• 한국환경농학회지
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• 제39권3호
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• pp.197-203
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• 2020

BACKGROUND: Most lakes have increased concerns about water pollution due to the inflow of non-point sources caused by human activities. Therefore, the lake water quality survey was conducted in order to propose effective plans for water quality management by analyzing the characteristics of lakes and the change of water quality. METHODS AND RESULTS: In order to investigate the physicochemical water quality in Daedong lake, water quality analysis was undertaken from July 2018 to June 2019. Water temperature was ranged from 7.8 to 34.3℃ and pH varied from 6.9 to 10.2. The concentration of Dissolved oxygen, Suspended solid, Biochemical Oxygen Demand (BOD), and Chemical Oxygen Demand (COD) were 5.6 ~ 17.2 mg/L, 2.4 ~ 35.3 mg/L, and 4.5 ~ 15.1 mg/L, and 0.9 ~ 2.8 mg/L, respectively. The Total Nitrogen (T-N) concentration ranged from 0.974 ~ 2.126 mg/L, and Total Phosphorus (T-P) concentration ranged from 0.014 ~ 0.057 mg/L. The Chlorophyll-a (Chl-a) ranged from 2.7 ~ 37.9 mg/㎥. Through Carlson TSIm assessment using T-P and Chl-a results, evaluating trophic state, Daedong lake was evaluated as mesotrophic. CONCLUSION: Water pollution management plan needs such as nutrient removal technology and nonpoint source management for prevention of eutrophication in Daedong lake.

• 한국물환경학회지
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• 제33권6호
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• pp.670-679
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• 2017

An experiment to study the effect of temperature, light, and dredging on release of nutrients downstream from Gongjicheon in the Uiam reservoir was carried out in the laboratory using sediments from different depths. At various water temperatures, dissolved total nitrogen was not released, but the average nutrient flux of dissolved total phosphorus was increased (0.034 at $15^{\circ}C$, 0.005 at $20^{\circ}C$, 0.154 at $25^{\circ}C$, $0.592mg/m^2/d$ at $30^{\circ}C$). Dissolved total phosphorous was released in controlled darkness. In contrast, in controlled light, the concentrations of dissolved total phosphorous and dissolved total nitrogen in the overlying water steadily decreased during the study period (70 d), because they were continuously consumed by the growth of photosynthetic algae. However, there was no significant relationship between water nutrient concentration, nutrient release, and the depth of the sediment. We concluded that the dredging of sediment would not affect the nutrient release rate of the sediment, because there were no significant differences in the nutrient concentrations released from the sediment. When the sediment was removed from the surface to 20 cm in depth, the nutrients were not transferred to the water body, implying that the sediment removal had little effect on secondary pollution.

• 한국식품과학회지
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• 제17권6호
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• pp.516-521
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• 1985

녹두, 대두, 참깨 및 들깨를 상온에서의 침지 및 발아 그리고 $60^{\circ}C$에서 incubation 및 $120^{\circ}C$에서 autoclaving시켰을 때 이들의 처리가 phosphorus와 phytic acid의 함량에 미치는 영향을 조사하였다. Total P는 24시간의 침지와 incubation에서 약간 감소하였고, $5{\sim}6$일간의 발아에서는 녹두와 대두에서 약간의 증가를 보이었으나 전체적으로 큰 변화는 없었다. Inorganic P는 24시간의 침지후에 전시료에서 그함량이 증가함을 보여주었고, 발아기간이 경과함에 따라 급속히 증가하였다. 10시간의 incubation에서 참깨와 들깨 inorganic P는 증가되었으나 두류에서는 별다른 변화가 없었고, 4시간의 autoclaving으로는 두류에서 $244{\sim}285%$정도 증가되었으나 깨종실에서는 별다른 변화가 없었다. Phytic acid는 침지시 녹두에서 25%로 가장 많이 감소되었고 둘째는 7%로 가장 적게 감소되었다. 이들 종실의 발아시는 $5{\sim}6$일 후에 녹두의 phytic acid는 92%, 대두는 76% 그리고 참깨는 78%나 크게 감소되었고, incubation시는 녹두와 대두에서 각각 83%와 61% 감소되었고, autoclaving시에도 대두에서 68%, 깨에서 17%까지 감소되었다.

• 한국환경농학회지
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• 제31권4호
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• pp.378-380
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• 2012

BACKGROUND: In Korea, green manure has been cultivated for reducing chemical fertilizer application, maintaining soil fertility, and feeding livestock in winter season. We evaluated the phosphate balance under green manure-rice cultivating system with different removal rates of green manure for maintaining soil fertility. METHODS AND RESULTS: The barley and hairy vetch mixture was selected as the green manure in this study. The barley and hairy vetch was sowed at a rate of 135 and 23 kg/ha, respectively, without fertilizer application. Total aboveground biomass was 12000 (barley: 5400 kg/ha, hairy vetch: 6600 kg/ha) kg/ha, and these green manure were incorporated with different input rates before rice planting. The input rates of green manure in this study were 0 (NPK+0%), 25 (NPK+25%), 50 (NPK+50%), 75 (NPK+75%) and 100 % (NPK+100) and the standard fertilization (NPK) without green manure cultivation. All treatments were applied with standard fertilizer (N-P-K: 90-19.6-48.3 kg/ha) before rice planting. The highest rice yield was observed in NPK+50% which was 20% higher compared with NPK. The phosphate balance with different incorporation rates of green manure was-104.0,-76.8,-52.9,-27.4, and 6.0 kg/ha for NPK+0%, NPK+25%, NPK+50%, NPK+75%, and NPK+100%, respectively. CONCLUSION(S): The use of green manure for livestock feeding in green manure-rice cropping systems could remove a huge amount of phosphate. This cropping system strongly requires phosphate application before green manure seeding for maintaining soil fertility.

• 한국환경복원기술학회지
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• 제10권6호
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• pp.88-98
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• 2007

The control of nonpoint source pollution from the urban paved areas with high imperviousness in is required to improve the water quality of aquatic resources. This research investigated the characteristics of urban runoffs and evaluate the effectiveness of the continuous deflective separation systems for stormwater best management practice. The systems were installed in the vicinity of a high-level road, an apartment complex, and the Cheonggye stream. Stormwater runoff was sampled in these sites. Biochemical oxygen demand ($BOD_5$), total suspended solid (TSS), total nitrogen (T-N), and total phosphorus (T-P) were analyzed. The removal efficiency of $BOD_5$, TSS, and T-P for the road was 10.9-81.0%, 11.7-93.4%, 0-37.5%, respectively. That of $BOD_5$, TSS, T-N, and T-P for the complex was 12.5-65.8%, 26.5-77.6%, 1.8-28.7%, and 20.0-37.5%, respectively. The abatement efficiency $BOD_5$, TSS, T-N, and T-P for the stream was 7.2-85.2%, 41.7-98.2%, 11.3-65.6%, and 2.0-71.5%, respectively. This study shows that the systems can be used to remove $BOD_5$ and TSS from urban runoffs efficiently.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.245-248
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• 2011

Many researches have been carried out to improve light absorption in the crystalline silicon solar cell fabrication. The rear reflection is applied to increase the path length of light, resulting in the light absorption enhancement and thus the efficiency improvement mainly due to increase in short circuit current. In this paper, we manufactured the silicon solar cell using the mono crystalline silicon wafers with $156{\times}156mm^2$, 0.5~3.0 ${\Omega}{\cdot}cm$ of resistivity and p-type. After saw damage removal, the dielectric film ($SiN_x$)on the back surface was deposited, followed by surface texturing in the KOH solution. It resulted in single-side texturing wafer. Then the dielectric film was removed in the HF solution. The silicon wafers were doped with phosphorus by $POCl_3$ with the sheet resistance 50 ${\Omega}/{\Box}$ and then the silicon nitride was deposited on the front surface by the PECVD with 80nm thickness. The electrodes were formed by screen-printing with Ag and Al paste for front and back surface, respectively. The reflectance and transmittance for the single-sided and double-sided textured wafers were compared. The double-sided textured wafer showed higher reflectance and lower transmittance at the long wavelength region, compared to single-sided. The completed crystalline silicon solar cells with different back surface texture showed the conversion efficiency of 17.4% for the single sided and 17.3% for the double sided. The efficiency improvement with single-sided textured solar cell resulted from reflectance increase on back surface and light absorption enhancement.

• 한국습지학회지
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• 제16권3호
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• pp.363-370
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• 2014

농촌 지역 마을하수도 보급률은 도시 지역에 비해 38% 정도 수준밖에 되지 않는다. 농촌 지역은 상수원 인근에 위치하여 농촌지역에서 발생하는 하수는 상수원 오염의 원인으로 알려져 있다. 그래서 정부에서는 마을하수도 관리에 많은 노력을 기울이고 있다. 본 연구에서는 동절기 마을하수도 영양염류 제거 효율을 분석하였으며, 안동 임하댐 인근에 위치한 봉화, 영양 그리고 안동의 신설된 마을하수도를 연구 대상으로 선정하였다. 동절기 마을하수도 영양염류 제거 효율은 체류 시간과 미생물 농도에 영향을 받는 것으로 나타났다. 따라서 마을하수도 운전 시 영양염류 처리를 위해 운전 조건 조절 및 유지관리가 필요하다는 것을 의미한다.

• Journal of Microbiology
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• 제44권2호
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• pp.155-161
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• 2006

Comparative analysis of microbial communities in a sequencing batch reactor which performed enhanced biological phosphorus removal (EBPR) was carried out using a cultivation-based technique and 16S rRNA gene clone libraries. A standard PCR protocol and a modified PCR protocol with low PCR cycle was applied to the two clone libraries of the 16S rRNA gene sequences obtained from EBPR sludge, respectively, and the resulting 424 clones were analyzed using restriction fragment length polymorphisms (RFLPs) on 16S rRNA gene inserts. Comparison of two clone libraries showed that the modified PCR protocol decreased the incidence of distinct fragment patterns from about 63 % (137 of 217) in the standard PCR method to about 34 % (70 of 207) under the modified protocol, suggesting that just a low level of PCR cycling (5 cycles after 15 cycles) can significantly reduce the formation of chimeric DNA in the final PCR products. Phylogenetic analysis of 81 groups with distinct RFLP patterns that were obtained using the modified PCR method revealed that the clones were affiliated with at least 11 phyla or classes of the domain Bacteria. However, the analyses of 327 colonies, which were grouped into just 41 distinct types by RFLP analysis, showed that they could be classified into five major bacterial lineages: ${\alpha},\;{\beta},\;{\gamma}-$ Proteobacteria, Actinobacteria, and the phylum Bacteroidetes, which indicated that the microbial community yielded from the cultivation-based method was still much simpler than that yielded from the PCR-based molecular method. In this study, the discrepancy observed between the communities obtained from PCR-based and cultivation-based methods seems to result from low culturabilities of bacteria or PCR bias even though modified culture and PCR methods were used. Therefore, continuous development of PCR protocol and cultivation techniques is needed to reduce this discrepancy.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.461-467
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• 2006

The growth pattern and the seasonal changes in nutrient contents of Humulus japonicus were investigated. Stem length of H. japonicus reached the maximum from 240 to 260 Julian date and the median value was found at 255 Julian date. The maximum leaf area was observed from 235 to 248 Julian date and the median value was at 240 Julian date. The maximum growth rate of the stem length ranged from 205 to 227 Julian date. The leaf area showed the maximum growth rate from 196 to 214 Julian date. The median date in the growth rate of the stem length and leaf area was 212 and 205 Julian date, respectively. The growth rate of H. japonicus was related to rainy season and precipitation. Phosphorus and sodium contents of H. japonicus were correlated with maximum potential rate of relative growth. Although stem biomass of H. japonicus was $ 1.5{\sim}3.5$ times larger than that of leaf, N content of the leaf ($4.48{\sim}5.27%$) was about 2 times higher than that of the stem ($2.00{\sim}3.62%$). High content of N might be responsible for the high growth rate of H. japonicus in summer. This result provides valuable information for appropriate timing for the removal of H. japonicus.

• 한국항해항만학회지
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• 제34권5호
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• pp.383-388
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• 2010

본 연구는 크루즈선에 적합한 생물학적 오 폐수처리장치 개발을 위하여 SBR, MBR, MSBR 공정을 Lab scale 실험을 수행하여 오염물 처리 효율과 크루즈선이라는 특수 환경과의 접목성을 검토한 결과 MSBR공정이 처리효율과 장치 운영 면에서 가장 적합한 공정으로 평가되었다. MSBR 공정은 처리 대상 물질이 특정 성분에 국한 되지 않고 유기물, 영양염류, 병원성 미생물 처리에 있어 모두 안정적인 효율을 나타내었으며, 소요용적 및 장치의 운영 면에서도 우수한 결과를 나타내어 선박이라는 특수한 현장 적용에 매우 유리한 공정으로 확인되었다. MSBR 공정의 BOD, COD 및 SS 제거 효율은 99%, 98%, 99%로 나타나 IMO의 규제 기준을 모두 만족하였으며, 총질소와 인의 제거 효율도 76%, 59%로 강화되어 가는 해양오염기준을 충만족시킬 수 있는 공정으로 판단되었다.