Phenolic Wastewater Research Articles

Treatment of phenolic wastewater by anaerobic fluidized bed microbial fuel cell filled with polyaniline–macroporous adsorption resin as multifunctional carrier

AbstractThe modified resin is used as a multifunctional biological carrier to treat phenolic wastewater (PW) in an anaerobic fluidized bed microbial fuel cell (AFB‐MFC). First, the modified resin was prepared, and the conductive polyaniline (PANI) was polymerized in situ on the surface and pores of the macroporous adsorption resin (MAR) to prepare the modified resin composite material (MAR/PANI). A series of modified resins with different mass ratios of resin and aniline were prepared. The modified resins were characterized by Fourier‐transform infrared spectroscopy, scanning electron microscopy (SEM), specific surface area, and pore structure analysis. Materials Studio (MS) software was used to study the internal interaction forces of PANI and MAR, and the molecular dynamics simulation method was used to analyze and calculate the cohesive energy density. The simulation results are qualitatively consistent with the experimental data. The sorption module in the MS software was used to study the adsorption behaviour of the modified resin to the organic components in the wastewater, and the adsorption mechanism was explained on the atomic scale. When the modified resin with m (MAR):m(An) = 1:0.6 was used in the AFB‐MFC, the chemical oxygen demand removal efficiency of wastewater was increased by 26.2%–88.90%, the voltage was increased by 98.46%–489.2 mV, and power density was increased by 303.28%–131.43 ± 0.17 mW/m2.

Removal of phenol by lignin-based activated carbon as an efficient adsorbent for adsorption of phenolic wastewater

Removal of phenol by lignin-based activated carbon as an efficient adsorbent for adsorption of phenolic wastewater

A Turbulent Mass Diffusivity Model for Predicting Species Concentration Distribution in the Biodegradation of Phenol Wastewater in an Airlift Reactor

In this study, a three-dimensional CFD transient model is established for predicting species concentration distribution in the biodegradation of phenol in an airlift reactor (ALR). The gas–liquid flow in the ALR is determined by the Euler–Euler method coupled with the standard k-ε model, and the bubble size is predicted by the population balance model (PBM). A turbulent mass diffusivity model is developed to simulate the turbulent mass transfer process and to predict the species concentration distribution. No empirical methods are needed as the turbulent mass diffusivity can be expressed by the concentration variance c2¯ and its dissipation rate εc. A good agreement is found between simulated and experimental results in the literature. It is not reasonable to assume a constant turbulent Schmidt number because the calculated distribution of turbulent mass diffusivity is not identical to that of turbulent viscosity. Finally, the hydrodynamic characteristics and biodegradation performance of the proposed model in a novel ALR are compared with that in the original ALR.

REVIEW ON ADVANCES IN BIODEGRADATION OF PHENOLS: KINETICS, MODELLING AND MASS TRANSFER

Harmful pollutants like phenol and its derivatives are found in wastewater from a wide range of industries, including oil refining, medicines, coal conversion, chemistry, and petrochemistry. The high concentration, high toxicity, and difficult-to-degrade characteristics of phenols in wastewater pose a serious threat to the environment and to human health. By employing different strains of microorganisms and biocatalysts to create biodegradation procedures of diverse pollutants and a wide spectrum of hazardous compounds, biotechnology has successfully addressed significant environmental challenges. Among various phenols removal techniques, biodegradation is both economical and environmentally friendly. During the study of microbial degradation processes, there is a great deal of interest in the potential for mathematical modelling to forecast microbial growth and degrade harmful or inhibiting environmental pollutants at variable quantities. Such mathematical models are frequently created using aromatic compounds like phenol. The review discusses the following topics: kinetics, modelling, and mass transfer; future scope and directions; diverse microorganisms, bioreactors, the metabolic pathway of phenol, influencing factors, and recent advancements in biological therapy.

Characterization and Biodegradation of Phenol by Pseudomonas aeruginosa and Klebsiella variicola Strains Isolated from Sewage Sludge and Their Effect on Soybean Seeds Germination.

Phenols are very soluble in water; as a result, they can pollute a massive volume of fresh water, wastewater, groundwater, oceans, and soil, negatively affecting plant germination and animal and human health. For the detoxification and bioremediation of phenol in wastewater, phenol biodegradation using novel bacteria isolated from sewage sludge was investigated. Twenty samples from sewage sludge (SS) were collected, and bacteria in SS contents were cultured in the mineral salt agar (MSA) containing phenol (500 mg/L). Twenty colonies (S1 up to S20) were recovered from all the tested SS samples. The characteristics of three bacterial properties, 16S rDNA sequencing, similarities, GenBank accession number, and phylogenetic analysis showed that strains S3, S10, and S18 were Pseudomonas aeruginosa, Klebsiella pneumoniae, and Klebsiella variicola, respectively. P. aeruginosa, K. pneumoniae, and K. variicola were able to degrade 1000 mg/L phenol in the mineral salt medium. The bacterial strains from sewage sludge were efficient in removing 71.70 and 74.67% of phenol at 1000 mg/L within three days and could tolerate high phenol concentrations (2000 mg/L). The findings showed that P. aeruginosa, K. pneumoniae, and K. variicola could potentially treat phenolic water. All soybean and faba bean seeds were germinated after being treated with 250, 500, 750, and 1000 mg/L phenol in a mineral salt medium inoculated with these strains. The highest maximum phenol removal and detoxification rates were P. aeruginosa and K. variicola. These strains may help decompose and detoxify phenol from industrial wastewater with high phenol levels and bioremediating phenol-contaminated soils.

Kinetic characterization of a new phenol degrading Acinetobacter towneri strain isolated from landfill leachate treating bioreactor

The objective of this study was to establish and to mathematically describe the phenol degrading properties of a new Acinetobacter towneri CFII-87 strain, isolated from a bioreactor treating landfill leachate. For this purpose, the biokinetic parameters of phenol biodegradation at various initial phenol concentrations of the A. towneri CFII-87 strain have been experimentally measured, and four different mathematical inhibition models (Haldane, Yano, Aiba and Edwards models) have been used to simulate the substrate-inhibited phenol degradation process. The results of the batch biodegradation experiments show that the new A. towneri CFII-87 strain grows on and metabolizes phenol up to 1000 mg/L concentration, manifests significant substrate inhibition and lag time only at concentrations above 800 mg/L phenol, and has a maximum growth rate at 300 mg/L initial phenol concentration. The comparison of the model predictions with the experimental phenol and biomass data revealed that the Haldane, Aiba and Edwards models can be used with success to describe the phenol biodegradation process by A. towneri CFII-87, while the Yano model, especially at higher initial phenol concentrations, fails to describe the process. The best performing inhibition model was the Edwards model, presenting correlation coefficients of R2 > 0.98 and modelling efficiency of ME > 0.94 for the prediction of biomass and phenol concentrations on the validation datasets. The calculated biokinetic model parameters place this new strain among the bacteria with the highest tolerance towards phenol. The results suggest that the A. towneri CFII-87 strain can potentially be used in the treatment of phenolic wastewaters.

Obtaining peroxidase from Zanthoxylum armatum DC. fruit and application in detoxification of phenol wastewater

The important role of peroxidase in plant physiology and biocatalysis has attracted much attention. To evaluate the specific properties of the peroxidase from Zanthoxylum armatum DC. fruit and its performance in phenol removal and detoxification. This study obtained low-purity peroxidase from Z. armatum fruit for the first time via three-phase partitioning with a yield of 160 mg/100 g, purification fold of 12.8, and recovery rate of 83 %. Afterward, SuperTandex-75 gel was used for further purification. The result of liquid chromatography-tandem mass spectrometry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and native-polyacrylamide gel electrophoresis revealed that the enzyme contained isoenzymes with different molecular weights (46.32, 39.41, 35.03, and 9.06 kDa). Enzymatic characterization study found that compared with commercial peroxidase, the enzyme showed better pH, temperature, and metal ion stability, however, 10 mM concentrations of ascorbic acid and citric acid could inhibit its activity by more than 90 %. Regarding the phenol bioconversion, when the enzyme activity of the system is 200 U/mL, the phenol concentration of 5–10 mM can be reduced by more than 80 % under optimal conditions. The detoxification effect of low-purity peroxidase on phenol water was tested using Vigna radiata (Linn.) Wilczek. The reduced toxicity of phenol water after treatment promoted the growth of plants, indicating that the phenol water after degradation by the low-purity peroxidase can be used in agricultural production, and it also proved that the enzyme is a promising peroxidase. In addition, the present study provides data for the selection of inhibitory peroxidase activity parameters in the food processing of Z. armatum fruit.

Semi – Automation Design Using Flow Injection Analysis System with Smart Phone for the Determination of Total Phenols in Wastewater

Smart phone used as supporting hardware in different applications in chemical analysis are becoming increasingly important in everyday life. Rapid, easy, and straightforward analytical system flow injection analysis system for the determination of the total phenols was conducted using 4-aminoantipyrine reagent. The detection method was based on the reaction total phenols with reagent in the basic media and subsequent formation of a yellow color product. The samples or standard solutions were injection into a carrier stream to react with 4-aminoantipyrine reagent and ammonium chloride with ammonium hydroxide to give yellow color product, which was detected by spectrophotometer at 510 nm. The experimental condition such as flow rate of reagent and carrier, reagent volume, length of reaction coil and concentration of reagent were optimized. A good linear calibration curve in the range of 250-2000 mg L-1 was obtained with regression equation (y=0.0108 x + 0.3453), (R= 0.9989). The limit of detection was in the amount of 0.0112 mg L-1. The method was successfully applied for the determination of the total phenols in wastewater.

Эффективный экстрагент в технологии очистки фенолсодержащих сточных вод

Phenol and its derivatives are among the most dangerous pollutants entering the environment as part of wastewater from oil refineries and petrochemical plants, as well as pharmaceutical industry and construction materials. In surface water bodies, phenols occur in the form of their derivatives, namely: free phenols, phenolate ions and phenolates. The listed compounds have different degrees of toxicity, forming humus-like compounds as a result of polymerization and condensation reactions. For this reason, the treatment of phenolic wastewater is a very urgent problem in the petrochemical industry due to the high carcinogenicity of these impurities. Deep purification of water effluents is complicated by the fact that none of the known methods of removing phenols can achieve, with relatively acceptable technical and economic indicators, the required degree of purification. In accordance with the guidance document RD 52.24.480-2006 and the "Instructions for the formation and presentation of operational information on extremely high and high levels of surface water pollution, as well as their accidental pollution" (IGCE, Moscow, 2001), when assessing the pollution of natural waters with phenols, in all cases, 0.001 mg/dm3 is used as the MPC.

전해산화를 위한 양극 전극제조 및 페놀 제거 특성

Recently, the electrochemical oxidation of refractory organic materials has received significant research attention. In this research, titanium electrodes coated with iridium and tin were prepared using pyrolysis and dip-coating, respectively, and the surface and chemical composition of the fabricated electrodes were determined using scanning electron microscopy and X-ray diffraction analysis. Following this, the elimination routes for the contaminants in phenol wastewater treated with the fabricated electrodes were examined. Phenols have complex degradation mechanisms making it difficult to determine their reaction pathways and produce stable discharge concentrations. In the electrochemical oxidation of phenols, several intermediate species such as benzoquinone and carboxylic acids are produced. Benzoquinone is known to be more harmful to the ecosystem than carboxylic acids. Therefore, in the present study, the partial degradation of phenols was investigated under electrochemical anodic oxidation in the presence of NaCl during wastewater treatment using the Ti/SnO₂ and Ti/IrO₂. electrodes. The presence of NaCl in the electrolyte catalyzed the oxidation of phenols only with the Ti/IrO₂ anode. This catalytic action of NaCl was attributed to the participation of electro generated ClO^- in the oxidation of phenols and their oxidation products near to the anode or/and in the bulk of the electrolyte. The phenol removal rate was excellent when the phenol concentration was low and the electrolyte concentration and cell potential were higher. In particular, the removal rate was 99.8% after 30 min when the phenol and electrolyte concentrations were 1,000 mg/L and 0.4%, respectively. The reaction velocity of electrolysis exhibited first order for the phenol concentration.

Energetic evaluation of phenol wastewater treatment by reverse electrodialysis reactor using different anodes

Efficient electrode materials are essential to convert salinity gradient energy into oxidative degradation energy and electrical energy by reverse electrodialysis reactor (REDR). In this context, comparative experiments of REDR using different anodes (Ti/IrO2–RuO2, Ti/PbO2 and Ti/Ti4O7) were conducted. The effects of output current and electrode rinse solution (ERS) flowrate on mineralization efficiency and energy output were discussed. Results demonstrated that the COD removal rate(ηCOD) rose almost linearly with output current and ERS flowrate when using Ti/Ti4O7 anode, but excessive operating conditions caused a slow increase or even decrease of ηCOD when using Ti/IrO2–RuO2 or Ti/PbO2 anodes. The order of electrode system potential loss (Eele) for the three anodes was Ti/Ti4O7> Ti/PbO2> Ti/IrO2–RuO2. High Eele was beneficial to ηCOD but had a negative effect on the net output power (Pnet) of REDR. Regardless of the applied anodes, increasing the current and decreasing the ERS flowrate was detrimental to Pnet due to higher Eele. Based on these findings, four energy efficiency parameters were defined to evaluate energy recovery from multiple perspectives by linking energy output with mineralization capacity. They were electrode efficiency (ηele), energy efficiency (EE), general current efficiency (GCE) and energy consumption (EC), respectively. Results showed that REDR with Ti/Ti4O7 anodes and suitable operating conditions achieved the optimal energy indicators and mineralization efficiency, which provided an efficient and economical option for wastewater treatment and energy recovery.

Enhanced photocatalytic decomposition of phenol in wastewater by using La–TiO2 nanocomposite

In this work, La–TiO2 nanocomposite was synthesized by loading lanthanum onto TiO2 and used for improving photodegradation of phenol in wastewater.The characterizations of La–TiO2 demonstrated that the loading of La onto TiO2 not only increased its adsorption light zone up to 470 nm but also decreased the band gap energy from 3.1 to 2.64 eV. Photoluminescence spectra of La–TiO2 confirmed the enhancing separation rate between electron and hole, leading to improve photodegradation efficiency of phenol. The removal rate of phenol was influenced by solution pH and alkaline conditions could bring better removal efficiency. In presence of light, the photodegradation efficiency of phenol by TiO2 was 64.1%, while it increased up to 93.4% by La–TiO2 photocatalyst. La–TiO2 nanocomposite was tested for five cycles and it showed only 13.8% dropping in the photodegradation efficiency of phenol. Besides, over 82% of phenol was removed from the wastewater sample by modified TiO2, demonstrating the potential of La–TiO2 photocatalyst for water pollution control.

Mesoporous LaVO4/MCM-48 nanocomposite with visible-light-driven photocatalytic degradation of phenol in wastewater

Dearomatization through photocatalytic oxidation is a swiftly rising phenolic compounds removal technology that works at trifling operations requirements with a special emphasis on the generation of nontoxic products. The study aims to develop a LaVO4/MCM-48 nanocomposite that was prepared via a hydrothermally approach assisting the employment of an MCM-48 matrix, which was then utilized for phenol degradation processes. Various techniques including UV–Vis DRS, FTIR, PL, Raman, TEM, and BET analyses are employed to characterize the developed photocatalyst. The developed photocatalyst presented remarkable characteristics, especially increased light photon utilization, and reduced recombination rate leading to enhanced visible-light-driven photodegradation performance owing to the improved specific surface area, specific porosities, and <2 eV narrow energy bandgap. The LaVO4/MCM-48 nanocomposite was experienced on aqueous phenol solution having 20 mg/L concentration under visible-light exposure, demonstrating exceptional performance in photodegradation up to 99.28%, comparatively higher than pure LaVO4. The conducted kinetic measurements revealed good accordance with pseudo first-order. A possible reaction mechanism for photocatalytic degradation was also predicted. The as-synthesized LaVO4/MCM-48 nanocomposite presented excellent stability and recyclability.

Research on advanced treatment of phenolic chemical wastewater and carbon replacement by the multi-layer biological activated carbon filter

After a series of biochemical processes, the wastewater engendered by the production of phenolic resin is ultimately left with a majority of difficult degradation organic matter. Most of these organic compounds are harmful to the water environment and require further advanced treatment before discharge. In this study, the original simple biological activated carbon (BAC) filter column device was improved. The new multi-layer BAC filter does not require backwash after improvement. The treatment efficiency of the multi-layer BAC filter was studied through long-term operation, and the variation of pollutants in the wastewater was analyzed. The results indicated that the multi-layer BAC filter could effectively remove hardly biodegradable organic matter, ammonium‑nitrogen (NH4+-N), and total nitrogen (TN), and its mechanism was mainly that hardly biodegradable organic matter and TN were removed by adsorption and biodegradation, while NH4+-N was only removed by microbial degradation. The pore-size distribution characteristics on the BAC surface were analyzed, and it was found that the adsorption and biodegradation reactions mainly occurred in the microporous region. The experiment on carbon replacement indicated that the service time of the BAC system could be prolonged by choosing the correct time of carbon replacement and adding the appropriate amount of microorganisms. Based on high-throughput sequencing, it was found that the microbial communities on BAC at the same height were significantly different before and after carbon replacement. The results of this paper are of some relevance for the upgrading of advanced treatment processes for chemical wastewater in practical engineering.

Fracking wastewater treatment: Catalytic performance and life cycle environmental impacts of cerium-based mixed oxide catalysts for catalytic wet oxidation of organic compounds

Water scarcity and the consequent increase of freshwater prices are a cause for concern in regions where shale gas is being extracted via hydraulic fracturing. Wastewater treatment methods aimed at reuse/recycle of fracking wastewater can help reduce water stress of the fracking process. Accordingly, this study assessed the catalytic performance and life cycle environmental impacts of cerium-based mixed oxide catalysts for catalytic wet oxidation (CWO) of organic contaminants, in order to investigate their potential as catalysts for fracking wastewater treatment. For these purposes, MnCeOx and CuCeOx were tested for phenol removal in the presence of concentrated NaCl (200 g L−1), which represented a synthetic fracking wastewater. Removal of phenol in pure (“phenolic”) water without NaCl was also considered for comparison. Complete (100 %) phenol and a 94 % total organic carbon (TOC) removal were achieved in both the phenolic and fracking wastewaters by utilising MnCeOx (5 g L−1) and insignificant metal leaching was observed. However, a much lower activity was observed when the same amount of CuCeOx was utilised: 23.3 % and 20.5 % for phenol and TOC removals, respectively, in the phenolic, and 69.1 % and 63 % in the fracking wastewater. Furthermore, severe copper leaching from CuCeOx was observed during stability tests conducted in the fracking wastewater. A life cycle assessment (LCA) study carried out as part of this work showed that the production of MnCeOx had 12–98 % lower impacts than CuCeOx due to the higher impacts of copper than manganese precursors. Furthermore, the environmental impacts of CWO were found to be 94–99 % lower than those of ozonation due to lower energy and material requirements. Overall, the results of this study suggest that the adoption of catalytic treatment would improve both the efficiency and the environmental sustainability of both the fracking wastewater treatment and the fracking process as a whole.

Efficient extraction of phenol from wastewater by ionic micro-emulsion method: Anionic and cationic

Phenolic wastewater is one of the priorities in the field of wastewater treatment, which poses a serious threat to the human health and nature environment. In this paper, cationic cetyltrimethylammonium bromide (CTAB) and anionic sodium oleate (NaOL) microemulsions were utilized to extract phenol from the wastewater. The optimal extraction factors were investigated by exploring the effects of microemulsion composition ratio and extraction conditions on the phenol extraction performance. Furthermore, the enhanced extraction mechanism of phenol by cations microemulsions is illustrated by studying the extraction process of cationic and anionic microemulsions in the extraction of phenol. The optimum components were obtained: surfactant concentration of 0.2 mol·L–1, isoamyl alcohol volume of 30%, internal aqueous phase concentration of CTAB microemulsion of 0.05 mol·L–1, and internal aqueous phase concentration of NaOL microemulsion of 0.09 mol·L–1. The extraction efficiencies were 96.44% and 82.0% when using CTAB and NaOL microemulsions under optimal conditions (water–emulsion ratio of 5, contact time of 9 min, extraction temperature of 298.15 K, and pH of 9), confirming the enhanced extraction of phenol by CTAB cationic microemulsion. It was analyzed that the enhanced extraction of CTAB microemulsion was due to the electrostatic adsorption of cations with phenol root ions.

Effect of co-culture with Halomonas mongoliensis on Dunaliella salina growth and phenol degradation.

The discharge of industrial phenol wastewater has caused great harm to the environment. This study aims to construct microalgae and bacteria co-culture system to remove phenol from simulated high-salt phenol wastewater and accumulate microalgae biomass. The degradation of phenol by marine microalgae Dunaliella salina (D. salina) and phenol-degrading bacteria Halomonas mongoliensis (H. mongoliensis) was investigated preliminarily, and then the effects of co-culture H. mongoliensis and D. salina on the degradation of phenol and the growth of D. salina were studied. The effects of D. salina/H. mongoliensis inoculation ratio, light intensity, temperature and pH on the performance of the co-culture system were systematically evaluated and optimized. The optimal conditions for phenol degradation were as follows: a D. salina/H. mongoliensis inoculation ratio of 2:1, a light intensity of 120μmol m-2 s-1, a temperature of 25°C and a pH around 7.5. Under optimal conditions, this co-culture system could completely degrade 400mg L-1 of phenol within 5 days. Correspondingly, the phenol degradation rate of D. salina monoculture was only 30.3% ± 1.3% within 5days. Meanwhile, the maximum biomass concentration of D. salina in coculture was 1.7 times compared to the monoculture. This study suggested that this coculture system had great potential for the bioremediation of phenol contaminants and accumulate microalgae biomass.

Effects of a novel Mg-C micro-electrolysis system for phenolic wastewater degradation: material characterization, influencing factors, and model optimization

ABSTRACT This study investigated a novel magnesium carbon micro-electrolysis (Mg-C ME) system for strengthening the removal of phenolic compounds in wastewater. The effects of the Mg/C mass ratio, aeration intensity, initial pH and reaction time on the degradation of three phenolic compounds and the COD removal efficiency in the simulated wastewater were evaluated using one-factor-at-a-time (OFAT) method. The optimum values obtained for the Mg/C mass ratio, aeration intensity, initial pH and reaction time were 3:1, 4.0 L/(L·min), 5.0 and 2.5 h, respectively. The experimental removal rates of catechol, resorcinol, and phenol, under the mentioned conditions, were obtained to be 95.6%, 71.5%, and 48.8%, respectively. Meanwhile, the COD removal rates were 63.8%,44.7%,34.0%, respectively. Moreover, experiments were designed and analyzed based on the box-based designing response surface (BBD-RSM) method. According to the results, the Mg/C mass ratio was the most significant variable showing incremental effect on the removal efficiency of catechol in a way that maximum removal efficiency of catechol was achieved in Mg/C mass ratio of 3.23:1. The validation experiments showed that the maximum removal efficiency of catechol was 96.24% under optimization conditions. Resorcinol degradation characteristics analysis indicated that the Mg-C ME system performed a key function in phenolic compounds elimination. Results showed that the Mg-C ME has a considerable capability in removing the phenolic compounds and COD. Thus, it could be considered as an efficient pretreatment choice for treating phenolic wastewater in the future.

A new eco-friendly method for efficient recovery and reuse of phenols in a semi-coke wastewater

Phenols in wastewater (WW SCP ) from semi-coke production pose a serious threat to human health and ecological environment due to its high concentration, high toxicity, and difficult-to-degrade characteristics. Single treatment method, such as extraction or catalytic conversion, has the problems of secondary pollution, high processing cost, and low catalytic efficiency. In light of the problems, this study developed an ecofriendly WW SCP treatment by the synergistic process of extraction and catalytic conversion, which can convert phenols in a WW SCP into anisoles. Using response surface method (RSM), the wastewater treatment process was optimized. The concentration of phenols in the WW SCP was optimally reduced from 5509 mg L −1 to 105 mg L −1 after three times of extraction with cyclohexane/dimethyl carbonate (DMC) as the extractant at 25 °C for 1 min of each extraction and the extract yield of phenols up to 98%. The phenols extracted from the WW SCP were completely converted over Na-CH 3 ONa/ γ -Al 2 O 3 at 213.48 °C for 2.00 h with phenols/DMC molar ratio of 1 : 4.00. Therefore, the synergistic process of extraction and catalytic conversion provides a pollution-free and more economic strategy for treating WW SCP . • A simple and green extraction- catalytic coupling process is proposed to treat Semi-coke wastewater. • Dimethylcarbonate is used not only as an extractant, but also as a O -methylating reagent for volatile phenol reaction. • Optimizing process conditions through response surface methodology.

Biodegradability enhancement of phenolic wastewater using hydrothermal pretreatment

A novel hydrothermal pretreatment was applied for the biochemical treatment of phenolic wastewater with high concentrations of phenolic substances. The results demonstrated that 250 °C was the reaction temperature dividing point for complete oxidation, hydrothermal gasification, and amino release from carbonaceous organics in phenolic wastewater. Before the dividing point reached, some of the large molecules were hydrolyzed into small molecules of volatile phenolic substances that were easily adsorbed by the activated sludge. After the integrated hydrothermal pretreatment and anaerobic/aeration process, the removal rate of volatile phenolswas respectively reached by 97 % and 88 % with hydrothermal temperature of 250 °C and without pretreatment. Functional microorganisms (i.e., Chloroflexi) responsible for aromatic compounds degradation were enriched, thus the dioxygenases, dehydrogenase reactions, and meta-cleavage of catechol were enhanced. This work provided an innovative approach to remove phenolic substances from phenolic wastewater, and in-depth understandings of microbial responses in biochemical systems.