• 한국지하수토양환경학회지:지하수토양환경
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• 제21권3호
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• pp.82-87
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• 2016

This study investigates effects of an aging period on arsenic (As) chemical forms in soils and phytotoxicity using artificially As-contaminated soils with a range of As concentrations (0-300 mg/kg) and aging periods (0 and 3 months). A sequential extraction procedure showed that the increasing As concentration in soils increased the ratio of non-specifically and specifically bound As, which are known to be bioavailable. This resulted in increasing As uptake by tomatoes with increasing As concentration (R²=0.87 for exponential fitting); however, the seed germination was not sensitive to the As concentrations of the soil samples. The seed germination was also statistically similar in the soils with 75 and 150 mg-As/kg regardless of the aging period. The time taken until the seed germination (i.e., lag phase), on the other hand, decreased from 10 d to 3 d with aging for 3 months. This can be attributed to the decreased amount of bioavailable As with aging. Overall, this study shows that when the toxic effects of the As-contaminated soils are assessed using tomato plants, it is better to use more sensitive methods than seed germination such as the As accumulation or the lag phase for seed germination.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1647-1654
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• 2008

The characteristics of arsenic(As) contamination were investigated on soils of 3 abandoned metal mine sites in Gangwon-do, Korea. Total forty nine soils were sampled to conduct standard methods(extraction by 1HCl), sequential extraction and column leaching test. Concentration of As extracted by 1N HCl was ordered as follows: A mine > B mine > C mine, and the concentration of arsenic in the soils of A mine was significantly greater than that at any other cases and all samples of A mine were exceeded the national regulation of $6mg \;kg^{-1}$. In the results of sequential extraction, the potential contamination risk for groundwater and plants was ordered as follows: C mine > B mine > A mine because the C mine showed the relatively greater mobility and bioavailability of fraction than any other mines. And, in colume test, concentration of As was ordered as follows: C mine > B mine > A mine, and it was expected that these results were connected with fraction characteristics of the mine sites. Therefore adequate leaching investigations should be used to simulate the effect of natural leaching conditions, and to predict both the potential mobility of metals to groundwater and their bioavailability to plants under natural conditions.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권6호
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• pp.1-11
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• 2017

This study was conducted to investigate the performance of four commercial chemical agents in stabilizing arsenic (As) in soil at the forest area near the former Janghang smelter site. After amending the stabilizing agents (A, B, C, and D) into As-contaminated soil samples, synthetic precipitation leaching procedure (SPLP) and solubility bioavailability research consortium (SBRC)-extractable As concentrations significantly decreased except for agent D, which is mainly composed of fly ash and calcium carbonate. Increase of SPLP and SBRC-extractable As concentrations in four soil samples (S1, S2, S3, and J2) was attributed to desorption of As adsorbed on iron oxides due to high pH generated by agent D. It is therefore necessary to consider application conditions according to soil characteristics such as pH and buffering capacity. Results of sequential extraction showed that readily extractable fractions of As in soil (i.e., sum of $SO_4-$ and $PO_4-extractable$ As in soil) were converted into non-readily extractable fractions by amending agents A, B, and C. Such changes in the As distribution in soil resulted in the decrease of SPLP and SBRC-extractable As concentration. A series of follow-up monitoring and management plan has been suggested to assess the longevity of the stabilization treatments in the site.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권4호
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• pp.52-61
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• 2014

Metal concentrations in the former Janghang smelter area were determined and human health risk of arsenic (As) with bioaccessibility was investigated. Site investigation of the area within 1.5 km from the Janghang smelter showed the As concentrations of 4.8~169.8 mg/kg (avg. 37.8 mg/kg). For 85 samples out of 126 samples, As concentrations were higher than the Worrisome Level of the Korean Soil and Environment Conservation Act, and seven samples exceeded the Countermeasure Standard. Risk assessment for As incorporated with the bioaccessibility revealed that potential human health risk of the carcinogenic ($1.8{\sim}5.0{\times}10^{-5}$) was above the acceptable risk range ($10^{-5}{\sim}10^{-6}$) while the risk of the non-carcinogenic was not found. Remediation goals based on risk incorporated with bioaccessibility of As ranged from 10.8 to 20.0 mg/kg. Such difference in the remediation goals resulted from various bioaccessibility of As (i.e., between 8.7~66.3%) at the study site.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권4호
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• pp.45-51
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• 2014

In accordance with the view on remediated soil as a resource, this study assessed the applicability of soil washing with the neutral phosphate for remediation of arsenic (As)-contaminated soil. Three soil samples of different land uses (i.e., rice paddy, upland field and forest land) were collected from the study site, and the aqua regia-extractable As concentrations were 59.2, 30.8 and 53.1 mg/kg, respectively. Among the neutral phosphate reagents, ammonium phosphate showed the highest As washing efficiency. The optimized washing condition was 2-hr washing with 0.5M ammonium phosphate solution (pH 6) and soil to liquid ratio of 1 : 5. The extraction efficiencies of As did not guarantee the residual soil As concentrations to satisfy the Korea soil regulatory level (i.e., Worrisome level) in the three soil samples. To enhance washing efficiency, the As-contaminated soil was submerged in washing solution (1 : 1, w/v) for 24 hr and 1-hr washing with 0.5M ammonium phosphate solution was tested. As extraction efficiencies of 36.1 (rice paddy), 21.4 (upland field) and 26.4% (forest land) were attained, which satisfied the Worrisome level for Region 1 (25 mg/kg of As) in rice paddy, but not in upland field and forest land.

• 한국지구과학회지
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• 제43권4호
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• pp.481-489
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• 2022

Various types of karst topographies are found worldwide. Owing to their global distribution, karst areas have been extensively studied by scientists who investigate new discoveries by linking the characteristics of karst topographies with their own research fields. However, there have been only a few studies on karsts in the Republic of Korea, and little research exists on their hydrogeology. Fragmentary studies have been conducted on the hydrochemical characteristics of groundwater in limestone areas, the causes of high arsenic concentrations in groundwater, and the hydraulic conductivity of limestone areas. Research on hydrogeological characterization and flow mechanisms in these areas has only began recently. Identification and the proper management of available groundwater resources in karst (limestone) areas is essential as their unique geological characteristics render it difficult to construct reservoirs or dams at appropriate scales. We have reviewed prior work on karsts in the Republic of Korea to provide information that supports water resource security in the karst areas, to improve the understanding of the equitable use of water resources, and to identify the best management practices for groundwater resource resilience improvement.

• 한국지하수토양환경학회지:지하수토양환경
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• 제13권2호
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• pp.12-20
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• 2008

본 연구는 chromated copper arsenate(CCA)로 처리된 목재로 지은 세 개의 통나무 구조물과 하나의 방음벽 주변 토양에서 CCA 금속들의 공간적인 분포를 조사하기 위해 수행되었다. 13개의 배경 토양 시료뿐만 아니라 목재 구조물 주변에서 66개의 지표 및 35개의 종단면 토양 시료를 채취하였다. 구조물에 인접한 곳에서 채취한 토양 시료에서 크롬, 구리 및 비소의 농도는 하나의 구조물을 제외하고는 모두 배경 토양에서의 농도보다 높았으며, 3년 된 구조물에 인접한 표토에서의 농도는 8년 된 구조물에서의 농도보다 높게 나타났다. 비록 금속들의 수평 분포는 구조물에 따라 다르긴 하였지만, 크롬과 비소는 각각 20-60 cm 및 40-100 cm 내에서 농도 구배를 보이는 것 같았다. 구리는 가장 이동성이 작아서, 단지 20 cm 이내에서만 농도 구배를 나타냈다. 종단면 토양 시료 분석에 따르면 어떤 금속도 명확한 수직 분포를 보이지는 않았지만, 크롬과 구리는 각각 5 및 10 cm까지, 그리고 비소는 35 cm까지 구배를 보였다. 이 연구의 대상지역에서 CCA로 처리된 목재로부터 토양으로 용탈된 금속들은 수평 및 수직으로 인근 지역에 한정적으로 이동하여 분포하고, 가능한 생태적인 영향은 작은 범위 내에서만 일어날 것임을 보여주었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제12권1호
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• pp.103-115
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• 2007

생태계 위해성평가는 유해물질의 노출로 인한 생태계 교란, 생물 공생의 파괴 및 부적합한 서식조건에 의한 생물집단구조의 문제를 적절히 평가할 수 있어야 한다. 초기의 위해성 평가는 오염의 수준을 숫자로 표기하여 단일된 공식으로 평가하였으나, 현재 이러한 평가는 실제로 생태계에 미치는 위해성을 평가하는데는 부적합하다. 따라서 지표종을 이용한 생태 위해성평가는 이러한 단점을 극복하며 육안적 지표의 변화 뿐만 아니라 유전자 수준에서의 변화까지도 감지함으로써 위해성 평가의 폭을 넓힐 수 있게 한다. 국외의 경우 오염의 평가 및 오염 지역 복원의 평가기준으로 여러 지표종을 이용하고 있으며, 여러 지표종을 국가 차원에서 종합적으로 관리하며 오염으로 인한 변화를 유전자 돌연변이 및 암발생 수준까지 연구함으로써 생태계 위해성 평가를 하는 추세이다. 국내의 경우에도 점차 지표종을 이용한 유해성 평가 연구가 진행되고 있으며, 오염물질의 인체에서의 발암 메커니즘, 동물실험을 통한 발암 메커니즘에까지 그 영역이 확대되고 있다. 본 논문에서는 현재까지 이용되는 여러 지표종을 개략적으로 살펴보고, 중금속으로 오염된 폐광산에서 발견된 생지표종인 고사리, 지렁이, 미생물 및 도룡뇽의 변화를 생태계 위해성 평가에 활용되어진 다양한 예가 소개되어 질 것이다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.239-242
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• 2004

Pilot-scale soil washing facility was developed and operation condition was determined in order to remediate a soil contaminated with As, Ni and Zn. Soil washing facility is composed of soil particle separation, soil washing and wastewater treatment process. Both oxyanionic As and cationic Ni and Zn were effciently removed using HCl rather 0than H$_2$SO$_4$ and H$_2$PO$_4$. This is why oxyanion and cation metals can be extracted simultaneously from the contaminated soil in acidic solution. Further, the contaminated soils include calcite and then demand much acidity, that is consumption of acid solution. Fine particles are enriched with contaminants, and coarse particles are removed effectively rather than fine particles. As, Ni and Zn are strongly associated with minerals, and then the residence time should be increased for a reaction with washing solution.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권2호
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• pp.18-23
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• 2010

Usability of soil quality monitoring network for ascertaining soil quality changes was evaluated by analysing soil quality monitoring results. Tolerance limits of soil quality monitoring results from 1997 to 2007 were calculated and compared with Korean soil quality standards. This study determined that soil quality was changed if the upper 95% tolerance limit value was greater than the soil quality standard. Fluoride most frequently exceeded the soil quality standard and nickel, zinc, arsenic, copper, lead and cadmium were followed. Analysis on land use showed that tolerance limits of industrial land use most frequently exceeded the soil quality standards and residential, road and various land uses then frequently exceeded. Tolerance limits of land uses expecting high contaminant loads frequently exceeded the soil quality standards. This fact imply that the soil quality monitoring network generates reasonable data to represent change in Korean soil quality. This study also suggested that representative sampling from well identified points should be done to improve data reliability and accurately ascertain soil quality changes.