• 한국환경보건학회지
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• 제35권1호
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• pp.64-70
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• 2009

The aims of this study is to examine the effects of the changes in HRT(Hydraulic Retention Time) and media charge in a water-mill, among other operation factors, on the nitrogen and phosphorus removal in order to use up-flow anaerobic reactors, anoxic reactors and water-mill aerobic reactors for sewage treatment. The extension of HRT improved the nitrogen removal efficiency, however the removal pattern was constant regardless of HRT. The removal of phosphorus was constant (80%-90%) regardless of the change in HRT. The removal rate with change in influx load varied such that at the OLR (Organic Load Rate) of 1-3 kg/d, the T-N removal efficiency was 80.7%-88.9% and the T-P removal efficiency was 82.9%-89.3% while at the NLR (Nitrogen Loading Rate) of 0.108-0.156 kg/d the removal efficiencies were 80.7-88.9% (T-N) and 82.9-89.3% (T-P). The analyses of the nitrogen and phosphorous removal characteristics with the C/N and C/P ratio showed that the mean T-N removal rate was 88% at the C/N ratio of 1.2-2.6, and that the mean T-P removal rate was 86% at the C/P ratio of 7.2-14.1. Also, the analysis of nitrogen and phosphorous removal characteristics were analyzed in relation to media charge. The comparison between with and without media charge in the water-mill showed that while the nitrogen removal efficiencies were 86-94% and 85-89% respectively, the difference of phosphorous removal efficiencies were between the two conditions was not significant, thus it suggested that the media charge has less effect on the removal efficiency of phosphorous compared to that of nitrogen.

• Asian-Australasian Journal of Animal Sciences
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• 제21권3호
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• pp.434-442
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• 2008

The objective of this study was to determine the optimum ratio of methionine to methionine plus cystine for growing pigs. A nitrogen balance trial was conducted using a total of 21 barrows (Large WhiteLandrace) over two replicates. The initial body weight was $20.36{\pm}1.22kg$ (mean${\pm}$SD) in the first replicate and $23.54{\pm}1.02kg$ (mean${\pm}$SD) in the second. For each replicate, the 21 pigs were randomly assigned to one of seven dietary treatments with three observations per treatment. The diets included a methionine and cystine-deficient basal diet with all other essential nutrients meeting nutrient requirements and six diets formulated with graded levels of DL-methionine (0.00, 0.03, 0.06, 0.10, 0.13, 0.16%) and $L-Cystine{\cdot}HCl{\cdot}H_2O$ (0.19, 0.15, 0.11, 0.07, 0.04, 0.00%). This resulted in ratios of methionine to methionine plus cystine of 41.3, 29.6, 35.3, 41.2, 46.0, 51.6 and 57.5%. Each experimental period lasted 12 days consisting of a seven-day adaptation period followed by a five-day total collection of urine and feces. During the collection period, pigs were fed 900 g/day for the first replicate and 1,200 g/day for the second replicate. The feed was provided in three equal portions at 0800, 1500, and 2200 h daily. Pigs had ad libitum access to water after feeding. There was a linear (p<0.01) and quadratic (p<0.01) effect on daily gain and feed conversion as the ratio of methionine to methionine plus cystine increased. Pigs receiving the diets providing a methionine to methionine plus cystine ratio of 51.6% had the best daily gain and feed conversion. Plasma urea nitrogen was also lowest for this treatment. Nitrogen retention increased (p<0.01) as the relative proportion of methionine increased up to 51.6% and then a downward trend occurred at 57.5%. The quadratic regression model, as well as one- and two- slope regression line models, were used to determine the optimum ratio of methionine to methionine plus cystine. Eliminating the 35.3% methionine to methionine plus cystine treatment resulted in $R^2$ values in excess of 0.92. The optimal ratio of methionine to methionine plus cystine was estimated to be 54.15% for nitrogen retention and 56.72% for plasma urea nitrogen.

• 멤브레인
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• 제22권6호
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• pp.489-501
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• 2012

두 개의 간헐반응조, 막분리조, 탈기조로 구성된 생물학적 MBR고도처리 공정에 동일한 유입수량과 수질의 하수가 유입되는 경우 운전 온도 및 SRT (Sludge Retention Time)변화에 따른 질소제거 특성을 컴퓨터 시뮬레이션을 통해 파악하였다. SRT가 25일이고 운전온도가 $25^{\circ}C$인 경우 간헐반응조를 간헐폭기 시키는 경우에 운전온도 $13^{\circ}C$의 59%에서 31%로 질소제거효율이 급격히 떨어지는데, 이는 운전온도 $13^{\circ}C$에 비해서 간헐반응조의 RBO (Readily Biodegradable Organic) 농도가 낮아져서 발생한 현상으로 파악되었다. 운전온도 $25^{\circ}C$에서 SRT를 12.6일로 운전하는 경우 간헐반응조 RBO농도는 증가하고 질소제거 효율은 회복되었다. 간헐반응조를 갖는 MBR시스템에서 SRT와 운전온도가 간헐반응조 RBO농도에 미치는 영향은 좀더 깊게 연구되어야 한다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.785-790
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• 2000

The effect of formaldehyde treatment of solvent and mechanical extracted cottonseed meal on the performance, digestibility and nitrogen balance was assessed in lambs. Four total mixed rations viz., A, B, C and D containing 40% untreated and treated solvent and mechanical extracted meal were prepared. Sixteen male lambs with average BW of 20-22 kg were randomly allocated to experimental rations and were fed individually during ninety days growth trial. The treatment of solvent extracted cottonseed meal resulted in a linear decrease in ruminal protein degradation. Maximum decrease (64%) in protein degradation was observed at 4 h incubation time with 0.3% formaldehyde treatment. Highest daily BW gain was observed in lambs fed on rations Band D compared to lambs fed on rations A and C. Daily BW gain was higher on rations having 0.3% for fromaldehyde treated cottonseed meals. Higher DM digestibility was observed on ration D compared to other rations. Higher (p<0.05) CP and CF digestibility was observed on rations Band D compared to rations A and C. Nitrogen retention as % age of nitrogen intake was (p<0.05) higher for lambs fed rations B and D compared to rations A and C. Similar pattern was observed for nitrogen retention as percent of nitrogen absorbed. The present study suggested that oil extraction methods of cottonseed did not alter their meal utilization in lambs, however, formaldehyde (0.3%) treatment of meals enhanced its efficiency for growth, digestibility and nitrogen balance in lambs.

• 한국식품영양과학회지
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• 제27권1호
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• pp.132-140
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• 1998

This study aimed to verify the nutritional and curative effects of protein hydroysate and optimal ratio between protein and protein hydroysate as nitrogen source in rats with cysteamine-induced duodenal ulcer. Duodenal ulcer rat model was established by intraperitoneal injections of cysteamine. Sprague-Dawley, female rats weighing approximately 200g were intrapertionealy injected twice cysteamine(13mg/100g BW) at intervals of 3hours per day. This procedure was repeated 3 times at intervals of 3 days. Animals fed on 10% casein diet for injection periods. After last injection, 5 kinds of kiets (the ratio of casein and casein hydrolysate was 100 : 0(C100), 75 : 25(CH 25), 50 : 50(CH 50), 25 : 75(CH 75), 0 : 100(CH 100)) were given. The rate were sacrificed after feeding diet, 1, 3, 5 days. Ulcer index, hexosamine content of stomach and duodeum, gastric motility, trypsin activity, blood glutathione, plasma total protein, albumin, amino-N, urinalry urea nitrogen, creatinine, hydroxyproline and retention rate of nitrogen were analyzed for nutritional effects of diet treatments. There were no differences among diet groups in the view of the growth and diet treatments. There difference of ulcer curation by diet was appeared after 3 days. The ulcer indexes of C100 and CH 25 of 3, 5 days were significantly higher than those of CH 50, CH 75 and CH 100. This result was the same as hexosamine content of stomach, plasma protein, albumin concentration and nitrogen retention rate. The more casein hydrolysate diet had, the lower trypsin activity was. The more casein gydroysate diet had, the higher excretion of hydroxyproline was. These results show that protein hydrolysate can be applied in diet therapy for the patients with gastronitestinal ulcer. It suggests that it has curative effect of diet when nitogen sources include at least over than 50% of protein hydrolysate.

• 한국물환경학회지
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• 제39권5호
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• pp.390-395
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• 2023

The feasibility of applying the shortcut nitrogen removal process to treat livestock wastewater on individual farms was examined, and appropriate operating parameters were established. As a result,, it was determined that the nitrification reaction was carried out under 550 mg/L of ammonium nitrogen concentration, but it was less effective under conditions of high ammonia concentration. Consequently, it was confirmed that a partial injection of inflow water was necessary to minimize the effects of ammonia toxicity. Following the sequential batch reactor (SBR) operation results, it was difficult to achieve the effluent quality standard without an external carbon source. Also, selection of the appropriate hydraulic retention time was critical for the optimal SBR operation. Following the livestock farm application, with external carbon source injecting, the total nitrogen concentration in the effluent was 85.1 mg/L. This result revealed that the standard could be accomplished through a single treatment on individual livestock farms. The ratio of nitrite nitrogen to ammonia nitrogen in the effluent was verified to be suitable for implementing the anammox process with a 10 days of hydraulic retention time. This study demonstrated the potential applicability of process in the future. However, in order to apply to livestock farms, managing variations in wastewater load across individual farms and addressing reduced nitrogen oxidation efficiency during the winter season are crucial.

• 한국습지학회지
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• 제14권2호
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• pp.265-275
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• 2012

최근에 기후변화와 수질관리의 중요성이 증가하면서 습지토양의 탄소와 영양물질 보유 특성에 대한 관심이 증가되고 있다. 본 연구에서는 연안퇴적물과 인공습지, 자연습지(내륙, 하구, 갯벌)와 같이 연안퇴적물 및 다양한 유형의 습지토양에서의 유기물과 영양물질의 보유특성을 알아 보고자하였다. 또한 유기물, 영양물질, 입도에 따른 상관관계를 분석하여 이들 항목 간의 연관성을 살펴보았다. 연구 결과 유기물이나 영양물질의 보유정도가 습지의 유형에 따라 달라지는 것으로 나타났는데 내륙습지가 하구나 연안습지보다 질소의 보유 능력이 큰 것으로 나타났으며, 같은 육상생태계에서도 더 오랜 기간 동안 오염물질이 유입되고 자체적으로 유기물을 생산하여 축적하고 있는 자연습지에서 유기물과 질소의 농도가 인공습지보다 더 높은 것을 조사되었다. 연안지역의 경우 해수의 흐름이 원활한 하구나 갯벌 보다 해수의 유통이 느린 만 지역에서 유기물과 질소 농도가 높게 나타났다. 또한 화학적산소요구량은 총유기탄소 및 총질소농도와 높은 상관관계를 보여주어 화학적산소요구량 자료를 이용하여 해당 습지의 총유기탄소나 총질소 농도를 효과적으로 추정할 수 있음을 보여주었다.

• 한국축산시설환경학회지
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• 제3권2호
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• pp.97-104
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• 1997

This research was carried out to determine the effect of dietary calcium(Ca) levels(low : 0.29, medium : 0.65 and high : 1.07%) on the digestibility, excretion and retention of nitrogen(N) phosphorus (P) in pigs fed diets supplemented with phytase(750U/kg). Twelve growing-finishing pigs(average body weight: 35kg) were divided into 3 groups and these pigs were reared in metabolism cage. After 10 days adaptation period, N and P balance experiments were carried out for 4 days. The results were summarized as follows ; 1. The High-Ca group was lower than the others in digestibility of P(Low-Ca and Medium-Ca group). 2. The amount of daily excretion of urinary N were 19.6g in Low-Ca group and 16.7g in high-Ca group. The High-Ca group was the lowest(22.71%/d) in the total N excretion. 3. The High-Ca group was the highest and the Low-Ca group the lowest in fecal P excretion. The urinary P excretions per day were 1.90g in Low-Ca group and 0.04g in High-Ca group. The medium-Ca group showed the lowest total P excretion(4.57g/d). 4. The N retention of the High-Ca group(20.50g) was greater than that of the Low-Ca group and Medium-Ca(5.02)g was the highest and the Low-Ca groups(3.92g) was the lowest in the P retention. These results indicate that dietary Ca level was an important factor influencing N and P utilization in pigs.

• 한국해양학회지:바다
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• 제18권1호
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• pp.47-52
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• 2013

생태계 질소 순환 연구에서 동위원소 추적자를 이용한 실험은 그 유용성에도 불구하고, 무기 질소의 안정동위원소 측정이 어려워 자료의 생산이 활발하지 못한 형편이다. Gardner et al. (1996)은 HPLC (high performance liquid chromatography)를 이용하여 비교적 간편하고 정밀하게 암모늄의 동위원소 비를 측정하는 방법을 개발해 질소순환 연구에 활발하게 활용하였다. 그러나 일반적이지 않은 syringe 펌프가 필요해 다른 실험실에 이 시스템이 도입되지는 못하였다. 본 연구에서는 최신 HPLC 펌프 기술을 활용하여 Dr. Gardner 그룹 이후 최초로 암모늄 동위원소비 측정 시스템을 구축하였다. 표준시료 측정 결과 RTS (retention time shift)는 안정동위원소 비와 좋은 상관관계를 보였다. 이 시스템은 측정 자료를 디지털 형태로 변환하는 장치까지 갖추어 컴퓨터 프로그램을 이용한 다양한 자료처리가 가능하다. 특히 Matlab$^{(R)}$ 이용하여 retention time 계산에 peak 면적을 이용함으로써 측정의 정확성을 높이고, 직선성을 향상할 수 있었다. 영산강 하구 해수를 가지고 실시한 $^{15}N$-암모늄 첨가 실험에서 $^{15}N/^{14}N$ 비율 변화를 HPLC-RTS법을 통해 측정하였으며, 식물성 플랑크톤에 의한 암모늄 섭취와 재광물화 과정을 각각 독립적으로 측정하는 것이 가능했다.

• 한국유기농업학회지
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• 제15권2호
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• pp.195-205
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• 2007

본 연구는 흑염소의 보다 효율적인 사양관리 체계의 확립에 기여하기 위하여, 조사료와 농후사료의 비율을 각각 70:30과 30:70으로 달리 하여,이들 배합비율에 생균제를 첨가하였을 때, 흑염소의 사료 섭취량, 영양소 소화율 및 질소 축적율에 미치는 영향을 조사하기 위하여 실시하였다. 본 연구에 사용된 생균제는 Lactobacillus case, Bacillus subtilis, Saccharomyces cerevisiae, Aspergillus oryzae 및 Streptomyces griseus의 균종을 함유하는 혼합된 형태였고, 사료 내 첨가비율은 0.2%이었다. 12두의 흑염소(male)를 네 처리구로 나누어 처리구당 3두씩 완전 임의 배치하여 개별 대사케이지에 수용하였고, 실험기간은 21일간 지속되었다. 결과를 살펴보면 1일 두당 건물 섭취량은 조농비율 및 생균제의 첨가에 의하여 영향을 받지 않았다. 가소화 건물 섭취량은 사료 내 조사료 비율이 증가함에 따라 유의하게 감소하였으며(p<0.05), 생균제 첨가에 의한 효과는 나타나지 않았다. 대사체중당 건물 섭취량과 체중에 대한 건물 섭취비율은 건물 섭취량과 유사한 양상을 나타내어 조농비율 및 생균제 첨가에 의한 효과는 나타나지 않았고, 이에 따라 처리군 간에 유의한 차이가 나타나지 않았다. 영양소 소화율은 조사료 비율이 낮을수록 유의하게 높은 소화율을 나타내었고(p<0.05), 생균제 첨가에 의한 효과는 나타나지 않았다. 뇨를 통한 질소 배설은 조사료 비율이 낮을수록 유의하게 감소하였으나, 생균제 첨가 효과는 두 사료에서 공히 유의한 차이가 나타나지 않았다. 질소 축적은 조사료 비율이 증가함에 따라 감소하였고, 두 사료 내 생균제의 첨가는 질소 축적을 다소 증가시키는 경향을 나타내었다. 이상의 결과로부터, 사료 내 조농비율이 다른 두 사료에 생균제의 급여는 사료 섭취량, 영양소 소화율 및 질소 축적에 유의한 영향을 미치지 않았고, 흑염소에 대한 이들 변수는 생균제에 의한 결과라기보다는 조농비율에 의하여 지배적으로 나타나는 것으로 나타났다.