• 한국농공학회지
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• 제45권5호
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• pp.151-159
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• 2003

Absorbent Biofilter Systems (ABS), composed of an anaerobic septic tank, a pump chamber and an absorbent biofilter tank, have been found to economically provide rural on-site wastewater treatment. This study was conducted to assess the potential of ABS effluent as an alternative water resource for agricultural and environmental use, with respect to the removal of pathogenic microorganism and their fertilization effect. A pilot scale ABS was used to compare its removal efficiency of pathogens from effluent water. Overall, more than 95 percent of Salmonella and E. coli were removed. This result demonstrates that a significant reduction in the pathogenic microorganism of effluents can occur in ABS, which implies the feasibility for the use of ABS effluent in agriculture and environment, with the provision of a further simple disinfection step, in order to satisfy the WHO guidelines for the microbiological quality in agriculture. In addition, because of the abundant nutritional content of ABS effluent, the substitution effect of fertilizer (N, P and K) in paddy irrigation, i.e. 2/3 for nitrogen, l/3 for phosphorus and 1/5 for potassium would be expected. Based on the experimental data, the ABS effluent could be used as a new alternative water resource for paddy irrigation, as well as for environmental purposes, such as supplying water to ecological parks in rural villages.

• 대한토목학회논문집
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• 제31권6B호
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• pp.551-563
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• 2011

수자원사업은 대규모의 예산이 투입된다. 따라서 수자원사업은 합리적이고 신뢰성 있는 의사결정이 필요한데 그동안 주로 경제성분석에 의존하여 왔다. 본 연구목적은 경제성분석위주의 기존 의사결정이 아닌, 사업의 필요성과 투자의 타당성을 다양한 각도로 평가할 수 있는 수자원사업 대안선정과 투자우선순위결정을 위한 다기준의사결정방법을 도출하는 것이다. 본 논문은 경제성 분석, 정책적 분석, 취약성 분석과 각각의 하위평가항목으로 평가기준을 구성하였다. 또한, 전문가 설문을 통한 사전 가중치를 제시함으로써, 일관성 있는 평가가 이루어지도록 하였다. 그리고 전문가 설문을 통해 평가항목의 속성별로 위험성향을 고려한 효용함수를 도출하였다. 종합평가점수는 평가항목별 가중치와 속성별 효용점수로 산정된다. 적용결과, 평가기준은 취약성 기준에 큰 영향을 받는 것으로 나타났다. 본 연구는 수자원사업에 대한 효율성과 취약지역에 대한 형평성을 제고하는데 기여할 수 있을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.629-638
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• 2014

This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1232-1237
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• 2009

Recently, we often encounter water shortage problem due to drought during dry season. Although we have built dams and expanded our tap water system greatly to meet the increasing demand of water, this approach has its inherent limitation including environmental destruction in the course of the dam construction. Therefore, this paper is aimed to analyze the water recycling models developed in other countries and modify them to fit into our system. Also the water recycling system in Busan municipal area was analyzed to propose an alternative method for reusing the recycled water from wastewater treatment area.

• 대한토목학회논문집
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• 제37권3호
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• pp.611-619
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• 2017

본 연구는 대체수자원시설 - 해수담수화, 식수용저수지, 용수전용댐, 지하댐, 그리고 두 개의 간접취수 방법인 강변여과와 청정지하저수지 - 을 고려한 다양한 용수공급시스템별 음용수 단위생산단가를 산정하기 위한 종합적인 방법과 분석결과를 제시한다. 대체수자원시설 건설부터 도수관로를 거쳐 후처리시설을 통한 음용수 생산 지점까지의 모든 건설비용과 운영관리비를 반영하기 위하여 필요한 데이터를 취합하고 개별 총사업비와 운영관리비 추정모델을 개발하였다. 단위생산단가에 영향을 주는 후처리시설과 도수관리의 길이, 그리고 음용수 생산용량에 대한 민감도 분석결과 청정지하저수지가 가장 비용이 작은 대체수자원시설로 분석되었으며 개별 대체수자원시설과 다양한 용수공급시스템별 경제성 정보는 수자원시설 계획 및 예산 분배 의사결정을 지원할 것으로 예상한다.

• 자원ㆍ환경경제연구
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• 제11권4호
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• pp.633-657
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• 2002

This study presents a demand modelling for landfill gas, which is used as alternative energy source for district cooling business. By analyzing the cost minimizing behavior of producer facing with three alternative energy sources such as electricity, cooling heat water, and gas, a demand function for landfill gas is derived from the optimal operating time of gas fired production facility, and estimated using unpublished data, which are associated with Seoul city's development plan for Sang-am area. The estimation results repeals that Seoul City could supply the land-fill gas of 13.76 million cubic meters each year at the price of about 16 won per cubic meters. However, if the investment costs associated with installation of gas collecting facilities are treated as sunk costs, annual amount of gas supplied is expected to increase to 14.22 million cubic meters at a lower unit price of 14.76 won.

• 자원ㆍ환경경제연구
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• 제9권4호
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• pp.747-771
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• 2000

This paper reports the results of a study to elicit willingness to pay (WTP) for changes in health risks from exposure to As, Pb, THM in tap water using experimental market method. The experimental market method, compared with other non-market valuation methods, allows us to use incentive compatible demand revealing scheme, to acquire market-like experience through repetitive auctions, and to incorporate learning process by providing new information during the session. Participants seemed to utilize the objective risk information in a 'rational' manner, and to change their WTP bids accordingly. Moreover they were able to reduce the 'ambiguity' in risk perception processes when objective risk probabilities provided are quite different from their subjective perceptions. Nonetheless, anchoring effects appeared to be still persistent in spite of market-like experience and learning opportunity. And implicit values entailed by WTP bid/risk tradeoffs indicate a wide variation in values across alternative risk reductions and overrated responses to very small risk reductions.

• Agribusiness and Information Management
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• 제9권1호
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• pp.7-17
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• 2017

Agricultural water management has gained enormous attention in the developing world to alleviate poverty, reduce hunger and conserve ecosystems in small-scale production systems of resource-poor farmers. The story of food security in the $21^{st}$ century in India is likely t o be closely linked to the story of water security. Today, the water resource is under severe threat. The past experiences in India in general and in Andhra Pradesh in particular, indicated inappropriate management of irrigation has led to severe problems like excessive water depletion, reduction in water quality, water logging, salinization, marked reduction in the annual discharge of some of the rivers, lowering of ground water tables due to pumping at unsustainable rates, intrusion of salt water in some coastal areas etc. Considering the importance of irrigation water resource efficiency, Krishna Western Delta (KWD) of Andhra Pradesh was purposively selected for this in depth study, as the farming community in this area are severely affected due to severe soil salinity and water logging problems and hence, adoption of different water saving crop production technologies deserve special mention. It is quite disappointing that, canals, tube wells and filter points and other wells could not contribute much to the irrigated area in KWD. Due to less contribution from these sources, the net area irrigated also showed declining growth at a rate of -6.15 per cent. Regarding paddy production, both SRI and semi-dry cultivation technologies involves less irrigation cost (Rs. 2475.21/ha and Rs. 3248.15/ha respectively) when compared to transplanted technology (Rs. 4321.58/ha). The share of irrigation cost in Total Operational Cost (TOC) was highest for transplanted technology of paddy (11.06%) followed by semi-dry technology (10.85%) and SRI technology (6.21%). The increased yield and declined cost of cultivation of paddy in SRI and semi-dry production technologies respectively were mainly responsible for the low cost of production of paddy in SRI (Rs. 495.22/qtl) and semi-dry (Rs. 532.81/qtl) technologies over transplanted technology (Rs. 574.93/qtl). This clearly indicates that, by less water usage, paddy returns can be boosted by adopting SRI and semi-dry production technologies. Both the system-level and field-level interventions should be addressed to solve the issues/problems of water management. The enabling environment, institutional roles and functions and management instruments are posing favourable picture for executing the water management interventions in the State of Andhra Pradesh in general and in KWD in particular. This facilitates the farming community to harvest good crop per unit of water resource used in the production programme. To achieve better results, the Farmers' Organizations, Water Users Associations, Department of Irrigation etc., will have to aim at improving productivity per unit of water drop used and this must be supported through system-wide enhancement of water delivery systems and decision support tools to assist farmers in optimizing the allocation of limited water among crops, selection of crops based on farming situations, and adoption of appropriate alternative crops in drought years.

• Environmental Engineering Research
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• 제18권3호
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• pp.117-121
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• 2013

For underpasses in Yeongjong Sky City business district, the guided drainage system, as a buoyancy prevention system has been designed, and is under construction. This paper investigates the safety of the guided drainage system for underpass structures being constructed in Yeongjong Sky City business district. This paper also calculates the amount of outflowing groundwater generated by the guided drainage system, and proposes alternative usages of the water. In order to investigate safety and field applicability of the guided drainage system for underpasses, characteristics of the surface flow for the area of interest have been analyzed, and the flow change of groundwater following the underpass structure construction has been evaluated using the 3-dimensional groundwater program MODFLOW. The influence of ground water on safety of the underpass structures has been calculated by FLAC2D analysis. For alternative usages for the outflowing groundwater generated by the guided drainage system, utilization methods of the outflowing groundwater in national and international resources have been researched. The amount of an outflowing groundwater to be generated in the area of interest has been analyzed, and efficient potential usages of this groundwater have been researched. When guided drainage technique is applied, the change in flow of groundwater must be evaluated and considered as safety factor relating to the buoyancy of the structure. As a result, safety factor demonstrated more than 1.2, meaning that the underpass structure is safe. The amount of subsoil drain generated by the guided drainage system was also analyzed. The quality and amount of water satisfied the standards and volume requirements, so as to make it applicable for a number of uses, such as X, Y, and Z, and should prove to be a valuable resource as the circumstances of the neighboring area change over time. These resources can be used as basic data for future urban water circulation studies, as well as generating research of alternative water usages.

• 자원ㆍ환경경제연구
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• 제14권2호
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• pp.475-491
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• 2005

공업용수 수요량 예측방법으로 현재 사용되고 있는 부지면적원단위법의 문제점을 분석하고 이에 대한 대안으로 수요함수를 이용하는 방법을 분석한다. 실제 조사 자료인 산업 총조사보고서의 자료와 비교하면 최근의 공업용수 수요량은 부지면적 원단법의 수요량 예측치보다는 본 연구에서 사용한 수요함수를 이용하여 추정한 수요량 예측치가 훨씬 더 정확하게 추정되었음을 보여준다. 그리고 가격 변화에 따른 수요량 변화 효과가 상당함을 보이고 있으므로 공업용수 수요량 관리를 위한 가격정책의 유효성을 보여준다. 따라서 향후 공업용수 수요량 추정에서는 부지면적원단위법보다는 용수 가격 및 산출량 등 경제적인 변수를 고려한 수요함수를 이용하는 것이 바람직하다.