• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.1-11
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• 2005

This study applied EK method to remediate contaminated soil by lead (Pb), tried increasing efficiency of remediation using adsorbent (apatite and zeolite) as enhanced EK remediation method to overcome the limit of traditional EK remediation method. Adsorption tests on Pb were practiced to extract EK, making different concentration of contaminated soil, voltage condition, operating time etc., transferring Pb-ion into the position of adsorbent, then tried immobilization. On this results, the efficiency of remediation is different on its test conditions. In addition, the efficiency of remediation was not only improved by adding electrode revεrsal and install position of adsorbent but also satisfied TCLP regulation of EPA in USA through the whole sample range. Finally, absorption and immobilization capacity of apatite and zeolite proved on its excellence and confirmed the possibility of application of apatite and zeolite as enhanced EK remediation method.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.52-52
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• 2018

목초지에서 비점오염원 유출특성은 가축밀도(stocking rate)와 방목형태(grazing management practice)에 기인하여 다르게 나타난다. 전통적인 방목형태는 한 대상지역에서 높은 가축밀도의 연속적인 방목(continuous grazing)을 취하는 것인데, 이 경우 토양압밀에 따른 강우의 침투량 감소, 가축의 배설물 축적 등으로 비점오염 유출량이 증가할 수 있으며, 식물의 재성장기간 부족으로 지속적인 방목지 운영이 어려울 수 있다. 순환방목(rotational grazing)은 이러한 연속적 방목 형태의 부정적인 영향을 개선하고자 대안으로 제시되었다. 방법은 구역을 나누고 초본식물의 생육상태를 고려하여 일정기간이 지나면 다른 구역으로 이동 시키며 방목하는 형태이다. 기존의 연구들은 단위 면적당 적정 가축밀도, 필드규모에서 방목형태에 따른 비점오염 유출특성에 초점을 두고 있으며, 결과들은 가축밀도의 영향보다는 방목형태에 의한 수문, 수질 영향이 더 크다고 지적하고 있다. 이에 본 연구에서는 이러한 가축밀도(Heavy vs Light) 및 방목형태(Continuous vs Rotational)가 유역의 비점오염 유출특성에 미치는 영향을 정량적으로 평가하고자, 미국 북텍사스 지역에 위치한 Clear Creek 유역을 대상으로 4개의 방목시나리오(heavy continuous[HC], light continuous[LC], multi-paddock[MP], no grazing)를 구성하고 Soil and Water Assessment Tool(SWAT) 모형에 적용하였다. SWAT 모형은 대상유역 내 4개의 방목지에서 측정한 토양수분 및 식물 바이오매스 자료, 유역 출구점에서 관측된 장기간의 수문 수질 자료를 이용하여 검증되었다. 연구결과는 순환방목(MP) 시나리오가 수질보호 및 토양침식 방지, 식생의 영양염류 흡수능력이 커지는 것과 같이 생태계서비스 기능의 개선 측면에서 최적의 방목형태(best grazing management)인 것으로 나타났으며, 이러한 결과는 가축밀도 보다는 방목형태에 기인한 것으로 필드와 유역스케일에서 동일한 결과를 보여주었다. 그러나 유역 내 목초지의 차지비율에 따라 순환방목 채택에 따른 비점오염 유출량의 감소효과는 다르게 나타나게 된다.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.7-13
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• 2006

The effects of electrolytes were investigated on the removal efficiency when several different electrolytes were used to change the electrode reaction in an electrokinetic (EK)-Fenton process to remediate phenanthrene-contaminated soil. Electrical potential gradient decreased initially due to the ion entrance into soil and then increased due to the ion extraction from soil under the electric field. Accumulated electroosmotic flow was $NaCl>KH_2PO_4>MgSO_4$ at the same concentration because the ionic strength of $MgSO_4$ was the highest and $Mg(OH)_2$ formed near the cathode reservoir plugged up soil pore to inhibit water flow. When hydrogen peroxide was contained in electrolyte solution, removal efficiency increased by Fenton reaction. When NaCl was used as an electrolyte compound, chlorine ($Cl_2$) was generated at the anode and dissolved to form hypochlorous acid (HClO), which increased phenanthrene removal. Therefore, the electrode reaction of electrolyte in the anode reservoir as well as its transport into soil should be considered to improve removal efficiency of EK-Fenton process.

• Journal of Soil and Groundwater Environment
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• v.18 no.2
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• pp.27-35
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• 2013

In this study, three dimensional and two dimensional laboratory experiments were conducted to investigate the effect of water table rising on DNAPL migration, contaminants mass discharge ($M_d$), and residual NAPL distribution. The accumulation of TCE in unsaturated zone was observed in both two and three dimensional experiments. This implies DNAPL sources could exist in unsaturated zone at contaminated sites. It has been investigated that the TCE concentration is proportional to the areal ratio of residual TCE. This means the residual TCE obviously could affect the TCE concentration in aquifer system. The results of the two-dimensional experiment indicated that the contaminant sources in unsaturated zone could lead the $M_d$ increasing with water table rising and the source zone heterogeneity could also highly affect the $M_d$.

• Land and Housing Review
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• v.13 no.3
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• pp.125-140
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• 2022

Road Deposited Sediment (RDS) is the solids formed from the wear of road, wear of vehicles, exhausts, and the input of the emissions from various sources out of the roads. RDS is seriously polluted by organic matter, nutrients, and metals. RDS plays an important role as the sink and the transport medium of the associated pollutants because RDS can be carried to the adjacent water system via stormwater runoff. In this regard, the heavy metals in RDS were investigated based on the publications. The contents of the metals in RDS were highly variable. The concentration of Cr, Ni, Cu, Fe, Zn, As, Cd, and Pb in urban RDS in various regions was in a range of 3.16-3,410, 1.15-1,382, 20.2-9,069, 2,980-124,853, 81-2,550, 2.3-214, 0.19-21.3, and 15.21-1,125 mg/kg, respectively. The anthropogenic enrichment of the metals in RDS was confirmed by the high concentration of Cu, Zn, Cd, and Pb. The contents of the metals were higher in industrial and traffic areas than in residential areas, while they were generally increased with decreasing particle size. It is believed that this study's results would contribute to quantifying the metals' load via RDS and establishing control strategies.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1998.11a
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• pp.92-92
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• 1998

반도체 기술의 경이적인 발전에 힘입이 최근 휴대용 이동통신기기, 노트북 컴퓨터 등 무선전자제품의 폭발적인 수요와 함께 이들의 소형화, 경량화가 요구되어 전원인 2차전지의 경량화, 고용량화, 장수명화의 필요성이 절실해졌다. Ni-MH 전지는 Ni-Cd전지에 비해 에너지밀도가 1.5~2배에 이르고 충방전 cycle이 길며 오염물질이 없어 환경 친화적이라는 장점이 었다. Ni-MH 전지의 성능은 음극재료인 수소저장합금에 의해 좌우되므로 수소저장능력이 크고 내식 성이 우수한 합금개발이 중요하다. $CaNi_5$는 수소저장능력이 크고 매장량이 많아 값이 싸다는 장점이 있지만 KOH 용액에서 내구성이 떨어진다는 단점이 있어 주로 Heat Pump 재료에만 사용이 제한되어왔다. 본 실험에서는 결정 구조의 nanocrystalline 및 amorphous화함으로써 해리압의 변화, 방전용량의 변화 등 새로운 전극 특성을 나타낸다고 보고되고 있는 MG (Mechanical Grinding)방법을 통해 CaNis 합금의 전극특성의 변화를 살펴보았고, 아울러 고상-기상반응에서 표면에 형성된 산화피막을 제거하여 안정한 불화물을 표면에 형성시킴으로써 불순물 가스에 대한 내구성을 높이고 활성화특성을 향상 시킨다고 보고되고있는 불화처리 방법을 이용하여 불화처리 시간을 달리하면서 용액 속에서의 pH의 변화, ICP분석, 전극의 성능 및 표면 특성변화를 충방전 test, SEM 등을 통해 고찰하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.86-86
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• 2023

최근에 들어 환경보전과 지속가능한 하천관리의 중요성이 대두되고 있으며, 통합물관리에 있어 수리량과 수질을 연계한 통합 모니터링의 필요성이 커지고 있다. 수리량과 수질 분야에 대한 모니터링 기술은 지속적인 연구가 이루어져 왔으나, 각 분야의 개별적 연구로 인해 수리량과 수질을 통합하여 모니터링 하는 기술 개발은 미흡한 수준이다. 또한 수질 측정은 수질오염공정시험기준에 있는 채수 기준에 따라 채수하여 측정하고 있으며, 채수 지점은 하천의 수심별로 달리하여 정해진다. 수리 측정은 현장계측을 통한 2차원적 계측으로 진행하고 있어 수질 측정 시 채수지점과 수리 측정지점은 일치하지 않는다. 동일 지점에서의 수질과 수리량을 동시에 고려하고 있지 못한 모니터링은 본류와 지류의 혼합거동이 많은 국내 하천 특성을 반영하지 못한다. 또한 현재의 수질·수리 모니터링은 ADCP나 다항목수질측정기 같은 고가의 장비를 운영하며, 홍수기와 같은 고위험 계측 조건에서 인력을 통해 측정하고 있기에 고비용의 장비운영비와 인명 피해를 야기시키고 있다. 따라서 무인 원격 기술을 적용한 하천 모니터링 기술과 수질과 수리량의 데이터 연계를 통한 3차원 모니터링 기술의 확보는 하천관리에 있어 매우 필수적이다. 본 연구에서는 수중 무인 원격이동체인 ROV와 무인 원격이동체(USV)를 활용한 3차원 수질·수리 모니터링 기술 개발에 관한 연구를 수행하였다. 국내 하천 특성을 고려한 혼합거동을 분석하기 위해 ROV에 수중 GPS 장비와 수질센서를 부착시켜 수중 내 2차원으로 측정되는 수리량과 동일한 좌표를 가지는 수질자료를 계측하여 하천의 연직 분포와 수평적 분포를 통해 화학적 수리적 거동을 분석하여 하천의 3차원 혼합거동 양상을 판단할 수 있었다. 이와 같은 무인 원격이동체를 통한 3차원 수질·수리 모니터링 기술은 하천의 3차원 분석에서 수질·수리량 보간 자료로 활용 가능하며, 효율적인 모니터링을 통하여 하천 전반 및 통합물관리에 있어 크게 기여할 것이라 사료된다.

• 한국지구물리탐사학회:학술대회논문집
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• 2001.09a
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• pp.122-140
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• 2001

We have applied the geophysical survey, mainly electric and electromagnetic (EM) methods, to a test site contaminated by hydrocarbon waste disposal and local spill. The multi-frequency, moving source & receiver EM survey along with ground penetrating radar (GPR) showed a fairly good performance in detection of buried metal pipes and objects. Magnetic survey measuring vertical and horizontal gradients were so sensitive to the small metallic objects spread over the surface that it's hard to discriminate the buried pipe. We chose electrical resistivity, EM and GPR survey to examine the soil contamination. Depth slices of resistivity distribution as the results of the inversion of resistivity and EM data coincided each other and closely matched the contaminated area determined by chemical analysis of the soil samples. GPR images did not show the reflection events related with contamination plume since there are no distinct spill in this site. We inferred the contamination using the penetration depth of the GPR energy, which could be used as auxiliary information to the resistivity and EM results. We summarized the applicability of each survey methods based on this results and proposed a desirable survey scheme for the determination of hydrocarbon contaminated site.

• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.21-34
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• 1997

Retention ponds have been dug along some of the motorways in France to minimize environmental pollution by preventing pollutants from spreading over the surrounding area. A series of studies have been conducted to determine the physicochemical characteristics of the particles settling down in such a pond to evaluate the effectiveness of the pond as a trap for heavy metals such as Pb, Zn and Cd. The highly contaminated roadside soil and the uncontaminated background soil were also studied for comparison. The settling particles exhibited heavy metal concentrations of 2 to 8 times as much as the background Sologne soil, depending on the metal species. However, the heavy metal concentrations in the roadside soil were 7 to 26 times higher than those in the· settling particles. Sequential extraction experiments illustrated that the highly contaminated roadside soil consisted mainly of the readily soluble fractions (FII, FIII and FIV) for all three heavy metals, but little W which is hardly soluble. The proportion of W considerably increased up to one third of the total in the settling particles for Pb and Zn. This result as well as the large concentration differences between the roadside soil and the settling particles indicates that most of the heavy metals were lost to the surroundings even before reaching the retention pond. Cd exhibited somewhat different behavior in that the most soluble FI, which is negligible for Pb and Zn, occupied as much as one fourth of the total in the roadside soil. In addition, FV for Cd did not increase in the settling particles.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.21-33
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• 2004

The objective of this study is to review of environmental assessment of heavy metals derived from various metalliferous mines in Korea. As a results of national wide research for heavy metal contaminations in the vicinity of metalleferous mines, the main contaminants are mine waste materials including tailings. From the materials, toxic elements including As, Cd, Cu, Pb and Zn can be dispersed into downstream through wind and water. Thus, soils around the mines contain elevated levels of those elements, which are over the guide values for environmental regulation of soils in Korea. Arsenic is one of the most important elements contaminated by mining activities, to a less extent, Cd, Cu, Pb and Zn. In spite of remediation works for some metal mines by the government, there are still lots of abandoned mines which are necessary for reclamation of mining sites. This study also includes that metal concentrations in soils and tailings can be varied upon various decomposition methods including 0.1N HC1 and aqua regia and sequential extraction scheme, with differences in each element, too. This may be due to geochemical characteristics of the elements, such as solubility, mobility and chemical forms in the geochemical environment. Finally, it is suggested that a certain organization should be runned by Korean government for management of abandoned mines.