• 물과 미래
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• 제6권2호
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• pp.19-29
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• 1973

The progressive contamination of water resulted from man's activity and the use of fertilizers is not restricted only to surface water, but also the shallow groundwater is affected. This type of groundwater contamination is mainly restricted to areas composed of permeable, nonconsolidated sediments forming a shallow aquifer. The chloride and the sulfate resulted from man's activity and the use of fertilizers were measured to study the variations of the groundwater contamination. In general, (1) When water level rises, the rate of groundwater contamination becomes less and when water level declines, the rate of contamination is increased. (2) The highly contaminated season is the early-summer and the less contaminated season is the winter or after rainy season. (3) The groundwater in weathering zone without covering layer. (4) The degree of contamination of wells is increased with the increase of well depth and lowing the water table, because of increasing contaminated water from enlargement of the area of influence of the well.

• Journal of Microbiology and Biotechnology
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• 제33권7호
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• pp.895-908
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• 2023

Disposal of waste containing heavy metals into the environment is a major threat to human health and can result in toxic or chronic poisoning in aquatic life. In the current study, metal-resistant Raoultella ornithinolytica was isolated from metal-contaminated samples collected from the Tanjaro River, located southwest of Sulaymaniyah, Iraq. R. ornithinolytica was identified by partial amplification of 16S rRNA. The uptake potency of heavy metals was assessed using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and indicated that R. ornithinolytica removed 67, 89, 63.4, 55.6, 56.5, 65, and 61.9% of Cd, Pb, Cr, Ni, Zn, Co, and Fe, respectively. These removal rates were influenced by temperature, pH, and contact time; at 35℃ and pH 5 with a change in the incubation time, the reduction rate improved from 89 to 95% for Pb, from 36.4 to 45% for Cu, and from 55.6 to 64% for Ni. Gene analysis indicated that R. ornithinolytica contained pbrT, chrB, nccA, iroN, and czcA genes, but the pcoD gene was absent. Energy-dispersive X-ray spectroscopy (EDS) images showed evidence of metal ion binding on the cell wall surface with different rates of binding. Transmission electron microscopy (TEM) detected different mechanisms for metal particle localization; cell surface adsorption was the main mechanism for Pb, Zn, and Co uptake, while Cd, Ni, and Fe were accumulated inside the cell. The current study describes, for the first time, the isolation of R. ornithinolytica from metal-contaminated water, which can be used as an eco-friendly biological expedient for the remediation and detoxification of metals from contaminated environments.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.117-119
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• 2005

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.319-320
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• 2018

• 한국물환경학회지
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• 제22권4호
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• pp.632-638
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• 2006

최근에 오염된 토양을 정화하기 위해서 다양한 방법들이 사용되고 있으나 이들 대부분은 이미 오염된 토양에 대한 정화기술로서 많은 비용이 수반되는 단점이 있다. 본 연구에서는 이들 방법과는 달리 잠재적인 토양오염지역에서 오염되기 전이나 혹은 진행 중일 때 지형학적인 특징, 지표 위나 아래의 배수시스템의 재배열 및 선행계획을 통해 토양자체의 정화능력을 이용하는 새로운 정화방법을 고찰하였다. 즉, 토양자체 정화과정이 왜, 어떻게 발전되는가에 대해 단계적으로 규명하였다. 해안지역에서 오염된 바닷물의 침투와 거주지역에서 유해 라돈가스($^{222}Rn$)의 조절 및 제거 등 두 가지 사례를 통해 흙의 자체정화 능력을 이용한 토양정화방법의 효율성을 평가하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 제3회 부산.경남지부 심포지엄
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• pp.14-28
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• 2001

As basic study for purpose bioremedation in oil-contaminated environment, Primarily, we isolated biosurfactant producer- strains utilized of oil-agar plate, and measured surface tension and emulsifying activity. We investigated in oil-contaminated soil and sea water. In this laboratory, Pseudomonas sp. EL-012S strain isolated from oil-contaminated soil was able to product novel biosurfactant under the optimal culture condition. Its condition was n-hexadecane 2.0%, NH$_4$NO$_3$0.4%, Na$_2$HPO$_4$0.6%, KH$_2$PO$_4$0.4%, MgSO$_4$.7$H_2O$ 0.02%, CaCl$_2$.2$H_2O$ 0.001%, FeSO.7$H_2O$ 0.001%, initial pH 7.0 and aeration at 3$0^{\circ}C$, respectively. This biosurfactant was produced in both late-exponential and early-stationary phase. The biosurfactant from Pseudomonas sp. EL-012S was composed of carbohydrate, lipid and protein. The purified-biosurfactant was examined two (biosurfactant type I, II) with the silica gel G60 column chromatography and the purified biosurfactant confirmed thin layer chromatography, high performed liquid chromatography and gas chromatography. The biosurfactant type I involved in carbohydrate-lipid-protein characteristics lowered surface tension of water to 27dyne/cm and interfacial tension 4.5dyne/cm aginst to n-hexadecane and the biosurfactant type B involved in carbohydrate lipid characteristics lowered surface tension of water to 30dyne/cm and interfacial tension 8dyne/cm against to n-hexadecane. Specially type I had the properties such as strong emulsifying activity, emulsion stability, pH-stability, thermo-stability, high cleaning activity and forming ability.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권6호
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• pp.37-48
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• 2014

Lab scale rhizofiltration by using four plants was performed to investigate the uranium removal efficiency from groundwater. Lettuce (Lactuca sativa L.), Chinese cabbage (Brassica campestris L.), radish sprouts (Raphanus sativus L.) and buttercup (Oenanthe javanica) were cultivated during 3 weeks in the phytotron. Glass jar ($12cm{\times}12cm{\times}8cm$ for each), containing 350 ml of the artificially uranium contaminated solution was used for 72 hours of the rhizofiltration. In experiments with different initial uranium concentration ($18.00{\mu}g/L$, $31.00{\mu}g/L$, $84.00{\mu}g/L$ and $116.00{\mu}g/L$) in solution, more than 70% of the initial uranium were removed by using lettuce, Chinese cabbage and radish sprouts and the residual uranium concentration in solution maintained lower than USEPA water tolerance limit ($30{\mu}g/L$). From the rhizofiltration experiments at various pH conditions, the highest uranium removal for all four plants was acquired at pH 3 in solution. Rhizofiltration experiments testing two field samples of groundwaters having high uranium concentrations ($86.00{\mu}g/L$ and $173.00{\mu}g/L$) were duplicated and more than 83% of the initial uranium were removed from the groundwater within 72 hours of rhizofiltration by using radish sprouts, which, suggests that the rhizofiltration can be a useful process to remediate uranium contaminated groundwater in the field. After the rhizofiltration experiment, the SEM and EDS analyses for the root surface of the radish sprouts were conducted, suggesting that the main mechanism of the rhizofiltration for the removal of uranium from groundwater would be surface precipitation on the root surface of the plant.

• 한국기계가공학회지
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• 제19권10호
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• pp.105-110
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• 2020

Radioactive Oxides are formed on the surface of the primary equipment in a nuclear power plant. In order to remove the oxide film that is formed on the surfaces of the equipment, chemical and physical decontamination technologies are used. The disadvantage of traditional technologies is that they produce secondary radioactive wastes. Therefore, in this study, the short-pulsed laser eco-friendly technology was used in order to reduce production of the secondary radioactive wastes. They were also used to minimize the damages that were caused on the base material and to remove the contaminated oxide film. The study was carried out using a Stainless steel 304 specimen that was coated with nickel-ferrite particles. Further, the laser source was selected with two different wavelengths. Furthermore, the depth of the coating layer was analyzed using a 3D laser microscope by changing the laser ablation conditions. Based on the analysis, the optimal conditions of ablation were determined using a 1064nm short-pulsed laser ablation technique in order to remove the radioactively contaminated oxide film from the irradiated stainless steel surface.

• 한국산업보건학회지
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• 제5권2호
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• pp.137-146
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• 1995

Twenty(20) large commercial buildings located in Seoul with friable sprayed-on surface insulation material on ceilings were investigated for asbestos content in bulk material by polarized light microscopy and for airborne fiber concentrations in buildings by phase contrast microscopy. In addition, such building-related variables as building age, numbers of traffic, airflow, surface conditions of the ceiling, temperature, and humidity were studied for any correlation with airborne fiber concentrations. The results were as follows: 1. Chrysotile asbestos was found in two bulk samples with 3-5% content and with <1%in one sample out of total 20 bulk samples collected. Glass fiber and mineral wool were the two major constituents of the bulk samples. 2. The ceiling surfaces were very friable in 16 buildings and were relatively hard in 4 buildings. The friability of the surface material was dependent upon the type and the amount of binder that had been mixed with the sprayed-on surface material. 3. Airborne fiber concentrations were log-normally distributed and the geometric mean(geometric standard deviation) fiber concentrations in the underground parking lots, inside buildings, and outdoor ambient air were 0.0063(1.97)f/cc, 0.0068(2.29)f/cc, and 0.0033(2.36)f/cc, respectively. 4. No significant relationship of airborne fiber concentrations and all building-related variables studied except humidity was found. The results of this study suggest that the sprayed-on surface insulation material found in some commercial buildings may possibly be contaminated with asbestos. Since most of the ceiling surfaces surveyed were very friable and poorly maintained and the airborne fiber concentrations were relatively high, there is a possibility of asbestos fiber contamination in these buildings, particularly at those buildings with asbestos-contaminated surface material. Since poorly maintained surface conditions were thought to be a source of high airborne fiber concentrations, there is a urgent need of a systematic operation and maintenance program. Further study of non-occupational asbestos exposure in general population utilizing advanced analytical technique such as transmission electron microscopy is highly recommended.

• 원예과학기술지
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• 제30권4호
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• pp.442-448
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• 2012

최근 상추와 같은 농산물에 의한 식중독사고가 발생하고 있으며 그 원인으로 병원성 미생물에 오염된 퇴비, 관개용수의 사용이라고 보고되고 있다. 따라서 본 연구는 육묘단계의 상토, 재배과정의 토양, 관개용수의 Escherichia coli와 Bacillus cereus 오염이 상추의 안전성에 미치는 영향을 구명하고자 수행하였다. 이를 위하여 상토는 두 균주로 7.5log CFU/g 수준으로 오염시킨 후 상추종자를 파종하고 28일간 생육시켰고, 오염되지 않은 토양과 6.0log CFU/g 수준으로 오염시킨 토양에 오염된 상토에서 21일간 자란 묘를 이식하고 49일간 인공기상동 ($25^{\circ}C$, 상대습도 70-80%)에서 생육시켰다. 또한 8.0log CFU/mL로 오염된 관개용수로 지표면관수법과 살수관수법으로 상추에 관수하고 40일간 병원성 미생물의 오염 및 생존을 조사하였다. 그 결과 육묘기의 상토와 상추 중 E. coli와 B. cereus는 시간이 경과함에 따라 점차 감소하였지만 육묘기 내내 생존 가능한 것으로 확인되었다. 토양에서는 42일간 E. coli와 B. cereus가 6.0log CFU/g 내외로 유의적인 감소 없이 유지되고 있었다. 오염된 토양에 이식된 상추는 21일째까지 E. coli와 B. cereus의 농도가 4.0log CFU/g 이상 유지되었고 이식 후 42일까지도 검출되었다. 또한 살수관수법으로 처리한 구에서 지표면관수법으로 처리한 구보다 상추의 오염수준이 5.0log CFU/g 정도 높았다. 따라서 본 연구의 결과는 병원성미생물에 오염된 상토, 토양, 관개용수는 농산물의 병원성미생물 오염에 직접적인 원인이 될 수 있음을 시사한다.