• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2001년도 정기총회 및 제3회 특별지포지움
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• pp.34-56
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• 2001

• 한국환경농학회지
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• 제22권3호
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• pp.177-184
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• 2003

Although clay can sorb significant amounts of inorganic contaminants from soils and wastewater, the hydration of exchangeable cations in clay minerals makes it hydrophilic at the clay mineral surfaces and interlayers. Thus, natural clays are often ineffective in complexing and stabilizing toxic organic contaminants in soils and groundwater environment. But, substituting these hydrated cations with cationic surfactant such as QAC(Quaternary ammonium Compound) can change the natural clay from hydrophilic to hydropobic. Furthermore functionalized organoclay can act as a powerful dual function sorbent for both toxic metals and organic compounds. It also can be used as landfill clay liners, slurry walls, nano-composite materials, petroleum tank farms, waste treatment, and filter systems. To use this modified clay minerals effectively, it is required to understand the fundamental chemistry of organoclay, synthetic procedures, its engineering application, bioavailability of sorbed ion-clay complex, and potential risk of organoclay. In this review, we investigate the use, application and historical background of the organoclay in remediation technology. The state-of-the-art of organoclay research is also discussed. Finally, we suggest some future implications of organoclay in environmental research.

• 한국물환경학회지
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• 제23권5호
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• pp.665-675
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• 2007

In-situ Air Sparging (IAS, AS) is a remediation technique in which organic contaminants are volatilized from saturated zone to unsaturated layer. This study focuses on the removal and interaction of Volatile Organic Compounds (VOCs) and $CO_2$, and Total Petroleum Hydrocarbon (TPH) in saturated and unsaturated, and air space zone on the unsaturated soil surface. Soil sparging temperature of hot air has risen to $34.9{\pm}2.7^{\circ}C$ from $23.0{\pm}1.9^{\circ}C$ for 36 days. At the diffusing point, fluid TPH concentrations were reduced to 78.7% of the initial concentration in saturated zone when hot air was sparged. The TPH concentrations were decreased to 66.1% for room temperature air sparging. The amount of VOCs for hot air sparging system, in air space, was approximately 26% larger than constant air sparging system. The amount of $CO_2$ was 4,555 mg (in unsaturated zone) and 4,419 mg (in air space) when hot air was sparged was 3,015 mg (in unsaturated zone) and 3,634 mg (in air space) for room air temperature in the $CO_2$ amount. The removals of VOCs and biodegradable $CO_2$ through the hot air sparging system (modified SVE) were more effective than the room temperature air sparging. The regression equation were $Y=976.4e^{-0.015{\cdot}X}$, $R^2=0.98$ (hot air sparging) and $Y=1055e^{-0.028{\cdot}X}$, $R^2=0.90$ (room temperaure air sparging). Estimated remediation time was approximately 500 days, if final saturated soil TPH concentration was set to 1.2 mg/L application of tail effect.

• 한국물환경학회지
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• 제21권6호
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• pp.624-629
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• 2005

The purpose of this study is to investigate the performance of nitrogen removal using autotrophic microorganism in the Membrane-Attached Biofilm Reactor (MABR). The treatment system consists of an aerobic MABR (R1) for nitrification and an anaerobic MABR (R2) for hydrogenotrophic denitrification. Oxygen and hydrogen were supplied through the lumen of hollow-fiber membranes as electron acceptor and donor, respectively. In phase Ι, simultaneous organic carbon removal and nitrification were carried out successfully in R1. In phase II, to develop the biofilm on the hollow-fiber membrane surface and to acclimate the microbial community to autotrophic condition, R1 and R2 were operated independently. The MABRs, R1 and R2 were connected in series continuously in phase III and operated at HRT of 8 hr or 4 hr with $NH_4{^+}-N$ concentration of influent, from 150 to 200 mgN/L. The total nitrogen removal efficiency reached the maximum value of 99% at the volumetric nitrogen loading rate of $1.20kgN/m^3{\cdot}d$ in the combined MABR system with R1 and R2. The results in this study demonstrated that the combined MABR system could operate effectively for the removal of nitrogen in wastewater not containing organic materials and can be used stably as a high rate nitrogen removal technology.

• 한국물환경학회지
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• 제21권3호
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• pp.256-262
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• 2005

The purpose of this study is to investigate the performances of organic removal and methane recovery by using a full scale two-phase anaerobic system. The full scale two-phase anaerobic process was consists of an acidogenic anaerobic baffled reactor (ABR) and a methanognic upflow anaerobic sludge blanket (UASB) reactor. The volumes of acidogenic and methanogenic reactors were designed to $28.3m^3$ and $75.3m^3$. The two-phase anaerobic system represented 60-82% of COD removal efficiency when the influent COD concentration was in the range of 7,150 to 16,270 mg/L after screening (average concentration is 10,280 mg/L). After steady-state, the effluent COD concentration in the methanogenic reactor showed $2,740{\pm}330 mg/L$ by representing average COD removal efficiency was $71.4{\pm}8.1%$ when the operating temperature was in the range of $19-32^{\circ}C$. The effluent SCOD concentration was in the range of 2,000-3,000 mg/L at the steady state while the volatile fatty acid concentration was not detected in the effluent. Meanwhile, the COD removal efficiency in the acidogenic reactor showed less than 5%. The acidogenic reactor played key roles to reduce a shock-loading when periodic shock loading was applied and to acidify influent organics. Due to the high concentration of alkalinity and high pH in the effluent of the methanogenic reactor, over 80% of methane in the biogas was produced consistently. More than 70% of methane was recovered from theoretical methane production of TCOD removed in this research. The produced gas can be directly used as a heat source to increase the reactor temperature.

• 한국물환경학회지
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• 제20권3호
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• pp.215-222
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• 2004

The sewages produced from small villages, rural community, drinking water reservation area and park which doesn't have sewage piping system can be caused a serious water pollution at the restricted areas. The objective of this research was to suggest an economical and effective sewage treatment method by investigating the removal of the organics, nitrogen, and phosphorus in the multi-soil-layering reactor. Soil, natural zeolite, and iron slag were used as a supporting media of multi-soil-layering in this research. The purpose of natural zeolite addition was to maintain the consistent ammonium exchange capacity by providing a sequential environment, and that of iron slag addition was to remove phosphorus by adsorption. Continuous experiment of lab-scale single-soil-layering (S-1), multi-soil-layering (S-2), and mixed-soil-layering (S-3) methods were studied to compare and optimize three different types of the reactors. The organic removal efficiencies showed more than 90% in all three reactors. While S-1 and S-3 reactors showed about T-N removal of 31%, 45%, respectively, the average T-N removal efficiency of the S-2 reactor represented an 87%. In conclusion, that results suggest that the multi-soil-layering reactor could be effectively utilized as a plant for treatment of small village sewage.

• 디자인학연구
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• 제17권2호
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• pp.113-122
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• 2004

현대 사회는 다양한 정보 기술들이 유기적으로 연결되고, 커뮤니케이션 테크놀러지의 급속적인 발전으로 인해 뉴 미디어의 디지털화가 이루어짐에 따라 고도의 정보화 사회가 현실화되었다. 이러한 디지털 미디어 중에서도 웹의 등장은 가히 혁명적인 사건이라 할 수 있다. 단순히 텍스트만으로 구성된 서비스를 제공했던 웹에서 이용자나 사용자에게 이미지와 오디오, 동영상 등을 전달할 수 있는 웹의 발전은 새로운 경험을 제공하게 된 것이다. 이러한 발전이 가능하였던 것은 웹이 다양한 미디어를 리미디에이션 하는 것이 가능한 미디어적 특성을 가지고 있기 때문이다. 신문이나 잡지 등의 인쇄매체부터 TV, 오디오, 영화 등의 음향, 영상매체에 이르기까지 다양한 미디어들이 웹에 의해서 차용, 경쟁, 개선, 공격, 흡수의 형태로 리미디에이션 됨에 따라 우리는 각 미디어들의 특성을 웹이라는 한 가지 매체를 통해 누릴 수 있게 되었다. 본 연구는 미디어의 리미디에이션에 대한 이론적 고찰을 중심으로 웹디자인에서의 리미디에이션에 대한 사례연구를 통해 이의 효용성을 파악하여, 효과적인 표현방법을 모색하고 향후 리미디에이션의 발전 방향에 대해 연구하였다.

• 한국물환경학회지
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• 제21권6호
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• pp.637-642
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• 2005

The focus of this study was to examine the phosphorus removal characteristic by zirconium mesoporous structured material synthesized on various conditions. The zirconium sulfate-surfactant mesoporous structured material(ZS) was synthesized by hydro-thermal synthesis. The material has regular hexagonal array of surfactant micelles and sulfate ion ($HSO_4{^-}$). We confirmed that sulfate ion in zirconium mesoporous structured material can be ion-exchanged with phosphate ion ($H_2PO_4{^-}$) in phosphoric acid solution. On the X-ray diffraction (XRD) pattern of ZS, three peaks which shows the important characteristics of hexagonal crystal lattice were observed at (100), (110) and (200). The transmission electron micrograph (TEM) show high crystallization with pore size about $47{\AA}$. The maximum adsorption capacity of ZS was as great as 3.2 mmol-P/g-ZS. From the adsorption isotherm, correlation coefficients were higher for the Langmuir isotherm than the Freundlich isotherm. With the respect of chain length of surfactant, the adsorption capacity for phosphate synthesized with C12 was higher than C16 and C18. The highest amount of adsorbed phosphate on ZS was observed at the surfactant-to-zirconium molar ratio of 0.5 to 1.

• 방사성폐기물학회지
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• 제17권2호
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• pp.139-165
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• 2019

한국원자력연구원에서 개발 중인 해체기술 현황 및 전망에 대해 기술하였다. 특히, 해체의 핵심기술인 제염, 원격절단, 해체 폐기물처리 및 부지 복원 분야를 중점적으로 다루었다. 제염기술로는 부품제염과 원자력시스템제염 부분을 고찰하였고, 원격절단기술 관련해서는 절단기술, 원격제어 및 해체공정 모사기술이 다루어졌다. 해체 폐기물처리기술 관련해서는, 비록 해체 후 다양한 폐기물이 발생하지만, 주 폐기물인 금속, 가연성폐기물과 난처리성 특수 폐기물인 고염 고방사성 폐액, 유기혼성폐기물 및 우라늄 복합폐기물 처리기술 등을 주로 기술하였다. 마지막으로, 해체부지 복원 분야에서는 방사선 측정, 부지재이용의 안전성평가 그리고 부지 복원기술 등을 중점적으로 기술하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.283-286
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• 2002

Solubilization and partitioning of naphthalene was investigated in an aqueous system containing soils and surfactants. The environmental behavior of polycyclic aromatic hydrocarbons(PAHs) was mainly governed by their solubility and partitioning properties on soil media in a subsurface system. In surfactant-enhanced remediation systems, surfactants might be an additional variable. a natural soil ,silica and kaolinite were tested as soil media. two nonionic surfactants, Triton X-100 and Hydropropy1-$\beta$-cyclodextrin (HPCD) were employed for naphthalene solubilization. Naphthalene showed linear on natural soil while non-linear sorption on silica and kaolinite. Soils have higher sorption capacity for Triton X-100 than HPCD indicating Triton X-100 formed ad-micelle on the soil surface. Desorption study showed a hysterysis and reversible desorption. The partitioning coefficient(K$_{D}$) of naphthalene was increased as the concentration of surfactant was increased. (below CMC), however, the coefficient was decreased above CMC. This indicates that naphthalene is partitioned into the micelles and the partition occurs competitively on both ad-micelle and free micelles as surfactant concentration increases. Therefore, the target compounds to be dissolved into aqueous phase in a surfactant enhanced remediation system might be highly partitioned on to the ad-micelle resulting in an adverse effect rather increased solubilization would be achieved.d.