• 해양환경안전학회지
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• 제22권1호
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• pp.42-51
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• 2016

2014년 9월 동해 남서해역의 용존 영양염 분포 및 식물플랑크톤 군집구조와 우점종의 질소 화합물에 대한 이용성을 파악하였다. 용존 무기 질소(dissolved inorganic nitrogen; DIN)와 용존 무기 인(dissolved inorganic phosphorus; DIP)은 표층에서 낮고, 수심이 깊어짐에 따라 증가하였다. 반면에 용존 유기 질소(dissolved organic nitrogen; DON)와 용존 유기 인의 경우 무기태 영양염과 상반되는 분포를 보였다. DIN:DIP 비는 전체 수괴에서 약 20으로 Redfield ratio (16)보다 다소 높게 나타났지만, 혼합층의 경우 2로 식물플랑크톤의 생장에 대해 무기 질소가 제한요인으로 작용할 수 있는 것으로 보였다. 특히, 무기 질소가 제한된 혼합층에서 DON은 용존 총 질소(dissolved total nitrogen; DTN) 중 88 %를 차지하였다. 우점종 Chaetoceros debilis와 Prorocentrum minimum은 DIN 이외에 요소와 아미노산과 같은 다양한 DON을 이용하여 생장하였다. 따라서 식물플랑크톤의 DON 이용능력은 DIN이 제한된 동해에서 중요한 생존전략으로 작용할 것이다.

• 한국물환경학회지
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• 제33권4호
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• pp.409-415
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• 2017

This study aims to evaluate the effect of capping materials on blocking pollutant elution from contaminated sediment to water body. Experiments were carried out under conditions in which the elution rate was intensified artificially using compost with high concentration of organic compound and nutrient salts instead of sediments. Activated carbon (AC), modified activated carbon (MAC), P. putida immobilized activated carbon (PBAC) and effective microorganisms immobilized activated carbon (EBAC) were used as capping materials. Zeolite (ZT) and two kinds of commercially available microorganisms immobilized zeolite products (ZC, ZN) were used for comparison experiment. The elution rate of organic compound, nitrogen and phosphorus were compared with that of control experiment. The experiments were conducted for 56 days. Concentrations of chemical oxygen demand, total nitrogen, and total phosphorus were measured to use the comparison of release rate of organic compound, nitrogen and phosphorus. From the experimental results, AC based materials showed better performance to block the elution of organic compound and nitrogen than ZT based materials. Although ZT based materials were more effective than AC and PBAC to block phosphorus, MAC and EBAC showed the best performance of phosphorus elution blocking among the all candidate materials. In conclusion, EBAC is considered as the most effective capping materials, because organic compound, nitrogen and phosphorus will be degraded continuously by EM in the long term.

• 한국연초학회지
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• 제12권2호
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• pp.85-90
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• 1990

Pot experiment was conducted to find out the effect of decomposing degree of rice straw on growth characteristics of flue-cured tobacco, NC82. Tobacco growth was hindered by fresh straw of rice application. Generally, it was known that if organic matter of high Carbon/Nitrogen ratio had applied in soil, there was temporary nitrogen deficiency in plant caused by soil microorganism utilized nitrogen contained organic matter. In pot experiment, it was supposed that tobacco growth hindered by fresh straw of rice application was not nitrogen deficiency by soil microorganism, but gas toxicity by fresh straw of rice application.

• 유기물자원화
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• 제8권3호
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• pp.81-88
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• 2000

음식쓰레기, 슬러지 등과 같이 C/N비가 낮은 폐기물을 호기성으로 퇴비화하는 경우 질소 성분이 많이 손실될 수 있으며, 이는 비료성분의 손실, 악취를 비롯한 환경오염 발생 등을 유발할 수 있다. 본 연구에서는 퇴비화 공정에서 질소성 물질의 보존방법을 도출하기 위한 기초 연구로 음식쓰레기를 실험실 규모로 퇴비화하면서 일반적인 호기성 퇴비화 공정에서 일어나는 질소의 거동을 분석하였다. 음식쓰레기는 종이나 나무조각과 혼합하여 퇴비화하였으며, 질소성 물질의 거동을 평가하기 위해 퇴비시료에 포함된 암모니아, 산화성 질소, 유기성 질소를 측정하였다. 배가스로 손실되는 질소도 황산으로 흡수시켜 정량하였다. 퇴비화 반응의 활성화 여부가 유기성 질소의 무기화에 큰 영향을 미치는 것으로 조사되었다. 활성이 좋은 퇴비를 식종한 경우 반응 초기부터 유기성 질소의 무기화가 활발히 진행되어 많은 양의 질소가 손실된 반면 초기의 낮은 pH 기간이 길어지면 유기성 질소의 분해가 지연되는 것으로 나타났다. 암모니아 손실량은 주입된 공기량의 영향이 큰 것으로 판단되며, 암모니아 손실이 증가하면 퇴비의 암모니아 함량이 크게 감소하였다. 질소에 대한 물질수지 분석을 통하여 초기 질소의 28~38%가 암모니아로 전환되었으며, 전환된 암모니아의 77~94%가 가스로 손실된 것으로 나타났다.

• 멤브레인
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• 제7권1호
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• pp.22-30
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• 1997

Porous asymmetric membranes were prepared from polyetherimide polymer by the phase-inversion technique under different conditions. The performance of the membranes was tested for the removal of acetone vapour from nitrogen. A membrane which showed a high acetone permeability and a high selectivity was chosen and tested further for the separation of different organic vapours from nitrogen. The molecular structure of organic vapours and the selectivity were correlated. A strong correlation was also found between the chromatographic retention time of the organic vapour and the selectivity. These experimental results led to the conclusion that the sorption is the factor governing the separation of volatile organic compounds from nitrogen. A membrane was also prepared by coating the surface of a porous polyetherimide membrane with silicone rubber. The performance of membranes with and without silicone rubber coating was compared.

• 한국유기농업학회지
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• 제3권1호
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• pp.87-97
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• 1994

In the edible parts of chinese cabbage, the NO-3 accumulation was higher in the outer leaves than in the inner leaves and it was higher in the leaf midrib than in the leaf blade. In Radish, it was higher in the aerial part of the root than in the underground part of root. NO-3 accumulation in edible parts of chinese cabbage of organic farming fertilized with compost 8t/10a was about 4 times higher than those of conventional farming with recommended mineral nitrogen; and was similar to those of conventional farming fertilized with twice the mineral nitrogen rate. But, NO-3 accumulation in radish of organic farming with 8t/10a compost was lower than those of conventional farming with recommended mineral nitrogen. It showed NO-3 content in the edible parts of vegetables should be considered one of several parpmeters to judge a real safety vegetable to be certified by government.

• 상하수도학회지
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• 제21권3호
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• pp.295-303
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• 2007

Nitrogen compounds in municipal wastewater can be divided into biodegradable and nonbiodegradable fractions with biodegradability. Biodegradable nitrogen compounds can be removed through biological nitrification and denitrification processes, and nonbiodegradable nitrogen compounds affect the effluent quality of biological nutrient removal processes. The amount of nitrifiable nitrogen compounds, which are the sum of ammonia and biodegradable organic nitrogen, has been estimated by respirometry. Respirometry shows good estimation of the concentration of nitrifiable nitrogen when a synthetic sample of ammonium chloride is dosed. The estimated concentration of nitrifiable nitrogen compounds in municipal wastewater is close to ammonia concentration in municipal wastewater, but it is lower than that for the synthetic sample. If nitrogen assimilated into cell synthesis of nitrifiers and heterotrophs is considered, the total amounts of nitrifiable nitrogen compounds, which are nitrified and assimilated, could be more accurately estimated. The concentration of nitrifiable nitrogen compounds, which are biodegradable, is about 31 mg N/l, and this is 119% of ammonia and 94% of total nitrogen. Ammonia, nitrate, biodegradable organic nitrogen, and nonbiodegradable nitrogen are about 79%, 1%, 15%, and 5% of the total nitrogen in municipal wastewater, respectively.

• 한국유기농업학회지
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• 제13권2호
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• pp.211-221
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• 2005

This experiment was conducted to evaluate the effect of animal slurry on nitrogen uptake of hairy vetch and growth of chinese cabbage in cropping system. Hairy vetch was seeded on September 20 in 2003 . We examined the effect of cover crop(hairy vetch (Vicia villosa Roth) and slurry application(0, l00, 200kg N/ha) on yield and N uptake. Dry matter yield and nitrogen uptake of hairy vetch were measured. The chinese cabbage succeeding cover crop was harvested in 2004. The nitrogen uptake of hairy vetch was 84, 121, 148kg N/ha respectively, when the slurry application was 0, 100 and 200kg N/ha. In addition. N uptake of hairy vetch at the plot of 100kg and 200 kg N/ha slurry were 44% and 76% higher than that of the plot without slurry application respectively. Slurry application of hairy vetch could increase nitrogen uptake by application of green manure at the harvesting time. the content of organic matter and P-content of soil with hairy vetch plot was higher than that of fallow plot due to inhibition of soil erosion. The organic matter levels tend to improve with the addition of hairy vetch. Hairy vetch could improve soil quality by reducing erosion compared with bare fallow. The green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage. The hairy vetch residues decomposed rapidly releasing half of their residues within 40 days after burial. The yield of chinese cabbage was 90% in the plot of manure of hairy vetch compared with chemical fertilizer. The yield in the plot treated with green manure of hairy vetch and 50% of chemical fertilizer was reduced 5% less than that of chemical fertilizer. Therefore, it was estimated that the green manure of hairy vetch-chinese cabbage cropping system could reduce nitrogen chemical fertilizer as much as 84~148kgN/ha. the green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage.

• 미생물학회지
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• 제11권2호
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• pp.51-58
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• 1973

Three kinds of organic matter such as glucose, oxalic acid, and ethanol were added to the media(N-free or $NO_{3}$-riched) and their effects on the nitrogen fixation of Nostoc pruniforme were measured by manometric technique through the experiments in vivo. 1) The organic matters used in this experiments showed effective results as a role of substrate for the fixation of atmospheric nitrogen. 2) In the nitrogen-free medium treated with the both of flucose nad ethanol, the highest nitrogen uptakes were detected in the treated of low concentrations (glucose ; 0.1%, 0.5%, ethanol : 0.1%, 0.5%). On the contrary, the highest nitrogen uptakes in $NO_{3}$-riched medium were measured at the treated of high concentrations (glucose ; 2%, 1%, ethanol ; 1.5%, 1.0%). 3) The highest nitrogen uptakes in N-free medium treated with oxalic acid were measured at the concentration of 2% and 1%, respectively. In the medium of $NO_{3}$-riched, the nitrogen uptakes were in the opposite directions.

• 한국유기농업학회지
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• 제15권4호
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• pp.399-411
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• 2007

Korean organic farming has been well developed over the last two decades. It demonstrates that the number of certificated farm for organic agriculture and products have been drastically increased in recent year. However, the organic farmers have thought that organic farming rely only on organic fertilizer and they don't keep organic farming principle in which organic farmer should enhance biological activity and crop rotation. This study was to compare nutrient input, recommendation, cropping system and organic product circulation between the early $20^{th}$ century and beginning of the $21^{st}$ century. The population of Korea has increased 7.3 times more than that of a century ago but cultivated land has been decreased during 100 years. The rice production in 2002 was 4.2 times higher than that of production in 1912. The input of N, P and K in 1907 on the basis of King's suggestion was 95.6kg/ha, 15.9kg/ha and 3.0kg/ha, respectively. Nitrogen came from excreta (40%), green manure (55%) and compost (5%) in the early 20th century. On the other hand, organic farmer input organic resources such as wood chip (30.1%), compost (27.8%), rice straw (14%) and others (25%) these days. In terms of nutrient balance calculated nutrient and absorption by plants, organic rice farmer apply excessive nitrogen and phosphorus to the soil. They was used to put $7{\sim}10$ times more nitrogen than that of a century ago. Nutrient recommendation was similar in N and P between early 20th century and early $21^{st}$ century. Farmers in both century did not rotate crops in the field. Today, organic farmers engaged in more continuous cultivation than in early 20th century. Farmers in the early $20^{th}$ century produced locally, consumed locally the agricultural products, but organic farmers in the $21^{st}$ century produce the organic product in the local farmland and consumed in the large city and also a lot of foreign organic products have been imported in recent year.