scholarly journals Oxidative degradation of cyan flexo dye with Heterogeneous Fenton reagent - Fe2(MoO4)3 particle

2019 ◽  
pp. 77-85
Author(s):  
Vesna Gvoic ◽  
Miljana Prica ◽  
Djurdja Kerkez ◽  
Milena Becelic-Tomin ◽  
Aleksandra Kulic ◽  
...  
Keyword(s):  
Iron Concentration ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Process Efficiency ◽  
High Catalytic Activity ◽  
Organic Carbon Content ◽  
Fenton Reagent ◽  
Heterogeneous Fenton ◽  
Operational Conditions ◽  
Screening Design

Heterogeneous Fenton catalyst Fe2(MoO4)3 was prepared and the process efficiency was evaluated for oxidation of water-based Cyan flexo dye in synthetic aqueous solution and printing wastewater. The removal process of printing dye was analyzed by UV/VIS spectrophotometry, while dye mineralization was evaluated by the determination of total organic carbon content and chemical oxygen demand. Four determinants of the heterogeneous Fenton system, including initial dye concentration, iron concentration, pH and hydrogen peroxide concentration were investigated. Statistical method, definitive screening design was applied to generate optimal operational conditions of the four variables, which maximizes the process of dye removal. The initial dye concentration of 20 mgL-1, catalyst dosage of 0.75 mgL-1, pH of 2 and H2O2 concentration of 11 mM were chosen as the best operational conditions, contributing to 82% of the process efficiency. The Fenton process efficiency of 79% was achieved within the treatment of printing wastewater under optimal conditions for a 90 minute reaction time. The maximum COD removal efficiency was 61.1%, while 67% mineralization was achieved. The obtained results confirmed synergistic effect of Fe3+ and MoO4 2? which contributed to high catalytic activity and high heterogeneous Fenton efficiency.

scholarly journals The Application of Response Surface Methodology in the Study of Photodegraded Industrial Dairy Effluents by the Photo-Fenton Process: Optimization and Economic Viability

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Carla Cristina Almeida Loures ◽  
Hélcio José Izário Filho ◽  
Ivy dos Santos Oliveira ◽  
Gisella Rossana Lamas Samanamud ◽  
André Luiz de Souza ◽  
...  
Keyword(s):  
Oxygen Demand ◽  
Statistical Design ◽  
Cost Benefit ◽  
Process Efficiency ◽  
Organic Load ◽  
Maximum Efficiency ◽  
Fenton Process ◽  
Fenton Reagent ◽  
Benefit Evaluation ◽  
Dairy Effluents

This study presents results from an application of Photo-Fenton process for organic-load reduction in dairy effluents. Process efficiency was evaluated in terms of percentage dissolved organic carbon, chemical oxygen demand, and biochemical oxygen demand (DOC, COD, and BOD, resp.), whose initial values were 1658±145 mg O2 L−1, 9500±500 mg O2 L−1, and 2400 ± 100 mg O2 L−1, respectively. We applied a statistical design represented by Box-Behnken factorial design inclusive of Fenton's reagent, the power of applied radiation (W), and pH factors. The set temperature value was 30°C with a reaction time of 60 min. The maximum efficiency obtained was at pH=3.5, Fenton reagent in the proportion of 35 g H2O2 + 3.6 g Fe2+, and ultraviolet radiation potency of 28 W. The results obtained for DOC, COD, and BOD were 81%, 90.7%, and 78.8%, respectively. Regarding the cost/benefit evaluation, the variables and their levels should be the following: pH 3.5, 35.0 g H2O2/Fe2+ 3.6 g, and 28 W UV, obtaining a reduction in concentration of 79.5% DOC.

scholarly journals Heterogeneous Fenton-like degradation of EDTA in an aqueous solution with enhanced COD removal under neutral pH

2020 ◽  
Author(s):  
Junfeng Hua ◽  
Mei Huang
Keyword(s):  
Catalytic Activity ◽  
Ethylenediaminetetraacetic Acid ◽  
Oxygen Demand ◽  
Morphological Characterization ◽  
Cod Removal ◽  
High Catalytic Activity ◽  
Heterogeneous Fenton ◽  
Neutral Ph ◽  
Effects Of Ph ◽  
Fe3o4 Mnps

Abstract By providing the key carbon and nitrogen elements needed for eutrophication, the potential toxicity of ethylenediaminetetraacetic acid (EDTA) prompts the exploration of effective treatment methods to minimize the amount of EDTA released into the environment. In this study, Fe3O4 magnetic nanoparticles (MNPs) were prepared and used as catalysts to study the mineralization of EDTA in Fenton-like reactions under neutral pH. Fe3O4 MNPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer–Emmett–Teller (BET). The effects of pH, ferric ion leaching, and H2O2 concentration on chemical oxygen demand (COD) removal of EDTA were investigated. The morphological characterization of the nanoparticles suggests a quasi-spherical structure with small particle size and a surface area of 49.9 m2/g. The results show that Fe3O4 MNPs had good catalytic activity for the mineralization of EDTA under pH 5.0–9.0. The optimum conditions for the COD removal of 45% at pH 7.0 were: 40 mM H2O2, 10 mM Fe3O4, and 1 g/L EDTANa2·2H2O at 303 K. Fe3O4 MNPs maintained high catalytic activity after five cycles of continuous degradation of EDTA. According to reactive oxidizing species measurements obtained by electron spin resonance (ESR), it was confirmed that HO· free radicals, presented in the H2O2/Fe3O4 MNPs heterogeneous Fenton-like reaction, were the primary active group in the removal of EDTA. These features can be considered beneficial to the application of Fe3O4 MNPs towards industrial wastewater treatment.

Highly Active Heterogeneous Fenton-Like Systems Based on Fe3O4 Nanoparticles

2011 ◽  
Vol 233-235 ◽  
pp. 487-490 ◽  
Author(s):  
Wei Wang ◽  
Tie Long Li ◽  
Ying Liu ◽  
Ming Hua Zhou
Keyword(s):  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Catalytic Efficiency ◽  
Alkaline Media ◽  
Homogeneous Catalyst ◽  
Fenton Reagent ◽  
Heterogeneous Fenton ◽  
X Ray

In this work, magnetic nanoscale Fe3O4 particles were synthesized through coprecipitation of Fe(II) and Fe(III) in alkaline media. The structure, composition and properties of the nanoparticles prepared were characterized by transmission electron microscope (TEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM). Catalytic efficiency of the Fe3O4 nanoparticles was tested in degradation of phenol solution. At pH 7, the chemical oxygen demand (COD) removal rate reached 70% in 3 hours. The heterogeneous catalyst exhibited efficient catalytic activity close to that of iron homogeneous catalyst but with less than 3% leaching of irons cation. Further, it performed well under much wider pH range (pH 3~7) compared to classic Fenton reagent, providing potential alternative as a novel heterogeneous Fenton catalyst for environmental remediation.

scholarly journals Oxidative degradation of gentamicin present in water by an electro-Fenton process and biodegradability improvement

2019 ◽  
Vol 17 (1) ◽  
pp. 1017-1025
Author(s):  
Mohamed Réda Arhoutane ◽  
Muna Shueai Yahya ◽  
Miloud El Karbane ◽  
Kacem El Kacemi
Keyword(s):  
Chemical Oxygen Demand ◽  
Biological Process ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Polluted Water ◽  
Applied Current ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Appropriate Treatment ◽  
By Products

AbstractIn the context of environmental protection, where there is a need to develop effective operations for carrying out appropriate treatment of polluted water by pharmaceuticals. Therefore, the present study aims at evaluating the degradation for gentamicin through electro-Fenton (EF) operation, through taking into consideration the effect of several parameters of experimental in the process, namely, the concentration of initial gentamicin, the applied current and the Fe+2 (II) quantities. The (EF) operation employed involves a carbon-felt as cathode and platinum as anode at pH 3. Studies for the gentamicin kinetics is monitored by HPLC giving a pseudo-first order reaction following by a chemical oxygen demand, with a reached degree of mineralization 96% after of four hours of treatment through current 100 mA/cm2 with 0.1 mM of Fe+2. We find that the degradation for molecule of gentamicin is accompanied by an augmentation of the biodegradability, assesse through the Biochemical Oxygen Demand (BOD5) on chemical oxygen demand (COD) ratio, that augmentation from 0 to 0.41 before treatment after 30 min for EF treatment, showing that there is potential for conjugation of the EF process and the biological process. Furthermore, the by-products have been identified on the basis of HPLC-MS/MS results.

Savings with upgraded performance through improved activated sludge denitrification in the combined activated sludge–biofilter system of the Southpest Wastewater Treatment Plant

2008 ◽  
Vol 57 (8) ◽  
pp. 1287-1293 ◽  
Author(s):  
A. Jobbágy ◽  
G. M. Tardy ◽  
Gy. Palkó ◽  
A. Benáková ◽  
O. Krhutková ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Process Efficiency ◽  
Initial Value ◽  
Initial Profile ◽  
Biological Treatment System

The purpose of the experiments was to increase the rate of activated sludge denitrification in the combined biological treatment system of the Southpest Wastewater Treatment Plant in order to gain savings in cost and energy and improve process efficiency. Initial profile measurements revealed excess denitrification capacity of the preclarified wastewater. As a consequence, flow of nitrification filter effluent recirculated to the anoxic activated sludge basins was increased from 23,000 m3 d−1 to 42,288 m3 d−1 at an average preclarified influent flow of 64,843 m3 d−1, Both simulation studies and microbiological investigations suggested that activated sludge nitrification, achieved despite the low SRT (2–3 days), was initiated by the backseeding from the nitrification filters and facilitated by the decreased oxygen demand of the influent organics used for denitrification. With the improved activated sludge denitrification, methanol demand could be decreased to about half of the initial value. With the increased efficiency of the activated sludge pre-denitrification, plant effluent COD levels decreased from 40–70 mg l−1 to < 30–45 mg l−1 due to the decreased likelihood of methanol overdosing in the denitrification filter

scholarly journals Pilot-scale study of vertical flow constructed wetland combined with trickling filter and ferric chloride coagulation: influence of irregular operational conditions

2015 ◽  
Vol 71 (7) ◽  
pp. 1088-1096 ◽  
Author(s):  
B. Kim ◽  
M. Gautier ◽  
G. Olvera Palma ◽  
P. Molle ◽  
P. Michel ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Phosphorus Removal ◽  
Water Saturation ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Saturation Level ◽  
Vertical Flow ◽  
Trickling Filter ◽  
Operational Conditions ◽  
Vertical Flow Constructed Wetland

The aim of this study was to characterize the efficiency of an intensified process of vertical flow constructed wetland having the following particularities: (i) biological pretreatment by trickling filter, (ii) FeCl3 injection for dissolved phosphorus removal and (iii) succession of different levels of redox conditions along the process line. A pilot-scale set-up designed to simulate a real-scale plant was constructed and operated using real wastewater. The influences of FeCl3 injection and water saturation level within the vertical flow constructed wetland stage on treatment performances were studied. Three different water saturation levels were compared by monitoring: suspended solids (SS), total phosphorus (TP), dissolved chemical oxygen demand (COD), ammonium, nitrate, phosphate, iron, and manganese. The results confirmed the good overall efficiency of the process and the contribution of the trickling filter pretreatment to COD removal and nitrification. The effects of water saturation level and FeCl3 injection on phosphorus removal were evaluated by analysis of the correlations between the variables. Under unsaturated conditions, good nitrification and no denitrification were observed. Under partly saturated conditions, both nitrification and denitrification were obtained, along with a good retention of SSs. Finally, under saturated conditions, the performance was decreased for almost all parameters.

Study of structural and morphological changes during acсelerated oxidative degradation of mixtures of polyoxybutyrate with polycaprolactane

2021 ◽  
Vol 5 ◽  
pp. 60-69
Author(s):  
V. N. Vasilets ◽  
◽  
A. P. Pankina ◽  
E. A. Nemets ◽  
V. Yu. Belov ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Oxidative Degradation ◽  
Initial Mixture ◽  
Polymer Composite Material ◽  
Degree Of Crystallinity ◽  
Fenton Reagent ◽  
Dsc Method ◽  
The Degree Of Crystallinity ◽  
Composite Samples ◽  
Scanning Electron

Structural and morphological changes in the films of poly(oxybirutyrate-co-oxyvalerate) (P(OB-OV)) with poly-e-caprolactone (PCL) were studied by IR spectroscopy, DSC, and scanning electron microscopy during accelerated oxidative degradation under tests in Fenton reagent. It is shown by the DSC method that the phase separation of the P(OB-OV) and PCL components is observed in the initial mixture. The melting of various phases of P(OB-OV) is observed at temperatures of 147 °C and 157 °C, and PCL melts at a temperature of 61 °C. The degree of crystallinity of P(OB-OV) and PCL in the mixture is 67 % and 50 %, respectively. It was found that the degradation of poly(oxybirutyrate-co-oxyvalerate) prevails during incubation of composite samples in Fenton solution for 2 to 12 weeks. By changing the ratio of the components, it is possible to significantly change the rate of oxidative degradation, the molecular weight and the degree of crystallinity of the polymer composite material P(OB-OV):PCL.

scholarly journals Operational modifications for the development of nitrifying bacteria in a large-scale biological aerated filter and its impact on wastewater treatment

2018 ◽  
Vol 78 (8) ◽  
pp. 1704-1714 ◽  
Author(s):  
François-René Bourgeois ◽  
Frédéric Monette ◽  
Daniel G. Cyr
Keyword(s):  
Large Scale ◽  
Oxygen Demand ◽  
Bacterial Biofilm ◽  
Nitrifying Bacteria ◽  
Nitrification Rate ◽  
Total Biomass ◽  
Ammonia Oxidizing Bacteria ◽  
Operational Conditions ◽  
Nitrite Oxidizing Bacteria ◽  
Aerated Filter

Abstract To develop a better understanding for fixed biomass processes, the development of a nitrifying bacterial biofilm, as well as the performance of treatment during modifications to operational conditions of a full-scale submerged biological filter were examined. The development of the nitrifying biofilm was investigated at four depth levels (1, 2, 4 and 5 feet). The result of bacterial subpopulations analyzed by qPCR relative to the physico-chemical parameters of the wastewater during the various tests (sustained aeration, modified backwash parameters and inflow restriction) revealed an increase of the relative presence of nitrifying microorganisms throughout the biofilm (especially for nitrite oxidizing bacteria (NOB)), but this was not necessarily accompanied by a better nitrification rate. The highest observed nitrification rate was 49% of removal in the test cell during backwashing conditions, whereas the relative ammonia oxidizing bacteria (AOB) population was 0.032% and NOB was 0.008% of the total biomass collected. The highest percentage of nitrifying bacteria observed (0.034% AOB and 0.18% NOB) resulted in a nitrification rate of 21%. The treatment of organic matter determined by measuring the chemical and biochemical oxygen demand (COD, CBOD5) was improved.

Anaerobic co-digestion of winery waste and waste activated sludge: assessment of process feasibility

2013 ◽  
Vol 69 (2) ◽  
pp. 269-277 ◽  
Author(s):  
C. Da Ros ◽  
C. Cavinato ◽  
F. Cecchi ◽  
D. Bolzonella
Keyword(s):  
Activated Sludge ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Waste Activated Sludge ◽  
Organic Loading ◽  
Operational Conditions ◽  
Loading Rates ◽  
Thermophilic Conditions ◽  
Soluble Chemical Oxygen Demand

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m3d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm3biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.

The use of steel slags in the heterogeneous Fenton process for decreasing the chemical oxygen demand of oil refinery wastewater

2018 ◽  
Vol 78 (5) ◽  
pp. 1159-1167 ◽  
Author(s):  
Behnam Heidari ◽  
Mohsen Soleimani ◽  
Nourollah Mirghaffari
Keyword(s):  
Microwave Irradiation ◽  
Chemical Oxygen Demand ◽  
Steel Slag ◽  
Oxygen Demand ◽  
Oil Refinery ◽  
Fenton Process ◽  
Refinery Wastewater ◽  
Optimum Conditions ◽  
Heterogeneous Fenton ◽  
Oil Refinery Wastewater

Abstract The Fenton process is a useful and inexpensive type of advanced oxidation process for industrial wastewater treatment. This study was performed with the aim of using the steel slag as a catalyst in the heterogeneous Fenton process in order to reduce the chemical oxygen demand (COD) of oil refinery wastewater. The effects of various parameters including the reaction time (0.5, 1.0, 2.0, 3.0 and 4.0 h), pH (2.0, 3.0, 4.0, 5.0, 6.0 and 7.0), the concentration of steel slag (12.5, 25.0 and 37.5 g/L), and H2O2 concentration (100, 250, 400 and 500 mg/L) on the Fenton process were investigated. Furthermore, the effect of microwave irradiation on the process efficiency was studied by considering the optimum conditions of the mentioned parameters. The results showed that using 25.0 g/L of steel slag and 250 mg/L H2O2, at pH = 3.0, could reduce COD by up to 64% after 2.0 h. Also, microwave irradiation decreased the time of the process from 120 min to 25 min in the optimum conditions, but it consumed a high amount of energy. It could be concluded that steel slags had a high potential in the treatment of oil refinery wastewater through the Fenton process.

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