Kinetics Of Phenol Biodegradation Research Articles

Dynamical analysis of a chemostat model for 4-chlorophenol and sodium salicylate mixture biodegradation

We consider a mathematical continuous-time model for biodegradation of 4-chlorophenol and sodium salicylate mixture by the microbial strain Pseudomonas putida in a chemostat. The model is described by a system of three nonlinear ordinary differential equations and is proposed for the first time in the paper [Y.-H. Lin, B.-H. Ho, Biodegradation kinetics of phenol and 4-chlorophenol in the presence of sodium salicylate in batch and chemostat systems, Processes, 10:694, 2022], where the model is only quantitatively verified. This paper provides a detailed analysis of the system dynamics. Some important basic properties of the model solutions like existence, uniqueness and uniform boundedness of positive solutions are established. Computation of equilibrium points and study of their local asymptotic stability and bifurcations in dependence of the dilution rate as a key model parameter are also presented. Thereby, particular intervals for the dilution rate are found, where one or three interior (with positive components) equilibrium points do exist and possess different types of local asymptotic stability/instability. Hopf bifurcations are detected leading to the occurrence of stable limit cycles around some interior equilibrium points. A transcritical bifurcation also exists and implies stability exchange between an interior and the boundary (washout) equilibrium. The results are illustrated by lots of numerical examples.

Biodegradation Kinetics of Phenol and 4-Chlorophenol in the Presence of Sodium Salicylate in Batch and Chemostat Systems

The biodegradation of phenol, sodium salicylate (SA), and 4-chlorophenol (4-CP) by Pseudomonas putida (P. putida) was evaluated by batch and chemostat experiments in single and binary substrate systems. The Haldane kinetics model for cell growth was chosen to describe the batch kinetic behavior to determine kinetic parameters in the single or binary substrates system. In the single phenol and SA system, the kinetic constants of μm,P = 0.423 h−1, μm,A = 0.247 h−1, KS,P = 48.1 mg/L, KS,A = 71.7 mg/L, KI,P = 272.5 mg/L, and KI,A = 3178.2 mg/L were evaluated. Experimental results indicate that SA was degraded more rapidly by P. putida cells compared to phenol because SA has a much larger KI value than phenol, which makes the cells less sensitive to substrate inhibition even though the μm,P value is larger compared to μm,A. The ratio of inhibition of phenol degradation due to the presence of SA (IA1) to the inhibition of SA degradation due to the presence of phenol (IA2) is 2.3, indicating that SA has a higher uncompetitive inhibition on phenol biodegradation compared to that of phenol on SA biodegradation in the binary substrate system. In the ternary substrate system, the time required for the complete degradation of SA and phenol was 14 and 11.5 d and an approximately 90% removal efficiency for 4-CP was achieved within 14 d. In the chemostat system, the removal rates of phenol and SA were 96.6 and 97.0%, while those of SA and 4-CP were 91.4% and 95.2%, respectively. The model prediction agreed satisfactorily with the experimental results of the chemostat system.

Effect of Nickel as Stress Factor on Phenol Biodegradation by Stenotrophomonas maltophilia KB2.

This study focuses on the phenol biodegradation kinetics by Stenotrophomonas maltophilia KB2 in a nickel-contaminated medium. Initial tests proved that a nickel concentration of 33.3 mg·L−1 caused a cessation of bacterial growth. The experiments were conducted in a batch bioreactor in several series: without nickel, at constant nickel concentration and at varying metal concentrations (1.67–13.33 g·m−3). For a constant Ni2+ concentration (1.67 or 3.33 g·m−3), a comparable bacterial growth rate was obtained regardless of the initial phenol concentration (50–300 g·m−3). The dependence µ = f (S0) at constant Ni2+ concentration was very well described by the Monod equations. The created varying nickel concentrations experimental database was used to estimate the parameters of selected mathematical models, and the analysis included different methods of determining metal inhibition constant KIM. Each model showed a very good fit with the experimental data (R2 values were higher than 0.9). The best agreement (R2 = 0.995) was achieved using a modified Andrews equation, which considers the metal influence and substrate inhibition. Therefore, kinetic equation parameters were estimated: µmax = 1.584 h−1, KS = 185.367 g·m−3, KIS = 106.137 g·m−3, KIM = 1.249 g·m−3 and n = 1.0706.

Phenol and p-nitrophenol biodegradations by acclimated activated sludge: Influence of operational conditions on biodegradation kinetics and responding microbial communities

This study aims to evaluate the influence of operational factors (i.e. substrate concentration, activated sludge concentration and acclimation concentration) and the microbial communities of activated sludge on the aerobic biodegradation of phenol and p-nitrophenol (PNP). During the biodegradation process, the phenol or PNP biodegradation and activated sludge growth kinetics were determined and the interaction effects of the operational factors on the kinetics were assessed. The phenol biodegradation kinetics was well described by zero-order model (R2 > 0.813). At low phenol concentration (< 200 mg/L), the biodegradation rate can be enhanced by increasing activated sludge concentration and acclimation concentration. From the specific oxygen uptake rate (SOUR) analysis, lower SOUR values for PNP relative to phenol suggests higher toxicity of PNP, with inhibition detected above 50 mg/L for both phenol and PNP. In view of the inadequacy of zero-order equation for PNP biodegradation, the kinetic data was fitted into Haldane equation that incorporate the inhibitory effect. From the results, the value of critical PNP concentration was observed to increase at higher acclimation concentration, indicating the attenuation of inhibitory effects on PNP-acclimated activated sludge. For microbial growth, only the factor of acclimation concentration greatly affected the growth kinetics, in which the Ks/Ki ratio was greatly reduced when the acclimation concentration was doubled. Lastly, potential degrading strains of Acinetobacter sp. USM, Rhodococcus sp. USM1 and Caballeronia sp. USM2, were successfully isolated from the acclimated activated sludge. From the results of dioxygenase genes amplification, the phenol degradation mechanism was identified following ortho fission pathway.

Anaerobic biodegradation of phenol in wastewater treatment: achievements and limits

Anaerobic biodegradation of toxic compounds found in industrial wastewater is an attractive solution allowing the recovery of energy and resources but it is still challenging due to the low kinetics making the anaerobic process not competitive against the aerobic one. In this review, we summarise the present state of knowledge on the anaerobic biodegradation process for phenol, a typical target compound employed in toxicity studies on industrial wastewater treatment. The objective of this article is to provide an overview on the microbiological and technological aspects of anaerobic phenol degradation and on the research needs to fill the gaps still hindering the diffusion of the anaerobic process. The first part is focused on the microbiology and extensively presents and characterises phenol-degrading bacteria and biodegradation pathways. In the second part, dedicated to process feasibility, anaerobic and aerobic biodegradation kinetics are analysed and compared, and strategies to enhance process performance, i.e. advanced technologies, bioaugmentation, and biostimulation, are critically analysed and discussed. The final section provides a summary of the research needs. Literature data analysis shows the feasibility of anaerobic phenol biodegradation at laboratory and pilot scale, but there is still a consistent gap between achieved aerobic and anaerobic performance. This is why current research demand is mainly related to the development and optimisation of powerful technologies and effective operation strategies able to enhance the competitiveness of the anaerobic process. Research efforts are strongly justified because the anaerobic process is a step forward to a more sustainable approach in wastewater treatment.Key points• Review of phenol-degraders bacteria and biodegradation pathways.• Anaerobic phenol biodegradation kinetics for metabolic and co-metabolic processes.• Microbial and technological strategies to enhance process performance.

Biodegradation of Phenol by Rhodococcus sp. Strain SKC: Characterization and Kinetics Study.

This study focuses on the kinetics of a pure strain of bacterium Rhodococcus sp. SKC, isolated from phenol-contaminated soil, for the biodegradation of phenol as its sole carbon and energy source in aqueous medium. The kinetics of phenol biodegradation including the lag phase, the maximum phenol degradation rate, maximum growth rate (Rm) and maximum yield coefficient (Y) for each Si (initial phenol concentration, mg/L) were fitted using the Gompertz and Haldane models of substrate inhibition (R2 > 0.9904, RMSE < 0.00925). The values of these parameters at optimum conditions were μmax = 0.30 h−1, Ks = 36.40 mg/L, and Ki = 418.79 mg/L, and that means the inhibition concentration of phenol was 418.79 mg/L. By comparing with other strains of bacteria, Rhodococcus sp. SKC exhibited a high yield factor and tolerance towards phenol. This study demonstrates the potential application of Rhodococcus sp. SKC for the bioremediation of phenol contaminate.

Kinetics of Phenol Biodegradation by Heavy Metal Tolerant Rhizobacteria Glutamicibacter nicotianae MSSRFPD35 From Distillery Effluent Contaminated Soils.

Biodegradation of phenol using bacteria is recognized as an efficient, environmentally friendly and cost-effective approach for reducing phenol pollutants compared to the current conventional physicochemical processes adopted. A potential phenol degrading bacterial strain Glutamicibacter nicotianae MSSRFPD35 was isolated and identified from Canna indica rhizosphere grown in distillery effluent contaminated sites. It showed high phenol degrading efficiency up to 1117 mg L–1 within 60 h by the secretion of catechol 1,2-dioxygenase via ortho intradial pathway. The strain MSSRFPD35 possess both the catechol 1,2 dioxygenase and catechol 2,3 dioxygenase coding genes that drive the ortho and meta pathways, but the enzymatic assay revealed that the strain cleaves catechol via ortho pathway. Haldane’s kinetic method was well fit to exponential growth data and the following kinetic parameter was obtained: μ∗ = 0.574 h–1, Ki = 268.1, Ks = 20.29 mg L–1. The true μmax and Sm were calculated as 0.37 h–1 and 73.76 mg L–1, respectively. The Haldane’s constant values were similar to earlier studies and healthy fitness depicted in correlation coefficient value R2 of 0.98. Phenol degrading kinetic’s was predicted using Haldane’s model as qmax 0.983, Ki′ 517.5 and Ks′ 9.152. Further, MSSRFPD35 was capable of utilizing different monocyclic and polycyclic aromatic hydrocarbons and to degrade phenol in the presence of different heavy metals. This study for the first time reports high phenol degrading efficiency of G. nicotianae MSSRFPD35 in the presence of toxic heavy metals. Thus, the strain G. nicotianae MSSRFPD35 can be exploited for the bioremediation of phenol and its derivatives polluted environments, co-contaminated with heavy metals.

Kinetics of Phenol Biodegradation by an Indigenous Pseudomonas citronellolis NS1 Isolated from Coke Oven Wastewater

Coke oven wastewater from the iron and steel plant industry is composed of highly refractory and recalcitrant phenolic pollutants. To overcome the process instability, inhibition, and poor performance of coke oven wastewater treatment plants an efficient phenol degrading bacterial culture was isolated from the coke oven wastewater of a local steel plant industry in Odisha, India. In this study, the kinetics of phenol biodegradation by a newly isolated Pseudomonas citronellolis NS1 was carried out using batch shake flasks. The results revealed that the culture could degrade 1,500 mg/L−1 of phenol almost completely within 90 h as the sole source of carbon and energy. In addition, under these conditions, approximately 95.5% of the chemical oxygen demand (COD) and 98.5% of toxicity removal were achieved by the indigenous P. citronellolis NS1. The growth and biodegradation kinetics of the isolated Pseudomonas species were evaluated at phenol concentrations pf 50–1,500 mg/L−1. The specific growth rate of the culture followed the substrate inhibition kinetic pattern and the estimated biokinetic parameters were; μ = 0.246 h−1, Ksi = 890 mg/L−1, and Ks = 14.85 mg/L−1. Further, the effects of temperature on the biodegradation of phenol were carried out. The estimated values of maximum phenol biodegradation rate and the activation energy (Ea) of the enzyme-catalyzed reactions were 0.0152 h−1 and 47.21 kJ · mol−1 respectively at 36°C.

Biodegradation kinetics of phenol and 2-chlorophenol by mixed cultures in a fixed biofilm process

Biodegradation kinetics of phenol and 2-chlorophenol by mixed cultures in a fixed biofilm process

Biodegradation of phenol by entrapped cell of Debaryomyces sp. with nano-Fe3O4 under hypersaline conditions

Phenol-containing industrial wastewater disposal has received much attention in recent years due to its toxicity and slow biodegradation. In this work, the isolated fungal strain Debaryomyces sp. was entrapped into Ca-alginate beads with nanoscale Fe3O4 to improve phenol biodegradation ability. Freely suspended cells as well as Ca-alginate immobilized cells without nanoscale particles were also prepared. Phenol removal by free cells and two kinds of Ca-alginate beads was evaluated with different initial phenol concentrations, temperatures, and salinities. The phenol biodegradation kinetics and optimal dosage of nano-Fe3O4 during the preparation of Ca-alginate beads were also determined. The results showed that immobilized Debaryomyces strain had better biodegradation performance than free cells under harsh conditions. Phenol removal rates were highest when using magnetically immobilized cells, followed by nonmagnetically cells. More than 99.9% of phenol was degraded within 80 h by immobilized cells with nano-Fe3O4 when initial phenol concentration was over 900 mg L−1 while the phenol removal efficiencies of free cell and immobilized cells without nano-Fe3O4 were 34.5% and 81.3%, respectively during the same periods of time. The reusability tests were carried out and the results indicated good stability of immobilized cells in saline environments, which was practical in actual industrial wastewater treatment.

Biodegradation Kinetics of Phenol, 2,4,6-Trichlorophenol and Pentachlorophenol with ligninolytic enzymes from Dichomitus Squalens

Biodegradation of phenol, 2,4,6-trichlorophenol and pentachlorophenol was investigated using Dichomitus squalens cultivation media filtrates with initial laccase and manganese peroxidase activities of 1000 U L-1 and 300 U L-1, respectively. Decomposition of all three biocides was studied at T = 28 °C, pH = 4.5 and initial concentrations around 6 mg L-1 and the kinetics evaluated on the basis of the time course of the biocide concentration data. Integral analysis revealed 1st order reaction for all three pollutants and the corresponding reaction rate constants and initial concentrations for phenol, 2,4,6-TCP and PCP were estimated from linearized experimental data. The rate equations obtained allow estimation of the times necessary for a particular biocide conversion. The toxicity of reactants and products to the bacterium Vibrio fischeri before and after 48-hours degradation showed that the products were less toxic than the reactants in all three cases. The initial solutions of the three toxic substances caused 54 - 62 % inhibition of the bacterium Vibrio fischeri, while after 48 hours of degradation, 57 % reduction in the toxicity of phenol, 50 % reduction of 2,4,6-TCP and 29 % reduction of PCP was achieved.

Kinetics of phenol biodegradation at high concentration by a metabolically versatile isolated yeast Candida tropicalis PHB5

A highly tolerant phenol-degrading yeast strain PHB5 was isolated from wastewater effluent of a coke oven plant and identified as Candida tropicalis based on phylogenetic analysis. Biodegradation experiments with C. tropicalis PHB5 showed that the strain was able to utilize 99.4% of 2,400 mg l(-1) phenol as sole source of carbon and energy within 48 h. Strain PHB5 was also observed to grow on 18 various aromatic hydrocarbons. Haldane model was used to fit the exponential growth data and the following kinetic parameters were obtained: μ max = 0.3407 h(-1), K S = 15.81 mg l(-1), K i = 169.0 mg l(-1) (R (2) = 0.9886). The true specific growth rate, calculated from μ max, was 0.2113. A volumetric phenol degradation rate (V max) was calculated by fitting the phenol consumption data with Gompertz model and specific degradation rate (q) was calculated from V max. The q values were fitted with Haldane model, yielding following parameters: q max = 0.2766 g g(-1) h(-1), K S ' = 2.819 mg l(-1), K i ' = 2,093 (R (2) = 0.8176). The yield factor (Y X/S ) varied between 0.185 to 0.96 g g(-1) for different initial phenol concentrations. Phenol degradation by the strain proceeded through a pathway involving production of intermediates such as catechol and cis,cis-muconic acid which were identified by enzymatic assays and HPLC analysis.

Phenol Biodegradation Kinetics in the Presence of Supplimentary Substrate

Biodegradation of phenol in the presence of glucose as a supplementary substrate was investigated with mixed microbial consortium isolated from waste effluent of coke-steel factory. Batch experiments were carried out at room temperature and pH value of 7. Initial phenol and glucose concentrations were in the range of 25-1000 mg/l and 500-3000 mg/l, respectively. In a dual substrates system the concentration of supplementary source (glucose) was kept constant. It was obvious to find out that glucose as a simple carbon source was initially utilized in the presence of phenol. The rate of phenol degradation started once glucose concentration was significantly depleted. Phenol was known to be an inhibitory substrate, thus Haldane/Andrews kinetic model was applied to evaluate the growth kinetic parameters. The kinetic parameters, mm, Ks and Ki were 0.01 1/h, 27.04 and 127.55 mg/l, respectively. The specific growth rate of the culture in dual substrates system was expressed by SKIP model (R2> 0.951). The values of interaction parameters showed uncompetitive partially inhibition at high phenol concentration.

Biodegradation kinetics of phenol by predominantlyPseudomonassp. in a batch shake flask

Biodegradation of phenol by predominantly Pseudomonas species isolated from a sewage wastewater treatment plant was investigated in batch shake flasks. Phenol with a lower concentration of 100 mg/L was degraded in 10 h and a highest of 800 mg/L in 69 h. The phenol degradation rate was observed to vary largely with the concentrations of phenol used and was found to be less than 10 mg/L/h at both the extremes of the initial concentrations. The degradation kinetics was found follow the three half-order kinetic model with the regression greater than 0.97. The specific substrate utilization rates of the culture at various initial phenol concentrations were fitted to modified substrate inhibition kinetic models of Edward, Haldane, Luong, Han–Levenspiel and Yano–Koga. Among these models the Edward was found to fit the data well with a minimum Root Mean Square error value of 0.0039.

Relevance of the Luong model to describe the biodegradation of phenol by mixed culture in a batch reactor

The kinetics of phenol biodegradation by mixed culture in a batch reactor was investigated over a wide range of initial phenol concentrations (40–350 mg L-1). The temperature (30°C), the stirring velocity (200 rpm), mineral salt supplementation, namely NaH2PO4 (3 g L-1), KH2PO4 (3 g L-1), MgSO4 (0.1 g L-1), (NH4)2SO4 (1 g L-1), as well as the initial pH (8) were kept constant. All experiments were carried out at a given initial bacterial concentration of 0.08 g L-1 (based on the optical density determination, 0.079). Irrespective of the culture conditions, total phenol degradation was recorded for a culture time ranging from 15.6 to 49.0 h. In addition, the optimal value of the maximum specific growth rate was observed for 125 mg L-1 of phenol. These results show the relevance of the specific microbial consortium used. The Luong equation accurately matched growth kinetics and enabled the relation between the maximum specific growth rates (μ m ) and the initial phenol concentration (S o ) to be described. It could also be used to deduce the substrate saturation coefficient (K s ) and the maximum substrate concentration (S m ) above which growth ceases. The kinetic constants of the Luong equation for phenol were $$ {\mu_m} = {1}.0{4} {{\text{h}}^{ - {1}}},{K_s} = {153}.{2} {\text{mg}} {{\text{L}}^{ - {1}}},{S_m} = {54}0 {\text{mg}} {{\text{L}}^{ - {1}}}\,{\text{and}}\,n = 0.{9} $$ , respectively.

Respirometry kinetics of phenol oxidation by Comamonas testosteroni Pb50 under various conditions of nutritional stress

Kinetics of phenol biodegradation using suspended biomass of Comamonas testosteroni Pb50 (monoculture) was measured under conditions of nutrient abundance, limitation, and prolonged cell starvation in a fed-batch reactor, with phenol being the sole carbon and energy source. The pre-washed cells were applied for measurement of the phenol and oxygen uptake rates at varied starting phenol concentrations with the kinetic parameters calculated using the Haldane model. The results revealed that nutrient limitation significantly suppressed the maximum value of exogenous respiration rate while the endogenous respiration rate, affinity and tolerance to phenol increased. By contrast, cell starvation resulted in a drop of both the exogenous and endogenous respiration rates by an order of magnitude.

The evaluation of benzene and phenol biodegradation kinetics by applying non-structured models

The biodegradation kinetics of the aromatic hydrocarbons benzene and phenol as single substrates and as a mixture were investigated through non-structured model analysis. The material balance equations involving the models of Monod and Andrews and representing the biodegradation kinetics of individual substrates in batch mode were numerically solved. Further, utilization of a benzene-phenol mixture was described by applying more sophisticated mathematical forms of competitive, noncompetitive and uncompetitive inhibition models as well as the sum kinetic interactions parameters (SKIP) model. In order to improve the performance of the studied models, some modifications were also proposed. The Particle Swarm Global Optimization method, coded in Maple, was applied to the parameter identification procedure of each model, where the least square method was used as a search statistical criterion. The description of the biodegradation kinetics of a benzene-phenol mixture by the competitive inhibition model was based on the information that the compounds could be catabolized via one metabolic pathway of Pseudomonas putida F1. Simulation results were in good agreement with the experimental data and proved the robustness of the applied methods and models. The developed knowledge database could be very useful in the optimization of the biodegradation processes of different bioreactor types and operational conditions.

Modelling phenol biodegradation by activated sludges evaluated through respirometric techniques

In this paper respirometric techniques were used to study the effect of pH, phenol and dissolved oxygen (DO) concentrations on the phenol biodegradation kinetics by activated sludges. In addition, a mathematical model was developed to interpret the obtained respirometric curves. Closed respirometer experiments showed that phenol inhibited the respiration rate of unacclimated sludges. On the contrary, oxygen uptake rate (OUR) of phenol acclimated sludges exhibiting the typical Haldane's substrate inhibition curve. The Monod equation adequately represented the relation between OUR of acclimated biomass and DO concentration. Within the tested pH range (4–12) the oxygen saturation coefficient was independent of pH. On the contrary, the maximum OUR was strongly affected by the pH, being its maximum between 9.5 and 10.5. Open respirometer experiments shows that as pH decreased from 10.2 to 5.8, the maximum OUR also decreased, in accordance with the trend observed in the closed respirometer experiments. Although the respiration rate of phenol degrading bacteria was strongly affected by pH, a constant phenol oxidation coefficient was observed within the studied pH interval. A mathematical model was proposed to interpret the open respirometry curves. The coefficients of the model were estimated using both pseudo steady state and dynamic conditions for different biomass concentrations. The model adequately predicted the whole OUR and DO profiles as a function of time during the biodegradation of phenol under different DO conditions. The mathematical model proposed in the present work is useful for predicting transient responses such as substrate concentration and DO concentrations as a function of time in bioreactors treating phenolic wastewaters under an overload of phenolic compounds.

Modelling of biological phenol removal in draw-fill reactors using suspended and attached growth olive pulp bacteria

The kinetics of phenol biodegradation in draw-fill suspended and attached growth reactors by olive pulp bacteria were investigated. The Haldane equation was adopted in order to describe phenol biodegradation in the draw-fill suspended-growth flask reactors. Kinetic constants of the Haldane equation obtained from batch culture experiments with phenol concentration ranging from 13 to 280 mg l −1, were μ max=0.054 h −1, K S=19.23 mg l −1, and K i=36.95 mg l −1. However, in the draw-fill experiments at the packed-bed reactor, phenol inhibitory effects were minimized increasing the inhibitory constant value K i′ at 1571 mg l −1. The model predicted phenol biodegradation in the packed-bed reactor adequately, for all initial phenol concentrations tested, apart from the highest phenol concentration of 1990 mg l −1, where clogging problems and insufficient aeration in the filter prevailed.

Degradation of phenol by aerobic granules and isolated yeast Candida tropicalis

Aerobic granules effectively degrade phenol at high concentrations. This work cultivated aerobic granules that can degrade phenol at a constant rate of 49 mg-phenol/g x VSS/h up to 1,000 mg/L of phenol. Fluorescent staining and confocal laser scanning microscopy (CLSM) tests demonstrated that an active biomass was accumulated at the granule outer layer. A strain with maximum ability to degrade phenol and a high tolerance to phenol toxicity isolated from the granules was identified as Candida tropicalis via 18S rRNA sequencing. This strain degrades phenol at a maximum rate of 390 mg-phenol/g x VSS/h at pH 6 and 30 degrees C, whereas inhibitory effects existed at concentrations >1,000 mg/L. The Haldane kinetic model elucidates the growth and phenol biodegradation kinetics of the C. tropicalis. The fluorescence in situ hybridization (FISH) and CLSM test suggested that the Candida strain was primarily distributed throughout the surface layer of granule; hence, achieving a near constant reaction rate over a wide range of phenol concentration. The mass transfer barrier provided by granule matrix did not determine the reaction rates for the present phenol-degrading granule.