Treatment Of Phenolic Wastewater Research Articles

In-situ Cu-loaded sludge biochar catalysts for oxidative degradation of bisphenol A from high-salinity wastewater

Safe disposal of excess sewage sludge (SS) produced from chemical/biochemical water treatment processes has been a worldwide concern. In this work, sewage sludge biochar-based Cu-loaded catalysts (CSBC) were synthesized by a simple impregnation-pyrolysis method. The impregnated Cu2+ in SS was converted to Cu0/CuI species after pyrolysis, which greatly improved the removal efficiency of bisphenol A (BPA). BPA (100 mg/L) could be completely removed within 130 min in CSBC/Peroxydisulfate (PDS) system, compared to 77.8% in sewage sludge biochar/PDS system. Meanwhile, CSBC performed well over a wide pH range of 3∼9. In CSBC/PDS system, singlet oxygen (1O2) dominated non-radical pathway had been proved to play an essential role in BPA degradation, boosting the oxidative treatment of phenolic wastewater under high-salinity. Results showed that the removal efficiency of BPA reached 93.6%, 91.0% and 84.6% in high-salinity wastewater with salinities of 16, 80, and 160 g/L, respectively. The total estimated cost of CSBC (1 kg) was $5.053 and the cost of BPA-containing wastewater (100 mg/L) treatment was estimated approximately 0.02 $/L, indicating its cost-effectively potential in practical applications. This study not only provides a new value-added reuse method for sewage sludge treatment and disposal, but also a new strategy for the effective treatment of high-salinity organic wastewater.

A Novel Treatment of Phenolic Wastewater Using Recyclable Rubbery Carrier for Heterogeneous Fenton's Process

A Novel Treatment of Phenolic Wastewater Using Recyclable Rubbery Carrier for Heterogeneous Fenton's Process

Liquid-liquid extraction of phenolic wastewater through a surface modified poly(vinylidene fluoride-co-hexafluoropropylene) hollow fiber membrane contactor and process optimization

BackgroundStrict environmental regulations have been recognized for phenolic wastewater treatment due to toxicity of the phenolic compounds. In this study, solvent extraction of a phenolic wastewater was investigated via a liquid-liquid membrane contactor system. MethodsPorous poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) hollow fiber membranes were modified by coating an ultra-thin layer of hydrophobic surface modifying macromolecule (SMM). The membranes were characterized by various tests such as SEM-EDS, nitrogen permeation, overall porosity, contact angle and critical water entry pressure (CEPw). Significant findingsFrom SEM, an open structure with combination of finger-like and sponge-like structure was produced. The membrane exhibited high surface hydrophobicity (water contact angle of 109°) with good wetting resistance, overall porosity of 82% and mean pore size of 18 nm. From response surface methodology (RSM), the maximum phenol extraction flux of 2.02 × 10−3 kg/m2s was estimated by the model at the optimum process variables as phenol concentration of 448 mg/L, feed temperature of 42 °C, aqueous phase flowrate of 196 mL/min and organic phase flowrate of 117 mL/min. The coefficient of determination (R2) of 0.972 showed a close proximity between the model and the experimental data. The membrane showed a reasonable flux that can be a favorable alternative for industrial phenolic wastewater treatment.

Coupling the recovery of spent lithium-ion batteries and the treatment of phenol wastewater: A “treating waste with waste” strategy

The recovery of spent lithium-ion batteries and the treatment of phenol wastewater are both environmental and social issues. In this study, the enhanced recovery of spent lithium-ion batteries and the efficient treatment of phenol wastewater are smartly coupled via a “treating waste with waste” strategy. Under optimal conditions, the leaching process involving phenol achieves 98% and 96% efficiency for Co and Li, respectively. After precipitation, Co and Li could be recovered as Co(OH)2 and Li2CO3, and the precipitated Co(OH)2 was further calcined to generate Co3O4. Furthermore, the organic contaminants that remained in the waste-leaching solution could be removed by a spent graphite-activating peroxymonosulfate (PMS) process. It is noteworthy that the total organic carbon (TOC) in the waste-leaching solution could be removed using fewer PMS compared with the original phenol wastewater owing to the pre-oxidation of phenol during the leaching process, further confirming the advantage of this “treating waste with waste” strategy.

Synergistic removal performance and mechanism in denitrification system under phenol stress

Based on the principle of heterotrophic denitrification, the synergistic removal mechanism of phenol and NO3--N in denitrification system under phenol stress was investigated. The denitrification process with phenol as the only carbon source was successfully achieved by running the UASB reactor for 119 days, which had excellent phenol and NO3--N removal efficiency (over 99.5%). Results showed that phenol stress enhanced the ATP level, key enzyme activities to increase denitrification and phenol degradation. Phenol stress also stimulated improvement of cell membrane permeability, which led to the increase of electron transport system activity. Meanwhile, phenol stress promoted the secretion of N-acylhomoserine lactones (AHLs), which increased bacterial activity by modulating EPS to mitigate the external environmental shock. Besides, AHLs-mediated quorum sensing (QS) might regulated the changes of microbial structural, resulting in the optimization of microbial communities within the whole denitrification system. Therefore, a synergistic removal mechanism was proposed to elucidate the excellent performance of the denitrification system under phenol stress. This work provided serviceable information for treatment of high concentration phenol wastewater and the synergistic removal mechanism.

Sulfur and nitrogen co-doped biochar activated persulfate to degrade phenolic wastewater: Changes in impedance

In this research, sulfur and nitrogen co-doped biochar was prepared by co-pyrolysis method. The degradation law of phenol in simulated wastewater by activated potassium persulfate(PDS) was studied, and the effects of preparation conditions on the purification performance of phenol were also discussed. The results show that the phenol degradation rate by biochar with a doping ratio of 20% to activate PDS is up to 98.5%. In addition, the cycle performance of the doped biochar can still maintain 76% at the fifth cycle, indicating a good recycling performance. The results of density functional theory(DFT) calculations and various characterization techniques show that the sulfur and nitrogen exist in the form of thiophene sulfur and graphite nitrogen in the biochar, respectively. The electron density distribution of doped biochar become uneven, and the electrochemical impedance decreases from 32.88 to 10.53, prompting the reaction to proceed via non-radical path. Finally, the purification experiment results reveal that the S,NBC/PDS system possesses an excellent purification effect on simulated coal gasification wastewater, providing a reference for the industrial phenolic wastewater treatment.

Copper oxidase and encapsulin shell protein in anammox bacteria reduces phenol toxicity from water

The inhibition of phenol on anammox bacteria limits the application of anammox in the treatment of phenol-containing wastewaters. The molecular mechanism of how anammox bacteria resist phenol toxicity in wastewater remains unclear. In this study, copper oxidase (Cop) and encapsulin shell protein (cEnc) from anammox bacteria Candidatus Brocadia fulgida were found to assist bacteria to resist phenol stress. The Cop and its complex with cEnc (cEnc–Cop) expressed in vitro by molecular biology had laccase-like activities (1.39 U/mg and 0.79 U/mg, respectively). Combined with real-time quantitative polymerase chain reaction, both the Cop and cEnc gene expression levels were upregulated by stimulating anammox bacteria with phenol for a short time. It was also found that hydrazine synthase genes increased first and then decreased. These results indicated that cEnc–Cop relieved the inhibition of phenol to hydrazine synthase by degrading phenol, and consequently restored anammox activity. These findings will contribute to a deeper insight into the mechanism of how anammox bacteria respond to phenol and phenolic compound stress, and provide a theoretical reference for the application of anammox technology to phenol and phenolic compound-containing wastewater treatment.

Comparative study of the adsorption performance of NH2-functionalized metal organic frameworks with activated carbon composites for the treatment of phenolic wastewaters

To better understand the role of the —NH2 group in adsorption process of phenolic wastewaters, NH2-functionalized MIL-53(Al) composites with activated carbon (NH2-M(Al)@(B)AC) were prepared. The results showed that the NH2 group could increase the mesopore volume for composites, which promotes mass transfer and full utilization of active sites, because hierarchical mesopore structure makes the adsorbent easier to enter the internal adsorption sites. Furthermore, the introduction of the NH2 group can improve the adsorption capacity, decrease the activation energy, and enhance the interaction between the adsorbent and p-nitrophenol, demonstrating that the NH2 group plays a crucial role in the adsorption of p-nitrophenol. The density functional theory calculation results show that the H-bond interaction between the —NH2 group in the adsorbent and the NO2 in the p-nitrophenol (adsorption energy of –35.5 kJ·mol−1), and base-acid interaction between the primary —NH2 group in the adsorbent and the acidic OH group in the p-nitrophenol (adsorption energy of –27.3 kJ·mol−1) are predominant mechanisms for adsorption in terms of the NH2-functionalized adsorbent. Both NH2-functionalized M(Al)@AC and M(Al)@BAC composites exhibited higher p-nitrophenol adsorption capacity than corresponding nonfunctionalized composites. Among the composites, the NH2-M(Al)@BAC had the highest p-nitrophenol adsorption capacity of 474 mg·g−1.

Efficiency of Multistep Process of Fenton Oxidation and Bentonite in the Treatment of Ammonia Phenolic Wastewater

Industrial production generates enormous amounts of wastewaters with a high content of organic and inorganic substances, which must be treated before discharging into a natural recipient to such a quality that it will not have a negative impact on the aquatic environment. This paper shows the possibility of applying a multi-stage process with Fenton reagents in combination with bentonite as an adsorbent in the treatment of ammonia-phenolic wastewater. The role of bentonite clay in this study was dye removal. The investigation was carried out under laboratory conditions, and the efficiency of the process was determined on the following parameters of COD, ammonia, phenol and thiocyanate. Also, the influence of the pH value, the concentration of oxidant hydrogen peroxide and catalyst iron sulphate heptahydrate was examined. The optimal values obtained for the pH, concentration of hydrogen peroxide and the catalyst iron sulphate heptahydrate was: 3; 30% and 23 g/l, where the efficiency of removal of the COD, ammonia, phenol and thiocyanate was: 96.42 %; 85.17 %; 100 % i 99.13 %.

Utilization of barks of Araucaria columnaris: Preparation of activated carbon/clay composite beads and adsorptive treatment of phenolic wastewater

The powdered form of carbon has several technical, handling, transportation, and health-related disadvantages, but careful transformation of powdered carbon into a technically favorable shaped structure can increase the practicality of this green material. This study presents the preparation of activated carbon from Araucaria columnaris bark with one-step activation and its fabrication into a spherical carbon/clay composite using a natural binder (Montmorillonite). The structure and surface of prepared activated carbon and its composite material were explored with SEM, ATR-FTIR, Surface area, and porosity measurements. The post-fabrication change in adsorption properties was investigated for phenol adsorption in light of the change in physicochemical properties. Under optimum conditions, the carbon (activated at 650 °C) and its composite adsorb about 132.28 and 80.52 mg·g−1of phenol, respectively. The thermodynamics and kinetics of adsorption on these materials were investigated with different models. The adsorption rate of composite (1.25 ×10−3 g·mg−1min−1) is twice that of activated carbon, and its adsorption enthalpy also increased to − 30.02 kJ·mol−1. The regeneration and reusability studies show that the composite retains the structural advantages of activated carbon and improves its reusability by 8.5%. The experiments with synthetic wastewater indicate that Araucaria columnaris-based activated carbon is an efficient adsorbent for wastewater treatment, and its reusability can be further improved with its fabrication into carbon/clay composite beads.

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.

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.

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.

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.

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.

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.

The role of bromides upon electrochemical mineralization of bisphenol A with boron-doped diamond anode

Anodic oxidation with boron-doped diamond (BDD) has been regarded as outstanding option for wastewater treatment. However, in the presence of halide, the extreme promise of the technology may be hampered by the formation of toxic halogenated by-products. While the behaviors of chloride are relatively understood, little is currently known about the role of bromide and its effect on the generation of brominated transformation by-products (BTPs). Herein, we reported for the first time the bromide-mediated electrochemical mineralization of bisphenol A with BDD anodes. Firstly, we employed statistical methodology to determine the impacts of the main operating variables on the mineralization performance, and the novel and peculiar roles of bromides during the electrolytic oxidations were identified. Next, LC/MS analysis was used to identify the reaction intermediates, and plenty of BTPs (including oligomers of complex structures) were thus detected. Detailed transformation mechanisms responsible for the BTPs were also proposed. Lastly, we used ECOSAR program to determine the ecological toxicity of all detected by-products, and the structure-toxicity relation involved was discussed. Overall, the above results are of particular interest to understand BTPs formation mechanism in electrochemical oxidation processes, which as well provide guidelines to minimize potential risks of BDD technology for phenolic wastewater treatment.

Efficient degradation of phenol in aqueous solution by Fe2+/H2O2/CaO2 system

The traditional Fenton treatment of phenol wastewater can achieve a good degradation efficiency. However, this technology requires pH adjustment before and after the treatment, which will corrode the reactor and increase economic loss. In this study, to overcome the disadvantages of traditional Fenton, a synergistic degradation method of phenol in water by adding calcium peroxide (CaO 2 ) in Fenton oxidation was proposed. Under the optimal dosage (Fe 2＋ : H 2 O 2 : CaO 2 = 1 : 2: 1), the COD removal rate (phenol 100 mg/L) reached 95.59% within 15 min. Results showed that the Fe 2 + / H 2 O 2 /CaO 2 system exerted a good degradation efficiency on phenol in a wide pH range (3–11). In addition, studies have showed that adding CaO 2 in Fe 2 + / H 2 O 2 system was more effective to increase the utilization rate of iron ions and H 2 O 2 , and the amount of reactive oxygen species (ROS) in the system was more than when the same amount of H 2 O 2 was added, free radical detection showed that ⋅ OH and system. The effects of anions (Cl − , NO 3 − , SO 4 2 − , and HCO 3 − ) on the performance of Fe 2 + / H 2 O 2 /CaO 2 were studied. Certain amounts of Cl − , SO 4 2 − , and HCO 3 − affected the COD removal rate more than NO 3 − . Finally, the degradation pathway of phenol was proposed based on mass spectra. This study provided a valuable method for the efficient degradation of industrial wastewater. • The addition of CaO 2 significantly improved organics degradation in the Fe 2 + / H 2 O 2 system. • The Fe 2 + / H 2 O 2 /CaO 2 system exerted a good degradation efficiency in a wide pH range (3–11). • Adding CaO 2 to the Fe 2 + /H 2 O 2 system effectively promoted the reduction of Fe 3＋ to Fe 2＋ and improved the utilization rate of iron ions and H 2 O 2 . • ⋅ OH and ⋅ O 2 − were identified as the main active substances in the Fe 2 + / H 2 O 2 /CaO 2 system.

Removal of phenol from wastewater by electrochemical bromination in a flow reactor.

Electrochemical methods have been widely applied in the treatment of phenol wastewater for the past few years. However, conventional electrochemical advanced oxidation processes (EAOPs) generally encounter the problem of electrode passivation and the energy consumption required for mineralization is high. In this work, we reported the treatment of phenol wastewater by electrochemical bromination method in a flow electrolysis cell. The Ti/Sb-SnO2/PbO2 electrode was prepared and used as anode. The experiments were carried out under different initial pH, KBr concentrations, current densities, and volumetric flow rates. The generated 2,4,6-tribromophenol (TBP) could be easily separated from the electrode surface and electrolyte. The brominated intermediates were identified by GC/MS. The removal efficiencies for phenol and COD were 100% and 82.7%, respectively, under the best operational conditions (current density of 40mAcm-2, KBr concentration of 0.074mol L-1, initial pH of 1.0, and volumetric flow rate of 114mLmin-1). Furthermore, our electrochemical bromination method offered a high apparent current efficiency (ACE) of 276.6% and a low energy consumption (EC) of 4.54 × 10-3 kWh gCOD-1 after 40min of electrolysis time, indicating that this process was suitable for phenol wastewater treatment.

Fe3O4–CuO@Lignite activated coke activated persulfate advanced treatment of phenolic wastewater from coal chemical industry

In this study, lignite activated coke (LAC) was used as the carrier for the first time, Fe3O4–CuO composite metal oxide was used as the main active material, and the nano-scale magnetic supported composite metal oxide Fe3O4–CuO@LAC catalyst was synthesized for the first time, which can effectively activate the active oxygen in peroxodisulfate (PS). XRD, FTIR, BET, SEM, XPS and other analysis results showed that there was particulate matter with spherical structure on the surface of the active coke, and its diffraction peaks matched well with the characteristic peaks of Fe3O4 and CuO, and it was a mesoporous structure with a specific surface area of 619.090 m2 g−1. By optimizing the experimental conditions, the results showed that more than 92% of hydroquinone can be removed under the conditions of hydroquinone concentration of 50 mg/L, pH = 5, adding 0.1 g/L catalyst and 3 mmol/L PS. EPR and quenching experiments proved that there were four reactive oxygen species in the reaction system ·OH, SO4−·, O2−· and 1O2. According to the degradation products of hydroquinone detected by LC-MS, the possible degradation path was deduced which laid a foundation for solving the problem of difficult treatment of phenol-containing wastewater in coal chemical industry.