Kinetics of toluene degradation in a biofilm system under denitrifying conditions

1994 ◽  
Vol 29 (10-11) ◽  
pp. 393-400 ◽  
Author(s):  
J. P. Arcangeli ◽  
E. Arvin
Keyword(s):  
Utilization Rate ◽  
Yield Coefficient ◽  
Toluene Degradation ◽  
Reducing Conditions ◽  
Nitrite Production ◽  
Half Saturation Constant ◽  
Single Compound ◽  
Kinetics Of ◽  
Variability Study ◽  
Maximum Utilization

In this paper a variability study of the kinetics of toluene biodegradation in biofilm systems under nitrate reducing conditions is presented. A total of 10 kinetic experiments were performed: 4 with toluene as a single compound and 6 with toluene in the presence of a mixture of aromatic compounds (benzene, ethylbenzene and xylenes: BEX). When toluene was the only substrate the maximum utilization rate, kx, and the half saturation constant, Ks, ranged between 1.3 to 1.8 d−1, and 0.17 and 1.7 mg/L respectively. Based on the nitrite production, the average yield coefficient was 1.0 to 1.2 mg biomass/mg toluene degraded. Furthermore, it was shown that the presence of benzene, xylenes and ethylbenzene significantly decreased the toluene removal.

scholarly journals Kinetics of Cometabolic Transformation of 4-chlorophenol and Phenol Degradation by Pseudomonas putida Cells in Batch and Biofilm Reactors

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1663
Author(s):  
Yen-Hui Lin
Keyword(s):  
Pseudomonas Putida ◽  
Specific Growth ◽  
Competitive Inhibition ◽  
Phenol Degradation ◽  
Inhibition Constant ◽  
Utilization Rate ◽  
Transformation Rate ◽  
Biofilm Reactors ◽  
Half Saturation Constant ◽  
Kinetics Of

The biodegradation kinetics of 4-chlorophenol (4-CP) and phenol and microbial growth of Pseudomonas putida (P. putida) cells were estimated in batch and biofilm reactors. The kinetic parameters of cells on phenol were determined using the Haldane formula. The maximum specific growth rate of P. putida on phenol, the half-saturation constant of phenol and the self-inhibition constant of phenol were 0.512 h−1, 78.38 mg/L and 228.5 mg/L, respectively. The yield growth of cells on phenol (YP) was 0.618 mg phenol/mg cell. The batch experimental results for the specific transformation rate of 4-CP by resting P. putida cells were fitted with Haldane kinetics to evaluate the maximum specific utilization rate of 4-CP, half-saturation constant of 4-CP, and self-inhibition constant of 4-CP, which were 0.246 h−1, 1.048 mg/L and 53.40 mg/L, respectively. The negative specific growth rates of cells on 4-CP obtained were fitted using a kinetic equation to investigate the true transformation capacity and first-order endogenous decay coefficient, which were 4.34 mg 4-CP/mg cell and 5.99 × 10−3 h−1, respectively. The competitive inhibition coefficients of phenol to 4-CP transformation and 4-CP to phenol degradation were 6.75 and 9.27 mg/L, respectively; therefore, phenol had a higher competitive inhibition of 4-CP transformation than the converse. The predicted model examining cometabolic transformation of 4-CP and phenol degradation showed good agreement with the experimental observations. The removal efficiencies for phenol and 4-CP were 94.56–98.45% and 96.09–98.85%, respectively, for steady-state performance.

The effect of heterotrophic yield on the assessment of the correction factor for anoxic growth

1996 ◽  
Vol 34 (5-6) ◽  
pp. 67-74 ◽  
Author(s):  
D. Orhon ◽  
S. Sözen ◽  
N. Artan
Keyword(s):  
Correction Factor ◽  
Domestic Sewage ◽  
Yield Coefficient ◽  
Heterotrophic Growth ◽  
Metabolic Processes ◽  
Anoxic Conditions ◽  
Industrial Wastewaters ◽  
Systems Modelling ◽  
Kinetics Of ◽  
Very High

For single-sludge denitrification systems, modelling of anoxic reactors currently uses the kinetics of aerobic heterotrophic growth together with a correction factor for anoxic conditions. This coefficient is computed on the basis of respirometric measurements with the assumption that the heterotrophic yield remains the same under aerobic and anoxic coditions. The paper provides the conceptual proof that the yield coefficient is significantly lower for the anoxic growth on the basis of the energetics of the related metabolic processes. This is used for the interpretation of the very high values for the correction factor experimentally determined for a number of industrial wastewaters. A default value for the anoxic heterotrophic yield coefficient is calculated for domestic sewage and compatible wastewaters and proposed for similar evaluations.

scholarly journals Kinetics of Biofilm Detachment

1992 ◽  
Vol 26 (9-11) ◽  
pp. 1995-1998 ◽  
Author(s):  
B. M. Peyton ◽  
W. G. Characklis
Keyword(s):  
Steady State ◽  
Utilization Rate ◽  
Carbon Utilization ◽  
Biofilm Thickness ◽  
First Order ◽  
Detachment Rate ◽  
Biofilm Detachment ◽  
Biofilm Modeling ◽  
Kinetics Of ◽  
Sensitive Variable

In predictive biofilm modeling, the detachment rate coefficient may be the most sensitive variable affecting both the predicted rate and the extent of biofilm accumulation. At steady state the detachment rate must be equal to the net growth rate in the biofilm. In systems where organic carbon is growth-limiting, the substrate carbon utilization rate determines the net biomass production rate and, therefore, the steady state biomass detachment rate. Detachment rates, first order with biofilm thickness, fit the experimental data well, but are not predictive since the coefficients must be determined experimentally.

scholarly journals A kinetic model of ferrous iron oxidation by Acidithiobacillus ferrooxidans in a batch culture

2005 ◽  
Vol 11 (2) ◽  
pp. 59-62 ◽  
Author(s):  
Dragisa Savic ◽  
Miodrag Lazic ◽  
Vlada Veljkovic ◽  
Miroslav Vrvic
Keyword(s):  
Kinetic Model ◽  
Acidithiobacillus Ferrooxidans ◽  
Ferrous Iron ◽  
Bubble Column ◽  
Iron Oxidation ◽  
Yield Coefficient ◽  
Transfer Rates ◽  
Ferrous Iron Oxidation ◽  
Menten Kinetic ◽  
Kinetics Of

The batch oxidation kinetics of ferrous iron by Acidithiobacillus ferrooxidans were examined at different oxygen transfer rates and pH in an aerated stirred tank and a bubble column. The microbial growth, oxygen consumption rate and ferrous and ferric iron were monitored during the biooxidation. A kinetic model was established on the basis of the Michaelis-Menten kinetic equation for bacterial growth and the constants estimated from experimental data (maximum specific growth rate 0.069 h-1, saturation constant 2.9 g/dm3, and biomass yield coefficient based on ferrous iron 0.003 gd.w./gFe). Values calculated from the model agreed well with the experimental ones regardless of the bioreactor type and pH conditions.

The Kinetics of Dissolution of UO2(s) under Reducing Conditions

1988 ◽  
Vol 44-45 (1) ◽  
Author(s):  
JORDI BRUNO ◽  
IGNASI CASAS ◽  
IGNASI PUIGDOMENECH
Keyword(s):  
Reducing Conditions ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

Kinetics of Toluene Degradation by Denitrifying Aquifer Microorganisms

1994 ◽  
Vol 120 (5) ◽  
pp. 1327-1336 ◽  
Author(s):  
Pedro J. J. Alvarez ◽  
Paul J. Anid ◽  
Timothy M. Vogel
Keyword(s):  
Toluene Degradation ◽  
Kinetics Of

The Dissolution of Irradiated Fuel Under Hydrothermal Conditions

1981 ◽  
Vol 6 ◽  
Author(s):  
Lawrence H. Johnson ◽  
Henry H. Joling
Keyword(s):  
Experimental Studies ◽  
Fission Products ◽  
Redox Chemistry ◽  
Hydrothermal Conditions ◽  
Product Release ◽  
Reducing Conditions ◽  
Dissolution Behaviour ◽  
Low Ionic Strength ◽  
Kinetics Of ◽  
Irradiated Fuel

ABSTRACTUranium dioxide, the major component of irradiated CANDU fuel, shows good hydrothermal stability under the appropriate redox conditions. The thermodynamic stability of UO2 in low ionic strength granite groundwater at 150°C under oxidizing and reducing conditions is briefly reviewed in order to provide a basis for discussion of the results of irradiated fuel dissolution experiments. Fuel chemistry characteristics that influence the kinetics of fission product release are also discussed.Experimental studies demonstrate the influence of redox chemistry on irradiated fuel dissolution behaviour. Undero9 trongly reducing conditions, both uranium and 99Tc concentrations in solution decrease to the detection limit, whereas appreciable concentrations of both elements accumulate under oxidizing conditions. The release of some fission products, such as 90Sr and 137Cs, does not seem to be strongly affected by changes in redox chemistry. Under oxidizing conditions, the rate of 90Sr release to solution increases by a factor of ten to twenty between 25 and 150°C.These studies indicate the need for further work in certain areas, in particular on the relative amounts of important fission productsreleased by leaching versus matrix dissolution, and on the effect of the products of α–radiolysis of water on the dissolution of irradiated fuel.

scholarly journals Batch Kinetics of Nutrients Removal from Synthetic Meat Processing Wastewater by using Microalgae Botryococcus Sp.

2018 ◽  
Vol 7 (4.30) ◽  
pp. 553
Author(s):  
Vikneswara A. Shanmugan ◽  
Radin M.S.R. Mohammed ◽  
Amir H.B.M. Kassim ◽  
Adel A.S. Al-Gheethi ◽  
Nur A.A. Latiffi
Keyword(s):  
Reaction Rate ◽  
Ammonia Nitrogen ◽  
Reaction Rate Constant ◽  
Synthetic Wastewater ◽  
Nutrients Removal ◽  
Meat Processing ◽  
Chl A ◽  
Half Saturation Constant ◽  
Kinetics Of ◽  
High Range

Disposed meat processing wastewater contains high range of nutrients such as ammonia nitrogen and orthophosphate which will cause eutrophication and lead to destruction of ecosystem. Therefore, batch experiments were conducted to explore the influence of the range of initial concentration of ammonia nitrogen and orthophosphate found in meat processing wastewater in the removal of those nutrients during phycoremediation of synthetic wastewater by using microalgae Botryococcus sp. Michaelis-Menten rate expression was applied to generate biokinetic coefficients k, reaction rate constant, Km, half saturation constant and Y, yield coefficients. The experiment was conducted using synthetic wastewater with initial NH4-N concentration varying between 30-480 mg/l and PO43- concentrations varying between 14-239 mg/l. The results demonstrate removal efficiency of NH4-N between 42-100 % and PO43- between 63-96 %. Biokinetic coefficients were established as k = 1.72 mg NH4-N /mg chl a/day, Km = 52.29 mg/L and YN = 0.027 mg chl a/mg NH4-N for ammonia nitrogen and k = 1.13 mg PO43-/mg chl a/day, Km = 44.45 mg/L and YP = 0.038 mg chl a/mg PO43- for orthophosphate.  

scholarly journals Kinetics and Performance of Biological Activated Carbon Reactor for Advanced Treatment of Textile Dye Wastewater

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 129
Author(s):  
Yen-Hui Lin ◽  
Bing-Han Ho
Keyword(s):  
Experimental Data ◽  
Activated Carbon ◽  
Removal Efficiency ◽  
Utilization Rate ◽  
Textile Dye ◽  
Yield Coefficient ◽  
Dye Wastewater ◽  
Monod Kinetics ◽  
Biological Activated Carbon ◽  
And Performance

The kinetics and performance of a biological activated carbon (BAC) reactor were evaluated to validate the proposed kinetic model. The Freundlich adsorption capacity (Ka) and adsorption intensity constants (n) obtained from the batch experiments were 1.023 ± 0.134 (mg/g) (L/mg)1/n and 2.036 ± 0.785, respectively. The effective diffusivity (Ds) of the substrate within the activated carbon was determined by comparing the adsorption model value with the experimental data to find the best fit value (4.3 × 10–4 cm2/d). The batch tests revealed that the yield coefficient (Y) was 0.18 mg VSS/mg COD. Monod and Haldane kinetics were applied to fit the experimental data and determine the biokinetic constants, such as the maximum specific utilization rate (k), half-saturation constant (KS), inhibition constant (Ki), and biomass death rate coefficient (kd). The results revealed that the Haldane kinetics fit the experimental data better than the Monod kinetics. The values of k, KS, Ki, and kdwere 3.52 mg COD/mg VSS-d, 71.7 mg COD/L, 81.63 mg COD/L, and 4.9 × 10−3 1/d, respectively. The BAC reactor had a high COD removal efficiency of 94.45% at a steady state. The average influent color was found to be 62 ± 22 ADMI color units, and the color removal efficiency was 73‒100% (average 92.3 ± 10.2%). The removal efficiency for ammonium was 73.9 ± 24.4%, while the residual concentration of ammonium in the effluent was 1.91 ± 2.04 mg/L. The effluent quality from the BAC reactor could meet the discharge standard and satisfy the reuse requirements of textile dye wastewater.

Co-metabolic biodegradation of 4-bromophenol in mixture of pollutants system by Arthrobacter chlorophenolicus A6

2021 ◽  
Author(s):  
Mitali Madhusmita Sahoo ◽  
Sangeeta Raut ◽  
Achlesh Davery ◽  
Naresh Kumar Sahoo
Keyword(s):  
Biomass Yield ◽  
Yield Coefficient ◽  
Paper Pulp ◽  
Substituted Phenols ◽  
Negative Interaction ◽  
Mixed Substrate ◽  
Initial Concentration ◽  
Arthrobacter Chlorophenolicus ◽  
Full Factorial ◽  
Kinetics Of

Abstract Brominated phenols are listed as priority pollutants, and are the key components of paper pulp wastewater together with nitrophenol and chlorophenol. However, the biodegradation of bromophenol in a mixed substrate system is very scanty. In the present investigation, simultaneous biodegradation kinetics of three substituted phenols (4-bromophenol, 4-BP; 4-nitrophenol, 4-NP; and 4-chlorophenol, 4-CP) were investigated using Arthrobacter chlorophenolicus A6. A 23 full factorial design was applied with varying 4-BP and 4-CP from 75–125 mgl− 1and4-NP from 50–100 mgl− 1. Almost complete degradation of this mixture of substituted phenols was achieved at an initial concentration combination of 125, 125, and 100 mgl− 1of 4-CP, 4-BP, and 4-NP, respectively in 68 h. Statistical analysis of the results revealed that among the three variables, 4-NP had the most prominent influence on both degradations of 4-CP and 4-BP. While the concentration of 4-CP had a strong negative interaction effect on the biodegradation of 4-NP. Irrespective of the concentration levels of these three substrates, 4-NP was preferentially biodegraded over 4-CP and 4-BP. Further, 4-BP biodegradation rates were found to be higher than that of 4-CP followed by 4-NP. Besides, the variation of biomass yield coefficient of the culture was investigated at different initial concentration combinations of these substituted phenols. Although the actinomycetes consumed 4-NP at a faster rate, the biomass yield was very poor. This revealed that the microbial cells were more stressed when grown on 4-NP compared to 4-BP and 4-CP. Overall, this study revealed the prospective of A. chlorophenolicus A6 for the degradation of 4-BP in mixed substrate systems.

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