Phenol Degradation Research Articles

Use of biokaolinite clay for the microbial removal of phenol from real industrial wastewater samples by Dermacoccus nishinomiyaensis and Kocuria rosea

AbstractPhenol bioremediation was investigated using two bacteria (primarily cocci) Dermacoccus nishinomiyaensis, Kocuria rosea strains and the one actinomycetes Nocardiopsis lucentensis which were isolated from samples of activated sludge from the wastewater treatment plant (WWTP) in Beni‐Suef, Egypt as sole carbon and energy sources. This was applied on real industrial wastewater sample taken from Ul HAWA textile plant, Middle Egypt. Degradation of phenol by microbes adsorbed on natural kaolin clay was studied compared with free microbes. In case of 50 mg/L as starting phenol concentration, the percentage removal using free microbes was 68%, corresponding to 98% in case of microbes adsorbed on kaolin clay after the passage of 48 h under incubation at 30°C and neutral pH at 150 rpm. Also, 300 mg/L of phenol achieved degradation frequency of 80% compared to 38% after ≈48 h without clay addition. High concentrations of an organic pollutant are usually inhibitory for the microorganisms. Kaolin clay has a pronounced effect in accelerating phenol degradation through biofilm formation resulting in decreasing the degradation time, increasing the percentage of removing efficiency under high phenol concentration conditions due to its buffering effects on pH fluctuations of the degradation system. Kaolin clay protects microorganisms against unfavorable environment, resists the adverse effects of substrate inhibition and accelerates the degradation process. The adsorption process was demonstrated by the pseudo‐first‐order, pseudo‐second‐order, Weber–Morris adsorption kinetic models, and four isotherm models namely, Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich have been applied to express the adsorption process. The SEM images of microbes adsorbed on kaolin clay explain their adsorption mode on the clay surface as biofilm (Bio kaolinite).

Phenol degradation and Sb(V) adsorption by superparamagnetic CTAB-modified iron calcium composite

The heavy metal ions and organic dyes in textile wastewater treatment pose a significant environmental burden and are challenging to effectively manage. A magnetic cationic surfactant hexadecyltrimethylammonium bromide (CTAB), modified iron-calcium composite (referred to as CIC), was prepared using a straightforward method from iron-calcium composites as raw materials. The simultaneous catalytic degradation and adsorption efficiency of phenol and Sb(V) from textile wastewater were evaluated using this material. The results indicate that under conditions of pH 5.0 and a duration of 180 min, both phenol and Sb(V) removal rates exceed 90%. Characterization and experimental findings reveal that CIC possesses magnetic properties, facilitating easy separation, and offers a large surface area, ensuring abundant adsorption sites and stability. Additionally, CIC can assist in the enhanced degradation of phenol by H2O2. Pseudo-second-order kinetics describe the adsorption of Sb(V) by CIC, while oxidative kinetics explain the degradation of phenol. The primary removal mechanisms involve the oxidation and degradation of phenol through the generation of hydroxyl radicals by H2O2 and the formation of Fe-O-Sb complexes between Sb(V) and the iron sites on CIC, as well as the precipitation of Ca-O-Sb compounds between Sb(V) and the calcium sites on CIC. Therefore, the synergistic effect of CIC and H2O2 offers an efficient and environmentally friendly method for the simultaneous removal of Sb(V) and phenol in coupled wastewater, presenting broad prospects for application in wastewater treatment.

Fabrication of pollution-free coal gangue-based catalytic material utilizing ferrous chloride as activator for efficient peroxymonosulfate activation

Novel coal gangue-based persulfate catalyst (CG-FeCl2) was successfully synthesized by the means of calcinating under nitrogen atmosphere with the addition of ferrous chloride tetrahydrate (FeCl2·4H2O). The phase transformation of the prepared materials and gas products during the heating process are thoroughly investigated. It is suggested that ferrous chloride participated in the phase transformation and formed Si-O-Fe bonds. And the main gaseous products are H2O, H2, and HCl during the heating process. Besides, the ability of CG-FeCl2 to activate peroxymonosulfate (PMS) for catalytic degradation of polycyclic aromatic hydrocarbons (PAHs) and phenol was deeply studied. More than 95% of naphthyl, phenanthrene and phenol were removed under optimizied conditions. In addition, 1O2, ·OH, and SO4·− were involved in the CG-FeCl2/PMS system from the free radical scavenging experiment, where 1O2 played a major role during the oxidation process. Furthermore, CG-FeCl2/PMS system exhibited superior stability in a relatively wide pH range and the presence of common anion from related degradation experiments. Overall, the novel CG-FeCl2 is an efficient and environmentally friendly catalyst, displaying potential application prospect in the field of PAHs and phenol-contaminated wastewater treatment.

Degradation of phenol in wastewater through an integrated dielectric barrier discharge and Fenton/photo-Fenton process

In this study, a non-thermal dielectric barrier discharge-Fenton/photo-Fenton process was investigated to remove phenol from synthetic wastewater. The changes and optimal values of influencing parameters, including treatment time, iron concentration, phenol initial concentration, and pH, were investigated based on the central composite design (CCD) method. The presence of 0.4 mmol/L of iron in the phenol solution with a concentration of 100 mg/L increased the removal efficiency and pseudo-first-order kinetic constant compared to dielectric barrier discharge cold plasma (DBDP) alone from 0.0824 min−1 and 56.8% to 0.2078 min−1 and 86.83%, respectively. The phenol removal efficiency was reduced to 52.9%, 45.6% and 31.8% by adding tert-butyl alcohol (TBA) with concentrations of 50, 100, and 200 mg/l, respectively. After 12 min of DBDP irradiation, the pH of the sample decreased from 5.95 to 3.42, and the temperature of the sample increased from 19.3 to 37.2 degrees Celsius. The chemical oxygen demand (COD) of the sample containing 100 mg/L phenol under plasma-Fenton/photo-Fenton irradiation decreased from 241 mg/L to 161 mg/L. Phenol removal efficiency after 10 min of treatment in the presence of 0.4 mmol/L of iron with the reactor volume of 50 mL was 87%, but the efficiency decreased to 76%, 47%, and 9% by increasing the volume to 100, 200, and 400 mL, respectively. Reducing the power led to a decrease in the removal efficiency from 56.8% for 100 W power to 10.8% for 40 W. The energy efficiency for 50% removal by DBDP and plasma-Fenton/photo-Fenton systems was 5.86×10−3 kWh/mg and 1.27×10−3 kWh/mg, respectively.

Analysis of Photocatalytic Degradation of Phenol by Zinc Oxide Using Response Surface Methodology.

In this study, the photocatalytic degradation of phenol, which is commonly found in industrial wastewater at high rates, was investigated using a zinc oxide (ZnO) catalyst. It is thought that our findings will contribute to the removal of phenol in industrial wastewater. The experimental study was conducted in a batch-type air-fed cylindrical photocatalytic reactor, and a central composite design (CCD) was chosen and analyzed using response surface methodology (RSM). The study aimed to explore the effects of initial phenol concentration, catalyst concentration, airflow rate, and degradation time on the photocatalytic degradation of phenol and the removal efficiency of total organic carbon (TOC). A quadratic regression model was developed to establish the relationship between phenol degradation, TOC removal effectiveness, and the four factors mentioned. The validity of the model was assessed through an analysis of variance (ANOVA). A good agreement was observed between the model results and the experimental data. As a result of the experiments carried out under optimized conditions, the degradation percentage of phenol was found to be 77.15 %, and the degradation percentage of TOC was 59.87 %. Additionally, pseudo-first-order kinetics were used in the photocatalytic degradation of phenol.

Effects of Fe/Fe–Mn oxides loaded biochar on anaerobic degradation of typical phenolic compounds in coal gasification wastewater: Performance and mechanism

In this study, two kinds of magnetic biochar (BC) were synthesized by loading Fe (FeBC) and Fe–Mn oxides (FMBC) and their effects on anaerobic phenolics degradation were investigated. Compared with BC/FMBC, FeBC addition achieved the superior phenolics biodegradation even for 3,5-xylenol. Compared with control, FeBC addition enhanced CH4 production by 100.1 % with the lag time shortened from 9.5 days to 6.6 days while it increased to 11.2 days with FMBC addition. FeBC addition activated adsorption-biodegradation and Fe (III) reduction with the improved electron transfer activity, adenosine triphosphate and cytochrome C concentrations. Abundant phenol degrading bacteria, electroactive bacteria, syntrophic partners could be enriched by FeBC addition, contributing to the enhanced benzoyl-CoA and methanogenesis pathways. However, this enhancement was inhibited by FMBC addition owing to the accumulation of reactive oxygen species. This study provided novel insights into the application of magnetic BC to enhanced anaerobic treatment of phenolic wastewater.

Bacterial degradation of phenol: a review of the current state of knowledge

Phenol is a toxic and recalcitrant contaminant widely used in various industries, including petrochemical, pharmaceutical, and agrochemical industries. Bacterial degradation of phenol is a promising method for treating phenol-contaminated wastewater. The biodegradation of phenol by bacteria can effectively remove it from the environment, making it a valuable alternative to traditional chemical treatment methods. This review summarizes the current knowledge on the bacterial biodegradation of phenol, including those in the petrochemical, pharmaceutical, and agrochemical sectors, the metabolic pathways involved in phenol degradation, and the factors that influence the efficiency of phenol biodegradation. This paper also discusses the challenges and limitations of using bacteria for the biodegradation of phenol, including the need for further research to improve the efficiency and sustainability of the process. The outcome of this review demonstrates that bacterial biodegradation is a promising and effective method for treating phenol-contaminated wastewater and provides a foundation for future research to improve the efficiency and continuous use of this process.

Novel surface structure of LaFeO3/nitrogen-deficient g-C3N4 nanocomposites to improve visible-light photocatalytic performance toward phenol removal.

Herein, novel surface structure LaFeO3/nitrogen-deficient g-C3N4 nanocomposites (LaFeO3/g-C3N4-H) have been successfully synthesized by a two-step process. First, nitrogen-deficient graphitic carbon nitride (g-C3N4-H) was produced by thermally condensing melamine that had been treated with acetic acid as a precursor. After that, LaFeO3 was incorporated into the g-C3N4-H nanosheets. The as-prepared nanostructured materials were characterized by XRD, FT-IR, N2 adsorption-desorption experiments, FESEM, and TEM, demonstrating the formation of interfacial interaction and heterogeneous structure in LaFeO3/g-C3N4-H nanocomposites. Additionally, UV-vis diffuse reflectance spectra (DRS) and photoluminescence spectra (PL) have been used to assess the optical properties of the nanohybrids. The results show that the LaFeO3/g-C3N4-H nanocomposite was successfully produced with a reliable interfacial interface, and produced a good heterojunction relationship between g-C3N4-H and LaFeO3 which may significantly boost the photocatalytic activity as compared to prinstine g-C3N4 and LaFeO3. Phenol degradation under visible light irradiation was used to test the photocatalytic activity of LaFeO3/g-C3N4-H, and the results showed that 10%-LaFeO3/g-C3N4-H had significant photocatalytic activity and remarkable adsorption efficiency, with an overall removal rate of phenol up to 88% after 180min of visible light irradiation. This study may present a novel method for developing highly efficient artificial photocatalytic systems.

Acidovorax benzenivorans sp. nov., a novel aromatic hydrocarbon-degrading bacterium isolated from a xylene-degrading enrichment culture.

A Gram-stain-negative strain, designated as D2M1T was isolated from xylene-degrading enrichment culture and characterized using a polyphasic approach to determine its taxonomic position. The 16S rRNA gene sequence analysis revealed that strain D2M1T belongs to the genus Acidovorax, with the highest 16S rRNA gene similarity to Acidovorax delafieldii DSM 64T (99.93 %), followed by Acidovorax radicis DSM 23535T (98.77 %) and Acidovorax kalamii MTCC 12652T (98.76 %). The draft genome sequence of strain D2M1T is 5.49 Mb long, and the G+C content of the genome is 64.2 mol%. Orthologous average nucleotide identity and digital DNA-DNA hybridization relatedness values between strain D2M1T and its closest relatives were below the threshold values for species demarcation confirming that strain D2M1T is distinctly separated from its closest relatives. The whole genome analysis of the strain revealed a phenol degradation gene cluster, encoding a multicomponent phenol hydroxylase (mPH) together with a complete meta-cleavage pathway including an I.2.C-type catechol 2,3-dioxygenase (C23O) gene. The strain was able to degrade benzene and ethylbenzene as sole sources of carbon and energy under aerobic and microaerobic conditions. Cells were facultatively aerobic rods and motile with a single polar flagellum. The predominant fatty acids (>10 % of the total) of strain D2M1T were summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). The major ubiquinone of strain D2M1T was Q8, while the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Based on polyphasic data, it is concluded that strain D2M1T represents a novel species of the genus Acidovorax, for which the name of Acidovorax benzenivorans sp. nov. is proposed. The type strain of the species is strain D2M1T (=DSM 115238T=NCAIM B.02679T).

MXene assisted solvent-free synthesis of a hybrid Fe/TiO2/ZSM-5 catalyst for phenol degradation

MXene assisted solvent-free synthesis of a hybrid Fe/TiO2/ZSM-5 catalyst for phenol degradation

Degradation of aqueous phenol by combined ultraviolet and electrochemical oxidation treatment

The industrial wastewater containing phenol is characterized by its elevated toxicity, resistance to biodegradation, and pronounced bioaccumulation. Traditional treatment methods frequently fall short in effectively removing phenol. In this study, a UV photoelectrochemical synergistic catalytic oxidation process was employed for the efficient elimination of phenol. The investigation systematically assessed the impact of various factors, including electrolyte type, concentration, current density, and initial pH, on phenol degradation. Furthermore, the degradation products were analyzed using high-performance liquid chromatography and gas chromatography-mass spectrometry. The results indicate that the oxidation and degradation of phenol in the UV photoelectrochemical synergistic catalytic system adhere to a first-order kinetic equation. Moreover, the combined UV and electrochemical catalytic degradation process demonstrated a synergistic effect, significantly enhancing the efficiency of phenol degradation. This study aimed to elucidate the mechanism of UV combined electrochemical catalytic degradation of phenol and provide reasonable speculation on the degradation pathway of phenol under UV electrochemical co-catalytic oxidation.

Sulfur-doped porous carbon sheets embedded with rich iron sites for 1O2 dominated peroxymonosulfate activation

Porous carbon films co-doped with iron, nitrogen, and sulfur were synthesized via a one-step pyrolysis process, which have multiple active sites and can produce bulk 1O2 through PMS activation, which is effective in phenol degradation.

Magnetic self-doped TiO2-x /Fe3O4@g-C solar-driven photocatalytic composite for water decontamination.

Declining water resources and their contamination with chemicals risk the aquatic environment. Therefore, this work was devoted to designing a magnetically recyclable photocatalyst suitable for water treatment, namely, a TiO2-x /Fe3O4@g-C composite. Different preparation conditions were investigated together with the corresponding characteristics. The pure defective anatase TiO2-x phase of low band gap energy was detected through XRD and DRS analyses. Low charge recombination after the formation of defects was confirmed. The performances of the prepared photocatalysts in phenol degradation under solar light were evaluated, revealing the superior efficiency of TiO2-x prepared hydrothermally at 200 °C/24 h relative to intact TiO2. This best sample was incorporated with Fe3O4@g-C to facilitate its recovery and reuse. This successful combination was confirmed using XRD, Raman and XPS tools. TiO2-x /Fe3O4@g-C 2 : 1 formulation was found to be the most photoactive and could be reused up to five times without significant loss in its efficiency. Therefore, the precisely developed magnetic photocatalyst is promising for application in the water-treatment process.

Disinfection of Water and Solid Surfaces: Possibilities for Deep Degradation of Phenol and Tetracycline by Corona Electric Discharge

Disinfection of Water and Solid Surfaces: Possibilities for Deep Degradation of Phenol and Tetracycline by Corona Electric Discharge

Highly uniform platinum photodeposited hollow mesoporous titania nanoparticles for photocatalytic degradation of phenol

Pt-photodeposited hollow mesoporous titania nanoparticles exhibit excellent phenol degrading photocatalytic efficiency by providing abundant reaction sites, improved mass transport, Pt-enhanced absorption band extension, reduced e− h+ recombination.

Improved phenol degradation by catalytic wet air oxidation on the Co3O4 spinel catalysts supported on SBA-15 modified with TiO2

The removal of phenol from aqueous industrial effluents by catalytic wet-air oxidation (CWAO) is a challenging process that requires novel catalysts resistant to leaching of the active phases during residence time in a batch reactor. In this sense, this work demonstrated that this can be archived with the catalyst having the spinel phase Co3O4 supported on mesoporous silica SBA-15 doped with an optimized amount of TiO2 (3 wt%). In the phenol CWAO reaction carried out at 160 °C and 10 bar O2, this best Co3O4/TiO2/SBA-15 catalyst showed an increase of phenol conversion from 49.0 % to 68.3 % and of CO2 selectivity from 87 % to 98 %. The extensive catalyst characterization and overall activity results indicated that this was related to the strength and nature of the acid sites and the oxidation states of the cobalt oxide phases. Combined factors influenced the final behaviour of the catalyst, such as its intrinsic activity, dispersion of the active phase, inhibition of CoSiO4 phase formation, high Lewis acidity and the large amount of active Co3O4 spinel phase. The presence of TiO2 nanoparticles (NPs) decorating the support surface improved the stability of the catalyst by inhibiting the leaching of cobalt species during the reaction. After three reaction cycles, the most efficient Co/3Ti/S15 catalyst showed high CO2 selectivity (∼92.7 %) and low selectivity towards carboxylic acid (∼5.3 %) and polyphenolic compounds (∼2%). It is proposed that surface oxidation is the rate-determining step in the CWAO reaction over TiO2/SBA-15-supported Co3O4 spinel catalysts.

Ultrafast removal of organics via peroxymonosulfate activation over Co2P/TD hollow spheres derived from ZIF-67.

Co2P/tetrasodium diphosphate (TD) derived from ZIF-67/sodium phytate was newly developed and synthesized, and exhibited excellent degradation ability toward various refractory organics via peroxymonosulfate activation. A corresponding reaction mechanism was proposed. In addition, a continuous-flow operation of phenol degradation was realized.

Physicochemical Properties, Bioactive Compounds Degradation Kinetics, and Microbiological Counts of Fortified Pomegranate Gummy Candy (GC) during Ambient Storage

This study explored the potential of fortified pomegranate gummy candies (GC) as a solution for insufficient vitamin C and phenol intake. It entailed two objectives: assessing the impact of ambient storage (20±2 ℃) on various GC properties and developing kinetic models to predict vitamin C and phenol degradation during storage. The study involved the preparation of GC using a modified formulation and examined moisture content, water activity, texture, vitamin C, total phenolic content, and microbiological counts during 15-day-storage. Findings revealed that the moisture content decreased from 21.82% to 13.41%, potentially affecting texture. Water activity remained high (0.84-0.86), posing potential microbiological risks. The textural analysis indicated high hardness, springiness, gumminess, and chewiness, which may impact consumer acceptance. Adhesiveness remained minimal. Vitamin C decreased from 2,176.90 mg AA/100g to 1,419.10 mg AA/100g, possibly influenced by moisture and oxygen. Phenolic content decreased from 2,845.97 mg GAE/100g to 2,183.70 mg GAE/100g, remaining remarkably high. Kinetic modeling revealed that zero-order kinetics best described degradation, with constant degradation rates. In conclusion, fortified pomegranate GC demonstrate potential as functional food. However, further research is necessary to optimize texture properties, improve formulation and understand complex interactions between gelatin and phenolic compounds for enhanced consumer acceptance and health benefits.

Assembly of MOF derived composite catalyst on the PVDF membrane matrix for high-efficient phenol removal

Integrating the heterogeneous catalysts with the membrane matrix is a promising approach for wastewater decontamination. In this study, a ZIF-67 derived cobalt‑manganese spinel catalyst MnCo2O4.5@Carbon (MCOC) was prepared using a one-pot pyrolysis process and was then blended with a polyvinylidene fluoride (PVDF) membrane through the phase inversion method. The introduction of the MCOC catalyst not only improved the permeance of the membrane but also constructed active reaction sites within the membrane matrix. As a result, the PVDF/MCOC membranes exhibited both satisfactory degradation capabilities by activating peroxymonosulfate and favorable permeation performance. Remarkably, about 99 % of phenol (20 mg/L) can be removed within 30 min, with a water flux of 649.0 L/m2∙h. Besides, the PVDF/MCOC catalytic membrane possessed favorable anti-fouling properties and stability. The flux recovery rate of the PVDF/MCOC membrane reached 85 % after three fouling/washing cycles, while the phenol removal efficiency remained consistent at 95 % after 5 consecutive cycles. Radical quenching tests and electron paramagnetic resonance analysis further indicated that sulfate radicals and singlet oxygen were the primary reactive oxygen species in the phenol degradation processes. Consequently, this work highlights an effective method to fabricate a catalytic membrane with high permeance and catalytic efficiency, potentially expanding the application of heterogeneous catalysts in wastewater decontamination.

Phenol Biodegradation by Free and Immobilized Acinetobacter calcoaceticus K5 and Candida tropicalis YM2 Isolated from Persian Gulf

Phenols exhibit high solubility in water, leading to their potential to contaminate significant volumes of freshwater, wastewater, groundwater, oceans, and soil. The primary objective of this study is to isolate and identify bacterial and yeast isolates with optimal phenol degradation capabilities from Persian Gulf. Sea water and sediment samples were collected to isolate bacterial and yeast isolates, which were then evaluated for their ability to degrade phenol both in their single-cell form and when encapsulated in chitosan and alginate. The phenol-degrading strains were quantified using colony-forming unit (CFU) and most probable number (MPN) methods. The most promising microorganisms were selected and identified using phenotypic and polymerase chain reaction techniques. The selected isolates were immobilized in alginate and chitosan carriers, and their bioremediation potential was assessed at different phenol concentrations. The removal of phenol by the isolates was confirmed using Gas Chromatography. Through molecular techniques, Acinetobacter calcoaceticus K5 and Candida tropicalis YM2 were identified as the most efficient phenol-degrading strains. Acinetobacter calcoaceticus K5 exhibited the highest growth at phenol concentrations of 200 and 300 ppm, while Candida tropicalis YM2 showed optimal growth at a concentration of 700 pp. In case of Acinetobacter calcoaceticus, chitosan immobilization and a phenol concentration of 500 ppm proved to be the best conditions for phenol bioremediation. In the case of Candida tropicalis YM2, the highest percentage of phenol removal was achieved using the chitosan carrier at a concentration of 1000 ppm. Comparing the immobilized strains to their free counterparts, it was observed that the stabilized bacteria exhibited greater phenol removal efficiency, particularly at a concentration of 500 ppm, with a significant difference between the two conditions. This study demonstrates that the novel strains Acinetobacter calcoaceticus K5 and Candida tropicalis YM2 are efficient strains for the bioremediation of various phenol-contaminated seawater and this is the first report to show such rapid phenol degradation by these organisms isolated from sediment and seawater samples collected from Persian Gulf.