scholarly journals Electro-generation of hydrogen peroxide for electro-Fenton: Application in Glyphosate herbicide treatment

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Thanh Son Le ◽  
Tran Manh Hai ◽  
Doan Tuan Linh
Keyword(s):  
Hydrogen Peroxide ◽  
Ph Value ◽  
Current Intensity ◽  
H2o2 Production ◽  
Aquatic Life ◽  
Herbicide Treatment ◽  
Initial Ph ◽  
Glyphosate Herbicide ◽  
Save Energy

One of the major and serious pollution issues in an agriculture-based country as Vietnam is derived from herbicide, especially Glyphosate herbicide which can cause a massive quantity of adverse effects and acute toxicity to aquatic life and human health. Hence, this research focused on setting up an electro-Fenton system with a Pt gauze anode and a commercial carbon felt cathode for Glyphosate herbicide treatment with the primary mechanism based on the in situ hydrogen peroxide electro-generation and ferrous ion catalyst regeneration. This study investigated effect of initial pH and current intensity on both the amount of hydrogen peroxide production and the Glyphosate mineralization performance. The results indicated that the pH value was 3, the quantity of H2O2 production on cathode reached largest, then the Glyphosate mineralization performance was optimum, approximately 0.15 mg/L and 60% at 50 electrolysis time respectively. Moreover, when current intensity increased, the amount of H2O2 electro-generation increased, leading to better Glyphosate mineralization efficiency. Nonetheless, in order to minimize the electrode corrosion as well as save energy cost, the optimum current intensity was found being 0.5 A.

scholarly journals Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3844
Author(s):  
Lijuan Li ◽  
Bingdong Li ◽  
Liwei Feng ◽  
Xiaoqiu Zhang ◽  
Yuqian Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction System ◽  
Reaction Medium ◽  
Pure Tio2 ◽  
H2o2 Production ◽  
Tio2 Photocatalyst ◽  
H2o2 Decomposition ◽  
Spin Resonance ◽  
Photocatalytic Synthesis

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F− modification inhibits the H2O2 decomposition through the formation of the ≡Ti–F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F− modification and without F− modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

Degradation of Ciprofloxacin in Aqueous Solution by the Fenton Process

2012 ◽  
Vol 610-613 ◽  
pp. 352-355 ◽  
Author(s):  
Ji Feng Yang ◽  
Hong Hui Chen
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Oxidation Process ◽  
Ph Value ◽  
Fenton Process ◽  
Ferrous Ions ◽  
Reaction Conditions ◽  
Initial Ph ◽  
Optimum Reaction ◽  
Ciprofloxacin Removal

The present study provides results describing the degradation performance of ciprofloxacin antibiotic via Fenton treatment. The effect of reaction conditions including the initial pH value, and dosages of ferrous ions and hydrogen peroxide on ciprofloxacin and COD removal was investigated. Ciprofloxacin removal efficiency of more than 90% was achieved under optimum reaction conditions of pH value of 2, dosages of 0.75 mmol/L of ferrous ion, and 2.0 mmol/L of hydrogen peroxide after 10min. However, the change of COD in aqueous solution was not obvious and further study about intermediate products during oxidation process should be carried out in the future.

Study on Catalytic Wet Oxidation of H-Acid Containing Water over Fe/SiO2 Catalyst

2013 ◽  
Vol 641-642 ◽  
pp. 281-284
Author(s):  
Hong Ya Li ◽  
Bin Xia Zhao ◽  
Wei Li Bai ◽  
Xiao Li Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Temperature ◽  
Ph Value ◽  
Removal Rate ◽  
Disulfonic Acid ◽  
Peroxide Oxidation ◽  
Catalytic Wet Oxidation ◽  
Hydrogen Peroxide Oxidation ◽  
Initial Ph ◽  
Catalyst Dosage

This study has investigated the degradation of H-acid (1-amino-8-naphthol-3, 6-disulfonic acid) containing water by catalytic wet hydrogen peroxide oxidation method, in which the catalyst of Fe/SiO2 was prepared by impregnation technology. The effect of catalyst dosage, initial pH value, amount of hydrogen peroxide and reaction temperature on the degradation process have been discussed, and the results indicated that wet hydrogen peroxide oxidation is an effective method for treating the wastewater containing H-acid, under the conditions that: catalyst dosage was 2 g, initial pH value was 7, amount of hydrogen peroxide was 10 mL (0.83 time of theoretical required amount) and reaction temperature was 80 °C, the COD and color removal rate can reach 87.3% and 96.5%, respectively.

scholarly journals Optical measurement of the catalase-hydrogen peroxide intermediate (Compound I) in the liver of anaesthetized rats and its implication to hydrogen peroxide production in situ

1975 ◽  
Vol 146 (1) ◽  
pp. 67-77 ◽  
Author(s):  
N Oshino ◽  
D Jamieson ◽  
T Sugano ◽  
B Chance
Keyword(s):  
Hydrogen Peroxide ◽  
Ethanol Oxidation ◽  
Optical Measurement ◽  
Intermediate Compound ◽  
Whole Body ◽  
H2o2 Production ◽  
Compound I ◽  
Anaesthetized Rats ◽  
Endogenous Substrates

The spectrophotometric determination of the catalase-H2O2 intermediate (Compound I) was extended to the liver in situ in anaesthetized rats. The rate of H2O2 production was determined for the liver in situ with endogenous substrates, and in the presence of excess of glycollate. Glycollate infusion doubled H2O2 production rate in the liver of air-breathing rats, and caused a fourfold increase when rats breathed O2 at 1 times 10(5) Pa. Hyperbaric O2 up to 6 times 10(5) Pa did not increase H2O2 generation supported by endogenous substrates, nor did it increase H2O2 production above that produced by 1 times 10(5) Pa O2 in glycollate-supplemented rats. The rates of ethanol oxidation via hepatic catalase and via alcohol dehydrogenase in the whole body were separately measured. The contribution of hepatic catalase to ethanol oxidation was found to be approx. 10 percent in endogenous conditions and increased to 30 percent or more of the total ethanol oxidation in rats supplemented with glycolate.

Oxidation of hydrogen peroxide at the dropping mercury electrode

1984 ◽  
Vol 49 (10) ◽  
pp. 2320-2331 ◽  
Author(s):  
Miroslav Březina ◽  
Martin Wedell
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Ph Value ◽  
Mercury Electrode ◽  
Electrode Process ◽  
Electrochemical Processes ◽  
Dropping Mercury Electrode ◽  
Oxidation Of Hydrogen ◽  
Decreasing Ph ◽  
Rate Controlling Step

Reduction of oxygen and oxidation of hydrogen peroxide at the dropping mercury electrode are electrochemical processes strongly influenced both by the pH value and the anions in solution. With decreasing pH, both processes become irreversible, especially in the presence of anions with a negative φ2 potential of the diffusion part of the double layer. In the case of irreversible oxygen reduction, the concept that the rate-controlling step of the electrode process is the acceptance of the first electron with the formation of the superoxide anion, O2-, was substantiated. Oxidation of hydrogen peroxide becomes irreversible at a lower pH value than the reduction of oxygen. The slowest, i.e. rate-controlling step of the electrode process in borate buffers at pH 9-10 is the transfer of the second electron, i.e. oxidation of superoxide to oxygen.

scholarly journals Regression Analysis of Orthogonal, Cylindrical and Multivariable Color Parameters for Colorimetric Surface pH Measurement of Materials

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3682
Author(s):  
Katarína Vizárová ◽  
Izabela Vajová ◽  
Naďa Krivoňáková ◽  
Radko Tiňo ◽  
Zdenko Takáč ◽  
...  
Keyword(s):  
Ph Value ◽  
Critical Factor ◽  
Ph Measurement ◽  
Ph Indicator ◽  
Water Quality Control ◽  
Quality Management Systems ◽  
Surface Ph ◽  
Regression Parameters ◽  
Ph Detection

The surface pH is a critical factor in the quality and longevity of materials and products. Traditional fast colorimetric pH detection-based tests such as water quality control or pregnancy tests, when results are determined by the naked eye, cannot provide quantitative values. Using standard pH papers, paper-printed comparison charts, or colorimetric microfluidic paper-based analytical devices is not suitable for such technological applications and quality management systems (QMSs) where the particular tested material should contain a suitable indicator in situ, in its structure, either before or after the process, the technology or the apparatus that are being tested. This paper describes a method based on the combination of impregnation of a tested material with a pH indicator in situ, its exposure to a process of technology whose impact on pH value is to be tested, colorimetric pH measurement, and approximation of pH value using derived pH characteristic parameters (pH-CPs) based on CIE orthogonal and cylindrical color variables. The hypotheses were experimentally verified using the methyl red pH indicator, impregnating the acid lignin-containing paper, and preparing a calibration sample set with pH in the range 4 to 12 using controlled alkalization. Based on the performed measurements and statistical evaluation, it can be concluded that the best pH-CPs with the highest regression parameters for pH are √∆E, ln (a),√∆H (ab), a/L, h/b and ln (b/a). The experimental results show that the presented method allows a good estimation of pH detection of the material surfaces.

scholarly journals Carbon nitride nanotubes with in situ grafted hydroxyl groups for highly efficient spontaneous H2O2 production

2021 ◽  
Vol 288 ◽  
pp. 119993
Author(s):  
Liang Zhou ◽  
Juying Lei ◽  
Fuchen Wang ◽  
Lingzhi Wang ◽  
Michael R. Hoffmann ◽  
...  
Keyword(s):  
Carbon Nitride ◽  
H2o2 Production ◽  
Hydroxyl Groups ◽  
Highly Efficient

scholarly journals Hydrothermal Synthesis of Various Shape-Controlled Europium Hydroxides

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 529
Author(s):  
Hongjuan Zheng ◽  
Kongjun Zhu ◽  
Ayumu Onda ◽  
Kazumichi Yanagisawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ph Value ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Hydrothermal Reactions ◽  
Starting Solution ◽  
Initial Ph ◽  
Shape Controlled ◽  
Scanning Electron

Eu(OH)3 with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal reactions. The products were characterized by XRD (X-Ray Powder Diffraction), FE-SEM (Field Emission- Scanning Electron Microscopy) and TG (Thermogravimetry). The influence of the initial pH value of the starting solution and reaction temperature on the crystalline phase and morphology of the hydrothermal products was investigated. A possible formation process to control morphologies and size of europium products by changing the hydrothermal temperature and initial pH value of the starting solution was proposed.

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