• 한국자원공학회지
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• 제55권6호
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• pp.517-526
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• 2018

본 연구는 가학광산 오염토양 정화를 위해 토양 세척 최적조건을 수립하는데 목적이 있다. 연구지역 내 토양은 다양한 중금속에 의해 오염되어 있는데 특히 구리, 납, 아연의 농도가 높게 나타난다. 염산을 활용한 세척실험 결과 1 M의 농도로 30분 세척 시 중금속의 제거 효과가 가장 좋게 나타났다. 전체 토양의 38%는 1.18 mm 이상의 굵은 입자로 오염도가 상대적으로 낮으나 0.075 mm 이하의 작은 입자들은 오염도가 높아 고농도의 염산용액과 긴 세척시간에도 불구하고 오염도를 기준치 이내로 낮추기 어려웠다. 따라서 오염도가 높고, 중금속 농도 저감이 어려운 작은 토양입자들을 토양세척 이전에 물리적인 방법으로 분리할 필요가 있는 것으로 판단된다. 습식 사이클론을 활용한 연속식 토양세척 실험 결과 20% 이상의 미립자를 제거한 경우 오염토양의 중금속 농도를 기준치 이내로 저감시킬 수 있었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.499-502
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• 2004

Groundwater chemistry in a coastal region having complex contaminant sources was investigated. Water analysis data for 197 groundwater samples collected from the uniformly distributed sixty-six wells were used. Chemical analysis rand results indicate that groundwaters show wide concentration ranges in major inorganic ions, reflecting complex hydrochemical processes of pollutants. Due to the complexity of groundwater chemistry, Results illustrate that thirty five percent of the wells do not fit for drinking based on nitrate and chloride concentration in the study area. the samples were classified into four groups based on Cl and NO$_3$ concentrations and the processes controlling water chemistry were evaluated based on the reaction stoichiometry. The results explained the importance of mineral weathering, anthropogenic activities (nitrification and oxidation of organic matters), and Cl-salt inputs (seawater, deicer, NaCl, etc.) on groundwater chemistry. It was revealed that mineral dissolution is the major process controlling the water chemistry of the low Cl and NO$_3$ group (Group 1). Groundwaters high in NO$_3$ (Groups 2 and 4) are acidic in nature, and their chemistry is largely influenced by nitrification, oxidation of organic matters and mineral dissolution. In the case of chloride rich waters (Group 3), groundwater chemistry is highly influenced by mineral weathering and seawater intrusion associated with cation-exchange reactions.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권1호
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• pp.17-24
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• 2022

This work examined the effect of mixing transition metal-based additives [FeCl₃, Fe-containing paper mill sludge (PMS), CoCl₂·H₂O, ZrO₂, and α-Fe₂O₃] on the thermochemical conversion of coffee waste (CW) in carbon dioxide-assisted pyrolysis process. Compared to the generation amounts of syngas (0.7 mole% H₂ & 3.0 mole% CO) at 700℃ from single pyrolysis of CW, co-pyrolysis in the presence of Fe- or Zr-based additives resulted in the enhanced production of syngas, with the measured concentrations of H₂ and CO ranging 1.1-3.4 mole% and 4.6-13.2 mole% at the same temperature, respectively. In addition, α-Fe₂O₃ biochar possessed the adsorption capacity of As(V) (19.3 mg g^-1) comparable to that of ZrO₂-biochar (21.2 mg g^-1). In conclusion, solid-type Fe-based additive can be highly considered as an efficient catalyst to simultaneously produce syngas (H₂ & CO) as fuel energy resource and metal-biochar as sorbent.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.62-72
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• 2015

This study investigates the in-situ implementation of bio-regenerated iron mineral catalyst to remove explosive compounds in ground water at a military shooting range in operation. A bio-regenerated iron mineral catalyst was synthesized using lepidocrocite (iron-bearing soil mineral), iron-reducing bacteria Shewanella putrefaciens CN32, and electron mediator (riboflavin) in the culture medium. This catalyst was then injected periodically in the ground to build a redox active zone acting like permeable reactive barrier through injection wells constructed at a live fire military shooting range. Ground water and core soils were sampled periodically for analysis of explosive compounds, mainly RDX and its metabolites, along with toxicity analysis and REDOX potential measurement. Results suggested that a redox active zone was formed in the subsurface in which contaminated ground water flows through. Concentration of RDX as well as toxicity (% inhibition) of ground water decreased in the downstream compared to those in the upstream while concentration of RDX reduction products increased in the downstream.

• 한국유기농업학회지
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• 제21권1호
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• pp.69-78
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• 2013

비가림하우스에서 고랭지배추 유기재배 시 시용량 및 토양비옥도에 따른 시용질소의 이용률과 배추의 수량성을 검토하였다. 무비구에서의 구중은 사양토 토양에서 현저히 낮았으며, 비옥도가 낮은 사양토에 비해 비옥도가 높은 식양토에서 높았다. 시비량에 따른 구중의 변화는 비옥도가 높은 식양토에 비해 비옥도가 낮은 사양토에서 더 크게 나타났다. 질소이용률은 토양의 비옥도가 높고, 질소시비량이 많을수록 낮았다. 질소함량 1%의 사양토에서도 계분퇴비 2톤/10a과 표준시비량 수준의 천연무기질자재의 시용으로 질소함량 6%의 식양토의 약 90% 수준의 수량을 나타냈다. 질소, 인산, 및 칼리질 천연광물자원인 구아노, 인광석 및 황산가리고토 등은 친환경 자재로서 균형적 시비를 꾀하는 유기재배에서 널리 활용될 수 있을 것으로 보인다.

• Geomechanics and Engineering
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• 제22권2호
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• pp.143-152
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• 2020

In this research, soil samples of the Kerman sedimentary basin, Iran, were investigated through laboratory tests such as petrography (Scanning Electron Microscopy (SEM), X-Ray Fluorescence Spectroscopy (XRF) and X-Ray Diffraction (XRD)), physical and mechanical characteristics tests. The soil in this area is dominantly CL. The petrography results showed that the dominant clay mineral is Illite. This soil has made some problems in the earth dams due to the low shear strength. In this study, a set of samples were prepared by adding different amounts of lime. Next, the petrography and strength tests at the optimum moisture content were performed. The results of SEM analysis showed substantial changes in the soil structure after the addition of lime. The primary structure was porous and granular that was changed to a uniform and solid after the lime was added. According to XRD results, dominant mineral in none stabilized soil and stabilized soil are Illite and calcite, respectively. The pozzolanic reaction resulted in the reduction of clay minerals in the stabilized samples and calcite was known as the soil hardener material that led to an increase in soil strength. An increase in the hydrated lime leads to a decrease in their maximum dry unit weight and an increase in their optimum moisture content. Furthermore, increasing the hydrated lime content enhanced the Unconfined Compressive Strength (UCS) and soil's optimum moisture. An increase in the strength is significantly affected by the curing time and hydrated lime contents, as the maximum compressive strength is achieved at 7% hydrated lime. Moreover, the maximum increase in the California Bearing Ratio (CBR) achieved in clay soils mixed with 8% hydrated lime.

• 농업과학연구
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• 제42권4호
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• pp.319-324
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• 2015

An estimation of the requirement of minerals based on growth stage and cropping pattern is very important for greenhouse zucchini. This study was performed at farmer's field which was applied with a fertigation system and a semi-forcing cultivation from Feb. to July in 2014, and nitrogen levels were set up with x0.5, x0.75, x1.0 and x1.5 of the NO3-N-based soil-testing recommendation for zucchini cultivation. Top dressing of nitrogen (basal : top = 4 : 6) and potassium (basal : top = 3 : 7) was applied with an interval of every two weeks from two and six weeks after transplanting, respectively, and phosphorus was totally supplied with basal dressing. The nitrogen uptake was the order of x1.0, x0.75, x1.5 and x0.5, phosphorus, x1.0, x0.75, x0.5 and x1.5, and potassium, x0.75, x1.0, x1.5 and x0.5. From these results, it was suggested that highest mineral uptake could be reached between x0.75 and x1.0 of the NO3-N-based soil-testing recommendation. In conclusion, nutrient management based on the growth stage was proven to be better method for favorable growth and yield of zucchini.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권4호
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• pp.113-121
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• 2015

The contaminated soil at abandoned smelter areas present challenge for remediation, as the degraded materials are typically deficient in nutrients, and rich in toxic heavy metals and metalloids. Bioremediation technique is to isolate new strains of microorganisms and develop successful protocols for reducing metal toxicity with heavy metal tolerant species. The present study collected metal contaminated soil and characterized for pH and EC values, and heavy metal contents. The pH value was 5.80, representing slightly acidic soil, and EC value was 13.47 mS/m. ICP-AES analytical results showed that the collected soil samples were highly contaminated with various heavy metals and metalloids such as lead (183.0 mg/kg), copper (98.6 mg/kg), zinc (91.6 mg/kg), and arsenic (48.1 mg/kg), respectively. In this study, a bacterial strain, Bacillus cereus KM-15, capable of adsorbing the heavy metals was isolated from the contaminated soils by selective enrichment and characterized to apply for the bioremediation. The effects of heavy metal on the growth of the Bacillus cereus KM-15 was determined in liquid cultures. The results showed that 100 mg/L arsenic, lead, and zinc did not affect the growth of KM-15, while the bacterial growth was strongly inhibited by copper at the same concentration. Further, the ability of the bacteria to adsorb heavy metals was evaluated.

• 지질공학
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• 제18권3호
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• pp.311-319
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• 2008

주파수 인피던스를 이용하는 ThetaProbe ML2x인 ADR 형식의 토양함수비센서를 적용하여 주문진 표준사, 상주 화강 풍화토, 장수 편마암풍화토을 대상으로 실험을 수행하였다. 시험의 목적은 측정센서의 측정 정밀도를 측정로드부 삽입 깊이에 따른 변화 양상을 파악하였다. 흙매질은 체적함수비 함량과의 관계를 비교하기 위하여 건조상태와 습윤상태로 구분하여 수행하였다. 측정결과에서 측정로드부가 흙매질 내 5cm 이상 삽입되면 측정전압의 변화폭이 크게 감소하는 것을 파악하였다. 또한, 표준사와 같이 균질한 입자를 가진 흙보다는 점토와 실트 등과 같은 세립질을 함유한 화강풍화토와 편마암풍화토에서 측정전압이 안정적인 형태를 갖는 것으로 나타났다. 따라서, 측정치는 측정로드부가 다공질매질과의 접촉 면적이 커질수록 안정적인 값을 제공한다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.507-512
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• 2000

The main objective of this study is to provide a soil surface information, which represent a soil reflectance spectrum, by remote sensing technology. The soil reflectance of the soil was measured using a spectroradiometer in the wavelength range from 300nm to 1100nm. Measurements of soil reflectance have been made in four different soils. The results suggest that the reflectance properties of soils are related to their mineral composition and soil moisture. Increasing soil moisture resulted in an decrease in the rate of reflectance which leads to parallel curves of soil reflectance spectra. The soil line representing the relationship between red and near-infrared soil reflectance is characterized by soil types.