• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1902-1905
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• 2010

일반적으로 퇴적물로부터 인의 용출은, 산소조건, 수온, 유속 등 여러 환경의 변화에 의해서 이루어지며, 환경에 따라 용출되는 인의 형태 또한 다르다. 따라서 어떠한 기작을 통해 얼마나 많은 양의 인이 용출되는지는 수체의 물리 화학적 조건과 퇴적물에 포함된 인의 존재형태에 의해 결정된다. 따라서 본 연구에서는 담수호의 부영양화 원인물질이면서 부영양화 발생을 제어할 수 있는 가장 중요한 인자로 작용하는 인의 거동특성을 파악하기 위하여 이루어 졌다. 본 연구는 경기도 화성시에 위치한 화성호에서 이루어 졌으며, 대표성을 나타낼 수 있는 3개의 지점을 선별하였다. 퇴적물은 Grap sampler를 이용하여 채취하였으며. Methods for P Analysis, G. M. Pierzynski(2009, G,m Pierzynski)에 의거하여 무기태 인을 loosely and soluble P, Al-P, Fe-P, Reductant soluble-P, Ca-P 5가지 형태로 분류하여 진행하였다. 화성호 퇴적물의 인의 형태별 분류를 실시하여 화성호 퇴적물 내의 무기태 인의 형태 분류와 이를 분석함으로서 인 용출에 의한 수질오염 가능성을 평가해보고자 하였다. 무기태 인의 형태는 세지점 모두 Fe-P > Al-P > Loosely and soluble-P > Reductant Soluble-P > Ca-P 비율로 나타났다. 가장 높은 비율을 차지하고 있는 Al-P 및 Fe-P의 경우, 호소수의 pH에 영향을 크게 받으며 특히 높은 pH에서 수층으로 용출이 활발히 일어날 수 있고, 호소의 물질순환에 있어서 다른 형태의 인보다 식물체에 단기간 이용될 수 있다는 점 때문에 관심이 높은 형태이다. 주로 이들 형태는 도시하수 및 산업폐수의 유입으로 인하여 영향을 받는다. 본 조사결과에서 화성호의 pH는 모든 지점에서 중성인 것으로 조사되었기 때문에 용출가능성은 상대적으로 적다고 판단된다.

• Resources Recycling
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• v.30 no.2
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• pp.14-23
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• 2021

To investigate the potential for leaching of heavy metals by bacteria from ores stacked on actual mining sites, leaching tests of a complex metallic ore (Pb-Zn-As ore) were conducted over 60 days using acidophile bacteria Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans under initial acidic conditions. Initially, a small amount of heavy metals was leached due to the initial acidic conditions. After 20 days, when A. thiooxidans in the reactor was adapted to the ore, the amount of leached heavy metals rapidly increased; the concentrations of leached arsenic, iron, and zinc reached a maximum of 2800, 3700, and 2500 mg/L, respectively. On the other hand, in the presence of A. ferrooxidans or in the control test without bacteria, heavy metals, except zinc, were barely detected in leaching. Through this study, it was confirmed that (i) bacteria could leach heavy metals at mining sites under acidic conditions and (ii) leaching of heavy metals from a high arsenic-containing ore by A. thiooxidans was more significant than that by A. ferrooxidans.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.2
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• pp.76-81
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• 2006

The leaching behavior of heavy metal ions with pH and colloid/interface property was analyzed by ICP and SEM. The heavy metals in EAF dust are 'amphoteric metal' and the heavy metal ions leached a little at pH 10. And the leaching concentrations of heavy metals at pH 12 were higher than the that at pH 8. The leaching concentrations of heavy metal ion were decreased with adding the clay to the EAF dust. Especially, the leaching concentrations of heavy metal ion were effectively decreased at pH 12. The observation of colloid/interface properties shows that the soluble silicon hydroxide from clay at pH 12 was precipitated at the surface of the heavy metal and clay particles. This silicon hydroxide precipitates were named the PSHP. The leaching concentrations of heavy metal ion were effectively decreased by the formation of PSHP when adding the clay to the EAF dust and controlling the pH of the slurry at 12.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.577-584
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• 2003

This study investigated the modeling of dissolution Diesel to estimate the behavior of contaminants in the ground. The modeling based on the initial concentration change considering dissolution potential of pure Diesel and Xylene was performed using VISUAL MODFLOW, and was compared with general modeling ignored the initial concentration change condition.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.4
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• pp.397-404
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• 2008

Excessive amount of groundwater flowed into tunnel, while constructing Incheon international airport railway. Tunnel passes under subway line no. 2 with only 1.76 m below. To protect the existing structure, TRcM excavation method was applied. As station and construction shaft are already constructed, which are located back and forth of TRcM section, 86.4 ton per day of groundwater inflow is against expectation. To identify mechanism of excessive water inflow, hydraulic back analyses were performed. Then, hydro-mechanical coupled analysis were also performed with the hydrogeologic parameters identified, whose results are investigated for checking the stability of adjacent structures to the tunnel under construction. And a number of mechanical analyses were also performed to check the hydro-mechanical coupling effect. The result from the mechanical analysis shows that subsidence and tunnel ceiling displacement will be 0.85 mm and 1.32 mm. The result of hydro-mechanical couple analysis shows that subsidence and maximum tunnel ceiling displacement will be 1.2 mm and 1.72 mm. Additional displacements caused by groundwater draw down were identified, however, displacement is minute.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.27-27
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• 2012

나노필라멘트는 단면직경이 수백 나노미터에서 수십 나노미터 수준인 초극세 장섬유를 말하며, 해도형 복합방사로 얻어진 섬유를 알칼리 감량을 통해 해성분을 용출하여 도성분에 해당하는 나노필라멘트를 얻는다. 이러한 나노필라멘트사는 극세사와 마찬가지로 단위중량당 표면적이 크고, 작은 굴곡반경 및 낮은 굴곡 반발성으로 인하여 일반 합성섬유에 비하여 고가성 및 새로운 기능성을 부여하는 제품에 응용될 수 있다. 나노필라멘트 편물은 원사섬도, 편물의 조직, 밀도 및 중량 등에 따라 분할율과 용출 특성이 상이하므로 후가공 공정에 있어서 감량공정은 매우 중요하다. 또한 나노필라멘트와 같은 세사의 경우 일반사보다 비표면적이 증가하여 동일한 염색조건에서 옅은 색상을 나타낸다. 이로 인해 같은 색상을 위하여 보다 많은 염료를 투입해야 하며, 결과적으로 견뢰도 문제가 발생할 우려가 있다. 이 연구에서는 800nm급 해도형 나노필라멘트 PET 100% 또는 나노필라멘트와 일반 PET사를 복합한 편물을 이용하여 알칼리 감량거동 및 분산염료에 대한 염색성과 견뢰도를 연구하였다. 알칼리 감량이 진행됨에 따라 감량률이 증가하였으며, SEM분석, DSC분석, 양이온염료 염색법 등을 통하여 해성분 용출 및 도성분 분할이 진행되는 정도를 평가할 수 있었다. 나노필라멘트 편성물은 염료농도가 증가함에 따라 지속적으로 K/S값이 증가하였으나, 일반 극세사 편성물에 비해 낮은 K/S값을 얻었다. 또한 나노필라멘트/일반 PET 복합편물에 있어서 염색온도가 110에서 $130^{\circ}C$로 증가함에 따라 K/S값이 감소하였는데, 이는 고온에서 분산염료가 나노필라멘트로부터 일반 PET사로 이염이 더 많이 발생하였기 때문이라고 생각된다. 세탁견뢰도의 경우 양호하였으나, 일광견뢰도의 경우 1등급으로 매우 낮았다.

• Economic and Environmental Geology
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• v.42 no.6
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• pp.609-618
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• 2009

High permeable faults are important geological structures for fluid flow, energy, and solute transport. Therefore, high permeable faults play an important role in the formation of hydrothermal fluid (or hot spring), high heat flow, and hydrothermal ore deposits. We conducted 2-D coupled thermal and hydraulic modeling to examine thermohydraulic behavior in fault zones with various permeabilities and geometric conditions. The results indicate discharge temperature in fault zones increases with increasing fault permeability. In addition, discharge temperature in fault zones is linearly correlated with Peclet number ($R^2=0.98$). If Peclet number is greater than 1, discharge temperature in fault zones can be higher than $32^{\circ}C$. In this case, convection is dominant against conduction for the heat transfer in fault zones.

• Economic and Environmental Geology
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• v.37 no.3
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• pp.311-324
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• 2004

We investigated the contamination and behavior of heavy metals in stream sediments within the watershed of Juam Reservoir. Many abandoned mines within the reservoir can act as a potential contaminant source for water quality. Heavy metal concentrations (Cr, Cu, Ni, Pb and Zn) in stream sediments from watershed are very low, indicating that content of heavy metals in the sediments probably do not affect the water quality in Juam Reservoir. However Pb concentration in the stream sediments increases downward streams, suggesting the possible diffusion of Pb contamination. According to the leaching ratio for stream sediments at a strong acidic condition in the abandoned mine areas, the relative mobility for metals decreases in the order of Pb＞Zn=Cu＞Ni＞Cr, indicating that Pb can have a bad effect upon the water quality in Jum Reservoir. Moreover, if contaminated sediment is placed in the bottom of reservoir (i.e., reducing condition), the relative mobility of Pb is the highest, indicating that Pb in the bottom sediments can be leached to water at interface between water and sediment with changing in physicochemical conditions.

• Journal of Navigation and Port Research
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• v.36 no.6
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• pp.513-519
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• 2012

Understanding the behavior of pollutants in the marine environment is essential for coping with the marine pollution problems such as eutrophication. In this study, the effects of environmental parameters on phosphorus release from marine sediment to sea water were investigated. The environmental parameters such as pH in the range of 7 to 9, temperature from 10 to 20C and dissolved oxygen levels (DO) renging 0.7 to 7.0mg/L were examined. Phosphorus release data were taken from batch tests excluding biotic effects, and analyzed using a first-order kinetic model. The effects of environmental parameters were quantified using a statistical methodology. High pH, high temperature, and low DO increased phosphorus release from the sediment to sea water. pH from 7 to 9, temperature from 10 to $20^{\circ}C$, or DO from 7.0 to 0.7 mg/L magnified the equilibrium phosphorus concentration up to 2~3 times.

• Journal of the Korean Ceramic Society
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• v.39 no.8
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• pp.728-734
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• 2002

Stabilization behavior of Cr, Cd, Cu, Pb, Fe and Zn heavy metals in the EAF dust was investigated by adding EAF dust to clay or white clay, respectively, up to 50 wt% with 10 wt% intervals and sintering at temperatures between 200 and $1200^{\circ}C$ with $200^{\circ}C$ intervals with an aid of ICP-AES followed by TCLP test to evaluate heavy metal cation exchange capacity of the clay or the white clay. The clay or the white clay had a better Cr ion exchange capacity than that of zeolite. The TCLP leaching test for the sintered specimens showed that Cr and Fe were rarely detected for all the specimens and the concentration of Cd and Zn decreased with increasing sintering temperature and decreasing EAF dust contents respectively. When the clay or the white clay were mixed with EAF dust, cation exchange may occur between the clay and the EAF dust so that the first stabilization of the mixtures containing semistabilized heavy metals may happen. Stabilization of heavy metals in the ceramic bodies was further completed probably due to the eutectic reaction caused by the sintering of semi-stabilized mixtures. It was conceivable that the white clay rather than the clay may be a better stabilizer for the EAF dust containing heavy metals.