• Journal of the Korean Society of Groundwater Environment
• /
• v.7 no.1
• /
• pp.55-58
• /
• 2000

Methyl tertiary butyl ether (MTBE) is a gasoline additive that boosts the oxygen content in fuel (an oxygenate), resulting in less air-polluting carbon monoxide being released from vehicle exhaust systems. Then, groundwater contamination problems have been developed in areas where the chemical is used. Common sources of water contamination by MTBE include leaking underground gasoline storage tanks and leaks and spills from above ground fuel storage tanks, etc.. Studies on the chemical and these problems are going on abroad vigorously. These studies should be performed in our country as well more actively. This paper reviews on articles on these studies and focuses on the identification of the chemical as a groundwater contamination source.

• Economic and Environmental Geology
• /
• v.41 no.6
• /
• pp.645-655
• /
• 2008

The Cr(VI) concentrations at the shallow aquifer well (MPH-0-1) of the Moonpyung groundwater monitoring station were in the range of 0.5 to 3.1 mg/L exceeding 10 to 62 times the guideline for drinking-water quality, indicating continuous contamination. However, Cr was not detected at the deep bedrock well and the other subsidiary monitoring wells except for MPH-1 and 6. Cross-correlation analyses were conducted for rainfall and groundwater level time series, resulting in the mean time of recharge after precipitation events to be 5.6 days. For rainy season, the water level was raised and the Cr(VI) concentration was several times lower than that during dry season at well MPH-0-1 well. Correlation of the Cr(VI) concentration with the groundwater-level showed that the Cr(VI) reduction was closely related with the groundwater-level rise in the well. However, the groundwater level rise during high water season induced the lateral migration of the Cr(VI)-contaminated groundwater at well MPH-4. We enriched and isolated a chromium reducing bacteria, Enterobacter aerogenes, from the Cr(VI)-contaminated groundwater in the wells MPH-0-1 and MPH-1. The bacteria may play an important role for immobilizing Cr(VI) in the Cr(VI)-contaminated groundwater. Therefore, the migration of the contaminant (Cr(VI) must has been restricted because of the natural attenuation by microbial reduction of Cr(VI) in the groundwater. This research suggests that the bioremediation of the Cr(VI)-contaminated groundwater by the indigenous bacteria may be feasible in the Cr(VI) contaminated groundwater.

• Journal of Korean Society on Water Environment
• /
• v.33 no.1
• /
• pp.1-7
• /
• 2017

Bioretention systems, an advance low impact development and green infrastructure approach were currently utilized in different parts of the world because it promotes biodiversity thereby mimicking and preserving the pre-developed state of an area. This study investigated and compared the capability of four bioretention systems to identify factors affecting the hydraulic capabilities and pollutant removal efficiencies of each system. The two bioretention type A referred as Type A-C and Type A-FC were planted with perennials such as Chrysanthemum and Fan columbine, respectively. On the other hand, the two type B bioretention systems referred as Type B-A and Type B-JM were planted with shrub plant species such as Azalea and Japanese Meadowsweet, respectively. Based on the results, TV, infiltration mechanism, filter media depth and plant species were identified as the factors affecting the difference in flow attenuation, retained volume and pollutant removal efficiency of Type A-C, Type A-FC, Type B-A and Type B-JM bioretention systems. The design of bioretention Type B-A and Type B-JM were advantageous considering greater volume retention, groundwater recharge, longer HRT and peak flow attenuation and greater pollutant removal efficiency. On the other hand, the design of bioretention Type A-C and Type A-FC was more appropriate for design considering reduced groundwater contamination.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.04a
• /
• pp.229-232
• /
• 2003

본 연구는 울산지역 지하수오염 저감기술의 개발에 필요한 대수층의 공간적 분포특성을 파악하는 데 목적이 있다. 울산 공업도시의 대수층에서 공간적 분포특성을 파악하기 위하여 시추조사가 많이 필요 하지만 비용 및 시간 관계상 어려움이 있기 때문에, 지질조사 보고서나 논문 등에서 지하수자료와 시추 자료를 획득하여 지구통계기법을 이용한 울산지역 대수층의 공간적 분포를 모사하였다. 그리고 인구가 밀집되어 있는 남구와 중구를 중심으로 대수층 단면 분포를 모사하였다. 이와 같은 분석결과는 표토층 하부경계부와 풍화대 하부경계부에서 유사한 분포심도로 나타났으며, 지하수 수위는 표토층 하부경계와 암반층 상부경계부인 풍화대에 분포하는 것으로 나타났다.

• Journal of Soil and Groundwater Environment
• /
• v.11 no.4
• /
• pp.25-32
• /
• 2006

In this study, a novel bioreactor system using a diffuser type hollow fiber membranes (hollow fiber membrane diffuser, HFMD) was applied to investigate the feasibility and biodegradation capacity for the treatment of a gaseous mixture consisting of benzene, toluene and p-xylene(BTX). First, A mixed culture pre-acclimated to toluene effectively biodegraded the BTX mixture at an overall removal efficiency of approximately 70% for a 20-day operational period. It was found that the biodegradation of toluene was slightly inhibited because of the presence of benzene and p-xylene. Second, the elimination capacity (EC) of total BTX increased up to 360 $g/m^3/hr$, which was substantially higher than maximum ECs for BTEX reported in the biofiltration literature. Consequently, the hollow fiber membrane diffuser was considered as an alternative method over other conventional VOC-treating technologies such as biofilters.

• Journal of Soil and Groundwater Environment
• /
• v.10 no.1
• /
• pp.18-25
• /
• 2005

For economic impact analysis on a R&D project of groundwater remediation in the metropolitan areas conducted as a fundamental research programme of KIGAM from 1998 to 2002, benefit/cost ratio(BCR), net present value(NPV), and internal rate of return(IRR) were calculated using a contingent valuation method(CVM). Measurable direct benefit parameters among the major outputs of this project consist of setup of drinking water facilities and groundwater information data valuation. In this study, economic impact of the project in NPV of year 2002, with applying a discount rate of $10.0\%$, was identified and estimated as 5.09 billion won in cost, 67.69 billion won in benefit, 62.60 billion won in NPV, 13.3 points in BCR, and $152\%$ in IRR, respectively.

• Economic and Environmental Geology
• /
• v.43 no.6
• /
• pp.565-571
• /
• 2010

An innovative application of surfactant-enhanced air sparging(SEAS) technique was developed in this study. Using a laboratory-scale physical model packed with water-saturated sand, air sparging was implemented to remove water-dissolved toluene that was introduced into a specific depth of the system with finite vertical width prior to sparging. An anionic surfactant(Sodium dodecylbenzene sulfonate) was introduced into the contaminated layer as in dissolved form in the toluene-contaminated solution for SEAS, whereas no surfactant was applied in the control experiment. Due to the suppressed surface tension of water in the surfactant(and toluene)-containing region, the toluene removal rate increased significantly compared to those without surfactant. More than 70% of the dissolved toluene was removed from the contaminated layer for SEAS application while less than 20% of toluene was removed for the experiment without surfactant. Air intrusion into the contaminated layer during sparging was found to be more effective than that without surfactant, enhancing air contact with toluene-contaminated water, which resulted in improved volatilization of contaminant. This new method is expected to open a new option for remediation of VOC(volatile organic compound)-contaminated aquifer.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.7
• /
• pp.548-553
• /
• 2017

The aim of this study was to develop a low impact development design technique that can be applied in the land use planning stage and verify quantitatively the effects of non-point pollution reduction. For this purpose, the low impact development design elements that can be applied in the land use planning stage were derived and applied to an actual site, and the non-point pollution reduction effect was analyzed using the LIDMOD2 program. The analysis showed that the permeability rate of the land use plan using low impact development decreased by 19.8% compared to the existing land use plan. In addition, annual surface runoff decreased by 19.0% and annual infiltration increased by 164.1%. In the case of non-point pollution, the annual loading, T-N, T-P, and BOD decreased by 18.7 ~ 22.8%. Therefore, compared to the existing land use plan, the land use plan using low impact development has a considerably large effect of reducing the non-point pollution without changing the floor area according to each application. Therefore, to maximize the reduction effect of non-point pollution, it will be necessary to establish a related plan by applying the low impact development technique from the land use planning stage to the existing LID facility-oriented plan.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2018.05a
• /
• pp.490-490
• /
• 2018

우리나라의 홍수대책은 제방 축제 및 보강, 하천의 홍수통수능 확대 등 하천 중심의 대책이 대부분이며, 도시 홍수에 대한 대책과 시설물은 홍수저감용 우수저류조가 대다수이나, 민원과 설치장소 확보 등으로 인해 많은 어려움을 겪고 있다. 또한 가뭄대책은 획일적으로 지하수관정 개발에만 의존하고 있다. 이는 우리의 후손을 위해 보존해야 할 의무가 있으며, 현 세대에서 가뭄을 극복하기 위한 수자원은 강우에 의한 지표수로 해결하려는 노력이 필요하다. 도시의 경우 가뭄 극복을 위해 우수를 저류하여 다양한 용도로 활용하는 기술이 필요하고 사회적으로 많은 관심을 불러일으키고 있다. 국내에 로터리 형태로 운영되던 회전교차로가 교통량 증가에 따라 2000년대 이후 성공적인 해외사례를 토대로 한 간혈적인 도입기를 거쳐 2010년 교통운영체계 선진화 방안에 의한 시범사업 이후 도입이 확대되고 있다. 본 연구에서는 LID(Low Impact Development, 저영향 개발) 기법을 적용하여, 홍수와 가뭄에 대한 대책으로 회전교차로 중앙교통섬을 활용한 초기 우수대응 기술을 개발하고 이를 실현할 수 있는 효과적인 회전교차로 설계 및 시공기술을 개발하고자 한다. 도시의 경우 강우시 초기강우에 의한 유출수에는 인체에 해로운 오염물질들이 포화되어 있기 때문에 초기우수에 의한 유출수를 효과적으로 배제하여 하천수질 등 개선하고자 하며, 이와 같은 초기우수에 대한 비점오염원 저감 시설과 우수를 집적하는 우수저류시설을 회전교차로 내에 설치하고 초기 우수에 대한 관리 기법을 개발하고자 한다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.386-390
• /
• 2003

To evaluate the potential capacity of mine wastes in the production of heavy metal containing acid water, samples from depths of 0, 30 and 60cm were collected and analyzed. The waste from surface showed the lowest pH which indicates the oxidation of wastes and the capacity of contamination of the area around the waste file. And the lower pH values of leachate of the wastes through the leaching tests with pH controlled water(3, 4, 5) may indicate that minerals producing the acidity still exist. Reduction of sulfur contents in wastes after the leaching test well fit to the increased contents of iron oxide.