Fenton's Reagent Dosage Research Articles

Unintended polyhalogenated carbazole production during advanced oxidation of coking wastewater

Polyhalogenated carbazoles (PHCZs) are emerging as dioxin-like global pollutants, yet their environmental origins are not fully understood. This study investigates the application of the Fenton process in coking wastewater treatment, focusing on its dual role in carbazole removal and unintended PHCZ formation. The common halide ions (Cl– and Br–) in coking wastewater, especially Br– ions, exerted a notable impact on carbazole removal. Particularly, the influence of Br– ions was more significant, not only enhancing carbazole removal but also shaping the congener composition of PHCZ formation. Elevated halide ion concentrations were associated with the heightened formation of higher halogenated carbazoles. The Fenton reagent dosage ratio was identified as a crucial factor affecting the congener composition of PHCZs and their toxic equivalency value. The coexisting organic substance (i.e., phenol) in coking wastewater was observed to inhibit PHCZ formation, likely through competitive reactions with carbazole. Intriguingly, ammonium (NH4+) facilitated the generation of higher and mixed halogenated carbazoles, possibly due to the generation of nitrogen-containing brominating agents with stronger bromination capacity. This study underscores the importance of a comprehensive assessment, considering both substrate removal and potential byproduct formation, when employing the Fenton process for saline wastewater treatment.

Efficient degradation of chromium picolinate with simultaneous chromium removal from aqueous solutions using the Fenton process

Chromium picolinate (Cr(pic)3) is widely used for feeding animals. Most Cr(pic)3 administered to animals is excreted without change. The land use of animal waste introduces Cr(pic)3 to the environment. Transformation of Cr(pic)3 in the environment releases hexavalent chromium (Cr(VI)), posing a chromium contamination risk. Because chromium (in trivalent valent) is complexed by picolinic acid (pic), removal of chromium in Cr(pic)3 form via direct adsorption and precipitation methods is rather difficult. Release of chromium from Cr(pic)3 first and then removal of it through the combination of adsorption and precipitation is advisable. To this end, the treatment of Cr(pic)3 using the Fenton process was first investigated in this work. Treatment parameters were optimized for Cr(pic)3 degradation and chromium removal (i.e., initial and final pH of 3.0 and 7.0, and the molar ratio of Fe(II) and H2O2 was 1:2). Adverse effects of the water constituents could be mitigated by flexible adjustment of the Fenton reagent dosages and the external addition of iron ions. The residual chromium in the aqueous phase was simultaneously lowered to the required standard, and Cr(VI) was barely detected in the aqueous phase. Mechanisms of Cr(pic)3 degradation and chromium removal were proposed by the intermediates determined. The results obtained indicate that the Fenton process is robust for degrading Cr(pic)3 and removing chromium simultaneously and is promising for treating Cr(pic)3-containing wastewater.

Chelate-modified Electro-Fenton process for mixed industrial wastewater treatment

ABSTRACT Mixed industrial wastewater (combined wastewater from small-scale industries) treatment is challenging due to the change in characteristics of the wastewater ( time and quantity). The Electro-Fenton (EF) process is one of the effective techniques for the degradation of organic pollutants from the wastewater, but it works under low pH condition, which is one of the major disadvantages of the EF process. To overcome this disadvantage, the chelate-modified EF process was used in this study. In the chelate-modified EF process, EDTA was used as the chelating agent to form complex with Fe ions and to enhance Fenton reaction at near neutral pH. Ti electrode coated with RuO2 was used as anode and graphite as cathode. The batch reactor was operated by varying initial pH, Fenton reagent dosage and chelating agent dosage. The results demonstrate that the chelate-modified EF process gives effective COD removal (67%) at near neutral pH, as comparable to that of the EF process (66%) at acidic pH. Highlights The Chelate-modified EF process for the removal of COD at near neutral pH Treatment of the mixed industrial wastewater with very low BOD/COD ratio Influence of Fenton catalyst and chelating agent dosage on COD removal. Comparable COD removal of 67% with Chelate-modified EF at near neutral pH and 66% with EF at acidic pH. Mineralization current efficiency and instantaneous current efficiency for COD removal.

Degradation characteristics of four major pollutants in chemical pharmaceutical wastewater by Fenton process

Present study deals with the treatment of simulated chemical pharmaceutical wastewater (SCPW) using Fenton oxidation process for the degradation of typical pollutants containing n-butanol, ethyl p-nitrobenzoate, 4, 7-dichloroquinoline and ethyl acetoacetate. The effects of operational parameters like the initial pH, H2O2/Fe2+ molar ratio, H2O2 dosage and reaction time on the degradation efficiency of pollutants and biodegradability of SCPW were investigated. The Fenton reaction steps and the removal kinetics of SCPW were analyzed. Finally, the effects of the molecular structure on the degradation efficiency of organics were investigated. The degradation ratio of n-butanol, ethyl acetoacetate, 4, 7-dichloroquinoline, ethyl p-nitrobenzoate and chemical oxygen demand (COD) in SCPW is 56%, 75%, 100%, 78% and 38%, respectively, for conditions of initial pH of 2.5, H2O2/Fe2+ molar ratio of 20, H2O2 dosage of 0.6 Q (Q is the theoretical dosage of Fenton reagent) and reaction time of 30 min. The reaction steps analysis indicated that the biodegradability of SCPW was improved mainly by the oxidation intermediate of pollutants. The kinetics study showed that the removal processes of pollutants and COD were consistent with the second-order kinetic model. Quantum chemical analysis showed that the correlation between the total energy ERB3LYP and removal kinetic constant K[RH] was most significant, and ERB3LYP was negatively correlated with K[RH]. The results indicated that the higher the total energy of the organics, the more difficult it was to be removed. The findings reported herein are significant to predict the treatment efficiency of pollutants in real pharmaceutical wastewater.

Efficient inactivation of antibiotic resistant bacteria and antibiotic resistance genes by photo-Fenton process under visible LED light and neutral pH

Antibiotic resistance has been recognized as a major threat to public health worldwide. Inactivation of antibiotic resistant bacteria (ARB) and degradation of antibiotic resistance genes (ARGs) are critical to prevent the spread of antibiotic resistance in the environment. Conventional disinfection processes are effective to inactivate water-borne pathogens, yet they are unable to completely eliminate the antibiotic resistance risk. This study explored the potential of the photo-Fenton process to inactivate ARB, and to degrade both extracellular and intracellular ARGs (e-ARGs and i-ARGs, respectively). Using Escherichia coli DH5α with two plasmid-encoded ARGs (tetA and blaTEM-1) as a model ARB, a 6.17 log ARB removal was achieved within 30 min of applying photo-Fenton under visible LED and neutral pH conditions. In addition, no ARB regrowth occurred after 48-h, demonstrating that this process is very effective to induce permanent disinfection on ARB. The photo-Fenton process was validated under various water matrices, including ultrapure water (UPW), simulated wastewater (SWW) and phosphate buffer (PBS). The higher inactivation efficiency was observed in SWW as compared to other matrices. The photo-Fenton process also caused a 6.75 to 8.56-log reduction in eARGs based on quantitative real-time PCR of both short- and long amplicons. Atomic force microscopy (AFM) further confirmed that the extracellular DNA was sheared into short DNA fragments, thus eliminating the risk of the transmission of antibiotic resistance. As compared with e-ARGs, a higher dosage of Fenton reagent was required to damage i-ARGs. In addition, the tetA gene was more easily degraded than the blaTEM-1 gene. Collectively, our results demonstrate the photo-Fenton process is a promising technology for disinfecting water to prevent the spread of antibiotic resistance.

Ultrasound-assisted electrochemical treatment for phenolic wastewater.

With the rapid development of industry, especially the rapid rise of the chemical industry, the problem of water pollution is becoming more and more serious. Among them, the discharge of organic pollutants represented by phenolic substances has always been at the forefront. In this paper, ultrasound-assisted electrochemical treatment for phenolic wastewater is investigated. The effects of ultrasonic frequency, current, pH value and the amount of fly ash-loaded titanium TiO2-Fe3+ particles on phenol removal from phenol-containing wastewater are investigated. The experimental results demonstrate that the removal rate of phenol in phenol-containing wastewater is the best when ultrasonic frequency is 45kHz, power is 200W, the current is 1.2 A, pH is 5 and the dosage of fly ash-loaded titanium TiO2-Fe3+ particles is 3g. In addition, microwave-assisted-Fenton reagent treatment for phenol wastewater is investigated. The effects of Fenton reagent dosage, initial pH value, microwave power density and radiation time on phenol degradation rate are investigated. The results show that microwave can accelerate the reaction rate, reduce the number of metal ions, save the process cost and reduce the difficulty of post-treatment. Finally, the research status of phenol wastewater treatment technology at the present stage is reviewed, and the future development direction is discussed.

Fenton Oxidation and Fungal Remediation of Different Pollutants from Kitchener Drain, Egypt.

Wastewater from Kitchener drain cause many effects not only on the surrounding environment but when being discharged into the Mediterranean Sea water. Using different remediation processes for heavy metals removal has important role in purification of different types of wastewaters aid in recycling process. This work is aimed to use Fenton as chemical remediation process for reduction of organic pollutants and to screen the efficiency of the fungal isolates in heavy metal removal process by generation of an immobilized fungal consortium. Parameters affecting the Fenton process as pH, dosages of Fenton reagents and temperature were taken into considerations in this research. Results showed that the optimum conditions to have high removal of organic matter from wastewater sample at the experiment were at FeSO4 (0.4 gm), hydrogen peroxide H2O2 (15%), at acidic medium (pH = 2) and temperature of about 40°C. It showed high removal of chemical oxygen demand COD concentration from sample with 80 to 95% removal. On the other experiment, a mixture of fungal spores was used to remove Chromium, Cadmium and Nickel ions in batch modes. In this mode, the immobilized biomass was enclosed in a hanged tea bag-like cellulose membrane to facilitate the separation of the biosorbent from the treated solutions, which is one of the main challenges in applying microbial biosorption at large scale. The chemical remediation approved the potentiality to reduce non-biodegradable components which can’t be consumed by bio-remediates i.e. fungi and bacteria. Where, all the obtained biosorbent isolates showed more significant efficiency in heavy metal removal. The most potential biosorbent fungi were identified and characterized. Finally, these remediation methods can be applied for removal of different pollutants from wastewaters.

Treatment of petroleum oil spill sludge using the combined ultrasound and Fenton oxidation process

In this paper, advanced oxidation process (AOP) combining ultrasound (US) and Fenton’s process was proposed for the treatment of total petroleum hydrocarbons present in oil spill sludge. The effect of several parameters like pH, ultrasonic power, weight ratio of hydrogen peroxide to iron [H2O2/Fe2+], Fenton reagent dosage, addition of salts and contact time were analyzed for the reduction of Petroleum Hydrocarbons (PHCs) in terms of hydrocarbon fractions (nC7–C10, nC11-C20). Chemical characterization of oil spill sludge was analysed by gas chromatography- mass spectrum (GC–MS) Elemental analyser, Fourier Transform Infra Red (FT-IR) Analyser and particle size analyser. Experiments were conducted for identifying the wide range of hydrocarbons fractions (nC7–C10, nC11–C20 and nC21–C30). Results shown that maximum solubilisation and PHC removal rate of up to 84.25% could be achieved at a pH of 3.0, sludge/water ratio of 1:100, ultrasonic power of 100 W with 40–50% ultrasonic amplitude, a H2O2/Fe2+ weight ratio of 10:1, and an ultrasonic treatment time of 10 min. The lower and medium fractions (nC7–C10, nC11–C20) were amenable to degradation due to ultrasound treatment compared to the heavier carbon fraction (nC21–C30). The study concludes that the combined sono-Fenton (SF) process significantly enhanced the degradation of oil spill sludge as compared to ultrasound treatment and Fenton oxidation alone. The enhanced solubilisation achieved by US alone is highly beneficial when we couple this with biodegradation which will be greatly facilitated by the enhanced solubility.

Mineralization of Hazardous Waste Landfill Leachate using Photo-Fenton Process

This study was conducted to evaluate the COD removal efficiency of Photo-Fenton oxidation process. The reagents used in the Photo-Fenton process are catalyst Fe2+ and H2O2 as oxidizing agent. A 16W UV lamp was used to carry out the experiments. All the experiments were performed in batch mode to investigate the influence of operating conditions viz., Fenton reagents dosage, molar ratio and reaction time. The maximum COD removal observed was 68% under optimum operating conditions. The operating conditions H2O2/Fe2+ molar ratio = 3 and reaction time = 90 minutes were found to optimum. The dosages of Fenton reagents i.e. hydrogen peroxide and Fe2+ were optimum at 0.09 mol/L and 0.03 mol/L respectively.

Treatment of hazardous waste landfill leachate using Fenton oxidation process

The efficiency of Fenton’s oxidation was assessed in this study for hazardous waste landfill leachate treatment. The two major reagents, which are generally employed in Fenton’s process are H2O2 as oxidizing agent and Fe2+ as catalyst. Batch experiments were conducted to determine the effect of experimental conditions viz., reaction time, molar ratio, and Fenton reagent dosages, which are significant parameters that influence the degradation efficiencies of Fenton process were examined. It was found that under the favorable experimental conditions, maximum COD removal was 56.49%. The optimum experimental conditions were pH=3, H2O2/Fe2+ molar ratio = 3 and reaction time = 150 minutes. The optimal amount of hydrogen peroxide and iron were 0.12 mol/L and 0.04 mol/L respectively. High dosages of H2O2 and iron resulted in scavenging effects on OH• radicals and lowered degradation efficiency of organic compounds in the hazardous waste landfill leachate.

Degradation of alachlor using an enhanced sono-Fenton process with efficient Fenton's reagent dosages

In this study, an enhanced sono-Fenton process for the degradation of alachlor is presented. At high ultrasonic power, low pH, and in the presence of adequate Fenton's reagent dosages, alachlor degradation can reach nearly 100%. The toxicity of treated alachlor wastewater, which was measured by changes in cell viability, slightly decreased after the Fenton or ultrasound/H2O2 process and significantly decreased after the enhanced sono-Fenton process. A satisfactory relationship was observed between the total organic carbon removal and cell viability increment, indicating that alachlor mineralization is a key step in reducing the toxicity of the solution. The formation of alachlor degradation byproducts was observed during the oxidation process, in which the first step was the substitution of a chloride by a hydroxyl group. In conclusion, the enhanced sono-Fenton process was effective in the degradation and detoxification of alachlor within a short reaction time. Thus, the treated wastewater can then be passed through a biological treatment unit for further treatment.

Decolorization of distillery spent wash effluent by electro oxidation (EC and EF) and Fenton processes: A comparative study

In this study, laboratory scale experiments were performed to degrade highly concentrated organic matter in the form of color in the distillery spent wash through batch oxidative methods such as electrocoagulation (EC), electrofenton (EF) and Fenton process. The effect of corresponding operating parameters, namely initial pH: 2–10; current intensity: 1–5A; electrolysis time: 0.5–4h; agitation speed: 100–500rpm; inter-electrode distance: 0.5–4cm and Fenton's reagent dosage: 5–40mg/L was employed for optimizing the process of spent wash color removal. The performance of all the three processes was compared and assessed in terms of percentage color removal. For EC, 79% color removal was achieved using iron electrodes arranged with 0.5cm of inter-electrode space and at optimum conditions of pH 7, 5A current intensity, 300rpm agitation speed and in 2h of electrolysis time. In EF, 44% spent wash decolorization was observed using carbon (graphite) electrodes with an optimum conditions of 0.5cm inter-electrode distance, pH 3, 4A current intensity, 20mg/L FeSO4 and agitation speed of 400rpm for 3h of electrolysis time. By Fenton process, 66% decolorization was attained by Fenton process at optimized conditions of pH 3, 40mg/L of Fenton's reagent and at 500rpm of agitation speed for 4h of treatment time.

Degradation of four pharmaceuticals by solar photo-Fenton process: Kinetics and costs estimation

Solar photo-Fenton process for degradation of four types of pharmaceuticals namely amoxicillin, ampicillin, diclofenac, and paracetamol was studied. Experiments were carried out by solar compound parabolic collectors (CPCs) reactor with borosilicate tubes and capacity of 4.0L. Oxidation of each pharmaceutical was investigated individually using 100mg/L synthetic solution. The influence of irradiation time, initial pH value, and dosage of Fenton reagent were investigated. Paracetamol, and amoxicillin were completely removed after 60 and 90min of irradiation respectively. Complete degradation of ampicillin and diclofenac was occurred after 120min. The removal of pharmaceuticals was significantly affected by changing pH values from 3 to 10. Complete removal of all pharmaceuticals was achieved under acidic conditions (pH 3). The optimum H2O2 and FeSO4.7H2O dosage were 1.5 and 0.5g/L, respectively. The results of photo-Fenton experiments fitted the pseudo-first order kinetic equation with high correlation. Costs estimation of 30m3/d full scale solar photo-oxidation plant was assessed.

Investigation of optimum conditions and costs estimation for degradation of phenol by solar photo-Fenton process

In this study, solar photo-Fenton reaction using compound parabolic collectors reactor was assessed for removal of phenol from aqueous solution. The effect of irradiation time, initial concentration, initial pH, and dosage of Fenton reagent were investigated. H2O2 and aromatic intermediates (catechol, benzoquinone, and hydroquinone) were quantified during the reaction to study the pathways of the oxidation process. Complete degradation of phenol was achieved after 45 min of irradiation when the initial concentration was 100 mg/L. However, increasing the initial concentration up to 500 mg/L inhibited the degradation efficiency. The dosage of H2O2 and Fe+2 significantly affected the degradation efficiency of phenol. The observed optimum pH for the reaction was 3.1. Phenol degradation at different concentration was fitted to the pseudo-first order kinetic according to Langmuir–Hinshelwood model. Costs estimation for a large scale reactor based was performed. The total costs of the best economic condition with maximum degradation of phenol are 2.54 €/m3.

A study on oxidative degradation of polyacrylamide in wastewater with UV/FENTON/C4H4O62−

ABSTRACTThe degradation of polyacrylamide (PAM) in simulate wastewater was studied in UV/Fenton/C4H4O62− system. The factors such as molecular ratio of H2O2/Fe2+/C4H4O62−, pH, and the dosage of Fenton reagent that could affect the PAM degradation in the UV/Fenton/C4H4O62− system were investigated. The experimental results showed that adding C4H4O62− to UV/Fenton system could form photosensitive ferrous complexes, which led to higher degradation efficiency of PAM. The degradation rate of PAM could be up to 95.2% under the following conditions: the concentration of H2O2, Fe2+, and C4H4O62− were 22.5, 2.25, and 2.25 mmol/L, respectively (i.e., molecular ratio of H2O2/Fe2+/C4H4O62− was 10:1:1), the pH value was 3.0.

UV light photo-Fenton degradation of polyphenols in oolong tea manufacturing wastewater

The UV light photo-Fenton degradation of oolong tea polyphenols in tea manufacturing effluent that color the wastewater to a dark brown has been examined. In order to elucidate the photo-Fenton degradation mechanism of oolong tea polyphenols and find the optimal dosages of the Fenton reagents, systematic study has been conducted. For the UV light photo-Fenton degradation of oolong tea effluent being 70 mg-(polyphenol) L−1, the optimum dosages of Fenton reagents were found to be 20 mgL−1 of total Fe and 500 mgL−1 of H2O2. The polyphenol degradation could be divided into two stages. The polyphenols concentration rapidly decreased to around 30% of the initial concentration within 2 min and the degradation rate significantly slowed down in the subsequent stage. After 60 min of UV light irradiation, 97% polyphenol removal was obtained. The initial quick degradation of oolong tea polyphenols suggests that hydroxyl radical generated by the photo-Fenton process might preferentially attack polyphenols having high antioxidant activity by scavenging hydroxyl radicals. Almost complete decolorization of the oolong tea effluent was achieved after 80 min. About 96% mineralization of 63 mgL−1 TOC loading was achieved within 60 min and then further mineralization was rather slow. The complete COD removal of 239 mgL−1 COD loading was obtained after 100 min. The present results indicate that the UV light photo-Fenton degradation process can treat tea manufacturing wastewaters very effectively.

Wastewater treatment of methyl methacrylate (MMA) by Fenton's reagent and adsorption

Oxidation-adsorption treatments were applied to improve the biodegradability of wastewater from the manufacture of acrylic resins with methyl methacrylate (MMA). MMA wastewater has an extremely complex composition, with a chemical oxygen demand (COD) concentration of 651.25-g O2/L, total organic carbon (TOC) concentration of 227.86g/L, N-NH3 concentration of 48.80g/L, and 352,500-PtCo units. In this study, the effects of operating parameters that include the Fenton reagent dosage, the initial pH, and the reaction time of the treatment efficiencies of the Fenton oxidation process were observed. The improvement in the biodegradability was attributed to the removal of ammonium and organic pollutants from the wastewater, which was confirmed using infrared spectroscopy. After this process, adsorption of organic matter from wastewater was also studied; kinetic and equilibrium adsorption studies were performed to evaluate the effect of the contact time and pH. Pseudo-second-order kinetics represented the experimental data well, and Langmuir and Freundlich isotherm models were tested to represent the data. The maximum adsorption capacity obtained was qm=1.15g/g for TOC and 11.65g/g for COD at optimum conditions. The removal efficiencies of the Fenton adsorption treatment were 96% of color, 58% of TOC, and 60% COD.

Structural characterization of natural organic matter and its impact on methomyl removal efficiency in Fenton process

This study aimed to characterize the NOM structural variation during Fenton process, in which the methomyl and humic acid were selected as the investigated compounds. The preliminary degradation experiments were conducted at various H2O2 and Fe2+ concentrations without the presence of NOM to determine the applied Fenton reagent dosages for subsequent NOM impact on Fenton degradation. The methomyl removal at 80% was observed at the Fenton reagent ratio ([H2O2]/[Fe2+]) of 1 while Fe2+ concentration was no less than 2mM. In the presence of NOM, the methomyl removal by Fenton process was further enhanced apparently. The NOM used in this study was found to be a macromolecule with tryptophan-like and tyrosine-like functional groups through fluorescence spectrometry analysis. The addition of ferrous ions in the NOM solution initiated the reactions between Fe2+/Fe3+ redox couples and NOM molecules, breaking the NOM into smaller organic fractions. These organic fractions were further oxidized into even smaller molecules by hydroxyl radicals after H2O2 addition. The NOM might compete with methomyl for hydroxyl radicals, and enhance the catalytical generation of hydroxyl radicals by reducing Fe3+ to Fe2+ at the same time. Apparently, the increase in OH generation was more than the OH consumption by NOM presence, resulting in the observed enhancement of methomyl removal.

Effect of the coupled action of ultrasonic waves and advanced oxidation reaction on the properties of bottom sediments originating from trout culture

The objective of this study was to determine the effect of preliminary ultrasound treatment of bottom sediments, a factor enhancing the reaction of advanced oxidation, on changes in the properties of sediments originating from the intensive aquaculture of rainbow trout. Experiments were conducted on a laboratory scale in model reactors with an active volume of 1.0 L, either under conditions of exposure to the ultrasonic field alone or under conditions of exposure to both the ultrasonic field and a chemical reagent: Fe3+/H2O2. The results we achieved showed that preliminary ultrasound treatment of bottom sediments increased the advanced oxidation reaction yield and consequently improved the physicochemical properties of the sediments. The highest yield was obtained upon 15-min ultrasound treatment at a Fenton reagent dosage of 1.5 g Fe3+ L−1 and g H2O2 L−1. These conditions enabled a 43% reduction in the concentrations of organic compounds in the filtrate, shortened the capillary suction time (CST) by 93%, decreased the concentration of volatile substances in the sediments by 13% and decreased the levels of total nitrogen in sediments by 9% and of total phosphorus in the filtrate by 21%, and additionally caused a decrease in the mineral and dry matter content in the sediments.

Pretreatment of dry-spun acrylic fiber manufacturing wastewater by Fenton process: Optimization, kinetics and mechanisms

Fenton process was applied to the pretreatment of wastewater from dry-spun acrylic fiber (DAF) manufacturing. The effects of operating parameters including the Fenton reagent dosage, the initial pH value, and the reaction time on the treatment efficiencies of the Fenton oxidation process were observed. About 47.0% of the chemical oxygen demand (COD) removal efficiency was reached under the optimum conditions: hydrogen peroxide of 90.0mM, ferrous ions of 20.0mM, pH value of 3.0, and reaction time of 120min. The COD degradation of the Fenton process followed the pseudo first-order reaction kinetics, and the apparent activation energy E, was determined to be 41.6kJmol−1. After the Fenton pretreatment under the optimum reaction conditions, the BOD5/COD ratio of wastewater increased from 0.32 to 0.69, which was suitable for further biological treatment. The improvement of biodegradability was attributed to the removals of aromatics and some other bio-refractory compounds from the wastewater, as confirmed by gas chromatography–mass spectrometry (GC–MS), Fourier transform infrared spectroscopy (FTIR) and fluorescence excitation–emission matrix (EEM) spectroscopy analyses. Fenton process was proven to be an effective method for the pretreatment of DAF manufacturing wastewater prior to biological treatment.