Barrier-Lowering Effects of Baird Antiaromaticity in Photoinduced Proton-Coupled Electron Transfer (PCET) Reactions.

Many popular organic chromophores that catalyze photoinduced proton-coupled electron transfer (PCET) reactions are aromatic in the ground state but become excited-state antiaromatic in the lowest ππ* state. We show that excited-state antiaromaticity makes electron transfer easier. Two representative photoinduced electron transfer processes are investigated: (1) the photolysis of phenol and (2) solar water splitting of a pyridine-water complex. In the selected reactions, the directions of electron transfer are opposite, but the net result is proton transfer following the direction of electron transfer. Nucleus-independent chemical shifts (NICS), ionization energies, electron affinities, and PCET energy profiles of selected [4n] and [4n + 2] π-systems are presented, and important mechanistic implications are discussed.

Combination of Selenium and UVA Radiation Affects Growth and Phytochemicals of Broccoli Microgreens.

Addition of selenium or application of ultraviolet A (UVA) radiation for crop production could be an effective way of producing phytochemical-rich food. This study was conducted to investigate the effects of selenium and UVA radiation, as well as their combination on growth and phytochemical contents in broccoli microgreens. There were three treatments: Se (100 µmol/L Na2SeO3), UVA (40 µmol/m2/s) and Se + UVA (with application of Se and UVA). The control (CK) was Se spraying-free and UVA radiation-free. Although treatment with Se or/and UVA inhibited plant growth of broccoli microgreens, results showed that phytochemical contents increased. Broccoli microgreens under the Se treatment had higher contents of total soluble sugars, total phenolic compounds, total flavonoids, ascorbic acid, Fe, and organic Se and had lower Zn content. The UVA treatment increased the contents of total chlorophylls, total soluble proteins, total phenolic compounds, and FRAP. However, the Se + UVA treatment displayed the most remarkable effect on the contents of total anthocyanins, glucoraphanin, total aliphatic glucosinolates, and total glucosinolates; here, significant interactions between Se and UVA were observed. This study provides valuable insights into the combinational selenium and UVA for improving the phytochemicals of microgreens grown in an artificial lighting plant factory.

Photocatalytic degradation of phenol in water under simulated sunlight by an ultrathin MgO coated Ag/TiO2 nanocomposite.

Phenol is one of the most widespread, toxic and recalcitrant compounds in water sources. Due to its persistent nature, conventional wastewater treatment methods are not effective to remove or degrade phenol from water. In this work, novel photocatalysts were developed to effectively degrade phenol under simulated sunlight. The catalysts were composed of one-dimensional titanium dioxide (TiO2) nanorods decorated with silver (Ag) nanoparticles, coated by an ultrathin magnesium oxide (MgO) overlayer through atomic layer deposition (ALD). Material properties of prepared catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-vis diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic performance of phenol degradation under simulated sunlight was evaluated and correlated with the material properties. The Ag nanoparticles promoted light absorption and transfer of photo-induced electron-hole pairs from within TiO2 nanorods to the catalyst surface. The ultrathin MgO overlayer with a sub-nanometer thickness did not hinder charge transfer to the surface, but rather, it further increased the light absorption and inhibited surface charge recombination through a surface passivation effect, promoting phenol degradation. The photocatalytic reaction mechanism was investigated by examining hydroxyl and superoxide radical production in the photocatalytic system. The results from this work demonstrated a new strategy for fabricating efficient solar-driven photocatalysts for the degradation of persistent water contaminants.

Gamma irradiation affects the total phenol, anthocyanin and antioxidant properties in three different persian pistachio nuts.

The effects of gamma irradiation (GR) on total phenol, anthocyanin and antioxidant activity were investigated in three different Persian pistachio nuts at doses of 0, 1, 2 and 4 kGy. The antioxidant activity, as determined by FRAP and DPPH methods, revealed a significant increase in the 1-2 kGy dose range. Total phenol content (TPC) revealed a similar pattern or increase in this range. However, when radiation was increased to 4 kGy, TPC in all genotypes decreased. A radiation dose of 1 kGy had no significant effect on anthocyanin content of Kale-Ghouchi (K) and Akbari (A) genotypes, while it significantly increased the anthocyanin content in the Ghazvini (G) genotype. In addition, increasing the radiation to 4 kGy significantly increased the anthocyanin content of K and G genotypes. To conclude, irradiation could increase the phenolic content, anthocyanin and antioxidant activity of pistachio nuts.

Visible-light photo-Fenton oxidation of phenol with rGO-α-FeOOH supported on Al-doped mesoporous silica (MCM-41) at neutral pH: Performance and optimization of the catalyst.

In this study, α-FeOOH on reduced graphene oxide (rGO-α-FeOOH) supported on an Al-doped MCM-41 catalyst (RFAM) was optimized for the visible-light photo-Fenton oxidation of phenol at neutral pH. The stability of the catalysts, effect of bubbling aeration, and degradation intermediates were investigated. Results indicated that RFAM with a large Brunauer-Emmett-Teller (BET) area and mesoporous structure displayed excellent catalytic activity for the visible-light-driven (VLD) photo-Fenton process. Phenol degradation was well described by a pseudo-first-order reaction kinetics model. Raman analysis demonstrated that an rGO-α-FeOOH (RF) composite is formed during the ferrous-ion-induced self-assembly process. Al-MCM-41 could uniformly disperse RF nanosheets and promote the mobility and diffusion of matter. The activity of the main catalyst α-FeOOH was enhanced after the incorporation of rGO nanosheets. The α-FeOOH crystal in RFAM showed catalytic activity superior to those of Fe3O4 and Fe2O3. The RFAM catalyst, with an optimal GO-Fe2+mass ratio of 2.33, exhibited a larger BET area, pore size, and pore volume, and thus exhibited high performance and energy utilization efficiency in the VLD photo-Fenton reaction with remarkable stability. Bubbling N2 inhibited catalytic performance, while bubbling O2 or air only slightly accelerated the phenol degradation. Visible light played an important role in accelerating the formation of reactive oxygen species (·OH) for the highly efficient phenol degradation. Analysis of degradation intermediates indicated a high phenol mineralization level and the formation of low-molecular-weight organic acids. This work would be helpful in providing an insight into a new type of catalyst assembly and a possible route to a promising heterogeneous catalyst applicable in the visible light photo-Fenton process for effective wastewater remediation at neutral pH.

Photocatalytic degradation of phenol using Ag core-TiO2 shell (Ag@TiO2) nanoparticles under UV light irradiation.

Ag@TiO2 nanoparticles were synthesized by one pot synthesis method with postcalcination. These nanoparticles were tested for their photocatalytic efficacies in degradation of phenol both in free and immobilized forms under UV light irradiation through batch experiments. Ag@TiO2 nanoparticles were found to be the effective photocatalysts for degradation of phenol. The effects of factors such as pH, initial phenol concentration, and catalyst loading on phenol degradation were evaluated, and these factors were found to influence the process efficiency. The optimum values of these factors were determined to maximize the phenol degradation. The efficacy of the nanoparticles immobilized on cellulose acetate film was inferior to that of free nanoparticles in UV photocatalysis due to light penetration problem and diffusional limitations. The performance of fluidized bed photocatalytic reactor operated under batch with recycle mode was evaluated for UV photocatalysis with immobilized Ag@TiO2 nanoparticles. In the fluidized bed reactor, the percentage degradation of phenol was found to increase with the increase in catalyst loading.

Fe-doped cryptomelane synthesized by refluxing at atmosphere: Structure, properties and photocatalytic degradation of phenol.

Fe-doped cryptomelanes were synthesized by refluxing at ambient pressure, followed by characterization with multiple techniques and test in photocatalytic degradation of phenol. The introduction of Fe(III) into the structure of cryptomelane results in a decrease in particle size and the contents of Mn and K(+), and an increase in the Mn average oxidation state (AOS), specific surface area and UV-vis light absorption ability. Mn and Fe K-edge extended X-ray absorption fine structure spectroscopy analysis indicates that some Fe(III) is incorporated into the framework of cryptomelane by replacing Mn(III) while the remaining Fe(3+) is adsorbed in the tunnel cavity. These Fe-doped cryptomelanes have significantly improved the photocatalytic degradation rate of phenol, with the sample of ∼3.04 wt.% Fe doping being the most reactive and achieving a degradation rate of 36% higher than that of the un-doped one. The enhanced reactivity can be ascribed to the increase in the coherent scattering domain size of the crystals, Mn AOS and light absorption, as well as the presence of sufficient K(+) in the tunnel. The results imply that metal doping is an effective way to improve the performance of cryptomelane in pollutants removal and has the potential for modification of Mn oxide materials.

A superior photocatalytic performance of a novel Bi2SiO5 flower-like microsphere via a phase junction.

A phase junction over a Bi(2)SiO(5) photocatalyst with the orthorhombic Bi(2)SiO(5) and the tetragonal Bi(2)SiO(5) structure was successfully synthesized via an ion exchange method using BiOBr solid microspheres as the sacrificial template. In the meantime, the as-prepared Bi(2)SiO(5) phase junction possesses a novel morphology of a flower-like microsphere with nanoparticles evenly embedded in its nano-petals. It was found that the Bi(2)SiO(5) phase junction not only showed a highly enhanced photocatalytic activity and excellent durability under UV or simulated solar irradiation, but also showed a remarkable visible-light activity for photo-degradation of phenol. Experimental results reveal that the tetragonal Bi(2)SiO(5) phase in this phase junction possesses a narrower band gap, thus leading to its extended light absorption. The efficient charge separation via a phase junction would make a great contribution to its highly enhanced photocatalytic activity under UV or simulated solar irradiation. The high efficiency in the degradation of organic pollutants makes the as-prepared photocatalyst a promising candidate for photocatalytic environmental purification.

Phenol photocatalytic degradation by advanced oxidation process under ultraviolet radiation using titanium dioxide.

BACKGROUND: The main objective of this study was to examine the photocatalytic degradation of phenol from laboratory samples and petrochemical industries wastewater under UV radiation by using nanoparticles of titanium dioxide coated on the inner and outer quartz glass tubes. METHOD: The first stage of this study was conducted to stabilize the titanium dioxide nanoparticles in anatase crystal phase, using dip-coating sol-gel method on the inner and outer surfaces of quartz glass tubes. The effect of important parameters including initial phenol concentration, TiO2 catalyst dose, duration of UV radiation, pH of solution, and contact time was investigated. RESULTS: In the dip-coat lining stage, the produced nanoparticles with anatase crystalline structure have the average particle size of 30 nm and are uniformly distributed over the tube surface. The removal efficiency of phenol was increased with the descending of the solution pH and initial phenol concentration and rising of the contact time. CONCLUSION: Results showed that the light easily passes through four layers of coating (about 105 nm). The highest removal efficiency of phenol with photocatalytic UV/TiO2 process was 50% at initial phenol concentration of 30 mg/L, solution pH of 3, and 300 min contact time. The comparison of synthetic solution and petrochemical wastewater showed that at same conditions the phenol removal efficiency was equal.

Mesopolymer modified with palladium phthalocyaninesulfonate as a versatile photocatalyst for phenol and bisphenol A degradation under visible light irradiation.

A novel versatile photocatalyst, FDU-PdPcS, was prepared by immobilizing palladium phthalocyaninesulfonate (PdPcS) onto the FDU-15 mesopolymer via multi-step chemical modification processes involving chloromethylation of the FDU-15 mesopolymer first with chloromethyl methyl ether, a subsequent amination reaction with ethylenediamine, and finally modification with palladium phthalocyaninesulfonate via ionic interaction. The obtained FDU-PdPcS photocatalyst was characterized by the X-ray diffraction (XRD), UV-Vis spectrosopy and inductively coupled plasma (ICP) techniques. This photocatalyst not only affords a high dispersion of monomeric PdPcS molecules, which may further be stabilized by the pi-electron of benzene rings of FDU-15, but also provides a number of diamino groups inside the mesopores, which could be advantageous for the photodegradation of phenolic pollutants. In photodegradation studies of phenolic pollutants, the FDU-PdPcS catalyst exhibited excellent visible light photocatalytic activity and reusability. The photodegradation products of phenol and bisphenol A were investigated by the gas chromatoghraphy-mass spectrometry (GC-MS) technique. The results showed that the photodegradation products were composed of carboxylic acids and CO2. Isopropanol, sodium azide and benzoquinone were used as hydroxyl radical (OH*), singlet oxygen (1O2) and superoxide radical (O2*-) scavengers, respectively. The results suggested that 1O2 and O2*- were the prominent active species during the photodegradation process. A possible mechanism for the photodegradation of phenol was also discussed.

Assessing the occurrence of the dibromide radical (Br2⁻•) in natural waters: measures of triplet-sensitised formation, reactivity, and modelling.

The triplet state of anthraquinone-2-sulphonate (AQ2S) is able to oxidise bromide to Br(•)/Br(2)(-•), with rate constant (2-4)⋅10(9)M(-1)s(-1) that depends on the pH. Similar processes are expected to take place between bromide and the triplet states of naturally occurring chromophoric dissolved organic matter ((3)CDOM*). The brominating agent Br(2)(-•) could thus be formed in natural waters upon oxidation of bromide by both (•)OH and (3)CDOM*. Br(2)(-•) would be consumed by disproportionation into bromide and bromine, as well as upon reaction with nitrite and most notably with dissolved organic matter (DOM). By using the laser flash photolysis technique, and phenol as model organic molecule, a second-order reaction rate constant of ~3⋅10(2)L(mg C)(-1)s(-1) was measured between Br(2)(-•) and DOM. It was thus possible to model the formation and reactivity of Br(2)(-•) in natural waters, assessing the steady-state [Br(2)(-•)]≈10(-13)-10(-12)M. It is concluded that bromide oxidation by (3)CDOM* would be significant compared to oxidation by (•)OH. The (3)CDOM*-mediated process would prevail in DOM-rich and bromide-rich environments, the latter because elevated bromide would completely scavenge (•)OH. Under such conditions, (•)OH-assisted formation of Br(2)(-•) would be limited by the formation rate of the hydroxyl radical. In contrast, the formation rate of (3)CDOM* is much higher compared to that of (•)OH in most surface waters and would provide a large (3)CDOM* reservoir for bromide to react with. A further issue is that nitrite oxidation by Br(2)(-•) could be an important source of the nitrating agent (•)NO(2) in bromide-rich, nitrite-rich and DOM-poor environments. Such a process could possibly account for significant aromatic photonitration observed in irradiated seawater and in sunlit brackish lagoons.

Sonochemical fabrication of novel square-shaped F doped TiO2 nanocrystals with enhanced performance in photocatalytic degradation of phenol.

A sonochemical method was developed for the fabrication of novel square-shaped TiO(2) nanocrystals doped with different F contents. The prepared samples were characterized by some physicochemical characterizations like X-ray diffraction (XRD), N(2) physical adsorption, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrum (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and UV-vis diffuse reflectance spectra (DRS). Phenol, as a hazardous chemical in water, was chosen to evaluate the photocatalytic degradation performance of the prepared TiO(2) nanocrystals under UV light irradiation. Results show that under ultrasonic irradiation conditions, F can easily be doped into TiO(2) and the obtained pure and F doped TiO(2) nanocrystals show mesoporous structures which were formed by the role of ultrasound-induced aggregation. Moreover, the doping of optimal content of F (1.3 mol%) gives 5.3 times increase in the phenol degradation rate. The high photocatalytic degradation activity of the doped TiO(2) could be attributed to the factor that F doping increases the surface hydroxyl groups over TiO(2) and effectively reduces the recombination rate of photo-generated electron/hole pairs, then producing more OH radicals to decompose the phenol molecules.

Effect of titanium dioxide nanoparticles on gamma-ray treatment of phenol in different matrices: implications in toxicity toward Daphnia magna.

Gamma-ray treatment of phenol was studied in terms of both chemical degradation and toxicological change. About 90% of phenol (5.0 × 10(-4) M) in ultrapure water (UW) was eliminated by gamma-irradiation at a dose of 10 kGy, but acute toxicity was dramatically increased, particularly for dose of 1 kGy, due to the formation of more toxic by-products such as hydroquinone, benzoquinone, resorcinol and catechol. The addition of TiO(2) nanoparticles had little effect on the removal of phenol in UW, but substantially enhanced the mineralization of phenol compared with gamma-irradiation alone. Additionally, degradation of phenol by gamma-irradiation was inhibited in a wastewater effluent (WE) matrix, likely due to the presence of dissolved organic carbon (22.06 mg L(-1)). Furthermore, lower concentrations of toxic by-products were generated both in WE and in the presence of TiO(2) nanoparticles, resulting in reduction of toxicity increase by gamma-irradiation. Meanwhile, the toxicity of gamma-ray treated phenol in WE was well estimated with simple summation of individual toxicity of phenol and by-products (R (2) = 0.9678).

Three-dimensional ordered macroporous bismuth vanadates: PMMA-templating fabrication and excellent visible light-driven photocatalytic performance for phenol degradation.

Three-dimension ordered macroporous (3D-OM) bismuth vanadates with a monoclinic crystal structure and high surface area (18-24 m(2) g(-1)) have been prepared using ascorbic acid (AA)- or citric acid (CA)-assisted poly(methyl methacrylate) (PMMA)-templating strategy with bismuth nitrate and ammonium metavanadate as the metal sources, HNO(3) as the pH adjuster and ethylene glycol and methanol as the solvent. The materials were characterized by a number of analytical techniques. The photocatalytic performance of the porous BiVO(4) samples was evaluated for the degradation of phenol in the presence of a small amount of H(2)O(2) under visible light illumination. The effects of the initial phenol concentration and the H(2)O(2) amount on the photocatalytic activity of the photocatalyst were examined. It is shown that the chelating agent, AA or CA, and the amount in which it is added had a significant impact on the quality of the 3D-OM structure, with a "(Bi + V):chelating agent" molar ratio of 2:1 being the most appropriate. Among the as-prepared BiVO(4) samples, the one with a surface area of ca. 24 m(2) g(-1) showed the best visible light-driven photocatalytic performance for phenol degradation (phenol conversion = ca. 94% at phenol concentration = 0.1 mmol L(-1) and in the presence of 0.6 mL H(2)O(2)). A higher phenol conversion could be achieved within the same reaction time if the phenol concentration in the aqueous solution was lowered, but an excess amount of H(2)O(2) was not a favorable factor for the enhancement of the catalytic activity. It is concluded that the excellent photocatalytic activity of 3D-OM BiVO(4) is due to the high quality 3D-OM structured BiVO(4) that has a high surface area and surface oxygen vacancy density. We are sure that the 3D-OM material is a promising photocatalyst for the removal of organics from wastewater under visible light illumination.

Activity and selectivity of photocatalysts in photodegradation of phenols.

Photodegradation of phenol and 4-chlorophenol over six different TiO(2) samples was tested in order to establish whether an interconnection between the activity and selectivity of photocatalysts exists. The obtained experimental data were analyzed using correlation analysis. Some correlations between the activity in phenol(s) photodegradation and selectivity toward formation of primary intermediate products were established. The type of correlations depends on the type of studied photoreactions. The discussion of the observed correlations between the activity and selectivity of photocatalysts is given in terms of the difference of surface concentrations of electrons and holes and corresponding surface active sites which might be dependent on the types of dominating surface faces. On the basis of the obtained results of correlation analysis it was assumed that a higher activity of photocatalysts could be achieved provided that both reduction and oxidation reaction pathways occur with equally high efficiency.

Photoelectrochemical performance of multi-layered BiOx-TiO2/Ti electrodes for degradation of phenol and production of molecular hydrogen in water.

Multi-layered BiO(x)-TiO(2) electrodes were used for the oxidation of chemical contaminants coupled with the production of H(2) characterized by a synergistic enhancement. The BiO(x)-TiO(2) electrodes were composed of a mixed-metal oxide array involving an under layer of TaO(x)-IrO(x), a middle layer of BiO(x)-SnO(2), and a top layer of BiO(x)-TiO(2) deposited in a series on both sides of Ti foil. Cyclic voltammograms showed that the BiO(x)-TiO(2) electrodes had an electrocatalytic activity for oxidation of phenol that was enhanced by 70% under illumination with AM 1.5 light. When the BiO(x)-TiO(2) anode was coupled with a stainless steel cathode in a Na(2)SO(4) electrolyte with phenol and irradiated with UV light at an applied DC voltage, the anodic phenol oxidation rate and the cathodic H(2) production rates were enhanced by factors of four and three, respectively, as compared to the sum of each light irradiation and direct DC electrolysis. These synergistic effects depend on the specific electrode composition and decrease on TaO(x)-IrO(x) and BiO(x)-SnO(2) anodes in the absence of a top layer of BiO(x)-TiO(2). These results indicate that the BiO(x)-TiO(2) layer functions as the key photo-electrocatalyst. The heavy doping level of Bi (25 mol%) in TiO(2) increases the electric conductivity of the parent TiO(2).

Electrospun nanofibers of Bi-doped TiO2 with high photocatalytic activity under visible light irradiation.

Bi-doped TiO(2) nanofibers with different Bi content were firstly prepared by an electrospinning method. The as-prepared nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence spectra (PL), and UV-vis diffuse reflectance spectroscopy (DRS). The results indicated that Bi(3+) ions were successfully incorporated into TiO(2) and extended the absorption of TiO(2) into visible light region. The photocatalytic experiments showed that Bi-doped TiO(2) nanofibers exhibited higher activities than sole TiO(2) in the degradation of rhodamine B (RhB) and phenol under visible light irradiation (λ>420 nm), and 3% Bi:TiO(2) samples showed the highest photocatalytic activities.

A non-aqueous synthesis of TiO2/SiO2 composites in supercritical CO2 for the photodegradation of pollutants.

Titania/silica composites with different Ti/Si ratios are synthesized via a nonconventional synthesis route. The synthesis involves non-aqueous reaction of metal alkoxides and formic acid at 75 °C in supercritical carbon dioxide. The as-prepared composite materials contain nanometer-sized anatase crystallites and amorphous silica. Large specific surface areas are obtained. The composites are evaluated in the photocatalytic degradation of phenol in aqueous medium, and in the elimination of acetaldehyde from air. The highest photocatalytic activity in both processes is achieved with a composite containing 40 wt % TiO2.

Effect of irradiation distance on degradation of phenol using indirect ultrasonic irradiation method.

Ultrasound is used as degradation of hazardous organic compounds. In this study, indirect ultrasonic irradiation method was applied to the degradation process of phenol, the model hazardous organic compound, and the effects of irradiation distance on radical generation and ultrasonic power were investigated. The chemical effect estimated by KI oxidation dosimetry and ultrasonic power measured by calorimetry fluctuated for the irradiation distance, and there was a relationship between the period of the fluctuation of ultrasonic effect and the wavelength of ultrasound. The degradation of phenol was considered to progress in the zero-order kinetics, before the decomposition conversion was less than 25%. Therefore, the simple kinetic model on degradation of phenol was proposed, and there was a linear relation in the degradation rate constant of phenol and the ultrasonic power inside the reactor. In addition, the kinetic model proposed in this study was applied to the former study. There was a linear relation in the degradation rate constant of phenol and ultrasonic energy in the range of frequency of 20-30 kHz in spite of the difference of equipment and sample volume. On the other hand, the degradation rate constant in the range of frequency of 200-800 kHz was much larger than that of 20-30 kHz in the same ultrasonic energy, and this behaviour was agreed with the former investigation about the dependence of ultrasonic frequency on chemical effect.

Biofilm coupled with UV irradiation for phenol degradation and change of its community structure.

The extensive use of phenol compounds and the inability to remove these compounds during wastewater treatment have resulted in the widespread occurrence of phenols in the natural environment. Phenols have been linked to serious risks to human and environmental health. Hence, the need to develop technologies that can effectively remove phenols from wastewater and source waters is a pressing challenge. In this study, light ceramic particles were immersed in activated sludge acclimated to degrade phenol, and microorganisms were allowed to attach to the particles surface to form biofilm. Then the ceramic particles with biofilm were moved into the photolytic circulating-bed biofilm reactor made of quartz glass, which was used for the degradation of phenol by three protocols: photolysis with UV light alone (P), biodegradation alone (B), and the two mechanisms operating simultaneously (photobiodegradation, P&B). The experimental results indicated that phenol removal rate was quickest by B experiment. However, P&B experiment gave more complete mineralization of phenol than that by other protocols. During P&B experiment, the microorganisms grown on porous ceramic carrier still kept the bioactivity degrading phenol, even under UV light irradiation. However, the dominant members of the bacterial community changed dramatically after the intimately coupled photobiodegradation, according to molecular biological analysis to the biofilm. Whereas Beijerinckia sp. was the dominant strain in the inoculum, it was replaced by Thauera sp. MZ1T that played a main role on degrading phenol during P&B experiment.