대적으로 비점오염원의 수질오염 기여도는 증가하고 있다. 비점오염물질은 도로상 오염물질, 도시지역의 먼지와 쓰레기, 지표상 퇴적오염물질, 농지에 살포된 농약, 축사에서의 유출물 등이 강우시 빗물과 함께 유출되면서 발생한다. 특히, 도시지역에는 대 소규모 공단들이 밀집되어 있기 때문 발생되는 비점오염물질의 특징은 단위면적당 오염부하가 크고 각종 유독성 물질을 함유하고 있다. 그러므로 본 연구에서는 도시유역의 개별 공장이 아닌 이러한 비점오염원 특징을 가진 대 소규모 공업단지(김해시 나전농공단지, 부산시 녹산 국가산업단지)를 선정하여 비점오염물질의 유출특성을 알아보고자 하였다.

• Analytical Science and Technology
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• v.28 no.6
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• pp.377-384
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• 2015

A survey of the artificial radionuclides in rivers and lakes was conducted to investigate their levels in surface water. Water samples were collected at 60 points and analyzed by gamma-ray spectrometry with a measurement time of 10,000 seconds for ¹³⁴Cs, ¹³⁷Cs, and ¹³¹I. The obained values were lower than MDA for all points, except one point for ¹³¹I that was 0.533±0.058 Bq/L. ¹³¹I is known as a radioactive material that occurs frequently in sewage treatment plants. Because it is often used for medical treatments and subject to spreading into the environment due to the excretion from the patients. For the point where ¹³¹I was detected, we conducted additional investigation on the upstream river point and the effluent points of nearby sewage treatment plant to find the source of ¹³¹I. ¹³¹I was not detected at the upstream points of one of the upstream sewage treatment plants but found at the downstream points with the level being 0.257±0.034 to 0.799±0.051 Bq/L, proving the sewage treatment plant was the ¹³¹Isource.

• Journal of Korea Water Resources Association
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• v.43 no.2
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• pp.131-138
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• 2010

Due to the increased water demand and severe drought as an effect of the global warming, the effluent from wastewater treatment plants becomes considered as an alternative water source to supply agricultural, industrial, and public (gardening) water demand. The effluent from the wastewater treatment plant is a sustainable water source because of its good quality and stable amount of water discharge. In this study, the water reuse system was developed to minimize total construction cost to cope with the uncertain water demand in future using two-stage stochastic linear programming with binary variables. The pipes in the water reuse network were constructed in two stages of which in the first stage, the water demands of users are assumed to be known, while the water demands in the second stage have uncertainty in the predicted value. However, the water reuse system has to be designed now when the future water demands are not known precisely. Therefore, the construction of a pipe parallel with the existing one was allowed to meet the increased water demands in the second stage. As a result, the trade-off of construction costs between a pipe with large diameter and two pipes having small diameters was evaluated and the optimal solution was found. Three scenarios for the future water demand were selected and a hypothetical water reuse network considering the uncertainties was optimized. The results provide the information about the economies of scale in the water reuse network and the long range water supply plan.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.112-121
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• 2004

A study was performed to examine the effects of UV-disinfected reclaimed water on microorganism concentration during rice culture. Four treatments were used and each one was triplicated to evaluate the changes of microorganism concentrations: stream water irrigation (STR), biofilter effluent irrigation (BE), UV-disinfected water irrigation with dose of 6 mW ${\cdot}$ s $cm{-2}$ (UV-6), and UV-disinfected water irrigation with dose of 16 mW ${\cdot}$ s $cm{-2}$ (UV-16). The indicator microorganisms of interest were total coliform (TC), fecal coliform (FC), and E. coli. The biofilter effluent from 16-unit apartment sewage treatment plant was used as reclaimed water and flowthrough type UV-disinfection system was used. Concentrations of indicator microorganisms in the treatment plots ranged from $10^2$ to $10^5$ MPN/100 mL during 24 hours after irrigation in May and June, where initial irrigation water for transplanting reparation was biofilter-effluent without UV-disinfection. It implies that initial irrigation using only non-disinfected reclaimed water for puddling in paddy field can be health-concerned because of more chance of farmer's physical contact with elevated concentration of microorganisms. The concentrations of microorganisms varied widely with rainfall, and treatments using UV-disinfected water irrigation showed significantly lower concentrations than others and their levels were within the range of paddy rice field with normal surface water irrigation. The mean concentrations of STR and BE during growing season were in the range of 4 ${\times}\;10^3$ MPN/100 mL for TC, and 2${\times}\;10^3$ MPN/100 mL for FC and E, Coli, While mean concentrations of UV-S and UV-lS were less than 1${\times}\;10^3$ MPN/100 mL for all the indicator microorganisms. Overall, UV-disinfection was thought to be feasible and practical alternative for agricultural reuse of secondary level effluent in Korea.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.99-110
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• 2023

Non-point source (NP) pollutants in an agricultural landuse are discharged from a large area compared to those in other land uses, and thus effective source control measures are needed. To develop appropriate control measures, it is necessary to quantify discharge load of each source and evaluate the degree of water quality improvement by implementing different options of the control measures. This study used Hydrological Simulation Program-FORTRAN (HSPF) to quantify pollutant discharge loads from different sources and effects of different control measures on water quality improvements, thereby supporting decision making in developing appropirate pollutant control strategies. The study area is the Gyeseong river watershed in Changnyeong county, Gyeongsangnam-do, with agricultural areas occupying the largest proportion (26.13%) of the total area except for the forest area. The main pollutant sources include chemical and liquid fertilizers for agricultural activities, and manure produced from small scale livestock facilities and applied to agriculture lands or stacked near the facilities. Source loads of chemical fertilizers, liquid fertilizers and livestock manure of small scale livestock facilities, and point sources such as municipal wastewater treatment plants (WWTPs), community WWTPs, private sewage treament plants were considered in the HSPF model setup. Especially, NITR and PHOS modules were used to simulate detailed fate and transport processes including vegitation uptake, nutrient deposition, adsorption/desorption, and loss by deep percolation. The HSPF model was calibrated and validated based on the observed data from 2015 to 2020 at the outlet of the watershed. The calibrated model showed reasonably good performance in simulating the flow and water quality. Five Pollutants control scenarios were established from three sectors: agriculture pollution management (drainge outlet control, and replacement of controlled release fertilizers), livestock pollution management (liquid fertilizer reduction, and 'manure management of small scale livestock facilities) and private STP management. Each pollutant control measure was further divided into short-term, mid-term, and long-term scenarios based on the potential achievement period. The simulation results showed that the most effective control measure is the replacement of controlled release fertilizers followed by the drainge outlet control and the manure management of small scale livestock facilities. Furthermore, the simulation showed that application of all the control measures in the entire watershed can decrease the annual TN and TP loads at the outlet by 40.6% and 41.1%, respectively, and the annual average concentrations of TN and TP at the outlet by 35.1% and 29.2%, respectively. This study supports decision makers in priotizing different pollutant control measures based on their predicted performance on the water quality improvements in an agriculturally dominated watershed.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.3
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• pp.212-221
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• 2011

Wastewater treatment plants (WWTPs) are required to meet the reinforced discharge standards which are differentiated as 0.2, 0.3 and 0.5 mg-TP/L for the district I, II and III, respectively. Although most of WWTPs are operating advanced biological phosphorus removal system, the supplementary phosphorus treatment facility using chemical addition should be required almost at all WWTPs. Therefore, water quality data from several exemplary full-scale plants operating phosphorus treatment process were analyzed to evaluate the reliability of removal performance. Additionally, a series of jar tests were conducted to find optimal coagulants dose for phosphorus removal by chemical precipitation and to describe characteristics of the reaction and sludge production. Chemical costs and the increasing sludge volume in physicochemical phosphorus removal process were estimated based on the results of jar tests. The minimum coagulant (aluminium sulfate and poly aluminium chloride) doses to keep TP concentration below 0.5 and 0.2 mg/L were around 25 and 30 mg/L (as $Al_2O_3$), respectively, in the mixed liquor of activated sludge. In the tertiary treatment facility, relatively lower coagulant doses of 1/12~1/3 the minimum doses for activated sludge were required to achieve the same TP concentrations of 0.2~0.5 mg/L. Increase in suspended solids concentration due to chemical precipitates in mixed liquor was estimated at 10~11%, compared to the concentration without chemical addition. When coagulant was added into mixed liquor, chemical (aluminium sulfate) cost was estimated to be 4~10 times higher than in secondary effluent coagulation/separation process. Sludge production to be wasted was also 4~10 times higher than secondary effluent coagulation/separation process.