• 한국습지학회지
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• 제18권3호
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• pp.267-274
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• 2016

농촌 지역 하수도 보급은 하천, 호소 및 습지와 같은 수계 수질 보호를 위해서 반드시 필요하다. 또한 안정적인 소규모 하수처리장 운영을 위해서는 유입 유량과 농도의 변화가 큰 소규모 하수도 특성을 고려해야 한다. 본 연구에서는 봉화군 18개의 소규모 하수처리장 운전 결과를 통해 유입유량비 (유입 유량 / 설계 유량) 특성, 소규모 하수처리장 처리 효율에 미치는 영향과 적정 유입유량비 산정에 관한 연구를 수행하였다. 분석 결과 유입유량비는 여름철에 가장 높은 것으로 나타난 반면, 유입 하수 농도는 가을철과 겨울철에 높은 것으로 나타났다. 유입유량비가 증가할수록 처리 효율이 증가하는 경향을 보였으며, 영양염류 처리 효율이 유기물과 부유물질 처리 효율에 비해 민감한 영향을 받는 것으로 나타났다. 안정적인 소규모 하수처리장 처리 효율을 위해서는 유입유량비 0.8 이상을 유지해야 할 것으로 판단된다.

• 상하수도학회지
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• 제19권5호
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• pp.572-581
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• 2005

This research is conducted to develop predictable method of real scale nanofiltration treatability with small scale nanofiltration experiments. As a result of comparing calculated values with measured values, they are in a good agreement for the concentrations in filtered water and concentrated water. The results of that are not affected by change of system recovery from 20% to 95%. The proposed method is produced using constant recovery of elements, that is, no considering the pressure change. we can predict filtrated flux and contaminant concentrations with the method. The method has the following steps. (1) Calculate recovery of each element with water quality level after fixing recovery elements, (2) Predict system recovery with recovery of elements in 1, 2, 3, and 4 banks, (3) Run small scale nanofiltration experiments in predicted water quality and (4) Simulate large scale nanofiltration system for forecasting actual water quality. As the cost for nanofiltration pretest will reduced if we use the proposed method, it will be a promising method for introducing nanofiltration to supply safe drinking water.

• Membrane and Water Treatment
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• 제6권1호
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• pp.43-52
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• 2015

A small-scale electro-dialysis system was constructed for domestic use. It is composed of six compartments in which five special polystyrene ionic membranes are housed. A series of experiments on the transport of sodium and chloride ions through polystyrene membranes was performed and the effects of electric current and voltage on the pH of water were investigated. This electrodialyser could reduce the NaCl content to an acceptable level (5307 mg/L) when water containing 9945 mg/L of sodium chloride is fed to the electrodialyser. The reduction was by the action of direct current 60 mA/100 mA when a 15 V / 20 V potential is maintained across the membrane. The results showed that the pH of the treated water attained a value in the range of 7-8, with the chloride concentration of 5307 mg/L when the voltage was in the range of 20 volts. This was achieved when two of the small-scale electro-dialysers were placed in series and the solutions from the respective compartments were mixed. This is considered useful because this complies to the requirement of drinking water standard both in terms of chloride and pH. Therefore, this type electrodialyserhas the potential for domestic uses in isolated houses where potable water supply is not available.

• 상하수도학회지
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• 제36권5호
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• pp.275-287
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• 2022

In order to overcome the small scale of Korea waterworks and to achieve comprehensive improvement and innovation transformation, the waterworks integration was reviewed. The effect of consolidation was confirmed by the integration of the water supply business in the southern Gangwon region and the western Gyeongnam region in Korea, such as an increase in the flow rate and a decrease in the production unit cost. After facing management and service limitations overseas, more than 1,000 small-scale waterworks projects in the UK were integrated into 27 waterworks providers, and Japan also revised the Waterworks Act in December 2019 and is in the process of integrating waterworks. It is considered appropriate to promote the integration of waterworks projects in Korea by respecting the autonomy of local governments, but using a participatory method, a win-win method, and a linkage method. For the integration of waterworks projects, three strategies are proposed: First creating a national foundation for integration (revision of the Waterworks Act), Second establishing a waterworks integration strategy led by local governments, Third forming an external consensus and providing incentives for participation.

• 상하수도학회지
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• 제25권4호
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• pp.581-589
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• 2011

Generally, treated water or raw water is transported into storage reservoirs which are receiving facilities of local governments from multi-regional water supply systems. A water supply control and operation center is operated not only to manage the water facilities more economically and efficiently but also to mitigate the shortage of water resources due to the increase in water consumption. To achieve the goal, important information such as the flow-rate in the systems, water levels of storage reservoirs or tanks, and pump-operation schedule should be considered based on the resonable water demand forecasting. However, it is difficult to acquire the pattern of water demand used in local government, since the operating information is not shared between multi-regional and local water systems. The pattern of water demand is irregular and unpredictable. Also, additional changes such as an abrupt accident and frequent changes of electric power rates could occur. Consequently, it is not easy to forecast accurate water demands. Therefore, it is necessary to introduce a short-term water demands forecasting and to develop an application of the forecasting models. In this study, the forecasting simulator for water demand is developed based on mathematical and neural network methods as linear and non-linear models to implement the optimal water demands forecasting. It is shown that MLP(Multi-Layered Perceptron) and ANFIS(Adaptive Neuro-Fuzzy Inference System) can be applied to obtain better forecasting results in multi-regional water supply systems with a large scale and local water supply systems with small or medium scale than conventional methods, respectively.

• 대한환경공학회지
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• 제32권6호
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• pp.563-580
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• 2010

2009년 환경부는 '농어촌지역 하수도정비 종합계획'을 발표하면서 도시지역과 농촌지역의 하수도 서비스 격차를 줄이고 농어촌지역의 생활환경을 개선하기 위하여 2015년까지 약 4조 7천억 원의 예산을 투입하여 농어촌지역의 하수도 보급률을 75%까지 향상하겠다고 밝혔다. 하지만 이번 종합계획은 소규모하수도의 문제점을 정확히 파악하지 못하고 있어 하수도 보급률 증가에 따른 수질개선 효과는 기대하기 어려울 것이다. 따라서 본 연구에서는 경기도의 2개 지역 마을하수도 정비 사례를 중심으로 마을하수도의 문제점과 해결방안에 대해서 알아보고, 종합계획을 추진하는데 고려되어야 할 사항들에 대해서 논의하고자 한다. 현장조사를 통하여 하수의 불균등 유입, 저유량, 저부하 등의 문제가 공통적으로 발생하고 있는 것을 파악하였다. 유입되는 부하량에 맞게 처리시설의 운전 방법을 개선해야 하지만 대부분의 시설들이 설계시 제시된 운전인자로 운전되고 있어 처리효율이 저하되는 것으로 조사되었다. 정밀진단에서는 문제점에 대한 해결방안으로 유량균등화, 포기/ 비포기 비율 조절 등을 검토하여 현장에 적용하였으며, 그 결과 유기물 및 탈질산화 반응에 의한 T-N의 처리효율 개선되는 것을 확인할 수 있었다.

• 상하수도학회지
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• 제29권1호
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• pp.1-9
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• 2015

A combined treatment system using multiple source water is becoming important as an alternative to conventional water supply for small-scale water systems. In this research, combined water treatment systems were investigated for simultaneous use of multi-source water including rainwater, ground water, river water, and reclaimed wastewater. A laboratory-scale system was developed to systematically compare various combinations of water treatment processes, including sand filtration, microfiltration (MF), granular activated carbon (GAC), and nanofiltration (NF). Results showed that the efficiency of combined water treatment systems was affected by the quality of feed waters. In addition, a simply approach based on the concept of linear combination was suggested to support a decision-making for the optimum water treatment systems with the consideration of final water quality.

• 디지털융복합연구
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• 제12권12호
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• pp.571-580
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• 2014

우리나라의 상수도 사업은 규모의 영세성, 지역에 따른 경영과 서비스의 불균형, 지역 간 수자원의 이용 및 관리에 있어 불합리한 문제점 등 취약한 산업구조로 인해 효율이 낮은 실정이다. 본 연구에서는 자료포락분석(data envelopment analysis)을 활용한 효율성 분석 및 맘퀴스트(Malmquist) 지수 그리고 통계적 방법을 통해 전라북도 지방상수도 사업소의 생산성 변화를 탐색적으로 파악해 보았다. 그 결과 규모 효율성이 1인 사업소가 6개로 나타났으며, 주로 군 단위 사업소에서 평균 이하의 생산성지수를 보임으로써 이들 사업소들은 생산성 증가를 위한 노력을 경주할 필요가 있음을 알 수 있었다. 본 연구는 DEA뿐만 아니라 맘퀴스트 생산성 분석을 통하여 생산성의 변화를 측정한다는 점에서 선행연구들과 차별화되는 바, 전라북도 지역 상수도 부문의 효율성을 제고하는데 기여할 것으로 사료된다.

• 한국환경보건학회지
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• 제46권5호
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• pp.513-524
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• 2020

Objective: The main purpose of this study is to evaluate the environmental and biological exposure of local residents who consumed arsenic-contaminated drinking water for less than one year. Methods: As a part of water quality inspections for small-scale water supply facilities, surveys were conducted of residents of two villages that exceeded the arsenic threshold for drinking water. The environmental impact survey consisted of surveys on water quality, soil, and crops in the surveyed area. Biological monitoring was performed by measuring the separation of arsenic species in urine and total arsenic in hair. Results: In the results of biological monitoring, the concentrations of AsIII and AsV were 0.08 and 0.16 ㎍/L, respectively. MMA and DMA were 0.87 and 36.19 ㎍/L. There was no statistically significant difference between the group who drank arsenic-removed groundwater or water from the small-scale supply facility and the group who drank tap water, purified water, or commercial bottled water. Some of the water samples exceeded the arsenic threshold for drinking water. There were no samples in the soil or rice that exceeded the acceptable threshold. Conclusion: In the case of short-term exposure to arsenic-contaminated drinking water for less than one year, there were no significant problems of concern from the evaluation of biological monitoring after arsenic was removed.

• 지질공학
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• 제29권1호
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• pp.37-50
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• 2019

지하수를 원수로 이용하는 소규모수도시설의 라돈 저감은 주로 저수조에서의 정치와 폭기에 의해 일어난다. 여름철 정치에 의한 32개 소규모수도시설 저수조와 꼭지수의 라돈 저감율은 -69.3~62.7%(평균 25.7%)와 -64.3%~83.1%(평균 30.3%), 가을철 정치에 의한 16개 소규모수도시설 저수조와 꼭지수의 라돈 저감율은 21.3%~78.0%(평균 42.8%)와 17.7%~66.9%(평균 44.8%)로 나타났다. 여름철보다 가을철의 라돈 저감률이 더 높은 것은 가을철의 지하수 사용량이 더 적어서 정치효과가 더 컸기 때문으로 판단된다. 폭기시설이 설치된 12개 저수조의 라돈 저감률은 47.4~94.0%(평균 78.9%)로 나타났는데 이 저감률에는 정치에 의한 라돈 저감률이 합쳐져 있다. 소규모수도시설 지하수의 라돈 저감을 위해서는 정치와 폭기를 이용할 수 있는데 보다 효율적인 활용을 위하여 지하수의 라돈 함량 변동성, 저수조의 크기와 형태, 지하수 사용량 변화, 폭기량, 환기시설 등을 고려한 라돈 저감 연구가 필요하다.