• Title, Summary, Keyword: kinetics

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Biodegradation Kinetics of Phenol and pcresol by Micrococcus sp. M1 (Micrococcus sp. M1에 의한 Phenol과 p-Creso의 생분해 Kinetics)

  • Son, Hong-Joo;Jang, Woong-Seok;Lee, Geon;Lee, Sang-Joon
    • Journal of Environmental Science International
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    • v.6 no.2
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    • pp.153-163
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    • 1997
  • In order to fad the most fitted biodegradation model, biodegradation kinetics model to the initial phenol and p-cresot concentrations were investigated and had been fitted by the linear regression. Bacteria capable of degrading p-cresol were isolated from soil by enrichment culture technique. Among them, strain Ml capable of degradillg p.rcresol has also degraded phenal and was identified as the genus Micrococcus from the results from of taxonomical studies. The optimal tonditlons for the biodegradation of phenal and p-cresol by Micrococcus sp. Ml were $NH_4NO_3$ 0.05%, pH 7.0, 3$0^{\circ}C$, respectively, and medium volume 100m1/250m1 shaking flask. iwicrococcus sp. Ml was able to grow on phenal concentration up to 14mM and p-cresol concelltration up to 0.8mM. With increasing substrate concentraction, the lag period increased, but the maximum specific growth rates decreased. The yield coefficient decreased with increasing substrate concentation. The biodegradation kinetics of phenol and p-cresol were best described by Monod with growth model for every experimented concentration. In cultivation of mixed substrate, p-cresol was degraded first and phenol was second. This result implies that p-cresol and phenol was not degraded simultaneously.

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Kinetics of water vapor adsorption by vacuum-dried jujube powder

  • Lee, Jun Ho;Zuo, Li
    • Korean Journal of Food Preservation
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    • v.24 no.4
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    • pp.505-509
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    • 2017
  • Water vapor adsorption kinetics of vacuum-dried jujube powder were investigated in temperature and relative humidity ranges of 10 to $40^{\circ}C$ and 32 to 75%, respectively. Water vapor was initially adsorbed rapidly and then reached equilibrium condition slowly. Reaction rate constant for water vapor adsorption of vacuum-dried jujube powder increased with an increase in temperature. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Good straight lines were obtained with plotting of $1/(m-m_0)$ vs. 1/t. It was found that water vapor adsorption kinetics of vacuum-dried jujube powder was accurately described by a simple empirical model, and temperature dependency of the reaction rate constant followed the Arrhenius-type equation. The activation energy ranged from 50.90 to 56.00 kJ/mol depending on relative humidity. Arrhenius kinetic parameters ($E_a$ and $k_0$) for water vapor adsorption by vacuum-dried jujube powder showed an effect between the parameters with the isokinetic temperature of 302.51 K. The information on water vapor adsorption kinetics of vacuum-dried jujube powder can be used to establish the optimum condition for storage and processing of jujube.

A Comparison of Substrate Removal Kinetics of Anaerobic Reactor systems treating Palm Oil Mill Effluent (Palm Oil Mill Effluent 처리 시 Anaerobic Hybrid Reactor의 기질 제거 Kinetics 비교)

  • Oh, Dae-Yang;Shin, Chang-Ha;Kim, Tae-Hoon;Park, Joo-Yang
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.6
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    • pp.971-979
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    • 2011
  • Palm Oil Mill Effluent (POME) is the mixed organic wastewater generated from palm oil industry. In this study, kinetic analysis with treating POME in an anaerobic hybrid reactor (AHR) was performed. Therefore, the AHR was monitored for its performances with respect to the changes of COD concentrations and hydraulic retention time (HRT). Batch tests were performed to find out the substrate removal kinetics by granular sludge from POME. Modified Stover Kincannon, First-order, Monod, Grau second-order kinetic models were used to analyze the performance of reactor. The results from the batch test indicate that the substrate removal kinetics of granular sludge is corresponds to follow Monod's theory. However, Grau second-order model were the most appropriate models for the continuous test in the AHR. The second order kinetic constant, saturation value constant, maximum substrate removal rate, and first-order kinetic constant were 2.60/day, 41.905 g/L-day, 39.683 g/L-day, and 1.25/day respectively. And the most appropriate model was Grau second-order kinetic model comparing the model prediction values and measured COD concentrations of effluent, whereas modified Stover-Kincannon model showed the lowest correlation.

Kinetics of nitrification and acrylamide biodegradation by Enterobacter aerogenes and mixed culture bacteria in sequencing batch reactor wastewater treatment systems

  • Madmanang, Romsan;Jangkorn, Siriprapha;Charoenpanich, Jittima;Sriwiriyarat, Tongchai
    • Environmental Engineering Research
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    • v.24 no.2
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    • pp.309-317
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    • 2019
  • This study evaluated the kinetics of acrylamide (AM) biodegradation by mixed culture bacteria and Enterobacter aerogenes (E. aerogenes) in sequencing batch reactor (SBR) systems with AQUASIM and linear regression. The zero-order, first-order, and Monod kinetic models were used to evaluate the kinetic parameters of both autotrophic and heterotrophic nitrifications and both AM and chemical oxygen demand (COD) removals at different AM concentrations of 100, 200, 300, and 400 mg AM/L. The results revealed that both autotrophic and heterotrophic nitrifications and both AM and COD removals followed the Monod kinetics. High AM loadings resulted in the transformation of Monod kinetics to the first-order reaction for AM and COD removals as the results of the compositions of mixed substrates and the inhibition of the free ammonia nitrogen (FAN). The kinetic parameters indicated that E. aerogenes degraded AM and COD at higher rates than mixed culture bacteria. The FAN from the AM biodegradation increased both heterotrophic and autotrophic nitrification rates at the AM concentrations of 100-300 mg AM/L. At higher AM concentrations, the FAN accumulated in the SBR system inhibited the autotrophic nitrification of mixed culture bacteria. The accumulation of intracellular polyphosphate caused the heterotrophic nitrification of E. aerogenes to follow the first-order approximation.

Removal of heavy metals in electroplating wastewater by powdered activated carbon (PAC) and sodium diethyldithiocarbamate-modified PAC

  • Kim, Tae-Kyoung;Kim, Taeyeon;Choe, Woo-Seok;Kim, Moon-Kyung;Jung, Yong-Jun;Zoh, Kyung-Duk
    • Environmental Engineering Research
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    • v.23 no.3
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    • pp.301-308
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    • 2018
  • We investigated simultaneous removal of heavy metals such as Cr, Ni, and Zn by adsorption onto powdered activated carbon (PAC) and PAC modified with sodium diethyldithiocarbamate (PAC-SDDC). Modification of PAC was confirmed by Fourier transform infrared spectroscopy and Scanning electron microscopy and energy dispersive X-ray spectroscopy. Both PAC and PAC-SDDC reached adsorption equilibrium within 48 h, and the adsorption kinetics followed a pseudo-second order reaction kinetics. The removal of metals was enhanced with increasing both adsorbent dosage and followed the descending order of Cr > Ni > Zn for PAC and Cr > Zn > Ni for PAC-SDDC, respectively. Adsorption kinetics followed pseudo-second order kinetics. Adsorption kinetic results were well fitted by the Freundlich isotherm except for Cr adsorption onto PAC. The optimum pH for heavy metal adsorption onto PAC was 5, whereas that for PAC-SDDC ranged from 7 to 9, indicating that modification of PAC with SDDC significantly enhanced heavy metal adsorption, especially under neutral and alkaline pH conditions. Our results imply that SDDC modified PAC can be applied to effectively remove heavy metals especially Cr in plating wastewaters without adjusting pH from alkaline to neutral.

Picosecond Absorption Kinetic Spectrometer with a Laser and a Streak Camera

  • Jang, Du-Jeon
    • Proceedings of the Optical Society of Korea Conference
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    • pp.172-176
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    • 1990
  • A high resolution picosecond absorption kinetic spectrometer utilizing dye emission and a streak camera is presented and compared with other methods of picosecond transient absorption measurements. Typical transient absorption and bleach recovery kinetics measured with this spectrometer are shown. Single wavelength transient absorption or ground state bleach recovery kinetics are determined on the basis of a single laser shot, so that the samples are relatively free frm decomposition by irradiation. Excellent kinetics may be obtained from the near UV to the near IR and are not subject to interference from luminescence of samples. The sensitivity of this spectrometer is very high and it is reasonably easy and convenient to set up and use.

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High Throughput Screening System for Kinetics of Brain Influx

  • Chung, Suk-Jae
    • Proceedings of the PSK Conference
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    • pp.88-89
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    • 2002
  • Traditionally, kinetics of brain influx of drugs has been evaluated by a number of experimental techniques. Brain uptake index and in situ brain perfusion study have been used for the determination of the kinetics; However, these methods generally focus on the accuracy of the uptake rate into the brain rather than the speed of the determination. In addition, application of radiolabelled substrates (e.g., $_{14}$C-labelled sucrose) further impedes the wide spread acceptance of these techniques for the application of high throughput screening system. (omitted)

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Oxidation Kinetics of Silicon by Inductively Coupled Oxygen Plasma

  • Choi, Yong-Woo;Ahn, Jin-Hyung;Kim, Sung-Chul;Ahn, Byung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.63-64
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    • 2000
  • The low-temperature Si oxidation kinetics by inductively coupled oxygen plasma has been studied. Linear rate constants had negative values when the oxide growth rate was described by linear-parabolic growth law. The analysis of transverse-optical mode frequencies and etch rates indicated that the density of surface oxide was lower than that of bulk oxide. The oxidation kinetics could be explained qualitatively by assuming a surface layer with larger diffusion coefficient and a bulk layer with smaller diffusion coefficient.

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Ergonomic Evaluation of Biomechanical Hand Function

  • Lee, Kyung-Sun;Jung, Myung-Chul
    • Safety and Health at Work
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    • v.6 no.1
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    • pp.9-17
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    • 2015
  • The human hand is a complex structure that performs various functions for activities of daily living and occupations. This paper presents a literature review on the methodologies used to evaluate hand functions from a biomechanics standpoint, including anthropometry, kinematics, kinetics, and electromyography (EMG). Anthropometry describes the dimensions and measurements of the hand. Kinematics includes hand movements and the range of motion of finger joints. Kinetics includes hand models for tendon and joint force analysis. EMG is used on hand muscles associated with hand functions and with signal-processing technology.

Function through Defects: Thermodynamic and Kinetics of Point Defects in Ionic Solids

  • Ko, Taegyung;Bang, Gyusuk;Shin, Jungmuk
    • The Korean Journal of Ceramics
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    • v.4 no.2
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    • pp.61-67
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    • 1998
  • The significance of point defects as relevant centers concerning electrochemical function is highlighted. Starting from the most simple case of dilute equilibrium bulk defect chemistry, influence of defect interaction and in particular the impact of interfaces on point defect redistribution are considered. Then recent progress in the field of kinetics in bulk and at boundaries is discussed. Finally, selected applications with emphasis on battery and sensor technology are presented.

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