• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.128-136
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• 2006

This study was conducted for developing the stability parameter in uncontrolled landfill by using a biomolecular investigation on the microbial community growing through leachate plume. Landfill J(which is in Cheonan) and landfill T(which is in Wonju) were chosen for this study among a total of 244 closed uncontrolled landfills. It addressed the genetic diversity of the microbial community in the leachate by 165 rDNA gene cloning using PCR and compared quantitative analysis of denitrifiers and methanotrophs with the conventional water quality parameters. From the BLAST search, genes of 47.6% in landfill J, and 32.5% in landfill T, respectively, showed more than 97% of the similarity where Proteobacteria phylum was most significantly observed. It showed that the numbers of denitrification genes, i.e. nirS gene and cnorB gene in the J site are 7 and 4 times higher than those in T site, which is well reflecting from a difference of site closure showing 7 and 13 years after being closed, respectively. In addition, the quantitative analysis on methane formation gene showed that J1 spot immediately bordering with the sources has the greatest number of methane formation bacteria, and it was decreased rapidly according to distribute toward the outer boundary of landfill. The comparative investigation between the number of genes, i.e. nirS gene, cnorB gene and MCR gene, md the conventional monitoring parameters, i.e. TOC, $NH_3-N,\;NO_3-N,\;NO_2-N,\;Cl^-$, alkalinity, addressed that more than 99% of the correlation was observed except for the $NO_3-N$. It was concluded that biomolecular investigation was well consistent with the conventional monitoring parameters to interpret their influences and stability made by leachate plume formed in downgradient around the uncontrolled sites.

• Journal of Environmental Impact Assessment
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• v.27 no.1
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• pp.83-91
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• 2018

Media (bio-stone), aquatic macrophytes (Oenanthe javanica) and herbivorous cladoceran (Daphnia similoides) have been used in artificial floating island (AFI) systems for water pollution control. Efficiency in chl-a concentration controlling of AFI was tested using different combinations of each device: G-BD-mixture bio-stone and Daphnia similoides, G-OB-mixture Oenanthe javanica and bio-stone, G-BOD-mixture bio-stone, Oenanthe javanica and Daphnia similoides, and the out-put water quality improvement was compared with G-C-control (no device was applied). We analyzed removal efficiency of chl-a concentration and nutrient concentrations in the artificially eutrophic water in the laboratory experimental facility. The results showed average removal rates of Chlorophyll a, TN and TP for different four groups: 69.24%, 16.61%, -0.61%; 68.39%, 14.11%, 10.52%; 78.30%, 6.69%, 25.09%; 35.42%, -3.47%, -25.18%, respectively. The results have suggested that the mixture of media, plants and zooplankton is the most efficient combination for Chlorophyll a control, while the mixture of macrophytes and bio-stone have better efficiency nutrient control.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.203-210
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• 2001

Here, we compared the effectiveness of 50 MeV($p{\to}RBe^+$) cyclotron fast neutrons versus $^{60}Co$ ${\gamma}$-rays by the apoptotic fragment frequency in both rat peripheral lymphocytes and crypt cells to check a radiobiological endpoint. The incidence of apoptotic cell death was increased in all irradiated groups, and radiation at all doses trigger rapid changes in both crypt cells and peripheral lymphocytes. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for these data of apoptotic fragments frequencies was $y=0.3+(6.512{\pm}0.279)D(r^2=0.975)$ after neutrons, while $y=0.3+(4.435{\pm}0.473)D+(-1.300{\pm}0.551)D^2(r^2=0.988)$ after ${\gamma}$-rays. In addition, $y=3.5+(118.410{\pm}10.325)D+(-33.548{\pm}12.023)D^2(r^2=0.992)$ after ${\gamma}$-rays in rat lymphocytes. A significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic cells with increasing dose. Dose-response curves for high and low linear energy transfer (LET) radiation modalities in these studies were different. The relative biological effectiveness (RBE) value for crypt cells was 1.919. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morphological findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis induction in both crypt cells and peripheral lymphocytes could be a useful endpoint of rat model for studying screening test and microdosimetic indicator to evaluate the biological effects of radiation-induced cell damage.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.5-13
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• 2019

This study was conducted to investigate the application effects of dried food waste powder (FWP) and mixtures of FWP and organic fertilizer (MFOs) on the growth of lettuce and Chinese cabbage. The physicochemical properties of FWP and MFOs were analyzed. As FWPs containing 3.11% NaCl was applied at 250 kg, 500 kg and 1,000 kg per 10a, growth factors of lettuce and Chinese cabbage, such as a number of leaf, leaf length, leaf width, and dry weight were decreased than those of control appling organic fertilizer. The higher the FWP ratio in the MFOs, the lower the concentrations of N and P₂O₅ in the MFOs, while the higher the concentration of NaCl. As compared to dry weight of control after treating MFOs, lettuce were not significant in MFOs treatments containing 10~30% FWP, and Chinese cabbage in MFOs treatment containing 10% FWP.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.255-262
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• 2010

This study was conducted at 5 sites of Bocheong Stream basin in May and September 2009 for the evaluate of fish assemblage and chemical water quality. For the study, the models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) were modified as 8 and 11 metric attributes, respectively. We also analyzed patterns of chemical water quality at the sampling site over the period of 2005~2009, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. The survey showed that total sampled fishes were 34 species and the most dominant species was Zacco platypus (24.3%). In Bocheong Stream basin, values of IBI averaged 28 (n=5), which is judged as a "Good". IBI score at B1, B4 and B5 indicating a "Good" condition whereas, B2 and B3 were as 21 and 22, indicating "Fair" condition, respectively. QHEI was 152 (n=5), judged as "Fair" habitat condition. Values of BOD and COD averaged 1.0 $mgL^{-1}$ (scope: 0.3~4.0 $mgL^{-1}$) and 2.3 $mgL^{-1}$ (scope: 0.3~18.7 $mgL^{-1}$), respectively. Total nitrogen (TN), total phosphorus (TP) and suspended solid (SS) were distinct spatial variation. Based on the IBI, QHEI and chemical water quality dataset, ecological health of Bocheong Stream basin was evaluated that generally good.

• Environmental Analysis Health and Toxicology
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• v.17 no.3
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• pp.245-252
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• 2002

Airborne pollutants in the subway facilities can be potentially harmful to the health of passengers. This study was designed to examine whether the suspended particulates have mutagenic or carcinogenic effect on the plant cell systems. Total suspended particulates were collected with a high volume air sampler, in the entrance, the waiting room, and the platform of each subway station. The biological end -points in this experiment were the pink mutations in stamen hairs and micronuclei in the pollen mother cells of Tradescantia. The exudates were collected by shaking the filter papers from the sampler in distilled water for 24 hours. All the plant cuttings exposed to the exudates resulted in positive responses. The micronucleus assay proved more reliable and sensitive to the test than the stamen hair assay. The results indicate that the air particulates can give an adverse effect on the health of subway passengers.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.274-288
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• 2018

This study investigated the environmental factors and fish assemblage in 42 wetlands between spring and autumn of 2017 to evaluate the fish distribution and deduce the management strategy for improving biodiversity in created wetlands located at the Nakdong River basin. The investigation identified a total of 30 fish species and found that the most of wetlands were dominated by exotic fishes such as Micropterus salmoides and Lepomis macrochirus. Fish species such as Rhinogobius brunneus, Opsariichthys uncirostris amurensis, Zacco platypus were less abundant in the area with high density of Micropterus salmoides (static area) because they preferred the environment with active water flow. The pattern analysis of fish distribution in each wetland using the self-organizing map (SOM) showed a total of 24 variables (14 fish species and 10 environmental variables). The comparison of variables indicated that the distribution of fish species varied according to water depth and plant cover rate and was less affected by water temperature, pH, and dissolved oxygen. The plant cover rate was strongly associated with high fish density and species diversity. However, wetlands with low plant biomass had diversity and density of fish species. The results showed that the microhabitat structure, created by macrophytes, was an important factor in determining the diversity and abundance of fish communities because the different species compositions of macrophytes supported diverse fish species in these habitats. Based on the results of this study, we conclude that macrophytes are the key components of lentic freshwater ecosystem heterogeneity, and the inclusion of diverse plant species in wetland construction or restoration schemes will result in ecologically healthy food webs.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.302-308
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• 2005

Nitrate is one of common contaminants frequently found in the bank filtrate. Biological autotrophic denitrification into permeable reactive barrier(PRB) system to reduce nitrate concentration in bank filtrate was implanted. The objectives of research are to investigate effect of inoculation, to evaluate alternative alkalinity sources, and to determine effect of hydraulic characteristics, such as retention time, flow rate on the performance of semi-pilot PRB system. Semi-pilot scale biological PRB system was installed using elemental sulfur and limestone/oyster shell as reactive materials near Nakdong River in Kyoungnam province, Korea. Nitrate concentration in bank filtrate was reduced by indigenous microorganisms in oyster shell as welt as by inoculating microorganisms isolated from the sludge of an anaerobic digester in a wastewater treatment plant. Oyster shell as well as limestone can be used as an alkalinity source. However, oyster shell resulted in suspended solids of effluent. As the flow rate in the system increased from 66 to 132 mL/min and accordingly the residence time decreased from 15 to 7.5 hours, nitrate concentration in effluent increased and nitrate removal efficiencies decreased from 75 to 58% at the fixed thickness of 80 cm of PRB.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.6
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• pp.79-90
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• 2015

유사는 오염물질을 저장 또는 운반하는 매개체로 하류 수체의 물리적, 화학적, 생물학적 과정에 큰 영향을 미친다. 따라서 유사 발생 및 운송 양의 추정은 수질개선을 위한 유역관리계획을 수립하는데 중요한 자료가 된다. 이러한 유사량 및 운송과정은 주로 모형에 의해 계산되고 모의되는데, 많은 유사운송모형들이 유사이송용량 (sediment transport capacity)식을 이용하여 유사 발생량, 이송량 및 퇴적량을 산정한다. 유출에 의한 유사이송용량을 산정하기 위한 기존의 식들은 각기 다른 목적과 환경에서 개발되어 보편적으로 적용할 수 있는 식은 전무한 실정이다. 이에 본 연구는 유사이송용량을 계산하기 위해 사용되는 식들의 개발 목적과 환경을 검토하고, 경사, 유량, 유사입경 및 토성에 따른 민감도를 조사하여 각 식의 적용성을 평가하였다. 본 연구에서 적용한 8개의 유사이송용량 산정식은 모두 경사도에 가장 민감하게 변화하는 것으로 나타났다. Abraham과 Yalin식 이외의 산정식을 이용하여 계산된 유사이송용량은 경사도가 0.1 % 보다 작을 때는 0 mg/l, 경사도가 100 % 보다 클 때는 이론최대치인 2,650 mg/l 을 넘는 것으로 나타나, 이들 산정식의 적용 가능한 경사도 범위를 0.1 %-100 %로 추정할 수 있었다. Abrahams식은 유량에, Bagnold식은 유사입경 및 토성에 민감한 것으로 나타났다. Low, Rickenmann, 및 Schoklitsch식은 유량에 민감하게 반응하지 않았고, Low와 Schoklitsch식은 토성에도 민감하지 않은 것으로 나타나, 이들 식의 제한된 적용성을 확인하였다. 한편, Yang식은 계산식에 포함된 로그항으로 인해 그 적용범위가 제한되는 경우가 있었다. Abrahams과 Yalin식을 이용하여 산정된 유사운송용량은 모든 인자들에 민감하게 반응하는 것으로 나타났으며, Yalin과 Low식의 경우, silt와 clay에 적용되었을 때 유량이 클수록 유사운송용량이 다소 작아지는 경향을 보임에 따라, 전체적으로 Abraham식의 적용성이 가장 높은 것으로 평가되었다. 본 연구결과는 향후 모형을 이용한 유사량 모의 시 적용대상 지역의 특성에 가장 적합한 유사운송용량 산정식을 선정하는데 유용한 정보를 제공할 것으로 기대된다.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.807-812
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• 2018

In this study, we investigated the conditions used in setting the recommendation level of general radiography diagnostic reference and tried to evaluate the effective dose and biological evaluation using PCXMC v2.0 program. As a result based on the effective dose of male in ICRP 60, the highest Pelvis AP was 0.794 mSv. The lowest Chest PA was 0.050 mSv. In the case of ICRP 103, the highest T-Spine AP was 0.906 mSv The lowest Chest PA was 0.052 mSv. For 40 years old male and female adults, effective doses of general radiography were evaluated and even if the medical exposures are not subject to the limit of dose, efforts should be made to reduce the medical exposures of the people by keeping the dose below the recommended amount in order to minimize the probable effect of radiation hazard.