• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
• /
• pp.192-195
• /
• 2003

As a part of our research project for in-situ bioremediation of nitrate contaminated. groundwater, screening studies to determine an effective electron donor (EO) and/or carbon source (CS) such as acetate, ethanol, formate, fumarate, lactate, and propionate were conducted. To evaluate the feasibility for the biological degradation of nitrate, soil microcosm studies using nitrate-contaminated soil and groundwater were performed. The nitrate removal percentage in the order from the highest to the lowest was: formate, fumarate, and ethanol > lactate > propionate. Essentially no nitrate consumption was observed In acetate-fed microcosms. The order of nitrate removal rate from the highest to lowest was fumarate, formate, lactate, ethanol, and propionate. These results suggest that fumarate and formate are promising EDs/CSs for in-situ bioremediation of nitrate - contaminated oxygenated groundwater.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.3-10
• /
• 2003

Soil and groundwater contamination by petroleum hydrocarbon products is only one of many environmental problems in Korea. However, many environmental consulting companies have been targeted their business on this subject because the petroleum-oil-lubricant (POL) products have been widely used product and accidental releases of the products from storages resulted numerous small and large contaminated sites throughout Korea. Therefore, many small and large companies are actively participating in environmental assessment and remediation projects for the POL contaminated sites. Remedial technologies for the POL contaminated sites have been developed for many years by government and private institutions throughout the world. Development of a new decontamination technology for the POL contaminated sites is no longer attractive issue in research community because scientific bases of most cost-effective remedial technologies are well understood and have been used in the field by commercial sector. Numerous sites contaminated by underground tanks at gas stations have been remediated by relatively small companies in this country. We should appreciate their noticeable contributions as a frontier under very difficult market environment in Korea. We heard many successful stories as well as a few failure stories. Soil-groundwater remediation of POL contaminated site is not a simple task as shown in the text books or protocols. Therefore, failure risk is always with us, which requires continuous efforts for improvement of the technologies by the users and developers. In this presentation, author will discuss technical problems encountered and improvement made during implementation of several remedial technologies applied by Samsung Environmental Team. This is not a presentation about research or case study. We want to share our thought and experience with environmental engineers actively engaged in soil and groundwater remediation projects in Korea.

• 자원환경지질
• /
• 제37권1호
• /
• pp.121-131
• /
• 2004

비소로 오염된 고로폐광산 주변 농경지 토양과 하천 퇴적토에 대하여, 토양 정밀조사를 통하여 규명된 오염 면적과 오염 지도를 바탕으로 복원 공정 설계를 실시하였다. 실내 실험을 통하여 오염 농경지 토양에 대하여는 석회를 첨가한 토양 안정화 공법의 처리 효율을 검증하였으며, 오염 하천 퇴적토에 대하여는 토양 세척법의 처리 효율을 규명하였다. 비수몰지역의 오염 농경지 토양의 복원 효율을 규명하기 위하여, 비소 농도가 다른 폐광산 주변 농경지 오염 토양 4종류에 대하여 비소 용출률 배치 실험을 실시한 결과, 석회를 혼합한 토양의 비소 용출이 오염 토양을 그대로 이용한 경우보다 평균 5배 이하로 감소하였다. 댐 건설 후 수몰되는 지역에서 저수지 바닥으로부터 저수지 수계로 용출되어지는 비소의 용출률을 예측하고, 석회를 첨가한 복토를 실시한 경우 저수지 바닥에서 용출되는 비소의 용출률 감소를 규명하기 위하여 아크릴 칼럼(지름 18.9cm, 높이 30cm)을 이용하여 저수지 바닥에서의 비소 용출 모의 실험하였다. 실험 결과 복토를 실시하지 않은 오염 토양에서의 비소 용출률은 연간 약 3.05∼3.89%를 나타내었으며, 석회 1%를 혼합하여 복토한 경우 저수지 바닥으로부터 비소 용출률은 연간 0.11∼0.05%를 나타내어 석회를 혼합한 복토처리 시 저수지 바닥에서 수계로의 비소 용출은 약 40배 이상 감소 할 수 있는 것으로 나타나, 수몰된 농경지 복원에 매우 적절한 방법으로 사용될 수 있을 것으로 판단되었다. 토양 세척법을 이용하여 하천 퇴적토를 복원하는 경우, 세척 효율을 규명하기 위하여 하천 퇴적토 3종류에 대하여 초산, 구연산, 염산 각 0.01, 0.05, 0.1, 0.5, 1.0N 수용액과 증류수에 대하여 각각 토양 세척 효율 배치 실험을 실시하였다. 실험 결과 염산과 구연산 용액으로 세척하는 경우 0.05 N에서 한 시료를 제외하고는 비소에 대하여 99.9% 이상의 제거 효과를 나타내었다. 결론적으로 비소로 오염된 하천 퇴적토는 적절한 세정용액을 이용한 세척과정에 의해서 충분히 제거 될 수 있는 것으로 나타나, 기존 오염 퇴적토 내 비소의 90% 이상을 효과적으로 제거할 수 있는 것으로 나타났다. 오염 지도에 근거하여 산출된 복원 물량에 대하여 토양세척법을 이용하는 경우 복원 비용을 산출하였으며, 이와 같은 자료는 고로폐광산 주변 오염 토양에 대한 실제 복원 공정의 설계에 중요한 자료로 활용될 수 있을 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제12권3호
• /
• pp.17-22
• /
• 2007

납으로 오염된 실제 토양을 처리하기 위해 토양세척기술의 적용성을 평가하였다. 세척제로는 염산을 사용하였으며, 0.2 M 염산을 사용하여 고액비 1:3으로 하여 10분간 접촉하여 2회 세척하여준 결과 96%의 제거율을 보였다. 세척액과 토양의 접촉시간을 5분에서 120분까지 증가하였을 때, 제거효율은 69.3%에서 81.9%로 증가하였다. 입경별 토양세척 효율은 온도와 교반시간에 영향을 받았으며, 20분 이상 교반하여 준다면, 0.075 mm 이하, 0.075 mm-2.0 mm, 2.0-4.0 mm 의 입경별 토양에서는 모두 99%의 제거효율을 보였다. 이상의 결과는 본 연구에 사용된 납 오염 토양은 토양세척기술을 적용하여 효과적으로 처리할 수 있는 것을 의미한다.

• 환경영향평가
• /
• 제16권1호
• /
• pp.27-33
• /
• 2007

Hexavalent chromium-contaminated soils are encounted at many unregulated discharge and improper handling of wastes from electroplating, leather tanning, steelmaking, corrosion control, and wood preservation industries. Contamination of hexavalent chromium in the soil is a major concern because of its toxicity and threat to human life and environment. Current technologies for hexavalent chromium-contaminated soil remediation are usually costly and/or cannot permanently prohibit the toxic element from entering into the biosphere. Thus, as an alternative technique, immobilization is seen as a cost-effective and promising remediation technology that may reduce the leachable potential of hexavalent chromium. The purpose of this paper is to develope an immobilization technique for the formation of the geochemically stabilized hexavalent chromium-contaminated soil from the reactions of labile soil hexavalent chromium forms with the added soluble phosphate and chromium reducing agent. From the liquid phase experiment, reaction order of chromium reducing agent, soluble phosphate, alkali solution shows the best removal efficiency of 95%. In addition, actual soil phase experiment demonstrates up to 97.9% removal efficiency with 1:1 molar ratio of chromium reducing agent and soluble phosphate. These results provide evidence for the potential use of soluble phosphate and chromium reducing agent for the hexavalent chromium-contaminated soil remediation.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제16권3호
• /
• pp.10-16
• /
• 2011

The experimental studies for remediation of diesel contaminated soils were performed using subcritical water in laboratory scale. Contaminated soils from industrial area and artificially contaminated soils were utilized for soil remediation. Experimental system was composed for subcritical water to flow upward through the soil packed column for extracting contaminants. 10 g of contaminated soil was packed into the column and water flow rate was 2 mL/min. To evaluate the effects of temperature, pressure and treatment time on the removal efficiency, temperature was changed from 100$^{\circ}C$ to 350$^{\circ}C$, pressure from 50 bar to 220 bar and treatment time at the predetermined temperature from 0 min to 120 min. The purification efficiency increased as temperature increased. However, the effect of pressure and treatment time was low. Temperature 250$^{\circ}C$, pressure 50 bar and treatment time 30 min were selected for optimal operating condition for this study.

• 한국환경농학회지
• /
• 제41권4호
• /
• pp.223-229
• /
• 2022

BACKGROUND: Mining activities, smelter discharges, and sludges are the major sources of heavy metal contamination to soils. The objective of this study was to determine the efficiency of magnetite and bottom ash derived from coal ash in remediating As-contaminated soil. METHODS AND RESULTS: An incubation experiment was conducted for 10 weeks. Magnetite and bottom ash at different rates and ratios were applied to each plastic bottle repacked with 1,000 g of dried As-contaminated soil. After 3-weeks of incubation, the concentrations of available As were measured by using Mehlich-3, SBET, and sequential extraction methods. All of the subjected soil amendments resulted in significant decreases in available As concentration compared to the controls. The addition of magnetite at the highest rate was the best to stabilize As in the soils; however, the values of As concentration varied with the extraction methods. CONCLUSION(S): To ensure the stabilization accuracy of heavy metals in soil, both single and sequential extractions are recommended. The magnetite derived from fly coal ash can also be applicable as a heavy metal stabilizer for the As-contaminated soil.

• 한국토양비료학회지
• /
• 제45권5호
• /
• pp.798-804
• /
• 2012

Although siderophores are induced primarily in response to iron deficiency, soil and other ecological factors can affect on this process. This study was to evaluate the production of siderophores by different fungal species isolated from heavy metal contaminated and uncontaminated soils. More than thirty fungal strains were isolated from heavy metal contaminated and rhizosphere uncontaminated soils. Chrome azurol sulfonate (CAS) was used for both quantitative and qualitative evaluation of siderophores production. No significant correlations were observed between the tested variables such as ultraviolet (UV) irradiation method and CAS-agar plate and heavy metal concentration in both soils. The production of siderophores in rhizosphere fungi was higher than those isolated from the contaminated soil; however, the difference was not significant. The siderophore production (%) by fungi isolated from heavy metal contaminated soil using UV irradiation method was positively correlated with the qualitative values using CAS-plate method (P<0.05). Pearson correlation test indicated a positive correlation between the quantitative and qualitative methods of detection for fungi isolated from rhizosphere and also those isolated from heavy metal contaminated soil.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 1999년도 추계학술발표회
• /
• pp.95-98
• /
• 1999

The goal of present study is to evaluate the potential of soil washing for removing metal contaminants from a contaminated soil. Remediation of a soil contaminated with copper, cadmium and phenol were performed by a soil washing using a biosurfactant. The removal of copper, cadmium and phenol from soil (sandy, kaoline, mixed one) was evaluated as a function of biosurfactant (wt %) concentration in the batch process. The results showed that overall rejection coefficient for copper, cadmium and phenol were grater than 50 %, 25 %, respectively.

• 한국농공학회논문집
• /
• 제47권5호
• /
• pp.63-71
• /
• 2005

In-situ soil remediation mechanism through the vertical drains (VDs) is analyzed with numerical model as the error and complementary error function. Results from in-situ test and analysis indicate that the contaminant concentration ratio as initial one ( C/$C_0$) increases as the radius ratio ( r/R) increases from the injection well, and also increases as the depth ratio ( z/ H) increases from the top of contaminated area. The elapse time needed to attain $50\%$ and $90\%$ clean up level ($ t_{50},\;t_{90}$) increases as the radius ratio ( r/R) and the depth ratio ( z/ H) increase. As above results, the procedure of soil flushing in contaminated area using vertical drains makes progress from the top of injection well to the bottom of extraction well.