• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1925-1928
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• 2007

Water cycle analysis was performed for Gunja basin located in metropolitan Seoul using Aquacycle model in order to assess the problems of urban water cycle. From the water cycle analysis of Gunja basin, it was found that 75% of total rainfall occurred in the form of surface runoff, and groundwater recharge only accounted for about 7%. This suggests serious distortion of water cycle which can be attributed to urbanization. Feasibility analysis of reuse scenarios such as rainwater use and wastewater reuse was then performed to examine their influences on improving the water cycle. From the analysis of water reuse options, it was shown that imported water supply savings of 13% can be achieved through rainwater use, and water supply savings of 31% through wastewater reuse.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.655-659
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• 2005

Pre-filter system that was consisted of wasted-tire, non-woven fabrics, and sponge was developed as a primary treatment process prior to rainwater reservation or a pre-treatment process of rainwater reuse system for reclamation. By using this system, SS concentration, TOC, COD, and turbidity could decreased by 86.7%, 62.6%, 69.1% and 66.5%, respectively. From the results of particle size distribution of treated water, the particles over than $30{\mu}m$ of diameter were completely removed by pre-filter system. But 90% of particles less than $20{\mu}m$ of diameter were passed through pre-filter. Optimal depth of wasted-tire and non-woven fabrics were 15cm and 2.4cm, respectively. Pre-filter system was considered as an effective alternative for pre-treatment of rainwater including non-point pollutants and it could be also applied for the treatment of combined sewer overflow (CSO).

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.271-276
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• 2014

The purpose of this study was to survey Suwon citizens over the age of 20 in order to provide basic data on the extent of coverage of the city's water reclamation system and to set guidelines for a policy on water reuse. The survey used a questionnaire with two fields, rainwater use and wastewater recycling, for analyzing factors that influenced water reuse. A factor analysis of 19 questionnaires gave a Cronbach's alpha coefficient greater than 0.4. Factors that influenced rainwater use were environmental protection, water charges, and the risk of climate change. Of the total explanatory power, the share of rainwater use and environmental protection was 39.7% and 28.1% respectively. Environmental protection (explanatory power 24.2%) had an effect on the explanatory power of wastewater reuse. When factors influencing wastewater recycling, like cost of recycling, water management policy, climate change, and suspension of tap water supply were included, the explanatory power of each of these factors went up by 4.3%, 2.8%, 3.3%, and 1.1%, respectively. For more effective wastewater recycling, a water management policy that factors in the above is required, along with a campaign to educate citizens on water management and environment conservation. Additionally, it may be necessary to improve the reliability and the quality of water supply.

• Journal of Soil and Groundwater Environment
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• v.28 no.5
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• pp.51-58
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• 2023

In this study, an empirical experiment was conducted to assess the feasibility of replacing groundwater with rainwater in melon cultivation using a smart rainwater harvesting system. The rainwater harvesting efficiency was calculated under three different melon cultivation scenarios. After cultivation, the quality of the fruits grown with rainwater and groundwater was compared by examining the weight, degree of sweetness, and flesh hardness of the products. The results revealed that the water quality of the smart rainwater harvesting device was suitable for melon cultivation to provide better hardness and chloride levels than groundwater. It was also estimated that about 40% of the total water demand for full growth of the melon could be supplied by rainwater. The fruit weight and sweetness were equivalent or slightly better for the melons cultivated with rainwater than those cultivated with groundwater. In particular, the flesh hardness was significantly improved by rainwater cultivation. These results collectively suggest that rainwater can be used as a substitute for groundwater to preserve groundwater resources without compromizing the produced fruit quality.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.144-151
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• 2015

With expansion of modern cities, a huge number of old industrial facilities have been abandoned. Thus, in the development of ecological city, this study aims to conclude on these old facilities and their ecological landscape designs by analyzing successful cases. The approaches adopted are as follows. Starting with literature review, whereby old industrial facility's definition and developing process are pinpointed, the paper studies representative cases with reuse and re-development theories of ecological design for old industrial facilities, of which renovation types, reuse effects, and design features are particularly examined. Case studies also demonstrate considerations in ecological reuse designs, such as ecological restoration, energy conservation, rainwater collection, and utmost pollution reduction, etc. However, technology, environment and circumstance differences determine that each design project requires concrete analysis, which should also be considered in future ecological design for old industrial facilities.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.12
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• pp.676-682
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• 2016

In this study, rainwater-greywater hybrid system was installed and operated for 1 year in order to evaluate its water quantity, water quality, and economic efficiency in building no. 39. This system was expected to overcome each disadvantages of and maximize each advantages. Low-greywater that was washed up from shower room was treated by MBR (Membrane Bioreactor) and ozone oxidation. Rainwater that was collected from the rooftop was stored in a reservoir, and then transferred to the storage tank that was mixed with treated greywater. After 1 year operating in building no. 39, rainwater and greywater was used to supply $2,599m^3$ of toilet flushing water. In terms of water quality, rainwater was satisfied far the greywater reuse standards except for E.coli. Moreover, low greywater quality was acceptable except for E. coli, BOD, SS, and turbidity. In addition, economic analysis was obtained from benefit-cost ratio (B/C) with 1.11. It implies that the feasibility of the project was reasonable. Furthermore, various research and policy to improve the economic efficiency of water recycling facilities is required to expand the use of water recycling facilities.

• Journal of Korean Society on Water Environment
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• v.34 no.6
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• pp.669-677
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• 2018

Torrential rain and drought are repeated due to the increase in the unpredictable fluctuating of rainfall patterns. It is time for stabilize water resource management in terms of disaster prevention. Distributed control from sources is needed to minimize damages caused by torrential rains and droughts. Rain barrel can be used to reduce the runoff as they collect and store rainwater. In response to this situation, Seoul Metropolitan Government and other local governments implemented a project to support the installation of rain barrel and provided 90% of the cost of installing it in private areas. However, with limited budget, it is difficult to distribute rainwater to the city which is mostly covered by private areas. In this study, Samho-dong, Ulsan, where pilot projects of water cycle leading city are underway, analyzed the effects of reducing the runoff with respect to the amount of rainwater that can be used, and analyzed the economics of recoverable investment cost when installed. From the analysis, it was established that it is possible to show sufficient efficiency with a small capacity without the need to install large rain barrel effectively in the private sector, and to support the installation cost of less than 70 percent of the rainwater can be recovered.

• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.269-276
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• 2012

The surface characteristics and performance of PTFE (polytetrafluoroethylene) hollow fiber membranes have been systematically investigated at lab- and pilot-scale to assess their application to membrane-bioreactor, particularly for integrating wastewater reclamation and rainwater harvesting. The PTFE membrane expressed some surface features, such as hydrophobicity, which might enhance membrane fouling. However, lab-scale performance and cleaning experiments under various conditions demonstrated that the PTFE membrane could produce the desirable water flux with good cleaning efficiency, implying easy operation and maintenance due to superior chemical resistance of PTFE membranes. Most of effluent water qualities were met with Korean standard for discharge and reuse, except color. Color level was further reduced by blending with rainwater at 75:25 ratio. Based on the lab-scale experimental results, the pilot plant was designed and operated. Pilot operation clearly showed sTable performance with satisfactory water quality, suggesting that PTFE membrane could be applied for decentralized MBR integrated with rainwater use.

• Journal of Korea Water Resources Association
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• v.51 no.4
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• pp.323-334
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• 2018

Recently, increased water demand and frequent droughts caused severe water shortages in South Korea. Thus, reusing the reclaimed water is receiving attention as an alternative water source rather than depending on the conventional water supply. In South Korea, three types of water reuse are mainly applied, such as rainwater reuse, gray water reuse and wastewater reuse. In this study, the wastewater reuse was analyzed since the amount of treated wastewater is relatively constant over the year and typically the water quality is acceptable for reuse. In Yongin-si, there are 26 golf clubs, which is about 10% of entire facilities currently operating in South Korea. The golf courses consume significant amount of water for landscaping; thus, if the reclaimed water used, the economic, social and environmental benefits would be tremendous. This study estimates the economic benefits and costs when supplying the reclaimed wastewater for landscaping of golf courses as a case study in Yongin-si.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.457-457
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• 2015

최근, 우리나라에서는 효과적인 수자원 관리와 추가적인 수원 확보 차원에서 빗물 재이용에 관한 관심이 크게 증대되고 있다. 하지만 국내의 관련된 제도와 기술 지침은 단지 규제 측면에서 빗물이용시설을 설치하도록 제시하고 있어 빗물이용시설의 실제 사용을 고려한 계획이 배제되어 있다. 본 연구의 목적은 실용적인 빗물이용시설의 계획을 위해 SWMM을 이용하여 빗물 재이용의 수요(빗물 재이용 목표량)와 공급(연간 강우량과 패턴)을 반영한 설계 방법을 제시하는 것이다. 이를 위해 SWMM 내에 구현되어 있는 빗물통 모의에 관한 수식을 이용하되, 수식을 목적에 맞도록 일부 변형하여 활용하였다. 그리고 빗물이용시설의 규모는 설정한 목표량을 만족할 수 있는 최소의 크기로 결정하는 것이 적절하고, 장기간의 강우자료를 이용한 물수지 석이 요구되므로 이를 고려하였다. 본 연구에서 제시한 빗물이용시설의 설계 방법은 송산 그린시티 동측지구에 계획된 빗물이용시설의 규모 결정에 활용되었다. 빗물 재이용의 목표량이 일정한 경우, 빗물이용시설의 크기가 커질수록 빗물 재이용 가능량은 로그함수의 형태로 증가하여, 빗물이용시설이 특정 규모 이상으로 커지더라도 빗물 재이용 가능량은 더 이상 증가하지 않는 임계점이 나타난다(그림 1). 따라서 빗물이용시설은 이러한 임계점이 나타나는 규모 정도로 설계하는 것이 합리적이다. 본 연구에서 제시한 빗물 재이용을 고려한 빗물이용시설의 계획은 빗물이용시설을 보다 합리적으로 계획하는데 도움을 줄 수 있을 것으로 판단된다.