Phenol Removal Process Research Articles

Performance study of phenol sequestration from agricultural wastewater by chemical activated Montmorillonite

Agricultural by-products possess potential as cost-effective adsorbents for the remediation of phenolic contaminants in environmentally treated wastewater. This research focuses on the utilization of Algerian montmorillonite clay, specifically modified montmorillonite (Mo-5N), treated with 5N hydrochloric acid (HCl), compared to its untreated form (Mo-0N), for phenol sequestration from pesticide-laden waters. We employed various analytical techniques, such as chemical analysis, X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR) spectroscopy, to characterize these adsorbents. The adsorption behavior was scrutinized under varying conditions, including pH, contact time, phenol concentration, and temperature. The maximum adsorption capacities achieved were 119.12 mg/g for Mo-5N and 100.89 mg/g for Mo-0N under optimal conditions of pH 5.72, a contact time of 120 minutes, and a temperature of 40°C. The kinetics of adsorption were best described by the pseudo-second-order and Elovich models, while the Freundlich isotherm model aptly described the equilibrium data. Thermodynamic analyses revealed that the phenol removal process using both forms of montmorillonite is spontaneous and endothermic. This study demonstrates the efficacy of Algerian montmorillonite clay in the removal of phenolic pesticides from agricultural wastewater.

Design of a two functional permeable reactive barrier for synergistic enzymatic and microbial bioremediation of phenol-contaminated waters: laboratory column evaluation

The present study aimed to develop a system using a combination of enzymatic and microbial degradation techniques for removing phenol from contaminated water. In our prior research, the HRP enzyme extracted from horseradish roots was utilized within a core-shell microcapsule to reduce phenolic shock, serving as a monolayer column. To complete the phenol removal process, a second column containing degrading microorganisms was added to the last column in this research. Phenol-degrading bacteria were isolated from different microbial sources on a phenolic base medium. Additionally, encapsulated calcium peroxide nanoparticles were used to provide dissolved oxygen for the microbial population. Results showed that the both isolated strains, WC1 and CC1, were able to completely remove phenol from the contaminated influent water the range within 5 to 7 days, respectively. Molecular identification showed 99.8% similarity for WC1 isolate to Stenotrophomonas rizophila strain e-p10 and 99.9% similarity for CC1 isolate to Bacillus cereus strain IAM 12,605. The results also indicated that columns using activated sludge as a microbial source had the highest removal rate, with the microbial biofilm completely removing 100% of the 100 mg/L phenol concentration in contaminated influent water after 40 days. Finally, the concurrent use of core-shell microcapsules containing enzymes and capsules containing Stenotrophomonas sp. WC1 strain in two continuous column reactors was able to completely remove phenol from polluted water with a concentration of 500 mg/L for a period of 20 days. The results suggest that a combination of enzymatic and microbial degrading systems can be used as a new system to remove phenol from polluted streams with higher concentrations of phenol by eliminating the shock of phenol on the microbial population.

Phenol Removal through Horseradish Peroxidase Immobilization on Ultrafiltration Membranes: Comparative Analysis of Immobilization Methods and Fouling Patterns

This research investigates the removal of phenol using pure peroxidase from horseradish grade I in conjunction with a dead-end ultrafiltration membrane. Various horseradish peroxidase (HRP) immobilization techniques— physical adsorption, covalent bonding, and cross-linking with glutaraldehyde—were applied to a regenerated cellulose (RC) membrane with a surface area of 44 m2 and a molecular weight cut-off of 30 kDa. The investigation examined factors influencing phenol removal, including phenol concentration, membrane fouling, and the reusability of immobilized enzymes. Results indicated that covalent bonding was the most suitable enzyme immobilization technique, achieving a remarkable 90.1% immobilization yield. Phenol removal efficiency reached 100% at 30 min under specific conditions: phenol concentration of 1 mg/L, pH 6.0, hydrogen peroxide concentration of 0.5 mM, and operating pressure set at 3 psig, with temperature maintained at 28 ± 3 °C. Membrane fouling resulted in a decrease in flux. The performance of fouling models was found to be influenced by phenol concentration, with the Cake Formation Model (CFM) proving most effective at low concentrations, while the Complete Pore Blocking Model (CBM) emerged as more suitable at higher concentrations. The immobilized enzyme exhibited reusability for five cycles, maintaining a phenol removal efficiency exceeding 50%. These findings contribute to understanding the enzymatic phenol removal process and the use of appropriate enzyme immobilization techniques for the effective and sustainable treatment of phenol-contaminated water.

Optimization and mechanistic insight of phenol removal using an effective green kaolin adsorbent through experimental and computational approaches

The discharge of phenols into the aquatic environment has detrimentally affected human health and the aquatic ecosystem. Hence, removing phenols from polluted water bodies has been a global concern. In this study, a natural and low-cost adsorbent, kaolin, was used to remove phenol from aqueous solutions. Experimental and computational approaches were applied to optimize the removal efficiency and provide mechanistic insight into the phenol removal process. Based on the response surface methodology findings, the optimum conditions were pH 1.6, 40 min, 50 mg/L, and 2 g with 92.19 % maximum percentage removal. The regeneration test shows that kaolin retained over 76.76 % of adsorption capacities. SEM and FESEM reveals the surface morphology and effectiveness of kaolin as phenol removal. The best fit for the Isotherm adsorption for the phenol on kaolin is Freundlich isotherm, which indicated multilayer adsorption. The hydroxyl group from phenol (-OH) and the siloxane group of kaolin (Si-O-Si) shifted, suggesting the presence of a hydrogen bond between kaolin and phenol during adsorption, as determined by one- and two-dimensional IR spectroscopy. Density functional theory calculations were used to support the experimental results by providing information on the Mulliken charge and electronic transition of the complex to improve understanding of the adsorption of phenol on kaolin. Based on the quantum theory of atoms in molecules analysis (QTAIM) and the reduced density gradient non-covalent interaction (RDG-NCI) technique, the chemical reaction occurring during the removal of phenol by kaolin was determined to occur through hydrogen bonding and classified as an intermediate type (∇2ρ(r) > 0 and H < 0). Further characterizations employing molecular electrostatic potential, global reactivity, and local reactivity descriptors were conducted to investigate the mechanism of the phenol adsorption on kaolin. The findings demonstrated that phenol functions as an electrophile while kaolin acts as a nucleophile during the formation of hydrogen bonds, where the interaction occurred between the O2 atom of kaolin (electron donor) and the H13 atom of phenol (electron acceptor).

Modeling the Kinetics, Equilibrium and Thermodynamics of Poly(acrylamide)/Sodium-Bentonite for Enhanced Phenol Removal from Aqueous Media

A composite based on polyacrylamide and Na-bentonite, designated as PAAm/Na-bentonite was prepared by in-situ radical polymerization using ammonium persulfate as an initiator and bis-acrylamide as a crosslinker. The structural and morphological features were examined by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunner − Emmet − Teller measurements. The results showed PAAm intercalation in the Na-bentonite layers. Equilibrium, thermodynamics, and kinetic studies were conducted by considering the effects of pH, initial phenol concentration, contact time and temperature. The zeta potential of the PAAm/Na-bentonite composite was calculated to understand the mechanism of phenol adsorption onto our product. The pollutant uptake behavior was determined by UV-Vis spectrophotometry. Adsorption results showed that PAAm/Na-bentonite composite showed a maximum adsorption of 160.3 mg.g−1 of 30 mg.L−1 phenol solution at pH 6 after 15 min of adsorption using 4 g.L−1 of the adsorbent. The presence of acrylamide modified the surface characteristics of the Na-bentonite and offered more adsorption sites as confirmed by XRD and SEM. Equilibrium modeling of the phenol removal process was carried out using Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) adsorption isotherms. The equilibrium adsorption data were well fitted with the Langmuir model. In addition, the kinetics of adsorption were best described by a pseudo-second-order expression rather than a first-order model. The interactions between phenol molecules and adsorbent were explained by electrostatic as well as hydrogen bonding interactions, as confirmed by the pseudo-second-order kinetic model. A model for the interactions between the composite and the phenol molecules is proposed. The negative values of Gibb’s free energy (ΔG°) confirmed that the process was spontaneous. The positive value of change in entropy (ΔS° = 0.922 JK−1mol−1) suggests that the randomness was increased at the solution/solid interface. We suggest, the results indicate that PAAm/Na-bentonite presents a significant potential as an adsorbent material for phenol removal from aqueous solutions.

A "Green" Approach for Phenol Removal from Synthetic Water, by Peroxidase Extracted from Cabbage Leaf Waste

This study underlines the idea of valorizing vegetable waste in a “green” approach for water bioremediation. In this research, the possibility of using unpurified peroxidase obtained from cabbage leaf waste in the process of removing phenol from aqueous solutions was examined. This biocatalyst exhibits catalytic activity in a wide range of temperatures, pH values, and pollutant concentrations. The efficiency of phenol removal was monitored spectrophotometrically, by measuring the change in the residual amount of phenol in the reaction mixture. The influence of peroxidase, phenol, hydrogen peroxide, and polyethylene glycol (PEG) concentrations, as well as incubation time, temperature, pH value, and shaking rate on the efficiency of the phenol removal process, was comprehensively evaluated. The results showed that the use of raw, unpurified peroxidase from cabbage leaf waste can successfully replace commercial peroxidase and thereby significantly reduce the procedure cost. In addition, the presence of PEG as a peroxidase stabilizer showed little effect on the phenol removal efficiency, indicating that the extracted crude peroxidase is stable even without a commercial stabilizer, which could further cheapen the phenol removal process.

Improvement of the activity of a new nano magnetic titanium catalyst by using alkaline for refinery wastewater oxidation treatment in a batch baffled reactor

In order to reach pure water, it is essential to develop new technology for eliminating phenol from the wastewater. In this work, a nano-composite catalyst (5 % Fe2O3 + 10 % alkaline/TiO2) has been prepared and its performance to enhance the activity of catalytic wet peroxide oxidation (CWPO) process for removal of phenol has been examined. The new nano-composite catalyst is tested by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Energy dispersive X-ray (EDX) and scanning-electron-microscopy (SEM). A baffled batch reactor is used to evaluate the activity of new nano-composite catalyst at various temperatures (30–80 °C) and reaction times (30–90 min), utilizing hydrogen peroxide (H2O2) as oxidizing agent. The new design of digital baffled batch reactor prevents the fuel swirling, thus improving agitation. The experimental data of the CWPO technology prove that the best phenol removal (95.931 %) was carried out at 80 °C, the reaction time of 90 min, and in the presence of nano-composite catalyst ((5 % Fe2O3 + 10 % alkaline)/TiO2). Modeling investigation for the CWPO is examined in order to estimate the better process kinetic. The simulation technique explains dramatic agreement in comparing with the experimental data (error < 5 %). The optimal CWPO conditions in order to achieve pure water (phenol removal >99 %) are at reaction time of 198 min, process temperature of 85 °C, and initial phenol concentration of 1000 ppm.

Insights into the activation of peroxymonosulfate by ZIF-L@ZIF-67 derived CoCN catalyst for highly effective removal of phenol in the presence of chloride ions

A novel catalyst with cobalt and nitrogen-codoped porous carbon matrix (CoCN-900) was successfully prepared, characterized and applied for activating peroxymonosulfate (PMS) to remove phenol in aqueous solution. The CoCN-900 material exhibited superior performance in activating PMS for phenol degradation and could completely remove phenol within 60 min. Radical quenching tests and electron paramagnetic resonance (EPR) analysis showed that 1O2 and SO4•– played a major role in the phenol removal process over the CoCN-900/PMS system. In addition, the influences of catalyst/PMS dose, initial phenol concentration, reaction temperature, natural organic matter and coexisting anions on phenol degradation were systematically investigated. Particularly, it was found that the chloride ions (Cl–) had a significant accelerative effect, increasing the phenol degradation rate from 0.142 to 0.600 min−1. In the presence of Cl–, the phenol degradation efficiency was primarily ascribed to the effects of 1O2 and O2•–, which were significantly different from those in the absence of Cl–. Meanwhile, Cl– could also accelerate the deactivation of the catalyst. Findings in this study provided new insight for the fabrication of high-performance zeolitic imidazolate frameworks (ZIFs)-derived carbon materials and evaluating the influences of anions on the degradation of phenolic contaminants in PMS-based advanced oxidation processes (AOPs).

Aromatic free Fenton process for rapid removal of phenol from refinery wastewater in an oscillatory baffled reactor

The need for clean, safe, and unpolluted water has recently become an important issue. Industrial processes such as petrochemical, pharmaceutical, pulp, and paper industries emit organic products in water, such as phenols, which are extremely toxic to aquatic life. The severe operating conditions, such as high pressure and temperature, of the conventional chemical oxidation processes of phenols cost a lot and limited the extensive application of the process. The present work depicts the development of a highly efficient and rapid oxidation process in an oscillating baffled reactor (OBR) to allow continuous and safe phenol removal under moderate operating conditions. Phenol conversion was studied as a function of initial concentration (300–500 ppm), pH (3–5), residence time (1–5 min), at constant amplitude (A = 4 mm), and frequency (f = 4 Hz) of oscillation and room temperature to achieve up to 94.6%. At 70 °C, 300 ppm starting concentration, pH = 3, 4 Hz frequency, and 4 mm amplitude, an exceptional removal of 99.858% phenol was achieved without additional extraction in just 3 min by optimizing the working parameters. This is a significant improvement over comparable processes at this temperature, and it was done in a reactor that scales up reliably, so this performance can likely be replicated on a large scale. Also, the present process was safe as it produced a nil concentration of the hazardous Fenton intermediate compounds.

Visible-Light-Responsive Nanofibrous α-Fe2O3 Integrated FeOx Cluster-Templated Siliceous Microsheets for Rapid Catalytic Phenol Removal and Enhanced Antibacterial Activity.

Visible-light-driven environmental contaminants control using 2D photocatalytic nanomaterials with an unconfined reaction-diffusion path is advantageous for public health. Here, cost-effective siliceous composite microsheets (FeSiO-MS) combined with two distinct refined α-Fe2O3 nanospecies as photofunctional catalysts were constructed via a one-pot synthesis approach. Through precise control of Fe2+ precursor addition, specially configured α-Fe2O3 nanofibers combined with FeOx cluster-functionalized siliceous microsheets of ∼15 nm gradually evolved from the iron oxide-bearing molecular sieve, endowing a superior light-response characteristic of the formed nanocomposite. The catalytic experiment along with the ESR study demonstrated that the produced FeSiO-MS showed reinforced photo-Fenton reactivity, which was effective for rapid phenol degradation under visible light radiation. Moreover, the phenol removal process was found to be regulated by the specially configured types and concentrations of iron oxides. Notably, the obtained composites exhibited a considerable visible-light-induced bactericidal effect against E. coli. The constructed FeSiO-MS nanocomposites as integrated and eco-friendly photocatalysts exhibit enormous potentials for environmental and hygienic application.

Synthesis of alginate-coated magnetic nanocatalyst containing high-performance integrated enzyme for phenol removal

Effluent containing phenol is hazardous wastewater for the environment and human health. In the current work, synthesis and characterization of a new bi-enzymatic, magnetic-core nanocatalyst was investigated, and its performance as nanocatalyst for phenol removal from wastewater was examined. The obtained data suggested that the maximum combination of Peroxidases (POD) and Polyphenol Oxidase (PPO) enzymes (CPPE) stabilization can be achieved at T = 20 °C, pH value of 8, glutehydrie concentration of 1.6%, and enzyme to nanoparticles ratio of 1:200. Furthermore, it was found that the immobilized enzymes had higher stability than free enzyme against change in pH, temperature and even their durability. The Immobilized enzymes were used for phenol removal, and 98.1% separation was observed after 145 min when H2O2 to phenol ratio was 1.2, and in high concentrations of phenol (in the range of 2–10 mM) in the presence of CPPE. Finally, the stabilized enzymes were used 7 times in the phenol removal process, and the enzymes retained about 50% of their initial activity after 6 uses. It seems that the CPPE-alginate nanocatalyst could be used in hazardous wastewater treatment in particular for phenol removal.

Optimization of phenol removal with horseradish peroxidase encapsulated within tyramine-alginate micro-beads

Removal of phenolic compounds from water is of major interest over the years, since they are one of the most common pollutants in aqueous systems. Horseradish peroxidase (HRP) is the most investigated biocatalyst for this purpose. Inactivation of the enzyme is a major issue which can be successfully overcome by the enzyme immobilization on different polymers. In this study, tyramine-alginate micro-beads were used as carriers for the immobilization of horseradish peroxidase. The effect of the oxidation degree of tyramine-alginates on a specific activity of the enzyme was tested. An increase in the concentration of oxidized alginate from 2.5 to 20% resulted in a gradual increase in the specific activity from 0.05 to 0.67 U/mL. HRP immobilized within these micro-beads was tested for the phenol removal in a batch reactor. Reaction conditions were optimized to achieve a high removal efficiency and substantial reusability of the system. In this study, for the first time, an internal generation of hydrogen peroxide from glucose and glucose oxidase was employed in the phenol removal process with HRP immobilized on tyramine-alginate. Within 6 h of repeated use 96% of phenol was removed when the system for internal delivery of H 2 O 2 , composed of 0.187 U/mL of glucose oxidase and 4 mmol/L of glucose was employed. A common straightforward addition of hydrogen peroxide provided the removal efficiency of only 42%, under the same reaction conditions. The highest efficiency of the phenol removal (96%) was obtained with HRP immobilized within 20 mol% oxidized tyramine-alginate micro-beads. Fifteen mol% oxidized tyramine-alginate showed lower removal efficiency in the first cycle of use (73%) but more promising reusability, since the immobilized enzyme retained 61% of its initial activity even after four consecutive cycles of use. • Oxidized tyramine-alginates were used for HRP immobilization. • Reaction conditions for the phenol removal in a batch reactor were optimized. • Higher removal efficiencies were achieved when using internal delivery of H 2 O 2 . • 96% of phenol was removed from the solution with 20 mol% tyramine-alginate. • Immobilized enzyme showed promising results in terms of reusability.

Extraction of phenolic pollutants from industrial wastewater using a bulk ionic liquid membrane technique

ABSTRACT The academia and chemical industry are actively searching for alternative solvents to meet technology requirements since the most widely used solvents are harmful and volatile. For ionic liquids, there are several advantages over conventionally using organic membrane solvents, including high thermal stability, negligible vapour pressure, low volatility, etc. Here in this study, we have analyzed the abilities of ionic liquids as pure solvents as well as their binary mixtures, to recover phenolic compounds from the industrial wastewater. The field of phenol extraction from wastewater using ionic liquids remains less exposed, and we presume that the work of this kind would open up more and more opportunities for the scientific community as well as industrial people. Based on all these assumptions, the present work includes experimental data of a work which explains the possibilities of room temperature ionic liquids (RTILs) as potential bulk liquid membranes (BLM) for extracting phenol and other phenolic compounds from the industrial affluents. Four high hydrophobicity ionic liquids namely: 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF6], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [Bmim][NTf2], 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim] [PF6] and 1-ethyl-3-methyimidazolium bis(trifluoromethanesulfonyl) imide [Emim][NTf2] were used for investigating the Phenol extraction efficiency and stripping efficiency. To provide a best comprehension of the influence of the phenolic structure as well as the nature of cation on the extraction ability of the ILs, we tried to understand the molecular interactions between the phenolic compounds and the solvents. The influence of hydrophobicity of ionic liquids and different kinds of anions on the extraction of phenol and efficiencies of stripping were investigated. All the experimental investigations performed here indicated that the only cation part of the ionic liquid is not an important aspect directly in this extraction, but the hydrogen bonding and the solute-solvent interactions play a significant role in the phenol removal process from aqueous phase to IL phase. First, the optimal conditions of operating (settling time and stirring) were analyzed for the clarity of the experiments performed. Concentration of NaOH in enhancing the performance of ionic liquids was also inspected here in this study. A binary mixture of ionic liquids (BMILs) membrane was examined for the optimized parameters, and the efficiency of phenol extraction was analyzed with the efficiency obtained for the single ionic liquid (SIL) membranes. The phenol concentration was determined by UV/visible spectrophotometer absorbance measurements. The highest phenol extraction efficiencies of 91% and 98.5%, were achieved by using [Bmim][NTf2] and [Bmim][NTf2+PF6] respectively, and the higher stripping efficiencies came up with 79% and 84% respectively, for [Emim][NTf2] and [Bmim + Emim][NTf2]. The results show that the binary mixture ionic liquid (BMIL) membrane is a better choice than single ionic liquid (SIL) membrane solvents. Hence, [Bmim] [(NTf2+PF6)] is an excellent selection as it provides high phenol stripping and extraction efficiencies with a minimal solvent loss and better stability in transport process.

Mineralization of phenol by ozone combined with activated carbon: Performance and mechanism under different pH levels

The degradation of phenol using ozone with activated carbon (O3/AC system) was investigated in this study. The O3/AC system was also compared with the single O3 and AC systems. The total organic carbon (TOC) removal efficiency in the O3/AC system was roughly 26% and 30% higher than the single AC and O3 systems, respectively. It was demonstrated that the phenol degradation rate and TOC removal efficiency were significantly affected by the ozone concentration, AC dosage, and solution pH. The pseudo-first-order and pseudo-second-order kinetic models were fitted to identify the mechanisms of the phenol removal process. The results of Scanning Electron Microscopy, Brunauer-Emmett-Teller, and Fourier-transform infrared spectroscopy of raw and used AC indicated that the surface morphology, microstructure, and functional group properties had been changed during the reaction process. The possible O3/AC system mineralization mechanism for phenol removal was tentatively proposed using scavenging active species such as ·OH, O2⋅−, and H2O2. The transformation byproducts generated during the application of the O3/AC system were identified by High Performance Liquid Chromatography and Gas Chromatography–Mass Spectrometry analyses. Therefore, the mineralization pathway of phenol in detail was proposed in acidic (pH 3.0) and alkaline (pH 11.0) conditions. This study provided a more systematic explanation of the mineralization mechanism for phenol in the O3/AC system.

Novel Immobilization of Pseudomonas Aeruginosa on Graphene Oxide and Its Applications to Biodegradation of Phenol Existing in Industrial Wastewaters

A new biodegradtion method for removal of phenol and its derivatives has been considered. In this study the biochemical pathway involved in degradation of phenol through Pseudomonas aeruginosa bacterial cells which are immobilized on graphene oxide (GO) has been investigated. Since phenol is a toxic substance and eliminating it through a biological method is difficult, the phenol removal ability of the bacterial cells of P. aeruginosa has been considered in comparison with phenol adsorption on graphene oxide as a nanostructured adsorbent and P. aeruginosa supported on GO as a new biochemical adsorbent. For this purpose, graphene oxide was initially synthesized using the modified Hummer’s method and the bacterial strain was supported on GO. Scanning electron microscopy was employed to identify their morphology and structure. Also surface functional groups were initially analyzed by FTIR. The variables involved in the phenol removal process including phenol initial concentration, adsorbent dosage, temperature. The best removal efficiency of the bacteria was carried out at optimum conditions of pH 7, biosorbent dose of 0.01 g and phenol initial concentration of 3 ppm after 45 min of contact time at 25°C and up to 55% of phenol was removed. Using 0.01 g of GO and using 0.01 g of P. aeruginosa/GO attained to this removal efficiency at pH 7 after 60 and 45 min. of contact time, respectively, whereas the removal efficiency of the modified biochemical adsorbent of P. aeruginosa/GO was up to 92% at pH 3 after 45 min. of contact time. At the same condition phenol degradation using free cells of P. aeruginosa and using GO nanoparticles were 10.15 and 88.63%, respectively. Pseudo-second order kinetics described the biodegradation of phenol by P. aeruginosa supported on GO.

Disposal of phenol waste water by CoFe2O4&AA activated peroxydisulfate

ABSTRACT The pathological changes caused by phenolic wastewater discharged from various industries has attracted extensive attention in recent years. In this study, a novel sulfate-radical-based advanced oxidation process (SR-AOP) was used to dispose the target pollutant – phenols. Firstly, a solid-phase active catalyst – cobalt ferrite (CoFe2O4) was prepared from a sol–gel process with the innovative addition of ascorbic acid (AA). Then the original AOP was modified by using a novel CoFe2O4/AA/PDS combined system (PDS: peroxydisulfate). CoFe2O4 was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and H-M magnetic hysteresis loops. The influence factors on degradation in the new system were determined. It was found the activated PDS () generated a strong oxidizer sulfate radical (SO4·) and the phenol removal process basically obeyed the pseudo-first-order kinetics. The phenol degradation rate maximized to 98.00% under the following optimal conditions: CoFe2O4 preparation temperature at 500°C, initial phenol concentration at 50.00 mg/L, PDS dosage of 4.20 mM, CoFe2O4 dosage of 1.00 gL−1, and AA dosage of 0.42 mM. The new system had a high phenol degradation performance in a wide range of pH 3-7. The easy oxidization of metal ion solutions in a homogeneous system and the application limitation of pH range were well solved. The synergistic effect of the novel CoFe2O4/AA/PDS combined system on activated PDS was verified. The separation and reuse of CoFe2O4 were improved owing to its magnetism. These findings will underlie the practical application of CoFe2O4 into disposal of phenol waste water.

Cationization of celluloisc fibers in respect of liquid fuel purification

Abstract Fuel upgrading is one of the globally requirements due to struggle the environmental impacts and to protect the humanity. Presence of oxygenated compounds such as phenol in liquid fuel caused serious problems in the fuel combustion and gums formation in the interior engines and consequently blocking the fuel filter. These problems are directly affected on both of the human's life and environment. Herein, functionalized viscose fibers were designed and applied for liquid fuel purification from phenol. Viscose fibers was firstly cationized by interaction with N-2-chloroethyl N,N diethyl ammonium chloride to produce cationized fibers with nitrogen contents of 0.32–0.52%. Sorption of phenol from n-octane by using the cationized fibers was systematically studied. Sorption capacities were significantly affected by the degree of substitution and were linearly increased with nitrogen contents. The maximum sorption capacities were 178.6 and 206.2–282.5 mg/g for untreated and cationized fibers, respectively. Sorption was obeyed to pseudo-second order and signified that cationization process accelerates the phenol removal process. Sorption of phenol onto fibers were well followed Langmuir isotherm profile which reflected the monolayer sorption. Sorption was taken place via weak interactions between phenol molecules and substituted functional groups of fibers achieving physisorption process. However, the maximum capacity was diminished by regeneration process, the maximum removal of phenol was 80% after 4 regenerated cycles. Cationized viscose fibers can be considered as quite good template to purify liquid fuel from phenols, able to apply several times with good economic viability.

Treatment of wastewater from syngas wet scrubbing: Model‐based comparison of phenol biodegradation basin configurations

AbstractA treatment process for the biological removal of phenol from wastewater generated from the wet scrubbing of syngas is discussed with the objective of reducing Hydraulic Retention Time (HRT) for the process. In phenol biodegradation, a major challenge is posed by the inhibitory effect of high inlet phenol concentrations on the functioning of degrading microorganisms, leading to excessively high HRT values. This study provides a theoretical insight on the effect of reactor configuration and operation mode on the residence time for high strength phenolic wastewaters. Two pre‐treated wastewater streams mainly contaminated with phenol, with different flow rates and phenol concentrations, have been considered for evaluation in this work. Various configurations to remove phenol have been studied and compared. The kinetics in the reactors have been estimated using the Haldane‐Andrews equation for a variety of microorganisms. The configurations which require minimum residence time for a given extent of phenol biodegradation are those employing two reactors in series with a certain reflux stream. Gulosibacter sp. YZ4 is found to be the most effective microorganism in removing phenol within the minimum retention period.

A novel hydrothermal releasing synthesis of modified SiO2 material and its application in phenol removal process

A modified SiO2 material (MSM) was successfully synthesized by using Na2SiO3 and a novel CO2SM in the presence of CTAB through an innovative hydrothermal releasing treatment protocol. The MSM was systemically characterized using several techniques, including N2 adsorption-desorption isotherm, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The CO2SM as a platform for CO2 capturing and releasing can be reversibly used for multiple cycles without significant loss of capabilities. The optimum conditions for the preparation of MSM were identified as follows: Na2SiO3 concentration, 0.2mol/L; hydrothermal temperature, 120 °C; CO2SM dosage, 6 g; CTAB concentration, 24 g/L, reaction time, 12 h. Additionally, the MSM exhibited high efficiency for the removal of phenol from aqueous solution: it showed a phenol adsorption capacity of 91.29mg/g when shaken with the aqueous phenol solution at 180 rpm for 1 h at 25 °C.

Feasibility of using a microalgal-bacterial consortium for treatment of toxic coke wastewater with concomitant production of microbial lipids

This study examined the feasibility of using an algal-bacterial process for removal of phenol and NH4+-N from differently diluted coke wastewater with simultaneous production of biomass. Under illumination, microalgal-bacterial (MSB) cultures performed complete phenol degradation at all dilutions of coke wastewater while sole microalgal culture (MSA) degraded a maximum of 27.3% of phenol (initial concentration: 24.0mgL−1) from 5-fold diluted wastewater. Furthermore, the MSB culture had the highest rate of NH4+-N removal (8.3mgL−1d−1) and fatty acid production (20mgL−1d−1) which were 2.3- and 1.5-fold higher than those observed in the MSA cultures, probably due to decreases in toxic organic pollutants. Multivariate analyses indicated that co-cultivation of activated sludge was directly correlated with the elevated removals of phenol and NH4+-N. In the presence of sludge, adequate dilution of the coke wastewater can maximize the effect of bacteria on NH4+-N removal and biomass production.