Fenton Method Research Articles

Employing Electrochemical-Fenton process for conditioning and dewatering of anaerobically digested sludge: A novel approach

In this study, for the first time, the occurrence mechanism of anaerobically digested sludge conditioning for dewatering process based on Electrochemical-Fenton technology was investigated and the optimum condition has been determined to employ a lab-scale reactor. Due to the results of current studies using electrochemical and Fenton methods, a comparative economic-technical investigation has been provided accordingly. The results showed that under optimum operational condition by utilizing Electrochemical-Fenton process e.g. H2O2 = 25 mg/g DS (dry solid), Fe2+ = 15 mg/g DS, retention time = 20 min, electrolysis voltage = 11 V, the specific resistance to filterability (SRF) and time to filter (TTF) parameters reduction equal to 93.8% and 75.9% respectively. The occurrence mechanism of the sludge conditioning was determined by evaluation of extracellular polymeric substances (EPS), particle size distribution, zeta potential and bound water tests. The dry solids concentration of the conditioned sludge by Electrochemical-Fenton process was increased from 2.3% to 41% by dewatering employing filter press system. Furthermore, the estimated cost of conditioning using this method is 41.82 USD$/t DS, which is less than other investigated methods e.g. traditional Fenton process. It can be concluded that the results reached in this comprehensive and comparative study could be a suitable basis for further investigations regarding utilization of novel electrochemical advanced oxidation technologies for efficient sludge conditioning and dewatering purposes.

New Approach of Integrated Advanced Oxidation Processes for the Treatment of Lube Oil Processing Wastewater

The treatment of lube oil processing industrial wastewater has been proposed by advanced oxidation processes such as Fenton and electro Fenton (EF) oxidation processes. The method of EF was further extended to homogeneous electro Fenton (Homo-EF) and heterogeneous electro Fenton (Hetero-EF) method of treatments. Three different types of anode materials were selected for the electrochemical oxidation against graphite as a cathode, i.e. SS304/graphite, graphite/graphite and Ti-MMO/graphite. Among the studied methods of treatment, the Hetero-EF performed by Ti-MMO/graphite electrode system showed maximum COD removal efficiency than the other electrode systems. The optimized conditions for the Hetero-EF by Ti-MMO/graphite were observed to be electrochemical oxidation time 120 min, solution pH 2.5, potential 7.5 V. Further, the instrumental analysis of UV–visible spectrophotometer confirmed the removal of organic concentration from lubricating oil processing wastewater.

Study on the degradation of rhodamine B by the cavitation impinging stream-fenton

Experiments of rhodamine B wastewater treatment by cavitation impinging stream (CIS) technology and CIS - fenton reaction coupling technology are carried out. Results showed that the removal rate of COD and colority reached 19.6% and 34.1% by using cavitation impinging stream technology only and 98.1% and 97.2% by CIS and fenton reagent combination, and 24.3% and 18.4% higher than that by using fenton method only, and higher than that by using the both mentioned above. These experiments showed that the two have synergy, also proved that the CIS and fenton reagent combination can be more efficient in organic wastewater treatment.

Degradation of macrolide antibiotics via sono or photo coupled with Fenton methods in the presence of ZnS quantum dots decorated SnO2 nanosheets

The ZnS quantum dots decorated SnO2 nanosheets were prepared by a hydrothermal synthesis method. The characteristic structure of ZnS QDs/SnO2 nanocomposites was analyzed using several instruments such as X-ray diffraction, transmittance electron microscopy, atomic force microscopy, X-ray photoelectron and UV–vis and photoluminescence spectroscopy. The average diameters of SnO2 nanosheets and ZnS QDs/SnO2 nanocomposites were 12.5 and 3.6 nm, respectively. The merits of sono–photo–Fenton treatment process were investigated using degradation of Roxithromycin. The process involved ultrasound and UV irradiation, and hydrogen peroxide generated in situ. The treatment performance of the US/UV/catalyst process was superior to the constituent processes and synergistic mechanisms in the US/UV/catalyst process were the result of the promotion of hydroxyl radical generation. For the constituent processes, the US/catalyst system showed to the best efficiency with used catalyst compared to the conventional Fenton reaction. It was also observed that the addition of catalyst to the test solution undergoing UV irradiation substantially improved Roxithromycin and clarithromycin degradation. The best experimental conditions for efficient CLA and RXM degradation in the US/UV/catalyst/H2O2 system were pH0 3, hydrogen peroxide concentration of 6 mmol L−1, ZnS QDs/SnO2 nanocomposites dose of 0.3 g L−1 and ultrasonic power of 75 W. The antibacterial experiment was investigated under visible light illumination and the ZnS QDs/SnO2 nanocomposite showed good efficiency as antibacterial.

Decolorization of Remazol Black B Solution by PbO2 Modified Fenton Method in a Scaled Up Reactor

Study on decolourization of remazol black B (RBB) solution has been performed in a scale up reactor. As an artificial waste, the dye sample that contains azo groups is difficult to decompose under ordinary environmental conditions so it requires further treatment before discharging to open aquatic system. Many efforts have been reported and further developed toward other azo dyes. One of an outstanding approach is Fenton method. This study modified the method with PbO2 rather than Fe2+. In this modification, the dyestuff was degraded by radical •OH resulting from reaction between H2O2 and Pb2+ ion generated from PbO2. In Preliminary works, decolourization was performed and optimized in lab-scaled. Analysis were conducted and the best condition was applied to decolorize the sample in a scale-up size. Characteristics of the reactor was also determined. Results showed that at optimum condition, 100 mL of 50 ppm remazol black B was decolorized up to 98.82 % within 15 minutes. On scale up to 1 L-sized reactor, within the time highest percentages of remazol black B decolourization was reached 82.02 % by addition of 10 % H2O2 and COD decrease to 98.96 %. In the 1 L reactor, RBB sample with concentration of 50 ppm, PbO2 1 gram and H2O2 10 % obey the proposed decolourization equation of D = -0,0011x2 + 0.5705x – 0.6788 with x = volume peroxide (in mL), D = percent of decolourization.

Advanced Heterogeneous Fenton Treatment of Coalbed Methane-Produced Water Containing Fracturing Fluid

This study investigated the heterogeneous Fenton treatment to process coalbed methane-produced water containing fracturing fluid and chose the development region of coalbed methane in the Southern Qinshui Basin as a research area. We synthesized the catalyst of Fe-Co/γ-Al2O3 by homogeneous precipitation method and characterized it by BET, XRD, SEM-EDS, FTIR, and XPS. Based on the degradation rate, we studied the influences of the heterogeneous Fenton method on the coalbed methane output water treatment process parameters, including initial pH, H2O2 concentration, and the catalyst concentration. We also investigated the impacts of overall reaction kinetics of heterogeneous catalytic oxidation on coalbed methane-produced water containing fracturing fluid. Results showed that Fe-Co/γ-Al2O3 as a Fenton catalyst has a good catalytic oxidation effect and can effectively process coalbed methane-produced water. This reaction also followed first-order kinetics. The optimal conditions were as follows: the initial pH of 3.5, a H2O2 concentration of 40 mol L−1, a catalyst concentration of 4 g/L, and an apparent reaction rate constant of 0.0172 min−1. Our results provided a basis to establish methods for treating coalbed methane-produced water.

Fenton treatment via oxidative mechanism and its kinetics on soil polluted with automatic gas oil

Abstract The effectiveness, viability and feasibility of applying Fenton reactants in treating soil contaminated with automatic gas oil (AGO) was investigated ex-situ. Soil was simulated to achieve 10% contamination using AGO (diesel) as the primary contaminant. Physicochemical properties and heavy metal contents were characterized using standard analytical methods, while total petroleum hydrocarbon (TPH) content was determined by molecular spectroscopy. An investigation of the soil physicochemical properties shows severe impact of the contaminant on pH, conductivity, phosphorus and (TPH) content. The optimum concentration of Fenton reactants determined from the optimization study was found to be 350,000 ppm H2O2 and 600 ppm FeSO4 at optimum room temperature range of 27–30 °C and optimum pH of 4.7. The highly exothermic Fenton oxidation treatment resulted in significant decrease in TPH content by 87.6% after 6 h of periodic monitoring; breaking down the hydrocarbons into non-toxic environmental friendly products. Kinetics analysis and evaluation shows pseudo - first order mechanism for the Fenton treatment with a calculated rate constant of 0.226 h-1 and half life of 3 h 4 min. The Fenton method is found to be very effective and efficient not only for the removal of the diesel contaminant, but also for the restoration of lost physicochemical properties occasioned by the effect of the contaminant. The environmental friendliness and fast response time towards effective clean up gives the technique a cutting edge advantage over other conventional methods. It therefore presents potentials for remediation experts in outright applications on real field challenges.

RESEARCH ON THE TREATMENT OF ALUMINUM ALLOY CHEMICAL MILLING WASTEWATER WITH FENTON PROCESS

The aluminum alloy chemical milling wastewater was treated by Fenton method. The effect of pH value, reaction time, rotational speed, H2O2 dosage, Fe2+ dosage and the molar ratio between H2O2 and Fe2+ on the COD removal rate of aluminum alloy chemical milling wastewater were investigated by single factor experiment and orthogonal experiment. The results showed that the optimum operating conditions for Fenton oxidation were as follows: the initial pH value was 3, the rotational speed was 250r/min, the molar ratio of H2O2 and Fe2+ was 8, the reaction time was 90 min. Under the optimum conditions, the removal rate of the wastewater’s COD is about 72.36%. In the reaction kinetics that aluminum alloy chemical milling wastewater was oxidized and degraded by Fenton method under the optimum conditions, the reaction sequence of the initial COD was 0.8204.

Treatment of real benzene dye intermediates wastewater by the Fenton method: characteristics and multi-response optimization

Benzene dye intermediates (BDI) wastewater has caused major environmental concern due to its potential carcinogenic, teratogenic, and mutagenic effects.

Relevance of pressure field accuracy for nonlinear Froude–Krylov force calculations for wave energy devices

Due to their computational convenience, linear mathematical models for wave energy converters are usually employed. Including nonlinearities may improve the accuracy of the results, but often at the price of an additional computational and complexity burden, which can be justified only if nonlinearities are significant. One of the sources of nonlinearity in fluid–body interactions is the wave field itself. Different wave models exist, among which are linear Airy’s theory, Wheeler’s stretching approach, the nonlinear Rienecker–Fenton method, and higher order spectral methods, all of which achieve a different compromise of accuracy and complexity. The impact of the accuracy of such wave theories strongly depends on the specific device (operating principle, power production region or survivability mode), and installation site (water depth, occurrences of each sea state in the scatter diagram of the installation site). This paper evaluates the performance of different wave field representations, firstly in absolute terms and, secondly, in relation to the associated computation of nonlinear Froude–Krylov forces for different wave energy devices, in regular and irregular sea states. It is shown that Wheeler’s stretching offers a good accuracy/complexity compromise for WECs operating in the power production region.

Detoxification of Pesticide-Containing Wastewater with FeIII, Activated Carbon and Fenton Reagent and Its Control Using Three Standardized Bacterial Inhibition Tests

Discharge of toxic industrial wastewaters into biological wastewater treatment plants may result in inhibition of activated sludge bacteria (ASB). In order to find an appropriate method of detoxification, the wastewater of a pesticide-processing plant in Vietnam was treated with three different methods (FeIII, powdered activated carbon (PAC), Fenton (FeII/H2O2)) analyzing the detoxification effect with the nitrification inhibition test (NIT), respiration inhibition test (RIT) and luminescent bacteria test (LBT). The heterotrophic ASB were much more resistant to the wastewater than the autotrophic nitrificants. The NIT turned out to be more suitable than the RIT since the NIT was less time-consuming and more reliable. In addition, the marine Aliivibrio fischeri were more sensitive than the nitrificants indicating that a lack of inhibition in the very practical and time-efficient LBT correlates with a lack of nitrification inhibition. With 95%, the Fenton method showed the highest efficiency regarding the chemical oxygen demand (COD) removal. Although similar COD removal (60–65%) was found for both the FeIII and the PAC method, the inhibitory effect of the wastewater was reduced much more strongly with PAC. Both the NIT and the LBT showed that the PAC and Fenton methods led to a similar reduction in the inhibitory effect.

Seismic Performance of the Pier Considering Structural-Fluid Interaction with ANSYS Software

Abstract In the present study, as the calculation of forces on the cylindrical structures of the sea has a special complexity, Morrison's mathematical model was used in the software. In addition, the kinematics of water particles is estimated to calculate their acceleration from the fifth-order non-static wave theory (Fenton method). In this paper, the analysis of the pier performance considering structural-fluid interaction using ANSYS soft is presented. Five models with the same period were considered and different wave heights and two different earthquake records of Tabas and Northwich were studied. Finally, node displacement, acceleration and reciprocal interaction forces were extracted and compared with the numerical values. The results indicated that the values of the studied parameters and the type of nodes were similar in the models without a record of earthquakes, but with the estimation of the earthquake, these values would be significant.

Yarn dyed wastewater treatment using hybrid electrocoagulation-Fenton method in a continuous system: Technical and economical viewpoint

ABSTRACT Yarn dyed wastewater has to be treated prior to disposal into the water bodies due to its high content of harmful organic compounds. In this study, the performance of Chemical Oxygen Demand (COD) removal and kinetic rate constant are investigated via hybrid electrocoagulation-Fenton in a continuous system using wastewater discharged from a yarn dyed industry in Surabaya city. The wastewater was treated in a batch mode using electrocoagulation to reduce Total Suspended Solid, followed by Fenton method in a continuous system to reduce COD level. Various Fe(II) feeding modes, molar ratio of Fe(II)/H2O2, initial pH of wastewater, and flow rate are used in this study. The results show that COD removal process obeys a pseudo-first order kinetics. At Fe(II)/H2O2 ratio of 1:10, initial wastewater pH of 3.0, and feed flow rate of 30 mL/min, the COD removal efficiency was observed to be 80%, and the kinetic rate constant is 0.07046 min-1. The chemical cost for the treatment estimated to be IDR 160 per L wastewater, which is cheaper than the previously reported batch system of IDR 256/L. Keywords: COD, Continuous system, Electrocoagulation, Fenton, Yarn dyed wastewater

Comparative study of electrochemical oxidation and electrochemical Fenton processes for simultaneous degradation of phthalic and para-toluic acids from aqueous medium

Degradation of binary component of purified terephthalic acid wastewater viz. phthalic acid and para-toluic acid from aqueous medium was investigated in this study. Aqueous solution was initially subjected to acid precipitation treatment at various pH (2–4) and temperature (15–60°C). After acid treatment, the solution was further subjected to electrochemical oxidation and electrochemical Fenton treatments using graphite electrodes. During electrochemical treatments, effect of process variables such as initial pH: (1–9), current density: (30.48–91.45A/m2), NaCl concentration: (0.5–1.5g/L), Fe2+ concentration: (0.5–1.5mmol/L) and time: (15–95min) was studied and optimized through central composite design. Maximum removal efficiencies during electrochemical oxidation treatment were 64.55%, 60.24% and 62.77% for phthalic acid, para-toluic acid and chemical oxygen demand respectively with an electric energy consumption of 28.50kWh/kgCODremoved at optimum conditions. The removal capacities during electro-Fenton treatment were found 75.21%, 65.19% and 68.15% for phthalic acid, para-toluic acid and chemical oxygen demand respectively with 20.11kWh/kgCODremoved energy consumption at optimum conditions. Both processes were compared based on removal efficiencies, electric energy consumption, kinetics and sludge characteristics. Sludge generated after electrochemical treatments was analyzed by various characterization techniques. In order to get maximum removal efficiencies and minimum energy consumption, electrochemical Fenton method was found more effective than electrochemical oxidation during this study.

Degradation of textile wastewater by modified photo-Fenton process: Application of Co(II) adsorbed surfactant-modified alumina as heterogeneous catalyst

Fenton method is well recognized for organic pollutant degradation. However, traditional Fenton method has several drawbacks for practical application. In this regard different catalysts and modified Fenton processes are developed for better efficiency. In this study, a new catalyst is developed for methylene blue (MB) and methyl orange (MO) degradation under heterogeneous photo-Fenton process in presence of H2O2 and visible light. Finally, the catalyst was successfully applied for real textile wastewater degradation also. Here the as-prepared catalyst is the Co(II), which is adsorbed on the bilayer structure of sodium dodecyl sulfate (an anionic surfactant) formed on alumina support. The catalyst is designated as Co-SMA. The degradation characteristics of both the dyes are discussed. The MB, being a cationic dye, gets fully adsorbed on Co-SMA surface and the reaction proceeds on the solid surface with zero order kinetics. On the other hand, the degradation of MO follows first order kinetics because of its low adsorption. The efficiency of decolorization of real wastewater is found to be >92% in 60min time of reaction with 10gL−1 of Co-SMA, 37.9mM H2O2 and 10,010lx light intensity. Leaching of cobalt from Co-SMA is very less during the reaction which is advantageous for environmental applications.

Fibrous material based on a combination of poly(acrylic acid‐co‐hydroxyethyl methacrylate) with iron ions as a heterogeneous Fenton catalyst for dye oxidative decomposition

ABSTRACTThe Fenton method has been used to remedy dye wastewater because hydroxyl radicals generated from the Fenton reaction can oxidize the dye into small molecules. In comparison with a homogeneous reaction, a heterogeneous reaction with a solid material as a catalyst is a more appropriate alternative for dye wastewater treatment. Because of the large specific surface area and excellent applicability, a novel fibrous material based on a combination of functional polymer with iron ions was designed in this study and used as a heterogeneous catalyst for dye wastewater treatment by the Fenton method. The fibrous material was found to have good catalytic activity for the oxidative decomposition of a variety of dyes and good reusability; additionally, the fibrous material could remove the dye to a greater extent and leave fewer iron ions in the treated wastewater than a homogeneous Fenton catalyst such as iron(II) chloride (FeCl2). What is more, the fibrous material could adsorb the residual iron ions from the treated wastewater and make these iron ions take part in the next catalyzation. The previous results make us believe that the prepared fibrous material might be used to create a green approach for dye wastewater treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44875

A COMPARATIVE STUDY OF YARN DYED WASTEWATER USING FENTON’S REAGENT AND OZONATION : REMOVAL EFFICIENCY AND ECONOMIC ANALYSIS

This study makes a comparison between Fenton and Ozonation processes treatment methods to examine the removal of COD in yarn dyed wastewater with initial concentration of 525 ppm. Results indicated that the COD degradation efficiency was in order of Fenton > Ozone. In Fenton method, the ratio of Fe2+/H2O2 used was 1 :10, the concentration of H2O2 was 10.2 gram/L. In ozonation, the ozone concentration used in the study was 5.8 % mol, and the agitation was 400 rpm. The effect of operational parameters including, initial pH and time were studied in both processes. The results indicated that it was 86.2 % COD were removed, when the pH was about 3 using Fenton’s reagent and 83.06 % COD removal in ozonation for one hour experiment. To achieve the standard requirement for allowable parameters in wastewater to be discharged, there is only 15 minutes needed for Fenton process to remove COD by 84.8 %, while the ozonation needs 30 minutes for 81 %removal. Fenton process is more economic feasible compare to ozonation which is almost one-tenth of the operation cost for 1 liter of wastewater being process. Though both processes can demonstrate the high removal efficiency to achieve the allowable COD concentration in the wastewater to be discharged, Fenton process is favor to ozonation.

Coke Plant Wastewater Posttreatment by Fenton and Electro-Fenton Processes

Abstract After conventional biological treatment processes, effluents of the coking industry contain high concentration of nonbiodegradable and refractory organic matters, which should be treated to satisfy the discharge water quality standards (chemical oxygen demand [COD] <150 mg/L, NH3–N < 25 mg/L). In this study, post-treatment of coke plant wastewater was treated by the direct Fenton and anodic electro-Fenton (EF-Feox) methods. COD and total organic carbon (TOC) values were selected as the target parameters. COD and TOC removal efficiency was investigated through changing some operating parameters such as initial pH, initial H2O2 concentration, and current density. Under the optimum operating conditions of each progress, COD and TOC were removed more efficiently in the EF-Feox system (90% and 84.4%) compared with that in the Fenton method (61.96% and 48.12%). Influence of H2O2 feeding on removal efficiency was also investigated in this study. Results indicated that gradual addition of H2O2 instead of...

Experimental particle paths and drift velocity in steep waves at finite water depth

The Lagrangian paths, horizontal Lagrangian drift velocity, $U_{L}$, and the Lagrangian excess period, $T_{L}-T_{0}$, where $T_{L}$ is the Lagrangian period and $T_{0}$ the Eulerian linear period, are obtained by particle tracking velocimetry (PTV) in non-breaking periodic laboratory waves at a finite water depth of $h=0.2~\text{m}$, wave height of $H=0.49h$ and wavenumber of $k=0.785/h$. Both $U_{L}$ and $T_{L}-T_{0}$ are functions of the average vertical position of the paths, $\bar{Y}$, where $-1&lt;\bar{Y}/h&lt;0$. The functional relationships $U_{L}(\bar{Y})$ and $T_{L}-T_{0}=f(\bar{Y})$ are very similar. Comparisons to calculations by the inviscid strongly nonlinear Fenton method and the second-order theory show that the streaming velocities in the boundary layers below the wave surface and above the fluid bottom contribute to a strongly enhanced forward drift velocity and excess period. The experimental drift velocity shear becomes more than twice that obtained by the Fenton method, which again is approximately twice that of the second-order theory close to the surface. There is no mass flux of the periodic experimental waves and no pressure gradient. The results from a total number of 80 000 experimental particle paths in the different phases and vertical positions of the waves show a strong collapse. The particle paths are closed at the two vertical positions where $U_{L}=0$.

Greener And Expedient Approach for the Wastewater Treatment by Fenton and Photo-Fenton Processes: A Review

Advanced Oxidation Processes (AOPs) have emerged as a promising technology for the treatment of wastewaters containing toxic, recalcitrant organic compounds such as dyes, pesticides etc. This review paper focuses on the Fenton and photo- Fenton technique which is one of the most efficient AOPs developed to decolorize and/or degrade organic pollutants. This oxidation method can produce biodegradable intermediates and mineralize complex organic pollutants effectively and efficiently. In this paper Fenton and photo-Fenton methods are categorised into two broad groups as homogeneous and heterogeneous Fenton and photo-Fenton processes. Applications of fundamental and advanced combined Fenton and photo-Fenton processes are also discussed.