• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.363-366
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• 2003

본 연구는 membrane bioreactor (MBR)을 질산화 위주로 운영하면서 질소폐수 처리 과정에서 나타나는 MBR의 운전특성 및 처리효율을 검토하고, 아울러 경제적인 질소처리 방법인 아질산화를 유도하기 위한 조건을 탐색하는 것이다. 반응기의 유효부피 8 L, 체류시간을 12시간으로 고정하고 유입폐수 중의 암모니아 농도를 증가시키는 방법으로 암모니아 부하를 $2\;kg/m^3{\cdot}day$까지 증가시켜 보았다. 운전 중반부에 이유를 명확히 알 수 없는 슬러지의 활성 저하 기간을 제외하고는 거의 98% 이상의 질산화 효율을 나타냈으며, 2 kg 이상의 암모니아 부하에서는 효율이 감소하였다. pH 조절, 유입수의 암모니아 농도 및 부하 조절에 의해 MBR 내의 free ammonia (FA) 농도를 변화시켜, FA 저해에 의한 유도한 아질산화는 매우 불안정하게 이루어졌다. 반면에, 공기 공급량을 변화시켜 반응기 내의 DO를 낮추는 방법으로 유도한 아질산 축적은 안정적인 경향을 보여 MBR에서 적절한 운전전략으로 판단된다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.4
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• pp.47-56
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• 1999

The concentration and load of T-N and T-P in paddy field areas in Chongwon, Chungbuk , Korea , were investigated during the irrigation period. The concentration of T-N and T-P in ponded water in paddies is higher than that in the irrigation, drainage and percolation waters. For T-N, the average concentration indrainage water was higher than that in irrigation water until end of Jung, But lower thereafter. The average T-N concentration in irrigation water was 2.3 ∼3.2mg/l and therefore the agricultural water quality standard at on-farm level for T-N should be established realistically . The expontial L(load)-Q(discharge) equations have higher coefficients of determination than the linear L-Q equations . Especially, the exponential L-Q equation of T_N showed a coefficient of determinatino of over 0.9 for irrigation water.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1999.04a
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• pp.91-93
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• 1999

충북 단양에 위치한 조일 광산에서 채취한 구리와 아연으로 오염된 광미 (광산 폐기물로서 금속 추출 후 남은 찌꺼기)를 효율적으로 처리하기 위하여 생물학적 용출기법(bioleaching)의 효율 증진에 관한 연구를 수행하였다. 기본 배지 조성(9K medium) 중 미생물의 성장 및 증식, 용출 효율에 영향을 미치는 인자인 에너지원, 인, 질소원의 농도를 변화시키며 배지 조성에 따른 중금속의 용출 효율을 관찰하였다. 그 결과 인 농도 변화는 인을 첨가하지 않았을 때, 아연과 구리의 용출 효율이 각각 98.8%와 47.5%로 나타났고, 질소원은 45mM 농도로 주입하였을 때 아연, 구리 각각 85%와 46.4%의 용출 효율을 보였다. 에너지원 변화에 서는 아연의 경우 에너지원을 첨가하지 않았을 때 93%의 용출 효율을 나타냈고, 구리의 경우는 160mM 첨가했을 때 46.4%로 가장 높은 용출 효율을 나타냈다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.418-418
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• 2019

낮은 수심, 저 유속의 수로 자갈층에 형성된 생물막을 이용하여 오염물질을 제거하는 박층류 자연정화기법의 효율적인 설계와 운영지침을 얻기 위하여 경기도 용인시 오산천 일부 구간에 현장적용을 위한 Test-bed를 조성하여 박층류 자연정화수로에서의 오염물질 제거 효율을 조사하였다. 오염물질은 녹조발생의 주요 원인물질인 인과 질소를 대상으로 하였고, 연구 조건은 일반적인 하천수에서의 오염 조건과 비점오염원으로부터 오염물질이 유입된 오염조건의 두 가지 조건을 가정하여 제거효율을 분석하였다. 분석 결과 모든 조건에서 박층류 수로를 통과할 때 오염물질의 농도가 감소함을 확인할 수 있었다. 특히 T-P 3 mg/L 이상, T-N 20 mg/L 이상의 고농도의 오염물질 유입시에 박층류 자연정화수로는 평상시보다 높은 60% 이상의 높은 제거 효율을 보였는데, 이를 통하여 박층류 자연정화기법이 고농도의 오염물질 제거에서도 제한적이지 않고 오히려 더 효과적임을 알 수 있었다.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.237-243
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• 2013

This study aims to examine the modified $A^2/O$ process is useful to reduce the environmental pollution caused by nutrient in wastewater. Specific results are as follows: The removal rate was evaluated at each time period, ie., 18h, 8h, 6h, and 3h after the reaction started. The anoxic rate was more than 94-97% from 18h to 6h but was less than 50% before 6h. Thus, the test of nitrification was done using 6h as the optimal anoxic retention time and the aerobic retention time set at 24h. When the flow change was 1:1, the average ammonia concentration inputted was $30mg/{\ell}$. Returned top nitric acid solution and the concentration of ammonia solution falling into the anoxic reactor was about 50％ of the initial concentration, and the flow change was 1:2, the concentration of ammonia falling into the anoxic reactor was about 62% of that of influxed ammonia. And the results of this study showed that the nitrogen removal rate can be improved by inputting untreated nitric acid and changing the flow of top nitrate solution using the modified $A^2/O$ method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.379-385
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• 1987

A field experiment was conducted to find out the effects of liming (soil pH) and sources of N on the chemical constituents of soil and leaf lamina of burley tobacco. Treatments consisted of liming (nonliming, liming to soil pH 5.5 and 6.5) as the main plot and N sources［compound fertilizer of containing 3.9% $NH_4-N$ and 6.1% $NH_2-N,\;NaNO_3,\;(NH_2)_2CO\;and\;(NH_4)_2SO_4$］as the sub-plot. The soil pH was high in $NaNO_2$ plot, while low in $(NH_4)_2SO_4$. But the differences of Ca concentration in top soil among N sources were not detected. The $NO_3-N$ concentration in top soil was high in high limed and $NaNO_3$ plot. The $NO_3-N$ content of leaf (lamina) at 75 days after transplanting was high in $NaNO_3$ plot and CaO con-tent of leaf at 45 days after transplanting was high in high limed plot. But neither liming nor N source had effect on the contents of total nitrogen, $P_2-O_{5}\;and\;K_2O$ of leaf during growing season. There was no significant differences in total alkaloid and total nitrogen contents of cured leaf (lamina) to liming and N source. But when the source of N was $NaNO_3$, the content of total alkaloid was increased by adding lime. When the source of N was $(NH_4$)_2SO_4$, the content of $K_2O$ in cured leaf was high while CaO was low. But neither liming nor N source had effect on the contents of $P_2-O_{5}$ and MgO in cured leaf.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.60-66
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• 2021

As the concentration of nitrogen in the sewage flowing into the sewage treatment plant increases due to urbanization and industrialization, the degree of adverse effects such as eutrophication and toxicity to the aquatic ecosystem is also increasing. In order to treat sewage containing high concentration of nitrogen, various studies on the biological nitrogen removal process are being conducted. Existing biological nitrogen removal processes require significant costs for supplying oxygen and supplementing external carbon sources. In this respect, as a high-level nitrogen removal process with economic improvement is required, an anaerobic ammonium oxidation process (ANAMMOX), which is more efficient and economical than the existing nitrification and denitrification processes, has been proposed. The purpose of this study is to confirm the stability of the ANAMMOX process in the water treatment process and to derive the ratio of ammonia nitrogen (NH4+) to nitrite nitrogen (NO2-) for the implementation of the mainstream ANAMMOX process. A laboratory-scale Mainstream ANAMMOX reactor was operated by applying the ratio calculated based on the substrate ratio suggested in the previous study. In the initial range, the removal efficiency of NH4+ was 58~86%, and the average removal efficiency was 70%. In the advanced range, the removal efficiency of NH4+ was 94~99%, and the average removal efficiency was 95%. As a result of the study, as the NH4+/NO2- ratio increased, the stability of the mainstream ANAMMOX process was secured, and it was confirmed that the NH4+ removal efficiency and the total nitrogen (TN) removal efficiency increased. As a result, the results of this study are expected to be used as basic data in the application of the ANAMMOX process in the mainstream.

• Economic and Environmental Geology
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• v.34 no.5
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• pp.485-498
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• 2001

This study was objected to identify the temporal and spatial variations oi groundwater quality and contamination using monthly groundwater monitoring data collected from 30 wells in Daejung watershed, Jeju Island. Water samples were analyzed for major cations. anions, and environmental isotopes including $^{18}0-H_2$O,$^{2}H-H_2$O and$^{15}$ N-NO$_3$The groundwater represented mostly Na(Mg)-HCO$_3$ type, with local change toward Ca-HCO$_3$ type and Na-Cl type. Groundwater quality depends upon various factors such as the local groundwater flowpaths, input of surface contaminants with recharge events, and sea-water intrusion along the coastal area. Nitrate contamination changed temporally according to recharge events and spatially. $\delta$$^{18}$ O-$\delta$$_2$H data for monthly sampled groundwaters showed distinctive clusters, implying that groundwater was originated from independent precipitation, and subsequently recharged very fash. Using$\delta$$^{15}$ N-NO$_3$ data, major sources of nitrate and its areas of influence could be identified. The areas under influence of livestock farms showed relatively high NO$_3$-N concentrations and$\delta$$^{15}$ N values higher than 5$\textperthousand$. The agricultural areas in southeastern part showed very high concentrations of NO$_3$-N with the $\delta$$^{15}$ N values of lower than 5$\textperthousand$.

• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.44-50
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• 1985

Effect of nitrogen sources on mycelial growth and sclerotial formation of Rhizoctonia solani causing rice sheath blight was studied by using sixty isolates from diseased samples of different localities in Chungbuk area. Based on the cultural characters, pathogenicity and sclerotial formation, three isolates of the fungus were selected. The virulence of the three isolates varied based on the percent of seeds germination, seedling blights and length and lesion number of lesions. As nitrogen sources, arginine, alanine, urea, ammonium sulfate and sodium nitrate were more effective for mycelial growth and sclerotial formation, than were cystine, methionine, lysine, histidine, tryptophan and thyrosine. The mycelium of R. so/ani grew well in a lower concentration of urea, sodium nitrate, arginine, ammonium sulfate and lysine, but in a higher concentration of proline, histidine, and alanine. In all nitrogen sources tested, high concentration of nitrogen nutrients greatly stimulated sclerotial formation of the fungus. Arginine, urea, and ammonium sulfate increased virulence of the fungus. All the isolates grown on the basic medium plus proline produced large sclerotia. Mycelial growth of the fungus was not well in the tryptophan-added medium, showing brown discoloration of medium.

• Korean Journal of Environmental Agriculture
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• v.15 no.2
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• pp.232-238
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• 1996

This study was conducted to find out the optimum condition for $NH_4-N$ removal from wastewater by a zeolite column. The removal efficiency of $NH_4-N$ by a glass column packed with decreased with the increase in initial concentration, percolation velocity and fraction number. The result of multiple stepwise regressions, $NH_4-N$ removal efficiency by the zeolite column showed a high correlationship with various parameters such as percolation velocity, initial concentration, adsorption amount and fraction number. Theoretical formula by parameter coefficients of multiple stepwise regression was found to be $NH_4-N$ removal $efficiency=0.620{\times}amount$ of zeolite $-0.456{\times}percolation$ velocity $-0.212{\times}initial$ concentration $-3.038{\times}fraction$ number+100.1 In the case of the $NH_4-N$ removal efficiency in cattle farming wastewater, the experimental data were nearly coincident with the theoretical formula.