Phenol Removal Efficiency Research Articles

Synthesis, Characterization, and Application of Ag-Biochar Composite for Sono-Adsorption of Phenol

The silver-embedded wheat straw biochar (Ag–WBC) composite was tailored effectively via the green synthetic route and was used as a nano-adsorbent for the removal of phenol by using adsorption and sono-adsorption processes. Ligustrum lucidum leaf extract was employed as a reducer to prepare silver nanoparticles, and biochar was synthesized from wheat straw via pyrolysis at 450–500°C. The synthesized biochar and Ag–WBC were characterized by using UV–Vis, SEM, EDX, and FTIR. The study confirms the ability of plant leaf extract of L. lucidum to synthesize AgNPs and Ag–WBC composites for the first time. UV–vis spectroscopic analysis confirms the formation of AgNPs and Ag–WBC composites (400–440 nm). SEM results showed that the size of the Ag–WBC composite is in the range of 80–100 nm. The elemental profile of the synthesized Ag–WBC composite shows a higher count at 3 kev due to silver. FTIR analysis revealed the presence of various functional groups involved in reducing Ag metal ions into Ag nanoparticles onto the surface of the composite. Batch experiments executed adsorption and sono-adsorption studies on WBC and Ag–WBC composites, and the results revealed that under optimum conditions, that is, pH= 3, adsorbate concentration= 10 mg L−1, adsorbents dosage= 0.05 g, time= 90 min, and US power = 80 W, the phenol removal efficiencies onto Ag–WBC composite were 78% using sono-adsorption compared to the non-sonicated adsorption. Langmuir and Freundlich isotherm models for fitting the experimental equilibrium data were studied, and the Langmuir model was chosen as an efficient model for the sono-adsorption process. The feasibility of the sono-adsorption process was also evaluated by calculating kinetics.

Preparation and performance of polyaniline modified coal-based carbon membrane for electrochemical filtration treatment of organic wastewater

Electrochemical filtration process, in which the active conductive membranes were employed as filtration membrane and electrochemical active electrode simultaneously, exhibited great prospect on the organic wastewater treatment. In this work, an efficient metal-free polyaniline-coated coal-based carbon membrane (PANI/CM) was fabricated via a facile electrochemical polymerization deposition method. Structural properties and electrochemical properties of PANI/CM were systematically characterized via SEM, XRD, FTIR, XPS and electrochemical workstation, etc. The electrochemical filtration treatment performance of PANI/CM for organic wastewater was systematically investigated. Results showed that the PANI was successfully deposited on the coal-based carbon membrane (CM) through electrochemical oxidative polymerization deposition method. The PANI coating can effectively improve the hydrophilicity of CM. Under the optimal preparation condition, the PANI/CM achieved a high permeability of 2564.67 L·m−2·h−1·bar−1 (1410.57 L·m−2·h−1·bar−1 for CM). In addition, PANI/CM possessed higher electrochemical activity and stability than CM, and the phenol and COD removal efficiencies of PANI/CM were up to >99.32% and 84.85%, respectively, under the operation condition of 2.0 V applied voltage, 50 mg·L-1 phenol, 2.5 g·L-1 Na2SO4 and 2.0 ml·min−1 flow rate, which were much higher than that of CM (70.12% and 63.64%, respectively). Additionally, the electrochemical oxidation mechanism of PANI/CM during the electrochemical filtration was explored, which included both indirect oxidation and direct oxidation. Furthermore, it was verified that PANI/CM also exhibited excellent applicability for different types of organic pollutants and the long-term stability.

Novel Cu-doped zeolitic imidazolate framework-8 membranes supported on copper foam for highly efficient catalytic wet peroxide oxidation of phenol

Cu-doped zeolitic imidazolate framework-8 (ZIF-8) membranes supported on three-dimensional copper foam were prepared for the first time and used for the catalytic wet peroxide oxidation of phenol in a fixed bed reactor. The properties of the new porous composite materials were studied by scanning electron microscope, energy-dispersive spectroscopy, Brunauer-Emmett-Teller surface area analysis, X-ray diffraction, thermal gravimetric analysis, Fourier-transform infrared, and X-ray photoelectron spectroscopy. The ZIF-8 membrane doped with 5% copper exhibited the best catalytic performance (the removal efficiency of phenol and H2O2 reached 100% and 95%, respectively). Reusability and stability experiments showed that a consistent complete phenol conversion and high H2O2 conversions of more than 94% were achieved using the 5% Cu-doped ZIF-8 membrane. The effects of reaction temperature, feed flow rate, and catalyst bed height on the catalytic performance were investigated to obtain the optimal reaction conditions. The material has the more economical characteristics of short reaction time, low metal loading, continuous operation, easy recycling, and good stability. The kinetics of the catalytic reaction of the Cu-doped ZIF-8 membrane were analyzed using the Power-rate Law Kinetic model. The experimental results show that the reaction is a first-order reaction, and the activation energy (Ea) of the catalyzed oxidation reaction is 66.4 kJ/mol. The initial oxidation rate equation (−rA0 = 3.24 × 108e−66400/RT CA) was obtained for Cu-doped ZIF-8 membrane–catalyzed phenol degradation.

Halophilic archaea and their extracellular polymeric compounds in the treatment of high salt wastewater containing phenol

Phenol is one of the major organic pollutants in high salt industrial wastewaters. The biological treatment of such waste using microorganisms is considered to be a cost-effective and eco-friendly method. However, in this process, salt tolerance of microorganisms is one of the main limiting factors. Halophilic microorganisms, especially halophilic archaea are thought to be appropriate for such treatment. To develop a novel effective biological method for high salt phenol wastewater treatment, the influence of phenol in high salt phenol wastewater on halophilic archaea and their extracellular polymeric substances (EPS) should be investigated. In the present study, using phenol enrichment method, 75 halophilic archaeal strains were isolated from Wuyongbulake salt lake sediment sample. The majority of the identified strains were phenol-tolerant. Six strains with high phenol tolerance were chosen, and the phenol scavenging effect was observed in the microbial suspension, supernatant, and EPS. It was noticed that the phenol degradation rate of suspensions of both strains 869-1, and 121-1 in salt water exhibited the highest rates of 83.7%, while the supernatant of strain 869-1 reached the highest rate of 78.2%. When combined with the comprehensive analysis of the artificial wastewater simulation experiment, it was discovered that in the artificial wastewater containing phenol, the phenol degradation rate of suspension of strain A387 exhibited the highest rates of 55.74% both, and supernatant of strain 630-3 reached the highest rate of 62.3%. The EPS produced by strains A00135, 558-1, 869-1, 121-1 and A387 removed 100% phenol within 96 h, and the phenol removal efficiency of EPS produced by 869-1 reached 56.1% under an artificial wastewater simulation experiment with high salt (15%NaCl) condition. The present study suggests that halophilic archaea and their EPS play an important role in phenol degradation. This approach could be potentially used for industrial high-salt wastewater treatment.

Acetamido-functionalized hyper-crosslinked polymers for efficient removal of phenol in aqueous solution

In recent years, functionalized hyper-crosslinked polymers (HCPs) have received increasing attention due to their high Brunauer − Emmett − Teller (BET) surface area (SBET), adjustable porosity and diversified functionality. Herein, the acetamido-functionalized HCPs namely PS-PDAT-FDA(SnCl4) were synthesized by two successive Friedel − Crafts reactions and the resultant polymers offered high SBET (756 m2/g), abundant N (4.6%) and O content (9.5%), and unique hierarchical porosity. The adsorption experiments indicated that the fabricated HCPs had a good adsorption of phenol with the predicted maximum capacity (qmax) of 214.5 mg/g. Increasing the Na2SO4 concentration slightly enhanced the adsorption, about 90 min was needed for the adsorption reaching the equilibrium, and the adsorption in tap water was also excellent. The adsorption mechanism revealed the uploaded C = O functionalities of the acetamido groups made a great positive contribution to the enhanced adsorption and strong hydrogen bonding between the C = O functionalities of the polymers and the phenolic hydroxyl groups of phenol was the main driving force.

Bacillus thuringiensis A1 improve phenol tolerance and phytoextraction by Acorus calamus L

Phenol, as a very toxic pollutant, exists widely in rivers in China. To explore the effect of bacterial augmentation on phytoremediation of phenol by Acorus calamus L., some plant growth and physiological parameters and percent removal of phenol were determined in hydroponics containing phenol with addition of Bacillus thuringiensis A1. The A. calamus L. and B. thuringiensis A1 consortium increased the growth rate of plant height, chlorophyll content, the activity of superoxide dismutase (SOD) and peroxidase (POD) in A. calamus L. 10.00–36.54%, 0.62 − 22.15%, 3.94 − 11.25% and 1.37–10.50% respectively compared with single plant treatments at same phenol concentrations. However, the addition of B. thuringiensis A1 decreased the content of malondialdehyde (MDA) and relative electrical conductivity (REC) in A. calamus L. 12.99–23.66% and 8.38–29.98% respectively compared with single plant treatments. The removal efficiency of phenol (increased from 1.56% to 13.78%) by the A. calamus L. and B. thuringiensis A1 consortium was higher than the removal efficiency of phenol of the independent A. calamus L. system. In conclusion, the addition of B. thuringiensis A1 alleviated phenol stress to A. calamus L and enhanced phenol removal due to phenol removal by bacterial augmentation. Novelty statement The addition of B. thuringiensis A1 alleviated phenol stress to A. calamus L. and enhanced phenol removal due to phenol removal by bacterial augmentation.

Phenol degradation in waters with high iodide level by layered double hydroxide-peroxodisulfate: Pathways and products

Recently, layered double hydroxide-peroxodisulfate (LDH-PDS) as an advanced oxidation system can effectively remove organics by the pathway of free radical. However, little has been known if there is a potential risk regarding the formation of high toxic iodine byproducts through another pathway when LDH-PDS is used in high iodide waters at coastal areas. Therefore, this study investigated phenol degradation pathways and transformation products to evaluate both removal mechanism and potential risk by LDH-PDS in high iodide waters. The results showed that in LDH-PDS system, with the degradation of PDS, phenol degraded till below detection limit in 1 hr in the presence of iodide, while PDS and phenol were hardly degraded in the absence of iodide, indicating iodide accelerated the transformation of PDS and the degradation of phenol. What is more, it reached the highest phenol removal efficiency under the condition of 100 mg/L LDH, 0.1 mmol/L PDS and 1.0 mmol/L iodide. In LDH-PDS system, iodide was rapidly oxidized by the highly active interlayer PDS, resulting in the formation of reactive iodine including hypoiodic acid, iodine and triiodide instead of free radicals, which contributed rapid degradation of phenol. However, unfortunately toxic iodophenols were detected. Specifically, 2-iodophenol and 4-iodophenol were formed firstly, afterwards 2,4-diiodophenol and 2,6-diiodophenol were produced, and finally iodophenols and diiodophenols gradually decreased and 2,4,6-Triiodophenol were produced. These results indicated that LDH-PDS should avoid to use in high iodide waters to prevent toxic iodine byproduct formation although iodide can accelerate phenol degradation.

Magnetic carbon microspheres as a reusable catalyst in heterogeneous Fenton system for the efficient degradation of phenol in wastewater

Starch-based magnetic carbon microspheres (MCMs) were successfully synthesized by the hydrothermal method to degrade the simulating phenol-containing wastewater. The morphology and structure of the as-prepared MCMs were characterized by SEM, FT-IR, XRD, and VSM in detail. The characterization results showed that the presence of magnetic Fe3O4 in MCMs was conducive to the efficient removal of phenol in the Fenton system. When pH = 3, V(H2O2) = 0.30 mL, m(MCMs) = 3.0 g, T = 40 ℃, and t = 12 h, the degradation rate of phenol reached a maximum of 93.11%. After six repeated use, the degradation rate of phenol by MCMs still attained 85.14%, showing excellent reusability, which was extremely attractive to removing actual phenol-containing wastewater. The growth test of water spinach further confirmed that MCMs could effectively reduce the harmfulness of phenol to aquatic plants, indicating it was expected to become a promising material for the practical dephenolization application. Finally, the degradation mechanism of phenol in wastewater was proposed based on the experimental.

Study on the treatment of phenol-containing wastewater by doping coal char

The single blending of biomass and S-TiO2 and the mixed modification of coal char were obtained by the method of coking with coal pyrolysis furnace. The adsorption performance of biomass and S-TiO2 was investigated by the adsorption experiment of phenol solution. The results show that under the optimal conditions the best performance of MCC-2 can achieve 94% removal efficiency of phenol. The adsorption efficiency is 20% higher than that reported in the literature, and the adsorption equilibrium time is several times shorter than that reported in the literature. The modified coal char has broad prospects as a substitute for activated carbon in practical application.

Construction of Cu-Fe Bimetallic Oxide/Biochar/Ag3po4 Heterojunction for Improving Photo-Corrosion Resistance and Photocatalytic Performance Achieves Efficient Removal of Phenol

Construction of Cu-Fe Bimetallic Oxide/Biochar/Ag3po4 Heterojunction for Improving Photo-Corrosion Resistance and Photocatalytic Performance Achieves Efficient Removal of Phenol

Developing a novel strategy for light-triggered reversible enzyme immobilization and reuse of support

The reuse of support material still hamper the practical application of enzyme immobilization technology in wastewater treatment. Here, a novel strategy based on light-triggered reversible β-cyclodextrin (β-CD)-Azobenzene(Azo) host-guest interaction was developed. First, magnetic Fe3O4 nanoparticles were coated with porous β-CD-containing polymers(PCDP), and then the Azo-modified enzyme was immobilized in normal condition. The immobilization would enhance the stability and catalytic performance of enzymes, and the easy separation from reaction medium could be available with external magnetic field. Over broad ranges of temperature and pH, the immobilized enzyme showed higher activity than free enzyme, and the phenol removal efficiency retained about 58.63% even after five cycles. Under UV light, the photoisomerization of Azo would lead to disassemble of β-CD-Azo interaction, resulting in the detachment of the enzyme, and phenol removal efficiency decreased to only 16%. The support materials could be recovered for continue enzyme immobilization, results based on cyclic process of enzyme immobilization and detachment strongly demonstrated the detachment of enzyme and excellent reusability of Fe3O4@PCDP. And this strategy was proved to be a practical method based on batch experiments on the removal of phenol by tyrosinase (Tyr)-based remediation.

Evaluation catalytic performance of Ag/TiO2 in dielectric barrier discharge plasma

Dielectric barrier discharge (DBD) plasma technology combined with Ag/TiO2 composites for phenol degradation was investigated. The TEM, XRD, XPS results showed that Ag was successfully doped on TiO2. PL results indicated that the doped Ag on TiO2 obviously decreased the recombination rate of electron-hole pairs. The effect of silver loading, Ag/TiO2 introduction dosages, initial phenol concentration, applied voltage on Ag/TiO2 catalytic performance were also studied and analyzed. With introduction of 0.2 g L−1 0.5 wt% Ag/TiO2, the phenol removal efficiency was enhanced by 6% at 17 kV and 20 kV, the addition of Ag/TiO2 has slightly inhibiting effect on phenol degradation at 22 kV. The NO2− and NO3− concentrations were also measured by IC. The results showed that NO3−-N concentration reached 37 mg L−1 at 22 kV, and NO3−-N obviously decreased from 37 mg L−1 to 25 mg L−1 and NO2−-N increased from 0.10 mg L−1 to 0.24 mg L−1 with adding Ag/TiO2. The reason of inhibiting effect of Ag/TiO2 at 22 kV could be that the NO3− from discharge was involved in Ag/TiO2 catalytic reaction, and the reduction of NO3− could inhibit the electrons transfer from the Ag metal to O2, resulting in the lower phenol removal efficiency.

Enhancing phenol removal from waste water by adding powder activated carbon to the lab-scale activated sludge system

In this study, the commercial powder activated carbon (PAC) was added to a bench scale conventional activated sludge (CAS) system to enhance phenol removal. The mixed liquor suspended solid (MLSS) concentration of CAS with adding PAC was stable in all stages of operation, while MLSS concentrations in CAS without PAC addition sharply decreased as the Phenol loading reached 1.8 g phenol/L.day. Higher removal of chemical oxygen demand (COD) and Phenol achieved with the CAS by PAC addition compared with those achieved with CAS without PAC addition. The difference in COD removal efficiency was 7 - 9% in stages 3 and 4 (0.8 and 1.2 g phenol/L.day, respectively), and about 33% in stage 5 (1.8 g phenol/L.day). The advantage of CAS with PAC addition was clearly observed in the highest phenol loading (1.8 g phenol/L.day) because the MLVSS/MLSS ratio of CAS with PAC addition increased and the COD and phenol removal efficiencies kept stable in this stage, while reverse trends were found for CAS without PAC addition. The results indicated that the adaptive ability of the CAS by adding PAC was significantly higher than the CAS without AC addition. This study offers useful preliminary results for applying a hybrid system between CAS and adsorption with PAC for further research and application in future.

Optimized remediation of treated agro-industrial effluent using visible light-responsive core-shell structured black TiO2 photocatalyst

The existing open ponding system for palm oil mill effluent (POME) treatment typically fails to eliminate phenolic compounds. The aim of this research was to develop an improved photocatalytic process that utilizes visible light to remediate phenol laden treated palm oil mill effluent (TPOME). The visible-light active core-shell structured black TiO2 (CS B-TiO2) was synthesized by a modified precipitation technique using glycerol as a renewable and environmentally friendly template. The photocatalytic process was first optimized using central composite design (CCD) in response surface methodology (RSM) for removal of model phenol and chemical oxygen demand (COD), and then used to remove the two substances from TPOME. Under non-optimized conditions, the synthesized CS B-TiO2 removed 76.05% of phenol, which is four times higher than the commercial TiO2 (P25). Through regression analysis, statistically significant quadratic polynomial models for phenol and COD removal efficiency were obtained. High R2 (0.9842) low mean square error (MSE, 0.086), and root mean square error (RMSE, 0.294) values indicated that the accuracy and generalization of both the optimization models were adequate. 90.73% and 94.43% of model phenol and COD were removed under optimal conditions of 1.27 g/L CS B-TiO2 loading, 0.06 mol/L H2O2 dosage, 30 ppm initial concentration of phenol, pH 7.2, and 180 min visible light irradiation. The removal efficiency of phenols and COD from TPOME matrix remained at 70.20% and 78.65 % , respectively. This study confirms that an optimized photocatalytic process based on CS B-TiO2, which is sensitive to visible light, is an effective solution for the remediation of agro-industrial wastewater .

Persulfate enhanced electrochemical oxidation of phenol with CuFe2O4/ACF (activated carbon fibers) cathode

Phenol wastewater is threatened to human living environment and should been treated carefully before discharging into the environment. For my research, electrochemical (EC) oxidation of phenol using CuFe2O4/ACF cathode and mixed metal oxide (RuO2/Ti) anodes was investigated. In order to increase the EC oxidation efficiency of phenol, persulfate (PS) was added into the EC system. Various systems including EC-1 oxidation (RuO2/Ti cathode and RuO2/Ti anode), EC-2 oxidation (ACF cathode and RuO2/Ti anode), EC-3 oxidation (ACF cathode and RuO2/Ti anode, adding CuFe2O4 particle), PS oxidation (only adding PS) and EC/PS oxidation (CuFe2O4/ACF cathode and RuO2/Ti anode, adding PS) for phenol removal were compared, and the removal efficiency of phenol was determined to be 19%, 25%, 46%, 43 and 85%, respectively. Effects of K2S2O8 concentration, current density and initial pH on the removal efficiency of phenol were analyzed. The optimal phenol removal efficiency (97%) was achieved after 60 min reaction under conditions: PS concentration of 1.00 mM, current density of 50 A/m2, and initial pH of 7.0. The generation of reactive oxidant species in solution was confirmed by the electron spin resonance technique, which was in accord with the radical quenching experiments results, indicating that oxidation of phenol was assigned to radical oxidation and non-radical oxidation processes.

Phenol removal by enhanced electrocoagulation process with persulfate salt

Introduction. Phenol is classified as priority pollutant. Phenol and its derivatives are stable in water, environmental contamination, and health concerns that are used as raw material in many chemical industries. This study investigated the removal of phenol by the reactivity of free sulfate radicals (SO4•–), activated by electrochemically generated Fe2+/Fe3+ ions which furthermore are evaluated to destroy phenol in aqueous solution.
 
 Materials and methods. In the present experimental study, electrocoagulation reactor by iron electrodes is used in the pre­sence of persulfate ions to phenol removing from aqueous solutions. In this regard, the effect of four independent variables including pH, electric current, persulfate dosage, and initial phenol concentration were studied on phenol removal.
 
 Results. The study determined the optimum conditions for maximum phenol removal using electro-persulfate process (EPS) as pH 3, 7.4 mM persulfate dosage, 27.78 mA/cm2 current density, and 100 mg/L initial phenol concentration at 30-min reaction time. The results showed that the efficiency of phenol removal was directly related to the initial persulfate dosage. In addition, the pH values, less than the phenol pKa, has slight effect onto the phenol removal. However, it was inversely correlated with a highly alkaline pH and higher phenol concentration.
 
 Conclusions. The study concluded that electro-persulfate process is an effective and robust process that can be used for handling of phenol containing wastewater.

Potential mechanism of enhanced anaerobic degradation of high concentration phenol-containing wastewater by hazardous waste fly ash with high iron content: Direct interspecies electron transport pathway

Micron-grade high iron-containing fly ash (MHIFA)—a processed hazardous waste containing Fe3O4—was added to an up-flow anaerobic sludge blanket reactor to improve the removal performance of high concentration phenol-containing wastewater. The chemical oxygen demand and total phenol removal efficiency with MHIFA were 72.13% and 81.83%, respectively. Moreover, MHIFA addition increased the contents of coenzyme F420 and extracellular polymeric substances, as well as higher electron transport system activity in activated sludge. Additionally, microbial community analysis revealed that the total methanogens contents increased at genera level, producing an increase in methane production, while enriched Geobacter along with archaea Methanothrix might collaborate in direct interspecies electron transfer (DIET) by MHIFA stimulation, promoting the effect of phenolic compound fermentation. Finally, this technology allows for resource utilization of hazardous waste and enhances anaerobic degradation of toxic and refractory pollutants.

Efficient removal of phenol in aqueous solution by the modified abandoned fine blue-coke: equilibrium, thermodynamic, kinetic, and adsorbent regeneration

The modified abandoned fine blue-coke (MAFB) was used to remove phenol from the aqueous solution efficiently. The effects of initial concentration, temperature, pH, and co-existing salt ions of the phenol solution on the adsorption capacity of MAFB for phenol were investigated. The adsorption equilibrium, thermodynamic, kinetic, and adsorbent regeneration were studied simultaneously. The results showed that the maximum adsorption capacity of phenol onto the MAFB was obtained as 151.74 mg g−1 at the initial solution concentration of 1100 mg L−1, the temperature of 328 K, and pH of 4.0–6.5. The salt ions of Na+, Cl−, SO2- 4 had little effect on the adsorption capacity. The adsorption isotherm belongs to the L isotherm and the Langmuir model can better describe the adsorption process. Thermodynamics results indicated that the adsorption was entropy increase, spontaneous and endothermic process. The adsorption kinetics was found to follow the pseudo-second-order model. The physical adsorption of π–π dispersion interactions could be used to describe the adsorption mechanism. The 60% regeneration rate of the MAFB was reached by three times alcohol desorption at 323 K for 4 h. Compared with other adsorbents, MAFB has better phenol adsorption performance, which makes it a promising and excellent adsorbent to remove phenol from wastewater.

Effects of Constant Electric Field on Biodegradation of Phenol by Free and Immobilized Cells of Bradyrhizobium japonicum 273

It is shown that bacteria Bradyrhizobium japonicum 273 were capable of degrading phenol at moderate concentrations either in a free cell culture or by immobilized cells on granulated activated carbon particles. The amount of degraded phenol was greater in an immobilized cell preparation than in a free culture. The application of a constant electric field during cultivation led to enhanced phenol biodegradation in a free culture and in immobilized cells on granulated activated carbon. The highest phenol removal efficiency was observed for an anode potential of 1.0 V/S.H.E. The effect was better pronounced in a free culture. The enzyme activities of free cells for phenol oxidation and benzene ring cleavage were very sensitive to the anode potential in the first two steps of the metabolic pathway of phenol biodegradation catalyzed by phenol hydroxylase—catechol-1,2-dioxygenase and catechol-2,3-dioxygenase. It was observed that at an anode potential of 0.8 V/S.H.E., the meta-pathway of cleavage of the benzene ring catalyzed by catechol-2,3-dioxygenase became competitive with the ortho-pathway, catalyzed by catechol-1,2-dioxygenase. The obtained results showed that the positive effect of constant electric field on phenol biodegradation was rather due to electric stimulation of enzyme activity than electrochemical anode oxidation.

Hybrid Photo-Fenton oxidation and biosorption for petroleum wastewater treatment and optimization using Box–Behnken Design

This study investigates the treatment of petroleum wastewater (PWTP) effluent using hybrid techniques (photo-Fenton oxidation and adsorption) to remove organic pollutants such as chemical oxygen demand (COD) and phenol. All the experiments were carried out in batch mode. The effects of pH, ferrous salt (Fe 2＋ ), and H 2 O 2 oxidation factors on the photo-Fenton process were studied. The response surface methodology (RSM) approach for experiment design and optimization yielded maximum COD and phenol removal at Fe 2＋ , H 2 O 2 , pH of 20 mM, 400 mM, and 3.8, respectively. In this optimal scenario, phenol reduction from the initial value of COD 12654.6 mg/L, phenol 213.0 mg/L was accomplished by 69.97% and 95.66%, respectively. Response surface methodology (RSM) photofenton based modeling and optimization was done using a Box–Behnken. The high coefficient of regression R 2 = 0 . 97 and 0.98 for COD and phenol oxidation is suggested by variance analysis (ANOVA). The PWTP effluent treated by Fenton oxidation with COD 4139.1 mg/L and phenol 70.1 mg/L was treated with Phragmites australis. Phragmites australis was chosen as an adsorbent. Phragmites australis was analyzed and characterized using several techniques, including Fourier transform infrared spectroscopy, Scanning Electron Microscopy, Zeta potential, and particle size distribution. The adsorption process step followed the photo-Fenton treatment process. The adsorption process achieved 69.04 % and 95.80% for COD and phenol removal. Kinetic studies showed that the statistics match very well in the nonlinear pseudo-first and second-order models based on the correlation coefficients (R 2 = 0 .999) and (R 2 = 0 .996), respectively, for COD and phenol removal in the adsorption phase. The severe adsorption potential for COD and phenol removal is 14421.97 mg/g and 374.90 mg/g, respectively. Finally, as a natural material, P. australis is a promising adsorbent material. • Box–Behnken Experimental Design (BBD) was used to determine the optimal removal efficiency for both COD and phenol for the photo-Fenton process. • Statistical analysis of the data indicated that H 2 O 2 significantly affected COD, phenol degradation for petroleum wastewater. • The optimum conditions for pH, Fe +2 , H 2 O 2 are 3.8, 20 mM, 400 mM for 69.97% COD, and 95.66% Phenol. • Phragmites australis was used as an adsorbent in the adsorption step. P. australis showed remarkable surface characteristics and adsorption ability. • The maximum adsorption capacity to remove COD and phenol of 14421.97, 374.90 mg/g, removal ratio 69.04%, and 95.80%, and the data fits very well in the nonlinear pseudo-first and second-order models.