• 한국지반환경공학회 논문집
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• 제7권4호
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• pp.63-71
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• 2006

본 연구에서는 공기주입 방식과 공기주입 시간이 매립지가스 안정화에 미치는 영향을 평가하고 매립지굴착사업 진행시 굴착작업 시간을 판단하고자 실시하였다. 간헐주입의 경우 혐기성에서 호기성으로의 전환되는데 연속주입보다 8배 정도 긴 시간이 소요되어 매립지굴착사업과 같이 혐기성 가스를 빠른 시간 내에 호기성 가스로 치환하여 굴착작업을 수행해야 하는 경우에는 연속주입이 더 적합할 것으로 판단되었다. $0.2m^3/min$ 유량으로 공기를 연속주입한 후 중단하였을 때 공기주입 시간과 호기성 조건($CH_4$ < 5%)이 유지되는 시간과는 비교적 높은 상관도($r^2$ = 0.95)를 나타내고 있었다. 공기주입 시간을 1이라고 볼 때 공기주입 중단 후 호기성은 약 1.5배 정도의 긴 기간 동안 유지되고 있었다.

• 상하수도학회지
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• 제32권1호
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• pp.11-18
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• 2018

As the sequencing batch reactor process is a time-oriented system, it has advantages of the flexibility in operation for the biological nutrient removal. Because the sequencing batch reactor is operated in a batch system, respiration rate is more sensitive and obvious than in a continuous system. The variation of respiration rate in the process well represented the characteristics of biological reactions, especially nitrification. The respiration rate dropped rapidly and greatly with the completion of nitrification, and the maximum respiration rate of nitrification showed the activity of nitrifiers. This study suggested a strategy to control the aeration of the sequencing batch reactor based on respirometry. Aeration time of the optimal aerobic period required for nitrification was daily adjusted according to the dynamics of respiration rate. The aeration time was mainly correlated with influent nitrogen loadings. The anoxic period was extended through aeration control facilitating a longer endogenous denitrification reaction time. By respirometric aeration control in the sequencing batch reactor, energy saving and process performance improvement could be achieved.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.777-783
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• 2000

Composting by negative aeration is a reasonable proposition to control odor generated during composting process. Cattle manure and rice hulls mixtures were composted in a bin composting system by negative aeration. Continuous(CA) and intermittent(IA) aeration methods were applied to analyze the composting characteristics. The composting temperature and the ammonia emission during composting were investigated according to the aeration methods. The main problem for the negative aeration was the generation of condensate in the suction line of blower. The quantity of condensate was significant for continuous aeration. The aeration method should be modified to escape from the cooling effect of continuous aeration at the initial stage of composting. It took a longer time to finish a composting for intermittent aeration on account of lower aeration. It was concluded that the composting by negative aeration could be accomplished by either continuous or intermittent aeration method if the flow rate would be controlled more efficiently and the water vapor in suction line of blower could be removed effectively. Ammonia emission increased up to maximum value of 675ppm for continuous aeration while 300ppm for intermittent aeration. However, the cumulative value of ammonia emission was larger for intermittent aeration than for continuous aeration.

• 한국식품과학회지
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• 제51권6호
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• pp.576-583
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• 2019

본 연구에서는 aeration 공정을 거친 홍삼 추출액의 유효성분 함량을 확인하고 항산화 활성에 미치는 영향을 알아보고자 하였다. Aeration 처리 유무에 따른 추출액의 색상 변화에서는 aeration 공정처리를 하지 않은 추출액과 aeration 공정처리 한 추출액 모두 추출시간이 경과함에 따라서 L값과 b값이 유의적으로 감소하였고, aeration 공정 처리 36시간 추출액에서 명도와 황색도가 가장 낮은 결과를 얻었다. a값은 non-aeration 처리에서는 추출시간이 경과함에 따라서 증가하였으나 aeration 처리할 경우에는 적색도가 감소되는 것을 확인할 수 있었다. 이와 같은 결과는 aeration 공정 처리를 할 경우에는 추출시간이 경과함에 따라 명도, 황색도, 적색도 모두가 감소되면서 갈색도가 증가하는 것을 의미하는 결과라고 할 수 있다. 총 폴리페놀 함량에서 non-aeration 홍삼추출액은 추출시간에 따라 0.62, 0.67, 0.72, 0.79 mg GAE/mL로 나타났으며 aeration 공정을 거친 추출액은 0.62, 0.70, 0.84, 0.96 mg GAE/mL로 추출시간에 따라 유의적으로 크게 증가하는 것을 확인하였다. 또한, 총 플라보노이드 함량은 aeration 공정을 거친 24, 36시간 추출액에서 21.77, 21.93 mg GAE/mL의 최고의 함량을 나타내었다. DPPH 라디칼 소거활성은 non-aeration 홍삼 추출액은 80.50-82.00% 범위에서 확인되었으며 aeration 공정을 거친 홍삼 추출액의 라디칼 소거능은 추출 시간에 따라 82.10, 81.90, 87.30, 87.10%로 나타났다. 이는 DPPH 라디칼 소거활성이 aeration 공정을 거침에 따라 활성이 증가한다는 것을 시사하는 결과이다. ABTS 라디칼 소거능은 24, 36시간에서 non-aeration 추출액이 96.80, 77.60%로 라디칼 소거활성이 떨어졌으나 aeration 공정을 거친 홍삼 추출액은 70.86, 98.60%로 추출 시간에 따라 유의적으로 소거활성이 증가하는 것으로 나타났다. 또한 10, 12, 24, 36시간 동안 aeration 공정을 거친 홍삼 추출액은 65.40, 65.03, 65.61, 63.26%의 hydrogen peroxidase 소거율을 보였고, 또한 0.87, 0.99, 1.04, 0.99로 환원력이 유의적으로 증가하는 것을 확인하였다. 이러한 결과들은 DPPH, ABTS의 경향과 유사하게 aeration 공정을 거침으로서 non-aeration보다 항산화능이 우수하다는 것을 나타냈다. Aeration 공정을 처리한 홍삼추출액으로부터 얻어진 진세노사이드의 함량은 non-aeration과 비교 했을 때 Rg3에서 현저히 차이가 나며, 저분자 진세노사이드 Rg3의 함량이 aeration 공정을 처리한 홍삼추출액에서 166.55, 219.71, 526.67, 581.13 ㎍/mL로 non-aeration 보다 많은 양이 생성되는 것을 확인 할 수 있었다. 이러한 결과들은 aeration 공정을 거친 홍삼추출액이 전반적으로 우수한 항산화 활성을 나타내었으며 향후 특정유효성분을 강화시킬 수 있는 새로운 공정방법으로 활용될 수 있을 것이라 사료된다.

• 상하수도학회지
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• 제33권6호
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• pp.481-489
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• 2019

As aeration is an energy-intensive process, its control has become more important to save energy and to meet strict effluent limits. In this study, predictive aeration control based on the respirometric method has been applied to the sequencing batch reactor (SBR) process. The variation of the respiration rate by nitrification was great and obvious, so it could be a very useful parameter for the predictive aeration control. The maximum respiration rate due to nitrification was about 60 mg O₂/L·h and the maximum specific nitrification rate was about 7.5 mg N/g MLVSS·h. The aeration time of the following cycle of the SBR was daily adjusted in proportion to that which was previously determined based on the sudden decrease of respiration rate at the end of nitrification in the respirometer. The aeration time required for nitrification could be effectively predicted and it was closely related to influent nitrogen loadings. By the predictive aeration control the aerobic period of the SBR has been optimized, and energy saving and enhanced nitrogen removal could be obtained.

• KSBB Journal
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• 제25권2호
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• pp.187-192
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• 2010

S. cerevisiae ATCC 24858을 이용한 ethanol 생산에서, aeration 효과를 ethanol 수율, specific ethanol production rate, ethanol 생산성 측면에서 분석하여, 반복 유가식 공정전략을 설계하였다. Ethanol 수율과 ethanol 생산성은 공기를 0.33 vvm 넣었을 때, 공기를 넣지 않고 배양한 것에 비하여 더 큰 값을 보였고, 24시간 마다 배지를 교체한 배양이 36시간 마다 배지를 교체한 배양 보다 더 큰 값을 보였다. 총 ethanol 생산량 값이 가장 큰 경우는 0.33 vvm의 공기를 넣고, 배지를 24시간마다 완전히 갈아주었을 때이고, 이때 가장 많은 703.8 g의 ethanol이 생산되었다.

• 한국환경보건학회지
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• 제31권2호
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• pp.152-159
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• 2005

Laboratory scale experiments were conducted to study the applicability, and to compare the performance of two types of sequencing batch reactor (SBR)systems, a conventional SBR and sequencing batch biofilm reactor (SBBR) on the biological nitrogen and phosphorus removal. The nitrification rate in SaR was higher than that in SBBR both in high influent TOC concentration. The denitrification was completed at the first non-aeration period in SBR, however, the additional non-aeration period should be installed or the first aeration period should be extended more in order to complete the nitrogen removal in SBBR. The time at the first aeration period was more needed as about 4-5 h in order to uptake all the released $PO_4^{3-}\;-P$ at the first non-aeration period. SBBR needed more operation time, especially the first aeration time, than SBR at the high influent TOC concentration in order to complete nitrogen and phosphorus removal.

• 한국농공학회지
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• 제42권
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• pp.61-67
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• 2000

Composting of hog manure amended with sawdust trials lasted three weeks and used pilot-scale in bin composting system. Results showed that the rise temperature and carbon dioxide evolution in compost during the composting decomposition process were affected by the aeration method, pH, C/N, moisture content, bulk density and particle size distribution. No significant differences existed in biophysical properties of the composit produced from the continuous and intermittent aeration method. The intermittent aeration was very successful in compost odor control and required less time to reach stability than the continuous aeration.

• 한국환경과학회지
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• 제12권10호
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• pp.1095-1100
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• 2003

In this study, it was performed using submerged nonwoven bioreactor(SNBR) for removal of organic matter, nitrogen and phosphate under different aeration intervals(intermittent aeration). We applied the SNBR at the cheap nonwoven fiber module instead of the expensive membrane. The SUBR was mainly made up of an activated sludge reactor and a transverse flow nonwoven module, with an innovative configuration being in application between them. In case of sewage, the aeration conditions experimented consist of continuous aeration and 60min/60min, 120min/60min, 120min/120min of aeration/nonaeration time intervals, respectively. In case of landfill leachate, the intermittent aeration condition was 120min/120min at aeration/nonaeration. Consequently, a high COD removal rate (about 94%) was achieved in sewage and leachate. Although nutrient removal rate was relatively high without any additional chemicals.

• 한국물환경학회지
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• 제20권3호
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• pp.269-274
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• 2004

The performance of a newly designed wastewater treatment process equipped with an anaerobic and two intermittent aeration tanks operated alternately was investigated. During the experimental period, several types of cyclic operating schedules with different aeration and non aeration time were examined for the optimization. At all modes, the removals of organic matter and SS were highly achieved. With respect to T-N removal, however, the cycle length for aeration on/off affected the efficiencies. At the optimal operating mode, the ORP bending point indicating the disappearance of nitrate was observed. Considering the influent wastewater characteristics and cyclic operating schedules, it can be suggested that T-P removal is much more BOD/T-P ratio and/or its load dependant rather than the aeration on/off time. The results obtained from pilot-scale test showed the competitive advantage of this alternating process through an omission of nitrate recycle and operational flexibility against influent load variations when comparing with other continuous flow processes.