• 제목/요약/키워드: dissolved oxygen

검색결과 1,380건 처리시간 0.026초

생물학적 수처리에 있어서 미생물 탈수소효소 활성도 측정에 관한 연구 (A Study on the Measurement of Microbial Dehyrogenase Activity in Biological Treatment)

  • 어경해;남상호
    • 한국환경보건학회지
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    • 제15권2호
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    • pp.41-49
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    • 1989
  • The assay on microbial dehydrogenase activity by using TTC was investigated. The experimental results are summarized as follows: 1. The TF production was affected by dissolved oxygen. Dissolved oxygen in samples could be effectively removed by adding $Na_{2}SO_{3}$ as reductant prior to incubation. 2. The toxic effect on TF formation was observed at up to 0.1% of final TTC concentration when VSS concentration was 2.7g/l. As the VSS concentration increased the effect decreased. 3. It was clearly revealed that the TF generation rate decreased with increasing VSS concentration. The dilution of sludge could be applicable when VSS level is below 3.5g/l. 4. The TF production of endogenous phase (De) could be used as a measure for the viable fraction of sludge over various sludge ages. The additional TF production (Ds) due to extracellular substrate responded to De, not to VSS concentration.

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Monascus sp. 의 적색색소생성에 대한 용존산소량의 영향

  • 박노환;성문수;오영숙;정욱진
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 춘계학술발표대회
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    • pp.267-270
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    • 2000
  • 이차대사산물의 생산에 영향을 미치는 인자 중 통기성의 조절을 통한 Monascus 적색색소의 생산을 증가 시켰다. 높은 산소공급조절은 균체량을 증가 시켰으며, 낮은 산소공급조절은 고농도의 적색색소를 생산하였다. 따라서, 산소 공급량의 조절을 통하여 적색색소 생합성 과정을 활성화 시킬 수 있다.

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전이함수잡음모형에 의한 공주지점의 용존산소 예측 (Forecasting of Dissolved Oxygen at Kongju Station using a Transfer Function Noise Model)

  • 류병로;조정석;한양수
    • 한국환경과학회지
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    • 제8권3호
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    • pp.349-354
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    • 1999
  • The transfer function was introduced to establish the prediction method for the DO concentration at the intaking point of Kongju Water Works System. In the mose cases we analyze a single time series without explicitly using information contained in the related time series. In many forecasting situations, other events will systematically influence the series to be forecasted(the dependent variables), and therefore, there is need to go beyond a univariate forecasting model. Thus, we must bulid a forecasting model that incorporates more than one time series and introduces explicitly the dynamic characteristics of the system. Such a model is called a multiple time series model or transfer function model. The purpose of this study is to develop the stochastic stream water quality model for the intaking station of Kongju city waterworks in Keum river system. The performance of the multiplicative ARIMA model and the transfer function noise model were examined through comparisons between the historical and generated monthly dissolved oxygen series. The result reveal that the transfer function noise model lead to the improved accuracy.

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Comparison with Water Quality of main Rivers in the world, based on OECD reports

  • Kambe, Junko;Aoyama, Tomoo;Nagashima, Umpei
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.935-940
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    • 2005
  • We are faced with water pollutions on a population explosion. Considering the importance, we research European rivers based on OECD reports. Observations in the reports have defects that make evaluation of environmental situations be difficult. By using interpolations in the compensation quantitative structure-activity relation ships (CQSAR), we complement the defects in the water quality of rivers through big cities. Thus, we get complete data set for dissolved oxygen, biochemical oxygen demand, and total phosphorus. Using the data set, we examine re-naturalization of the Rhein and the Donau in Germany. We investigate the effect of dams between Slovakia and Hungary, by using reconstructions of neural networks in CQSAR. The reconstructions have functions to extract a principal relation. On the investigation, we examine assertions of conservation groups. As the result, we confirm the re-naturalization is effective, and find a negative effect of the dam construction on changes of dissolved oxygens in the Hungary Donau. We investigate the Seine and the Thames, too.

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Zooplankton community distribution in shallow reservoirs during winter: Influence of environmental factors on Cyclops vicinus (Copepoda: Cyclopoida)

  • Choi, Jong-Yun;Jeong, Kwang-Seuk;Joo, Gea-Jae
    • Journal of Ecology and Environment
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    • 제37권2호
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    • pp.99-104
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    • 2014
  • We estimated the influence of environmental factors on zooplankton communities at 25 reservoirs during winter (December 2010 to January 2011). Among zooplankton groups, Cyclops vicinus is more dominant during winter, and this is positively related to withered vegetation area and dissolved oxygen level. Therefore, the presence of withered vegetation might be considered as an important factor to determine C. vicinus distribution during winter. We considered that withered vegetation might be utilized as a habitat for C. vicinus, as well as provide an attachment substrate for periphytic algae. Abundance of periphytic algae can lead to high concentration of dissolved oxygen. Although copepods prefer high water temperatures for increasing their population growth, if Cyclops can overcome low temperature stress that leads to disruption of population, their population growth initiation in the next growing season (i.e. next spring) is possibly propelled by the winter population.

Dissolved oxygen concentration regulation using auto-tuning PID controller in fermentation process

  • Hwang, Young-Bo;Lee, Seung-Chul;Chang, Ho-Nam;Chang, Yong-Keun
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.790-794
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    • 1989
  • A novel control method involving an automatic tuning of digital PID controller parameters has been developed for better regulation of DO (dissolved oxygen) concentration in batch fermentation processes. Heuristic reasoning allows the PID controller to reach improved tuning decisions based upon the supervision of certain control performance indices in the same cognitive manner as in an expert control.

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호수의 물 순환이 저니의 인 용출율에 미치는 영향 (Effects of Water Circulation on the Phosphorus Release Rate from Sediments in the Lake)

  • 김건하;정우혁;최승희
    • 한국물환경학회지
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    • 제21권6호
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    • pp.595-601
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    • 2005
  • In this research, effects of water circulation on phosphorus release from sediment into water body were studied. Sediments sampled at the Daechung Lake were used for the column experiments with circulation and non-circulation conditions. Deaeration coefficient, $K_1$ and reaeration coefficient, $K_2$ of non-circulation condition were 0.133 and 0, respectively, while $K_1$ and $K_2$ for circulation condition were 0.46 and 0.018, respectively. Oxidation Reduction Potential (ORP) showed a linear relationship with dissolved oxygen (DO) when DO is over 2 mg/L. Phosphorus concentration induced by phosphorus release from sediment was highly dependent upon DO, ORP, and pH. Under anaerobic condition, phosphorus release rate was higher for $Fe^{2+}$-bounded phosphorus compared to that of $Ca^{2+}$-bounded phosphorus.

생물학적 하수처리시스템에 적용된 Proportional, Integral 및 P-I 조절 시스템에 대한 비교 (Comparison of Proportional, Integral, and P-I Control Systems in Biological Wastewater Treatment Plants)

  • 김성표
    • 한국물환경학회지
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    • 제21권4호
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    • pp.410-415
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    • 2005
  • The main purpose of this study is to evaluate the characteristics of three sets of traditional control methods (proportional, integral, and proportional - integral controls) through lab-scale biological reactor experiments. An increase in proportional gain ($K_c$) resulted in reduced dissolved oxygen (DO) offset under proportional control. An increase in integral time ($T_i$) resulted in a slower response in DO concentration with less oscillation, but took longer to get to the set point. P-I control showed more stable and efficient control of DO and airflow rates compared to either proportional control or integral control. Developed P-I control system was successfully applied to lab-scale Sequencing Batch Reactor (SBR) for treating industrial wastewater with high organic strength.

Production of Antibacterial Violet Pigment by Psychrotropic Bacterium RT102 Strain

  • Nakamura, Yoshitoshi;Asada, Chikako;Sawada, Tatsuro
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제8권1호
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    • pp.37-40
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    • 2003
  • The antibacterial action of violet pigment, a mixture of violacein and deoxyviolacein, isolated from phychrotrophic bacterium RT102 strain was examined, and the operational conditions for the effective production of violet pigment were studied. The antibacterial activity of the violet pigment was confirmed for several bacteria such as Bacillus licheniformis, Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, and Pseudomonas aeruginosa, and the high concentration of violet pigment, above about 15mg/L, caused not only growth inhibition but also death of cells. The growth properties of RT102 strain were clarified under various incubation conditions such as pH, temperature, and dissolved oxygen concentration. The maximum violet pigment concentration, i.e. 3.7 g/L, and the maximum productivity of violet pigment, i.e. 0.12 g .L$\^$-1/H$\^$-1/, were obtained in a batch culture of pH 6, 20$^{\circ}C$, and 1 mg/L of dissolved oxygen concentration.

Optimum Operation of Thermophilic Aerobic Digestion Process for Waste Activated Sludge Minimization

  • Kim, Young-Kee;Choi, Jeong-Woo
    • Journal of Microbiology and Biotechnology
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    • 제12권4호
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    • pp.683-686
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    • 2002
  • To achieve optimum operation of a thermophilic aerobic digestion (TAD) process for waste activated sludge (WAS), TAD experiments using Bacillus stearothermophilus (ATCC 31197) were carried out to investigate the optimum concentration of dissolved oxygen (DO). TAD reactors were operated at DO concentrations of 0, 1, 2, 3, 4, and 5 ppm, and the results showed that the WAS could be successfully degraded by a TAD system operated with a DO concentration of 1 ppm and above. When the TAD system with an optimum additive (2 mM Ca ion), selected from a previous study, and 1 ppm DO concentration were combined with a thermal pretreatment ($121^{\circ}C$, 10 min), the results exhibited upgraded total suspended solids and an enhanced protein degradation.