Comparative performance of catalytic Fenton oxidation with zero-valent iron (Fe(0)) in comparison with ferrous sulphate for the removal of micropollutants

This research aims to depict the comparative performance of micropollutants’ removal by FeSO4- and zero-valent iron (Fe(0))-catalytic Fenton oxidation and to explore the possibilities of minimising the sludge production from the process. The emerging micropollutants used for the study were gabapentin, sulfamethoxazole, diuron, terbutryn and terbuthylazine. The Taguchi method, which evaluates the signal-to-noise ratio instead of the standard deviation, was used to develop robust experimental conditions. Though both FeSO4- and Fe(0)-catalytic Fenton oxidation were able to completely degrade the stated micropollutants, the Fe(0)-catalytic Fenton process delivered better removal of dissolved organic carbon (DOC; 70%) than FeSO4 catalytic Fenton oxidation (45%). Fe(0)-catalytic Fenton oxidation facilitated heterogeneous treatment functions, which eliminated toxicity from contaminated solution and there was no recognisable sludge production

Landfill leachate treatment by combination of electro - fenton and sequencing batch reactor method

Landfill leachate contains a large amount of organic, inorganic and heavy metal contents. Untreated leachate is a potential source to effect of soil, surface and groundwater. The combined treatment offers an alternative technique in dealing to leachate treatment. This research is to determine the effectiveness of combined electro-Fenton and sequencing batch reactor (SBR) method on the removal of SS, colour, COD and NH3-N. The experimental involved three major parts were coagulation-flocculation, electro-Fenton and SBR method. This process could be operated independently in a batch mode and optimum conditions for each treatment were identified. In the combined process, leachate was first fed to coagulation-flocculation for pre-treatment. Then, the effluent from that process was oxidized in electro-Fenton process. The final process is the effluent of leachate was fed to a SBR method. The combined treatment was operated under the optimum conditions for all the processes. The result of coagulation-flocculation shown PAC is more effective at 2500 mg/L of optimum dosage. After coagulation-flocculation process, the removal of SS, colour, COD and NH3-N were 80%, 77%, 61% and 35% respectively. The result of electro-Fenton shown Al-Al is more effective at 200 A/m2 of optimum current density, 25 minutes of optimum reaction time, 4 of optimum pH, 800 mg/L of optimum H2O2 dosage and 1000 mg/L of optimum FeSO4•7H2O dosage. After electro-Fenton process, the removal of SS, colour, COD and NH3-N were 87%, 95%, 82% and 65% respectively. The final process of SBR effluent was approaching neutral pH at 6.90 at 2800 mg/L of optimum MLSS and 6 h of optimum reaction time. The overall performance of combined treatment on the removal of SS, colour, COD and NH3-N were 84%, 82%, 87% and 78% respectively. Thus, this combined treatment offers as an alternative technique for landfill leachate treatment on the removal of pollutants

Fenton coupled with nanofiltration for elimination of Bisphenol A

Bisphenol A (BPA) is a typical Endocrine Disrupting Chemical (EDC), which is potentially harmful during wastewater reclamation. In this study, its degradation during Fenton's process under different operational conditions was investigated in combination with subsequent nanofiltration of low concentration remnant BPA and compounds derived from oxidation. The results indicate that BPA could be degraded efficiently in aqueous phase by Fenton, even at very low hydrogen peroxide doses. The treatment of up to 300 mg/L solutions of BPA with Fenton liquor at optimal conditions resulted in its complete removal in less than 2 min. The optimal conditions were found to be pH, = 3, H2O2/BPA = 020 and Fe2+/BPA = 0.012. Five NF polymeric membranes having different properties were used for the nanofiltration of treated and non-treated solutions. The nanofiltration of BPA solutions showed that rejection is related to adsorption ability of BPA on the membrane and size exclusion mechanism. In the nanofiltration of the effluent after Fenton oxidation, high TOC, COD, colour and Fe2+ (>77%) removal were achieved, although significant membrane fouling was also observed. The normalised water flux after membrane flushing with water was lower than 60% in almost all used membranes, which indicates significant non-easily removable fouling. (C) 2014 Elsevier B.V. All rights reserved.Peer ReviewedPostprint (author’s final draft

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

PENYISIHAN COD, TSS, DAN WARNA PADA LINDI HITAM DENGAN MENGGUNAKAN KOAGULASI, FENTON, DAN ADSORPSI DARI PROSES PRETREATMENT TANDAN KOSONG KELAPA SAWIT MENJADI BIOETANOL

ABSTRAK PENYISIHAN COD, TSS, DAN WARNA PADA LINDI HITAM DENGAN MENGGUNAKAN KOAGULASI, FENTON, DAN ADSORPSI DARI PROSES PRETREATMENT TANDAN KOSONG KELAPA SAWIT MENJADI BIOETANOL Limbah lindi hitam merupakan limbah yang berasal dari proses pretreatment tandan kosong kelapa sawit menjadi bioetanol, dimana sampai saat ini belum mendapatkan perhatian khusus. Lindi hitam mengandung senyawa diklorinasi, padatan tersuspensi, fenolat, dan lignin sehingga mempunyai karakteristik COD (113.750 mg/L) dan TSS (306,14 mg/L) tinggi serta berbahaya bagi ekosistem air jika dibuang langsung ke perairan tanpa pengolahan tertentu. Penelitian ini bertujuan untuk mengidentifikasi karakteristik lindi hitam dan mengetahui efisiensi pengolahan limbah lindi hitam dengan menggunakan kombinasi dari metode koagulasi – flokulasi, AOPs Fenton, dan adsorpsi. Penelitian ini menggunakan metode jartest, dengan variasi konsentrasi koagulan-flokulan, Fenton reagen, dan adsorben karbon aktif-pasir aktif berlapiskan Fe. Metode koagulasi-flokulasi menggunakan 30 g/L PAC dan 15 g/L alumunium sulfat mampu menyisihkan COD sebesar 81,68%, TSS sebesar 82,38%. Air hasil koagulasi-flokulasi diolah dengan metode Fenton. Efisiensi penurunan COD, TSS yang diperoleh adalah masing-masing sebesar 66,81% dan 53,91%. Penggunaan metode adsorpsi dengan karbon aktif 20 g untuk mengolah air hasil Fenton mampu menurunkan COD, TSS masing-masing sebesar 93,30%, 18,36%. Hasil akhir pengolahan pada parameter COD, TSS dengan kombinasi metode kimia ini masing-masing adalah 608 mg/L, 22 mg/L. Kata Kunci: Lindi Hitam, Koagulasi Flokulasi, AOPs, Fenton, Dekolorisasi   ABSTRACT Removal COD and TSS on Black Liquor Wastewater Using Coagulation, Fenton, and Adsorption on Pretreatment Process Oil Palm Empty Fruit Bunches Into Bioethanol Black Liquor is waste disposal that comes from the pretreatment process of bioethanol from oil palm empty fruit bunches. Which until now has not received special attention. Black liquor containing chlorinated compounds, suspended solids, phenolics, and lignin that has the characteristics of COD (113 750 mg / L) and TSS (306.14 mg / L) high and is harmful to aquatic ecosystems if discharged directly into waters without specific treatment. This study aims to identify the characteristics of black liquor and determine the efficiency of black liquor waste treatment using a combination of methods of coagulation - flocculation, AOPs Fenton, and adsorption. This study uses jartest, with variations in the concentration of coagulant-flocculant, Fenton reagent, and activated carbon adsorbent-active sand encrusted Fe. Coagulation-flocculation method using a 30 g / L PAC and 15 g / L of aluminum sulfate capable of removing 81.68% of COD, TSS of 82.38%. The results of coagulation-flocculation water mixed with Fenton method. The removal efficiency of COD, TSS obtained are respectively 66.81% and 53.91%. The use of activated carbon adsorption method with 20 g to treat the water from the Fenton able to reduce COD, TSS respectively by 93.30%, 18.36%. The final result of processing parameters COD, TSS by a combination of chemical methods is respectively 608 mg / L, 22 mg / L. Keywords: Black Liquor, Coagulation, Flocculation, AOPs, Fenton, Decolorizatio

Mineralisation of 2,4-dichlorophenoxyacetic acid by acoustic or hydrodynamic cavitation in conjunction with the advanced Fenton process

The mineralisation of 2,4-dichlorophenoxyacetic acid (2,4-D) in the presence of zero-valent iron and hydrogen peroxide (the Advanced Fenton process – AFP) whilst being subjected to acoustic or hydrodynamic cavitation is reported. If the reaction is merely stirred then there is 57% removal of TOC whilst on irradiation the figure is 64% although the latter reaction is more rapid. Use of ultrasound alone results in only 11% TOC removal in 60 min of treatment time. Addition of iron powder marginally enhances the extent of degradation but an appreciable increase is observed in the presence of hydrogen peroxide which acts as a source for hydroxyl radicals by Fenton chemistry as well as by dissociation in the presence of ultrasound. The use of hydrodynamic cavitation in conjunction with the advanced Fenton process has also been found to be a useful tool for continuous remediation of water contaminated with 2,4-D. After 20 minutes of treatment the residual TOC is reduced to 30% and this probably represents the remaining highly recalcitrant small organic molecules

Comparison of AOPs Efficiencies on Phenolic Compounds Degradation

In this work, a comparison of the performances of different AOPs in the phenol and 4-chlorophenol (4-CP) degradation at lab and pilot scale is presented. It was found that, in the degradation of phenol, the performance of a coupled electro-oxidation/ozonation process is superior to that observed by a photo-Fenton process. Phenol removal rate was determined to be 0.83mg L−1 min−1 for the coupled process while the removal rate for photo-Fenton process was only 0.52mg L−1 min−1. Regarding 4-CP degradation, the complete disappearance of the molecule was achieved and the efficiency decreasing order was as follows: coupled electrooxidation/ ozonation > electro-Fenton-like process > photo-Fenton process > heterogeneous photocatalysis. Total organic carbon was completely removed by the coupled electro-oxidation/ozonation process. Also, it was found that oxalic acid is the most recalcitrant by-product and limits the mineralization degree attained by the technologies not applying ozone. In addition, an analysis on the energy consumption per removed gram of TOC was conducted and it was concluded that the less energy consumption is achieved by the coupled electro-oxidation/ozonation process

Decolorization of Industrial Waste Using Fenton Process and Photo Fenton

Industrial waste water decolorization has been done using the method of Fenton and Photo Fenton. The experiment was conducted in order to obtain the optimum process conditions for industrial waste treatment method with Fenton and Photo Fenton. Industrial waste used in this experiment waste of blue batik making process derived from Rara Djograng Batik Yogyakarta. Factors were studied in this research are the effect of the amount of catalyst FeSO4.7H2O, the amount of oxidant H2O2, and the time of oxidation in the Fenton and Photo Fenton. The optimum conditions of decolorization of blue batik waste by Fenton and Photo Fenton methods occurred in the number of FeSO4.7H2O 25 mg, the amount of H2O2 25 mL, contact time of 15 min at pH 3.0. In these conditions efficiency of decolorization reached 77.5% for the Fenton and 98.5% for the Photo Fenton process

Regeneration of activated carbon by fenton and photofenton oxidation for the treatment of phenol wastewater

Advanced Oxidation Processes have emerged as promising technologies for the recovery of carbons saturated with aromatic molecules, owing to their potency to degrade a wide range of organic pollutants by the generation of very reactive and non selective free hydroxyl radicals. The purpose of this work is to study the adsorption of phenol on activated carbons (ACs) and the consecutive in-situ regeneration of carbon by Fenton oxidation. Two different processes have been carried out: - the first one is based on a complete batch system in order to investigate the influence of Fe2+ and H2O2 concentrations; - the second one consists in a continuous fixed bed adsorption, followed by a batch circulation of the Fenton’s reagent through the saturated AC bed, to examine the efficiency of the real process. Two different activated carbons have been also studied: a both micro- and mesoporous AC (L27) and an only microporous one (S23). In the batch reactor containing a 1 g/L phenol solution, the optimal conditions found for pollutant mineralization in the homogeneous Fenton system (Fe2+ = 10 mmol/L, [H2O2] = 1000 mmol/L, corresponding to 6.5 times the stoechiometric amount for complete mineralization) are not the best for AC regeneration: a continuous reduction of adsorption capacity of L27 from 100% to 23% is observed after 3 oxidations, due to the decrease of both AC weight and surface area. Higher concentration of Fe2+ (20 mmol/L) and lower concentration of H2O2 (2 times the stoechiometry) lead to a 50% recovery of the initial adsorption capacity during at least 4 consecutive cycles for L27, while about 20% or less for S23. In the consecutive continuous adsorption/batch oxidation process, the regeneration efficiency reaches 30% to 40% for L27 after two cycles whatever the feed concentration (0.1 g/L or 1 g/L of phenol) and less than 10% for S23 (0.1 g/L of phenol). During oxidation step, Total Organic Carbon removal is found to reach a limit, probably due to the formation of Fe3+/organic acid complex, hindering Fe2+ regeneration. Such complexes are stable in usual Fenton conditions, but can be destroyed by UV radiation. A photo-Fenton test performed on L27 indeed shows almost complete mineralization and improved recovery of AC adsorption capacity although not complete (56% after two cycles)

Effect of Formic Acid on Pollutant Decomposition in Textile Wastewater Subjected to Treatment by the Fenton Method

The aim of this research was to determine the effect of formic acid on pollutant decomposition in textile wastewater subjected to treatment by the Fenton method. To estimate the effect of formic acid on treatment efficiency for different types of textile wastewater tested, COD reduction in mixtures of wastewater and formic acid was calculated. The values of COD calculated were then compared with COD values obtained experimentally during the oxidation of samples of wastewater-formic acid mixtures in the Fenton process. It was found that the presence of formic acid did not deteriorate the conditions of wastewater treatment in the Fenton process. Thus the presence of formic acid in textile wastewater is more advantageous than that of acetic acid