• 유기물자원화
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• 제14권3호
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• pp.148-156
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• 2006

20,000ppm의 디젤로 오염시킨 토양으로부터 디젤 분해 활성이 있는 균주를 순수분리 하여 이를 동정하고 디젤유 분해능과 특성을 조사하였다. 분리된 균주는 각각 SJD2 및 SJD4로 명명하였으며, 최소배지에 디젤을 유일 탄소원으로 첨가하여 잔류 디젤 농도를 분석한 결과, SJD2 균주는 29.3%의 분해 효율을 가진 것으로 확인되었다. 각 균주의 16s-rDNA 염기서열 분석을 통해 SJD2 균주는 Bacillus fusiformis, SJD4 균주는 Bacillus cereus로 동정되었다. 실제 토양에서의 적용을 위해 microcosm을 제작하여 14일간 토양에서의 디젤 분해능을 측정한 결과, SJD2 균주가 24.9%의 분해 효율을 보였다. 두 균주 모두 $25^{\circ}C-37^{\circ}C$에서 생장이 활발히 일어나 실제 토양에서도 이용이 가능할 것으로 예상되며 pH 7-8, 디젤 농도는 2%일 때 디젤 분해 효율이 가장 높은 것으로 나타났다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.183-186
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• 2002

The objective of this study is to predict behavior of a contaminant plume and concentration of contaminants in soil through tile relations between the concentrations of contaminants in groundwater and in soil on the shallow sandy aquifer contaminated with petroleum hydrocarbons. The current state of the plume and its fate in the study area was simulated by using the MODFLOW-RT3D model and geochemical parameters of grounwater had been monitored and measured during 3 years (1999~2001). The relations between the concentrations of contaminants in each medium were taken from the investigation of site characterization conducted in 1999. Simulation results showed the center of the plume would migrate 407m twenty years later. At that time, the concentration would be decreased down to about 26 mg/$\ell$(93%). In comparison TEX concentration in the groundwater with that in the soil, the value of correlation coefficient (r=0.876) was as high as it could be used. Based on the high r-value, the linear equation was obtained from regression analysis. The results of model simulation by RT3D engine showed that the highest TEX concentration in the groundwater would be 58.8 mg/$\ell$ 16 years later, and then the TEX concentration in soil would be below the alarming level (80 mg/kg) of regulation criteria.

• Membrane and Water Treatment
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• 제11권2호
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• pp.167-172
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• 2020

The effectiveness of in situ sediment capping as a technique for heavy metal risk mitigation in Hyeongsan River estuary, South Korea was studied. Sites in the estuary were found previously to show moderate to high levels of contamination of mercury, methylmercury and other heavy metals. A 400 m x 50 m section of the river was selected for a thin layer capping demonstration, where the total area was divided into 4 sections capped with different combinations of capping materials (zeolite, AC/zeolite, AC/sand, zeolite/sand). Pore water concentrations in the different sites were studied using diffusive gradient in thin film (DGT) probes. All capping amendments showed reduction in the pore water concentration of the different heavy metals with top 5 cm showing %reduction greater than 90% for some heavy metals. The relative maxima for the different metals were found to be translated to lower depths with addition of the caps. For two-layered cap with AC, order of placement should be considered since AC can easily be displaced due to its relatively low density. Investigation of methylmercury (MeHg) in the site showed that MeHg and %MeHg in pore water corresponds well with maxima for sulfide, Fe and Mn suggesting mercury methylation as probably coupled with sulfate, Fe and Mn reduction in sediments. Our results showed that thin-layer capping of active sorbents AC and zeolite, in combination with passive sand caps, are potential remediation strategy for sediments contaminated with heavy metals.

• 한국환경보건학회지
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• 제38권6호
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• pp.529-540
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• 2012

Objective: This research was performed to evaluate the state of oil pollution in an area surrounding a railway station that has over 100 years of business history as a railway station in S City, Korea. The amount of polluted soil was estimated, and the target area for remediation was assessed in this study to restore the oil-polluted area. Methods: To accomplish this aim, five observation wells were installed for the sampling of groundwater, and soil was sampled at 33 points. Electric resistance studies and a trench investigation were undertaken to understand the geological conditions of the site, and the groundwater movement in this area was simulated by MODFLOW. Physiochemical analyses were conducted to determine the quality of the groundwater and the current state of oil pollution influenced by that of the soil. Results: The mean level of total petroleum hydrocarbons (TPHs) in this area was 1,059 mg/kg, and the area for remediation was determined to be 7,610 mg/kg. Levels of benzene, toluene, ethylbenzene, and xylene (BTEX) were determined to be under the legal standard. Conclusion: In terms of depth, the biggest area polluted by TPH found was between 0 and 1 m from ground level, and the affected area was 5,900 $m^3$. TPHs were not detected in groundwater. Diesel and lubricating oil were the main causes of TPH pollution at this railway station.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.44-52
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• 2002

Low temperature thermal desorption (LTTD) has become one of the cornerstone technologies used for the treatment of contaminated soils and sediments in the United States. LTTD technology was first used in the mid-1980s for soil treatment on sites managed under the Comprehensive Environmental Respones, Compensation and Liability Act (CERCLA) or Superfund. Implementation was facilitated by CERCLA regulations that require only that spplicable regulations shall be met thus avoiding the need for protracted and expensive permit applications for thermal treatment equipment. The initial equipment designs used typically came from technology transfer sources. Asphalt manufacturing plants were converted to direct-fired LTTD systems, and conventional calciners were adapted for use as indirect-fired LTTD systems. Other innovative designs included hot sand recycle technology (initially developed for synfuels production from tar sand and oil shale), recycle sweep gas, travelling belts and batch-charged vacuum chambers, among others. These systems were used to treat soil contaminated with total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbons (PAHs), pesticides, polychlorinated biphenyls (PCBs) and dioxin with varying degrees of success. Ultimately, performance and cost considerations established the suite of systems that are used for LTTD soil treatment applications today. This paper briefly reviews the develpoment of LTTD systems and summarizes the design, performance and cost characteristics of the equipment in use today. Designs reviewed include continuous feed direct-fired and indirect-fired equipment, batch feed systems and in-situ equipment. Performance is compared in terms of before-and-after contaminant levels in the soil and permissible emissions levels in the stack gas vented to the atmosphere. The review of air emissions standards includes a review of regulations in the U.S. and the European Union (EU). Key cost centers for the mobilization and operation of LTTD equipment are identified and compared for the different types of LTTD systems in use today. A work chart is provided for the selection of the optmum LTTD system for site-specific applications. LTTD technology continues to be a cornerstone technology for soil treatment in the U.S. and elsewhere. Examples of leading-edge LTTD technologies developed in the U.S. that are now being delivered locally in global projects are described.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.44-50
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• 2012

A new type of chemical oxidation technology utilizing micro bubble ozone oxidizer and a pneumatic fracturing equipment was developed to enhance field applicability of a traditional chemical oxidation technology using hydrogen peroxide as an oxidizer for in-situ soil remediation. To find an efficient way to dissolve gaseous ozone into hydrogen peroxide, ozone was injected into water as micro bubble form then dissolved ozone concentration and its duration time were measured compared to those of simple aeration of gaseous ozone. As a result, dissolved ozone concentration in water increased by 31% (1.6 ppm ${\rightarrow}$ 2.1 ppm) and elapsed time for which maximum ozone concentration decreased by half lengthened from 9 min to 33 min. When the developed pneumatic fracturing technology was applied in sandy loam, cracks were developed and grown in soil for 5~30 seconds so that the radius of influence got longer by 71% from 392 cm to 671 cm. The remediation system using the micro bubble ozone oxidizer and the pneumatic fracturing equipment for field application was made and demonstrated its remediation efficiency at petroleum contaminated site. The system showed enhanced remediation capacity than the traditional chemical oxidation technology using hydrogen peroxide with reduced remediation time by about 33%.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.25-32
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• 2014

The amount of TPH contaminated soil treated at off-site remediation facilities is ever increasing. For the recycle of the treated-soil on farmlands, it is necessary to restore biological and physico-chemical soil characteristics and to remove residual TPH in the soil by an economic polishing treatment method such as phytoremediation. In this study, a series of experiments was performed to select suitable plant species and to devise a proper planting method for the phyto-restoration of TPH-treated soil. Rye (Secale cereale) was selected as test species through a germination test, among 5 other plants. Five 7-day-old rye seedlings were planted in a plastic pot, 20 cm in height and 15 cm in diameter. The pot was filled with TPH-treated soil (residual TPH of 1,118 mg/kg) up to 15 cm, and upper 5 cm was filled with horticulture soil to prevent TPH toxic effects and to act as root growth zone. The planted pot was cultivated in a greenhouse for 38 days along with the control that rye planted in a normal soil and the blank with no plants. After 38 days, the above-ground biomass of rye in the TPH-treated soil was 30.6% less than that in the control, however, the photosynthetic activity of the leaf remained equal on both treatments. Soil DHA (dehydrogenase activity) increased 186 times in the rye treatment compared to 10.8 times in the blank. The gross TPH removal (%) in the planted soil and the blank soil was 34.5% and 18.4%, respectively, resulting in 16.1% increase of net TPH removal. Promotion of microbial activity by root exudate, increase in soil permeability and air ventilation as well as direct uptake and degradation by planted rye may have contributed to the higher TPH removal rate. Therefore, planting rye on the TPH-treated soil with the root growth zone method showed both the potential of restoring biological soil properties and the possibility of residual TPH removal that may allow the recycle of the treated soil to farmlands.

• 한국지하수토양환경학회지:지하수토양환경
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• 제12권1호
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• pp.87-96
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• 2007

본 연구는 경기도 소재 모 사격장의 주요 오염물질 여섯 가지에 대하여 홍수조절지가 건설된 이후 사격장 주변지역의 위해성을 예측하기 위하여 수행되었다. 해당 지역의 주요 오염물질 중 인체에 독성이 있는 화약물질 3종과 중금속 3종을 대상물질로 선정하였으며, 오염의 정도와 토지의 이용용도에 따라 네 지역으로 나누어 평가를 실시하였다. 위해성이 과대평가되는 것을 피하기 위하여 대상지역의 인문사회학적 특성 및 지반환경공학적 특성을 기반으로 노출경로모델(Conceptual Site Model)을 작성하였으며 각 노출경로에 따른 오염물질 이동모델 및 위해성 평가는 API's DSS(American Petroleum Institute's Decision Support System)를 이용하였다. 수용체나 지역의 특성을 하나의 값으로 대표할 수 없는 경우 위해성이 과소평가되는 것을 방지하기 위하여 가장 안전한 값을 사용하였다. 위해성 예측결과, 피탄지인 Ac 지역에서 TNT(Tri-Nitro-Toluene)와 카드뮴의 비발암위해도가 1을 조금 넘고, RDX(Royal Demolition Explosives)의 경우 50이 넘어, 대상지역 전체에 대한 총 비발암위해도는 62.828라는 매우 큰 값을 나타내었다. 한편, 발암위해도는 납이 약 $5\;{\times}\;10^{-4}$, 카드뮴이 약 $1\;{\times}\;10^{-3}$으로, 일반적으로 받아들여지는 발암위해도의 적정수준인 $10^{-4}{\sim}10^{-6}$에 비하여 $5{\sim}10$ 배 정도 크게 평가되었다. 이러한 위해성평가 결과를 통하여, 해당지역에 홍수조절지를 건설하기 전에 비발암물질과 발암물질 모두에 대한 즉각적인 복원사업이 진행되어야 하며, 홍수조절지 건설 후에도 사격장이 계속 운영될 경우 적절한 오염물질의 관리정책이 필요함을 알 수 있었다.

• 지질공학
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• 제33권3호
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• pp.371-388
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• 2023

지층구성이 복잡하고 저투수성의 토양이 분포하는 경우 정화효율은 급격히 저하되고 실질적인 정화가 이루어지지 않거나 정화기간이 증가하는 등의 문제가 발생한다. 효율적인 정화를 위해서는 투수성이 개선되어 오염된 구간으로 정화제 주입하여 오염물질과 충분한 접촉이 이루어져야 한다. 본 연구는 균열형성과 효과적인 정화제 유도를 위해 플라즈마 블라스팅, 공압파쇄, 진공추출을 복합적으로 활용하는 PPV 공법의 유체 전달특성을 분석하고 기존공법과의 비교를 통해 개선효과를 평가하였다. 연구는 TPH(Total petroleum hydrocarbons)로 오염된 실제 오염부지에 대한 정화제 전달효과를 확인하기 위한 실증시험을 수행하였으며 정화제의 전달특성과 영향범위 등을 산정하기 위해 주입량과 주입시간을 모니터링하고, 정성적인 지중환경 변화요인을 확인하고자 전기비저항탐사를 수행하였다. 또한, 투수시험을 수행하여 각 공법에 대한 투수성 변화를 평가하였다. 정화제의 주입량 모니터링 결과, 주입량은 대조군 대비 실험군의 주입량이 약 4.74~7.48배 증가하였고, 단위 시간 당 주입 유량(L/min)은 약 5.00~7.54배 실험군의 전달률이 빠른 것으로 분석되었다. 전기비저항탐사 결과, 실험군의 비저항변화비는 대조군과는 달리 지표까지 영향을 주어 비저항값이 전체적으로 감소하는 경향을 보인다. 따라서 실험군은 지표 상부에 분포하는 토사층까지 과산화수소 등의 유체 확산이 이루어져 저비저항 변화비가 감소하는 것을 볼 수 있으며 주입정과 추출정 사이의 수평적 변화비는 약 1.12~2.38배 비저항값이 감소되었다. 투수성의 경우, 대조군과 실험군 모두 유사한 초기 투수성을 보였으나 과산화수소의 정화기작 영향으로 투수성이 감소하는 특성을 나타내는 것으로 확인되었다. 수리전도도의 변화를 정량적으로 평가하면, 대조군은 시험 종료 후 초기 수리전도도 대비 21.1%의 수리전도도를 나타내어 투수성이 급격히 저하되는 양상을 보였으나 실험군은 실험종료 후 초기치 대비 81.3%로 초기 수리전도도와 근접한 값을 나타내는 것으로 파악되었다. 현장조사로 확인된 수리전도도와 정화재 주입실험을 통한 정화제 주입용량(m³/hr), 토양특성분석(함수비, 밀도)을 통한 공극률(%)의 분석을 통해 영향반경(ROI)을 산정산 결과, PPV 공법의 영향반경(ROI)은 대조군에 비해 평균 220% 개선되는 것으로 확인되었다. 이와 같은 성과는 PPV 공법 적용으로 인하여 기존공법 대비 보다 넓은 범위에 걸쳐 효율적인 정화제 전달이 가능하고 정화기작에서 나타나는 투수성 저해요인을 상당부분 극복할 수 있으며, 약 2배 이상의 영향반경 증대를 통해 정화효율을 높일 수 있음을 지시하는 중요한 지표로 볼 수 있다.

• 자원환경지질
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• 제27권1호
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• pp.101-113
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• 1994

강원도 상동지역의 옥동천 및 그 지류들을 대상으로 수질 파라메터(Eh-pH, 부유물질)의 측정과 하상퇴적물의 화학분석을 통하여 석탄광 및 금속 광산활동에 의한 옥동천의 수성 환경의 오염정도를 조사하였다. 옥동천의 조사유역을 상부와 하부 옥동천으로 구분할 때 상부 유역은 석탄광의 개발로 인한 황화물의 산화작용으로 인하여 수질은 매우 낮은 pH를 나타내 광산 산성수(Acid Mine Drainage)로 심하게 오염된 것으로 조사되었다. 또한 상부 옥동천에 용존된 철이 지류들의 유입과 하천의 aeration으로 철 산화물(floc)의 발생과 이의 침전으로 하천 바닥은 황갈색의 철산화물이 퇴적되어 있다. 그러나 상부 옥동천의 유속에 의해 일부 철 산화물이 침전되지 못한채 부유되어 옥동천은 매우 탁하게 보인다. 상부 옥동천온 천평천의 유입으로 인하여 낮은 pH의 산성수는 중화되지만 부유물질의 존재로 인하여 하부 옥동천은 계속 탁하여 광산 산성수의 영향이 지속되고 있다. sediment quality criteria와 비교해 볼 때 하부 옥동천의 하상퇴적물, 특히 상동 텅스텐-모리브덴늄 광미 저장댐과 인접된 지점의 하상퇴적물은 Pb, Cu, Zn, Co, Cd, As 및 Bi 등의 유해금속에 의해 농축되어 있어 퇴적물의 질이 상당히 악화되어 있다. 수중 및 저서 생물에 대한 서식처 및 수질을 개선하기 위해서 옥동천 상부에는 산성수를 중화시킬 수 있는 경제성 있는 수처리 장치의 도입과 중금속의 speciation의 연구가 필요할 것으로 사료된다.