• Membrane and Water Treatment
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• 제11권5호
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• pp.345-351
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• 2020

Eutrophication of surface waters is commonly caused by excessive inputs of nutrients such as nitrogen and phosphorus. Nakdong River basin was chosen as the study area to investigate the effect of point and non-point source pollution of nitrogen on eutrophication in water body. Non-point source inputs of nitrogen accounted for approximately 84% in the total nitrogen input of the upper Nakdong river watershed, which mainly consists of agricultural land and forests. However, point source inputs of nitrogen accounted for 58~85% in the total nitrogen input of the middle and lower watersheds, including urban area. Therefore, for watershed near urban area, control of point source inputs of nitrogen may be an optimal method to control eutrophication. In this respect, the enforcing reduction of nitrogen in the final effluent of wastewater treatment facilities is needed. On the other hand, to enact more stringent nitrogen regulations, the LOT (limit of technology) and environmental impact should be considered. In this study nitrogen data were analyzed to propose new nitrogen regulations.

• 한국환경보건학회지
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• 제28권5호
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• pp.1-3
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• 2002

This study was to evaluate on the removal efficiencies of total nitrogen and phosphorus in municipal wastewater at MUNR process using sludge carbon source for environmental micro-organism. The removal efficiencies of total suspended solid were 85.9~91％, total nitrogen were 38.6~87.2％ and total phosphorus were 30.8~39.0％, respectively. It was shown that removal efficiency of nitrogen was effectively influenced by sludge carbon source treated with ultrasonication. The removal efficiency of total phosphorus was low because the sludge was not wasted during this treatment.

• 한국환경보건학회지
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• 제28권1호
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• pp.93-97
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• 2002

The aim of this study was to evaluate on the removal effect of total nitrogen and phosphorus with municipal wastewater in ultrasonic nutrient removal (UNR) process using ultrasonic sludge carbon source. The removal efficiency for total nitrogen was 44.2% at biological nutrient removal (BNR) process, 50.8% at UNR process. The removal efficiency for total phosphorus was 45.6% at BNR process, 46.2% at UNR process. The removal of nitrogen was effectively influenced by ultrasonic sludge carbon source.

• 한국균학회지
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• 제41권3호
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• pp.149-159
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• 2013

국내 산림에서 수집한 외생균근균(13속 42균주)을 질소원이 서로 다른 4종류의 시험배지에 접종하고 56일간 순수 배양하여 질소원 요구성과 선호도를 조사하였다. 그 결과, 일본연지그물버섯(KFRI 1224), 비단그물버섯(KFRI 1232), 끈적쓴맛그물버섯(KFRI 1383), 젖비단그물버섯(KFRI 1997), 알버섯류(KFRI 1434) 등이 질소원 요구성이 높은 것으로 조사되었다. 검은머리그물버섯(KFRI 1362)을 비롯하여 총 시험균주의 45%는 질산염보다 암모늄 형태의 무기질소원을 더 선호하였다. 반면 큰비단그물버섯(KFRI 1125)을 비롯한 총 시험균주의 36%는 질산염 형태의 무기질소원을 더 선호하였다.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.979-985
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• 2002

The possibility of microalgal nitrogen treatment was tested in wastewaters with a low carbon/nitrogen (C/N) ratio. Chlorella kessleri was cultured in the two different artificial wastewaters with nitrate as a nitrogen source: one contained glucose for an organic carbon source and the other without organic carbon sources. The growth rates of the two cultures were almost identical when the aeration rate was over 1 vvm. These results suggest that microalgae could successfully remove nitrogen from wastewater, as far as the mass transfer of $CO_2$, was not limited. Nitrate was successfully reduced to below 2 mg $NO_3^-$-N/ml from the initial nitrate concentration of 140 mg $NO_3^-$-N/ml in 10 days, even in the wastewater with no organic carbon source. Similar results were obtained when ammonium was used as the sole nitrogen source instead of nitrate. Higher concentrations of nitrogen of 140, 280, 560 and 1,400 mg/ml were also tested and similar amounts of nitrogen were removed by algal cultures without showing any substrate inhibition.

• Journal of the Korean Wood Science and Technology
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• 제38권2호
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• pp.124-134
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• 2010

This study was performed to evaluate the efficiency of using softwood as the sawdust medium for Lentinula edodes cultivation, effect of nutrient on the mycelial growth, spawning, the mushroom yield, and quality. The nitrogen nutrition significantly enhanced the mycelial growth of L. edodes. The glutamic acid in the L. leptolepis and P. koraiensis, and asparagine in the P. densiflora were appeared to slight increase in the mycelial growth. The vegetable oil showed very effective on the mycelial growth in the P. koraiensis sawdust medium. Carbon/nitrogen ratio of all the test was reduced after mycelial growth. The mycelial growth was exclusively dependent on reduction of carbon. The mushroom yield (32.7%) of the P. densiflora sawdust medium (carbon source: 3% active carbon, nitrogen source: 0.4% asparagines) was the best in mushroom production of L. edodes, followed by the Q. variabilis sawdust (35.4%) of the control medium. The diameter of mushroom cap was obtained from the P. densiflora sawdust (carbon source: 3% sucrose, nitrogen source: 0.4% potassium nitrate) and P. koraiensis sawdust (carbon source: 3% sucrose, nitrogen source: 0.4% potassium nitrate), and the P. koraiensis sawdust (carbon source: 3% xylose, nitrogen source: 0.4% glutamic acid, supplement: 0.05% amino acid), with values 71.5 mm, 71.5 mm and 72.1 mm, respectively. In the polypropylene bag cultivation, the weight losses of the block medium gradually increased for 80 days in the dark (13.8~16.8%) and then became stable in the range of 20.7~25.8%.

• KSBB Journal
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• 제11권4호
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• pp.497-503
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• 1996

본 연구에서는 질소원의 종류와 농도 그리고 pH가 플루란 생산에 미치는 영향을 고찰하였다. A Aureobasidium pullulans에 의한 플루란 생산시 가장 좋은 질소원으로는 수율 62%를 얻은 peptone 이었고, 최적 질소원 농도는 유기질소원의 경우 탄 소원/질소의 비가 50j0.15N이었고 그 이상에서는 저해가 일어났다. 훈합질소원 I, II, III을 사용하 였을 때 각각 29.1, 27.4, 26.5g/L의 플루란 생산량 을 보였다. 그러므로, 혼합 질소원을 잘 이용하면 플 루란을 효과적으로 생산할 수 있었다. pH를 조절하 지 않을 때가 pH를 일정하게 할 때보다는 플루란 수율이 높았다. 또, 유가식배양시 탄소원과 질소원을 함께 공급하였을 때가 질소원만을 공급하였을 때 더 큰 플루란 수율을 보였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.279-281
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• 2003

This study is intended to give information on agricultural nonpoint source pollution and transport related to fertilizer application and irrigation practice. Field-simulated soil columns were set up and leaching studies on fertilizer components such as nitrogen and phosphorus were performed. Nitrogen and phosphorus in the leachate showed different trends in each column and nonpoint source pollution in agricultural areas may be expected to depend on planted crops, soil conditions, and climate as well as irrigation and fertilizing management.

• 한국미생물·생명공학회지
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• 제1권1호
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• pp.3-11
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• 1973

The biochemical characteristics of Astradix -P, isolated from Astragalus membranaceus Bunge as yeaststatic substance, were reported on a previous paper. And on this report, some relation to the nitrogen metabolism of yeast was studied. Inorganic or organic source of nitrogen easily uptaking yeast did not show any antagonistic action to the inhibitory action of Astradix -P on the yeast growth. Especially an organic nitrogen source, arginine, histidine and lysine, classified to basic amino acid, was reacted as an antagonistic substance to the sample. But, ornithine, a basic amino acid, did not show any antagonistic action to the sample. In the mixed media containing neutral and acidic amino acids as a nitrogen source, yeast growth was inhibited strongly. If the basic amino acid was added to the same mixed media, the yeast growth was not inhibited by Astradix-P therefore, the antagonistic action of basic amino acid to the Astradix-p was readily observed. The yeast static action of Astradix-P was partially related to the isoelectric point of amino acid as a nitrogen source. Yeast cells which propagated under the media containing growth inhibitor, Astradix -p, did not bring any remarkable denaturation of cell structure by electro-microscopic observation.

• KSBB Journal
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• 제6권4호
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• pp.369-377
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• 1991

Xanthomonas Campestris에 의한 Xanthan gum 생산에서 질소원의 영향에 관한 연구 결과를 요약하면 아래와 같다. Sodium glutamate를 질소원으로 채용한 xanthan gum 생산발효에서 세포 생산량에 대한 생산물 생성량, 세포 생산량에 대한 탄소원 소비량은 초기질소농도에 독립적이었다. 0.4-1.0g/L의 $S_o$범위에서 $B_s$와 ${\beta}_s$는 상수를 보였고 sodium glutamate질소원과 peptone질소원 사이에서 질소원 차이에 따른 차이는 없었다. Xanthan gum생산수율은 탄소/질소농도가 10-16일 때 최대값을 보였다. Peptone질소원은 sodium glutamate질소원보다 세포 성장에 더 효율적이다. Peptone만을 질소원으로 사용한 발효와 혼합질소원을 질소원으로 사용한 발효가 생산물 생산수율 및 발효시간이 유사하므로 xanthan gum생산시 혼합질소원을 질소원으로 사용할 경우 xanthan생산원가를 절감할 수 있다.