Phenol Degradation Efficiency Research Articles

Synthesis of Pd/CeOx/Nano-graphite composite cathode for electro-catalytic degradation of phenol

To improve the cathode electro-catalytic degradation performance of electrochemical advanced oxidation processes (EAOP), Pd metal and CeOx co-modified Nano-graphite (Pd/CeOx/Nano-G) composite was synthesized by chemical precipitation and reduction methods, and Pd/CeOx/Nano-G cathode was prepared by a hot-pressing method. The as-prepared composite and electrode were characterized by X-ray photoelectron spectroscopy, X-ray diffraction and scanning electrons microscopy. Results revealed that the mix-crystal structural CeOx (Ce2O3 and CeO2) and Pd0 metal were formed. The cathode was applied for the electro-catalytic degradation of phenol wastewater. The degradation efficiency of phenol by Pd1.0/CeOx5.0/Nano-G cathode reached 99.6% within 120 min degradation, which were higher than that of CeOx5.0/Nano-G and Nano-G cathodes. Both of the Pd metal and CeOx could improve the O2 reduction to H2O2 and promote the H2O2 dissociation to •OH for phenol oxidation. Additionally, the effects of electro-catalytic reaction parameters on the phenol degradation were investigated. The results indicated that Pd/CeOx/Nano-G cathode would have promise for further practical application in organic wastewater treatment.

Interfacial engineering coupling with tailored oxygen vacancies in Co2Mn2O4 spinel hollow nanofiber for catalytic phenol removal

Herein, one-dimensional Co2Mn2O4 (CMO) hollow nanofibers with a general spinel structure were constructed by electrospinning and tunning thermal-driven procedures. The resultant catalyst was endowed with appreciable active interfacial engineering effect, which revealed improved peroxymonosulfate (PMS) activation efficiency in catalytic phenol degradation with nearly 12.9 folds increment in reaction rate constant compared to the hydrothermally synthesized counterpart. Besides, tailored oxygen-vacancy sites including chemical environment and contents in the bimetallic spinel were rationally validated compared to the monometal spinel counterparts. The improved catalytic phenol degradation by reactive-oxidative-species (ROS) from PMS was well correlated with the more active Co(II) and Mn(II) species, reactive active oxygen-vacancy and the interfacial engineering effect in the CMO catalyst. These correlations were comprehensively demonstrated by various characterization techniques, catalytic results, and Density-Functional-Theoretical (DFT) calculations of the adsorption and activation of PMS. Besides, the results revealed that the specific content of cobalt species in the structural unit of the Co2Mn2O4 spinel resulting from the optimized thermal treatment could further improve the catalytic activity by the intermetallic synergy along with the beneficial electron transfer cycles. This work provides a practical understanding of the improvement of interfacial systems in catalysis efficiency and environmental remediation.

Novel Silanized Graphene Oxide/TiO2 Multifunctional Nanocomposite Photocatalysts: Simultaneous Removal of Cd2+ and Photodegradation of Phenols under Visible Light Irradiation.

Reduced graphene oxide (RGO)-TiO2 nanocomposites have exhibited effective photocatalytic degradation of various organic pollutants. However, their poor solubility could limit their application in water and other organic solvents. In this study, new graphene-based cross-linked ethylenediaminetetraacetic acid (EDTA)-RGO-TiO2 (ERGT) nanocomposites were synthesized for the removal of Cd(II) and photodegradation of phenol from wastewater by surface-functionalized cross-linking heavy metal chelating agent sodium edetate (EDTA) and photocatalyst titanium dioxide. The structural properties of fabricated nanocomposites were characterized using SEM, TEM, XPS, FTIR, XRD, UV–vis, gas sorption, and Raman spectroscopy analyses. Moreover, the adsorption of Cd(II) and the degradation of phenol under different conditions were studied. The experimental results revealed that the optimal catalytic degradation and adsorption performance could be achieved at pH 5.5, and the maximum absorption ratio of cadmium ions and the degradation efficiency of phenol can reach 178.2 mg/g and 90%, respectively. The results suggested that ERGT is a potential material for the removal of threatening pollutants from wastewater.

Environmentally persistent free radicals in bismuth-based metal–organic layers derivatives: Photodegradation of pollutants and mechanism unravelling

Formation of environmentally persistent free radicals (EPFRs) on carbonaceous material has aroused increasing research attentions. In terms of metal organic frameworks (MOFs) derivatives, however, scarce studies have dedicated to the relevant aspects. Herein, EPFRs have been detected in Bi-metal organic layers (Bi-MOLs) derivatives. The corresponding g-factors and concentrations of EPFRs on Bi2O3@C by pyrolyzed at different temperatures were 2.0041–2.0046 and 7.04 × 1019-1.77 × 1020 spins/g, respectively. Interestingly, similar EPFRs signals were also monitored in HKUST-1 based and UiO-66 based derivatives. We observed that Bi2O3@C system with the highest EPFRs concentration exhibited superior degradation and mineralization efficiency for phenol and tetracycline. Its excellent photocatalytic performance was mainly attributed to the interaction between the internal EPFRs and photoinduced active species, which promoted more generation of reactive oxygen species (ROS) radicals. This hypothesis was supported by line correlations for EPFRs concentration vs. degradation kinetics in samples pyrolyzed at different temperatures (R2 = 0.946). Most significantly, mechanism investigation combined with DFT calculation indicated that the EPFRs not only promote the generation of 1O2 and •OH via molecular oxygen activation pathway but also provided a possibility of enhancing water oxidation by holes. These findings pave the way for MOFs derivative's implication and insight into the role of EPFRs in photocatalysis.

Analysis of Phenol Biodegradation in Antibiotic and Heavy Metal Resistant Acinetobacter lwoffii NL1.

Phenol is a common environmental contaminant. The purpose of this study was to isolate phenol-degrading microorganisms from wastewater in the sections of the Chinese Medicine Manufactory. The phenol-degrading Acinetobacter lwoffii NL1 was identified based on a combination of biochemical characteristics and 16S rRNA genes. To analyze the molecular mechanism, the whole genome of A. lwoffii NL1 was sequenced, yielding 3499 genes on one circular chromosome and three plasmids. Enzyme activity analysis showed that A. lwoffii NL1 degraded phenol via the ortho-cleavage rather than the meta-cleavage pathway. Key genes encoding phenol hydroxylase and catechol 1,2-dioxygenase were located on a megaplasmid (pNL1) and were found to be separated by mobile genetic elements; their function was validated by heterologous expression in Escherichia coli and quantitative real-time PCR. A. lwoffii NL1 could degrade 0.5 g/L phenol within 12 h and tolerate a maximum of 1.1 g/L phenol, and showed resistance against multiple antibiotics and heavy metal ions. Overall, this study shows that A. lwoffii NL1 can be potentially used for efficient phenol degradation in heavy metal wastewater treatment.

Efficient Catalytic Degradation of Phenol with Phthalocyanine-Immobilized Reduced Graphene-Bacterial Cellulose Nanocomposite.

In this report, phthalocyanine (Pc)/reduced graphene (rG)/bacterial cellulose (BC) ternary nanocomposite, Pc-rGBC, was developed through the immobilization of Pc onto a reduced graphene–bacterial cellulose (rGBC) nanohybrid after the reduction of biosynthesized graphene oxide-bacterial cellulose (GOBC) with N2H4. Field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR) were employed to monitor all of the functionalization processes. The Pc-rGBC nanocomposite was applied for the treatment of phenol wastewater. Thanks to the synergistic effect of BC and rG, Pc-rGBC had good adsorption capacity to phenol molecules, and the equilibrium adsorption data fitted well with the Freundlich model. When H2O2 was presented as an oxidant, phenol could rapidly be catalytically decomposed by the Pc-rGBC nanocomposite; the phenol degradation ratio was more than 90% within 90 min of catalytic oxidation, and the recycling experiment showed that the Pc-rGBC nanocomposite had excellent recycling performance in the consecutive treatment of phenol wastewater. The HPLC result showed that several organic acids, such as oxalic acid, maleic acid, fumaric acid, glutaric acid, and adipic acid, were formed during the reaction. The chemical oxygen demand (COD) result indicated that the formed organic acids could be further mineralized to CO2 and H2O, and the mineralization ratio was more than 80% when the catalytic reaction time was prolonged to 4 h. This work is of vital importance, in terms of both academic research and industrial practice, to the design of Pc-based functional materials and their application in environmental purification.

Novel two-step synthesis method of thin film heterojunction of BiOBr/Bi2WO6 with improved visible-light-driven photocatalytic activity

A novel two-step ionic liquid assisted procedure was applied for a controllable synthesis of BiOBr/Bi2WO6 heterojunction thin films. The preparation route involved an anodic oxidation of tungsten foil and hydrothermal transformation of as-anodized oxide in the presence of bismuth precursor and ionic liquid, N-butylpyridinium bromide [BPy][Br]. The BiOBr plates with irregular shapes adhered to the surface of flower-like Bi2WO6 and formed a heterojunction between BiOBr and Bi2WO6, as confirmed by the analysis of their structure and composition. The highest efficiency of phenol degradation was achieved when the highest amount of IL was used (the apparent quantum efficiency was almost 8 and 71.5 times higher compared to BiOBr and Bi2WO6, respectively). In addition, superoxide radicals (•O2–) were found as the main factor responsible for the photodegradation. A possible reaction mechanism was further investigated as a function of monochromatic irradiation to determine the exact range of the composite photoactivity.

Revealing the heterogeneous activation mechanism of peroxydisulfate by CuO: the critical role of surface-binding organic substrates

Heterogeneous catalytic activation mechanisms of peroxydisulfate (PDS) by transition metal oxides are generally attributed to the interactions between catalysts and PDS, however, the role of the co-existed organic substrate was largely overlooked in the past studies. In this work, phenol was selected as the target organic pollutant in a CuO/PDS system to evaluate its deep-seated role in participating in the effective activation of PDS. First, optimized reaction conditions as pH of 6.0, CuO of 5.96 g·L−1 and PDS of 2.5 mM were obtained by the response surface methodology (RSM) with a phenol degradation efficiency of 84.0%. It was further found that pre-adsorption of phenol or PDS led to obviously different performances in the phenol degradation with/without the radical scavengers. Two different activation pathways of PDS, i.e., the non-radical pathway mediated by surface deprotonated phenol to generate 1O2 and the radical pathway mediated by structural Cu(I)/Cu(II) to produce SO4−, were therefore proposed, and the former was predominant in the CuO/PDS/phenol system. In addition, HCO3− and HPO42− could strongly inhibit the phenol degradation while Cl− and NO3− only performed negligible effects. NaOH washing could regenerate the surface hydroxyl groups and recover the catalytic ability of CuO. The result of this study integrated the interactions among the catalyst, oxidant and substrate, providing new insights into environmental-friendly PDS activation processes.

Facile in-situ synthesis of floating CeO2@ expanded graphite composites with efficient adsorption and visible light photocatalytic degradation of phenol

A facile solution to obtain efficient, stable and cheap photocatalysts was conducted in this work. CeO2@ expanded graphite (CeO2/EG) composites were in-situ synthesized with a new strategy, in which CeCl3 molecules inserted the graphite intercalation compound (GIC) and converted into CeO2 as GIC changed into EG via instant calcination. The introduction of EG has accelerated the adsorption of contaminant molecules, promoted the charge transfer and improved the photocatalytic efficiency. The best sample, containing 80.75 wt% CeO2 particles of nanometer scale, has achieved the highest pollutant removal efficiency of 97.3% for phenol, displaying the highest reaction rate constant of 0.0262 min−1, which was 35.4 times higher than CeO2. Besides, it possesses good stability and keeps floating in water pollution treatment, showing great advantages to work in natural water body. Phenol and its degradation intermediates were identified using HPLC/MS, and appropriate reaction pathways were proposed.

Ternary Photodegradable Nanocomposite (BiOBr/ZnO/WO3) for the Degradation of Phenol Pollutants: Optimization and Experimental Design.

The degradation of environmental contaminants with photocatalysts has bright prospects for application in the control of pollution. In this study, BiOBr/ZnO/WO3 heterojunctions have been documented to be reliable visible-light photocatalysts for phenol deterioration. X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, photoluminescence spectral analysis, electrochemical impedance spectroscopy (EIS), EIS Bode plots, linear sweep voltammetry, and UV–visible diffuse reflectance spectroscopy were employed to describe the heterojunction’s structure in addition to its optical features. The results revealed that the BiOBr/ZnO/WO3 ternary photocatalyst displayed more degradation activity in comparison to single-phase ZnO, WO3, or BiOBr, which is also higher than that of binary mixture photocatalysts with a phenol degradation efficiency of 90%. The influence of degradation variables, for instance, the potential of hydrogen (pH) and the initial organic contaminant content besides the heterojunction dose, on the deterioration efficiency was optimized using the response surface methodology. The degradation efficiency reached 95% under the optimal conditions of 0.08 g/0.03 L catalyst dose, a pH of 9, and an initial organic contaminant content of 10 mg L–1. However, the optimal phenol degradation efficiency of 39.37 mg g–1 was achieved under the conditions of 0.08 g/0.03 L catalyst dose, pH of 9, and 200 mg L–1 initial phenol concentration.

Co-MOF-74 based Co3O4/cellulose derivative membrane as dual-functional catalyst for colorimetric detection and degradation of phenol

Smart nanomaterials that can simultaneously detect and eliminate contaminants in water environment are significant for health protection. To achieve such goal, Co-MOF-74 was in-situ assembled on regenerated cellulose membranes followed by calcination process, thus achieving dual-functional Co3O4/cellulose derivative membrane (Co3O4/CDM) catalyst. The Co3O4 morphology was readily controlled by further recrystallization of the deposited MOF precursor. Combining the high enrichment ability of cellulose membrane and outstanding peroxidase-active of Co3O4, the fast color reaction for phenol was accomplished within 10 min by Co3O4/CDM with the assistance of H2O2 and 4-aminoantipyrine (4-AAP). Moreover, the Co3O4/CDM also portrayed an excellent degradation property for phenol elimination via sulfate radical-advanced oxidation processes (SR-AOPs). The degradation efficiency of phenol reached 93% in 20 min, and the possible mineralization mechanism was proposed based on the XPS and LC-MS analysis. Thus, Co-MOF-74 derived Co3O4/CDM shows excellent properties in aiding the colorimetric detection and degradation of phenol in aqueous solutions.

The responses of activated sludge to membrane cleaning reagent H2O2 and protection of extracellular polymeric substances

Hydrogen peroxide (H2O2) is evaluated as a potential replacement for chlorine to control biofouling in membrane bioreactors (MBRs). However, H2O2 might diffuse into the mixed liquor and damage microorganisms during membrane cleaning. This study comprehensively analyzed the impacts of H2O2 on microbes. Key enzymes involved in phenol biodegradation were inhibited with H2O2 concentration increased, and thus phenol degradation efficiency was decreased. Increase of lactic dehydrogenase (LDH) and intracellular reactive oxygen species (ROS) indicated more severe cell rupture with H2O2 concentration increased. At the same H2O2 concentration, Extracellular polymeric substances (EPS) extraction further led to inhibiting the activity of key enzymes, decreasing phenol degradation efficiency, and enhancing LDH release and ROS production, demonstrating that the existence of EPS moderated the adverse impacts on microbes. Spectroscopic characterization revealed the increase of H2O2 decreased tryptophan protein-like substances, protein-associated bonds and polysaccharide-associated bonds. Hydroxyl and amide groups in EPS were attacked, which might lead to the consumption of H2O2, indicated EPS protect the microorganism through sacrificial reaction with H2O2.

Band Gap Engineering in Vinylene-Linked Covalent Organic Frameworks for Enhanced Photocatalytic Degradation of Organic Contaminants and Disinfection of Bacteria.

Photocatalysis is regarded as one of the most promising technologies to remove organic contaminants. At present, most of the covalent organic frameworks (COFs) used as photocatalysts are connected by imine or borate bonds, which have relatively low stability and relatively poor π-delocalization. Herein, we report, for the first time, vinylene-linked COFs constructed by various diacetylene and triazine moieties for photocatalytic degradation of organic contaminants and disinfection of bacteria. The pioneering introduction of diacetylene moieties not only enhances conjugated π-electrons delocalization but also optimizes the electronic band structures that significantly improve photocatalytic activity. Therefore, the vinylene-bridged COFs have excellent photocatalytic activity with ultrahigh stability and great π-electron delocalization, thus exhibiting ultrafast photocatalytic degradation efficiency for phenol and norfloxacin (>96%, within 15 min). Our work provides a strong basis for the rational regulation of the chemical structure of COFs to enhance their photocatalytic activity, thus broadening the application of COFs in photocatalysis.

Heterogeneous activation of persulfate by Mg doped Ni(OH)2 for efficient degradation of phenol

Mg doped Ni(OH)2 was synthesized and investigated as an efficient material to activate persulfate (PS) for phenol degradation. The property of the Ni(OH)2 material was enhanced by Mg doping as the removal efficiency of phenol was increased from 74.82 % in Ni(OH)2/PS system to 89.53 % in Mg-doped Ni(OH)2/PS system within 20 min. Such a high removal efficiency revealed that doping Mg into Ni(OH)2 brings about more defects (oxygen vacancies), which facilitated the formation of more active species in the degradation process. The removal efficiencies of phenol increased with the increase of the initial pH from 3 to 11. The influences of Cl−, NO3− and HCO3− on the stability of the system were also studied and the results showed that removal rates of all systems in the presence of these different inorganic anions could reached about 90 % within 20 min. Based on the electron spin resonance (ESR) experiments, 1O2, O2·-, ·OH and SO4•− were identified as the active species in Mg-doped Ni(OH)2/PS system for phenol degradation and a degradation mechanism was proposed for this system. In addition, the as-prepared material retained its activation performance even after 3 repeated cycles.

Analysis of Photocatalytic Degradation of Phenol with Exfoliated Graphitic Carbon Nitride and Light-Emitting Diodes Using Response Surface Methodology

Response surface methodology (RSM) involving a Box–Benkhen design (BBD) was employed to analyze the photocatalytic degradation of phenol using exfoliated graphitic carbon nitride (g-C3N4) and light-emitting diodes (wavelength = 430 nm). The interaction between three parameters, namely, catalyst concentration (0.25–0.75 g/L), pollutant concentration (20–100 ppm), and pH of the solution (3–10), was examined and modeled. An empirical regression quadratic model was developed to relate the phenol degradation efficiency with these three parameters. Analysis of variance (ANOVA) was then applied to examine the significance of the model; this showed that the model is significant with an insignificant lack of fit and an R2 of 0.96. The statistical analysis demonstrated that, in the studied range, phenol concentration considerably affected phenol degradation. The RSM model shows a significant correlation between predicted and experimental values of photocatalytic degradation of phenol. The model’s accuracy was tested for 50 ppm of phenol under optimal conditions involving a catalyst concentration of 0.4 g/L catalysts and a solution pH of 6.5. The model predicted a degradation efficiency of 88.62%, whereas the experimentally achieved efficiency was 83.75%.

Facile construction of dual heterojunction CoO@TiO2/MXene hybrid with efficient and stable catalytic activity for phenol degradation with peroxymonosulfate under visible light irradiation

Photocatalysis and peroxymonosulfate (PMS) based advanced oxidation processes (AOP) are emerging technology for the degradation of refractory organic pollutant in the field of water treatment. Here we report a novel CoO@TiO2/MXene (CTM) hybrid through a facile sonication-hydrothermal method for efficient degradation of phenol via an integrated PMS activation-photocatalysis process. Benefiting from the proper position and superior suitability of the band structure, a dual interfacial charge transport channel was constructed, boosting the separation of photo-generated charge carriers and generating sufficient potential difference for redox reaction. Accordingly, the CTM hybrid not only possessed the outstanding photocatalytic activity but also dramatically accelerated PMS activation to generate considerable reactive radicals. As a result, over 96% phenol degradation was achieved in the 10% CTM/PMS/Vis system within 15 min. The radical quenching test and EPR analysis reveal that SO4•−, O2•− and 1O2 were predominant reactive species involved in the catalytic process. Moreover, the damaged chemical structure of CoO during PMS activation could be healed by the photo-actuated Co(II) regeneration to allow for continuous and stable catalytic process. This study offers a promising perspective for the rational design of competent and stable hybrid heterojunction catalyst to construct PMS activation-photocatalysis processes for the efficient degradation of organic contaminants.

Flow-through heterogeneous electro-Fenton system based on the absorbent cotton derived bulk electrode for refractory organic pollutants treatment

The electro-Fenton reaction is traditionally carried out in a batch or flow-by reactor. However, the electro-Fenton performance is restricted by low utilization efficiency of catalysts, limited contact time of reactants, and the slow mass transfer. In this work, a flow-through heterogeneous electro-Fenton reactor was designed by using absorbent cotton derived three-dimensional carbon fiber network with iron oxide nanoparticles loaded as cathode. This flow-through electro-Fenton system can electrochemically catalyze O2 molecule to produce ·OH. During the continuous test, the phenol degradation and mineralization efficiency achieved 92.7% and 65.1%, respectively, demonstrating the efficient and stable performance toward pollutant elimination of flow-through electro-Fenton system. Moreover, the flow-through system was demonstrated to be effective in the pH range of 5 ~ 9, and powerful for various refractory organic pollutants degradation including sulfamethoxazole, atrazine and benzoic acid. The high heterogeneous electro-Fenton activity was mainly attributed to the continuous in-situ ·OH generation. This study offers a facile method to construct flow-through heterogeneous electro-Fenton device, which provides a promising technology for wastewater treatment with low cost, high performance and good stability.

Comparative Study on Phenolic Wastewater Treatment by Advanced Electrochemical Oxidation Processes

Considering the direct and the indirect oxidation of AEOP's, the kinetic and therefore the reaction rate constant were significantly analyzed throughout the oxidation time. The phenol degradation efficiency has been investigated during the oxidation time with varied independent parameters like initial phenol concentration (100, 250,500) mg/L, applied current density (30, 50, 70) mAcm-2 and electrolyte circulation (6, 9, 12) L/hr. It was estimated that, for 180 min oxidation time, 70 mAcm-2 current density, 12 L/hr flowrate, and 100 mg/L initial phenol concentration, the direct anodic oxidation achieved phenol degradation efficiency of 74.4% with graphite and 83.7% with β-PbO2 anodes. Otherwise, the indirect oxidation at the same condition achieved phenol degradation efficiency of 88.9% with Fe anode and carbon felt cathode.

Photocatalytic activity of visible-light-driven ternary Ag/Ag2S/ZnO nanocomposites for phenol degradation in water

Silver sulphide (Ag2S) and zinc oxide (ZnO) nanoparticles were synthesized through a sol-gel method. The Ag constituent of the ternary was achieved by photodesposition of the binary Ag2S/ZnO resulting in a color change from brownish grey to purple indicating its formation. The synthesised particles were characterised using Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy-dispersive X-ray spectroscopy (EDX) to confirm its elemental presence and morphology. The crystallinity of the nanoparticles was determined using the X-ray diffractometer (XRD), and Brunauer–Emmett–Teller (BET) analysis surface area was 4.95 m2g-1. The progressive degradation of phenol was analysed and results showed that under visible light, the ternary composite Ag/Ag2S/ZnO, exhibited the highest phenol degradation efficiency (95 %) compared to the constituent compounds, ZnO (37 %) and Ag2S/ZnO (83 %) after 6 h of visible light irradiation respectively. However, investigations have revealed that extrinsic factors such as pH of the solution, the initial concentration of phenol and photocatalyst dosage could significantly affect the overall system performance.

The conversion of the nutrient condition alter the phenol degradation pathway by Rhodococcus biphenylivorans B403: A comparative transcriptomic and proteomic approach.

Highly toxic phenol causes a threat to the ecosystem and human body. The development of bioremediation is a crucial issue in environmental protection. Herein, Rhodococcus biphenylivorans B403, which was isolated from the activated sludge of the sewage treatment plant, exhibited a good tolerance and removal efficiency to phenol. The degradation efficiency of phenol increased up to 62.27% in the oligotrophic inorganic medium (MM) containing 500-mg/L phenol at 18 h. R. biphenylivorans B403 cultured in the MM medium showed a higher phenol degradation efficiency than that in the eutrophic LB medium. On the basis of the transcriptomic and proteomic analysis, a total of 799 genes and 123 proteins showed significantly differential expression between two different culture conditions, especially involved in phenol degradation, carbon metabolism, and nitrogen metabolism. R. biphenylivorans B403 could alter the phenol degradation pathway by facing different culture conditions. During the phenol removal in the oligotrophic inorganic medium, muconate cycloisomerase, acetyl-CoA acyltransferase, and catechol 1,2-dioxygenase in the ortho-pathway for phenol degradation showed upregulation compared with those in the eutrophic organic medium. Our study provides novel insights into the possible pathway underlying the response of bacterium to environmental stress for phenol degradation.