共查询到20条相似文献，搜索用时 0 毫秒
1.
J Beltran J Torregrosa J
R Dominguez J
A Peres 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(12):1243-1248
Oxidation of p‐hydroxybenzoic acid in aqueous solution by the photo‐assisted Fenton reaction (Fe2+ + H2O2 + UV) has been studied. The effects of ferrous ion concentration (0.05, 0.14 and 0.29 mmol dm?3), temperature (10, 20, 30 and 40 °C), and initial hydrogen peroxide concentration (0.7, 1.4, 2.2 and 2.9 mmol dm?3) on the p‐hydroxybenzoic acid conversion were established. Experimental results indicate that the kinetics of this oxidation process fits pseudo‐first‐order kinetics well. The overall kinetic rate constant was split into two components: direct oxidation by UV radiation (photolysis) and oxidation by free radicals (mainly OH·) generated in the system. The importance of these two reaction paths for each specific value of ferrous ion concentration, temperature and initial hydrogen peroxide concentration was evaluated. A semi‐empirical expression is proposed for the overall reaction rate which takes into account both oxidation pathways and is a function of operating variables. © 2001 Society of Chemical Industry 相似文献
2.
3.
《Journal of Industrial and Engineering Chemistry》2014,20(4):1468-1475
Here we report the study on the utilization of several advanced oxidation processes such as electro-oxidation and Fenton process in simultaneous treatment of two nitramine explosives: 2,4,6-trinitrophenyl-N-metylnitramine (Tetryl) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The preliminary tests indicated that the electrolytic method using a TiO2/IrO2/RuO2-coated electrode could rapidly degrade Tetryl but not RDX. While the addition of certain amount of H2O2 induced an increase of Tetryl degradation yield but had insignificant effect on RDX decomposition, the use of Fenton's reagent showed an enhanced efficiency in degradation of both nitramines. It can be concluded that among tested processes, Fenton process is the most effective for treatment of nitramine-containing wastewaters. 相似文献
4.
Pardeep Kumar Hossein Nikakhtari Mehdi Nemati Gordon Hill John Headley 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(5):720-725
BACKGROUND: High concentrations of phenol in wastewater are difficult to remove by purely biological methods. Chemical oxidation is one way to treat high concentrations of phenol but complete oxidation will make the treatment process uneconomical. For the purpose of integrating chemical and biological treatment, the oxidation of phenol using chlorine dioxide was investigated in a medium suitable for bioremediation. The effects of chlorine dioxide concentration (500 to 2000 mg L?1), temperature (10 to 40 °C) and pH (3 to 7) on the oxidation of 2000 mg L?1 of phenol were determined. RESULTS: Chlorine dioxide concentration was found to be the dominant parameter for the removal of phenol in the nutrient rich medium. The optimal concentration of chlorine dioxide to completely oxidize 2000 mg L?1 of phenol was 2000 mg L?1. Compared with Fenton's reagent, half as much chlorine dioxide was needed to oxidize 2000 mg L?1 phenol. The reaction of chlorine dioxide with phenol was very fast and reached equilibrium within 10 min. The main oxidation products were identified as 1,4‐benzoquinone and 2‐chloro‐1,4‐benzoquinone. CONCLUSION: Compared with Fenton's reagent, chlorine dioxide is a superior oxidant for removal of phenol from both pure water and bioremediation medium. Copyright © 2010 Society of Chemical Industry 相似文献
5.
6.
7.
The electro‐Fenton (EF) process is a promising method combining electrochemical reactions and Fenton's reagent. In this hybrid process, the electrical current induces the in situ generation of H2O2 via reduction of oxygen, and the catalytic reaction is propagated by Fe2+ regeneration, which can take place by reduction of Fe3+ with H2O2, hydroperoxyl radical, organic radical intermediates, or directly at the cathode. Recent advances in the EF process are discussed and several key variables analyzed, including electrode material, initial pH, and Fenton's reagents, in order to extend the applicability of this technology. 相似文献
8.
9.
10.
The effect and role of 1,10‐phenanthroline (o‐phen) and ortho phosphoric acid on graft polymerization of vinyl monomers from poly (vinyl alcohol) (PVA) in the presence of Fenton's reagent have been studied. Reaction conditions were optimized. Fourier transform infrared (FT‐IR) spectra were used for confirmation of grafting. A probable mechanism of grafting to elucidate the role of phenanthroline and phosphoric has been suggested. Thermal properties of the grafted polymer were studied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2335–2339, 2005 相似文献
11.
The total development trend in the world is towards continuously lower of sulfur content as a quality standard of diesel fuels. Integrating of an oxidative desulfurization unit with a conventional hydrotreating unit can bring benefits to producing low and/or ultra-low sulfur diesel fuels. Using the hydrotreated Middle East diesel fuel as a feedstock, four processes of the oxidative desulfurization have been studied: a hydrogen peroxide–acetic acid system and a Fenton's reagent system both without/with ultrasound. Results showed that the oxidative desulfurization reaction mechanics fitted apparent first-order kinetics. The addition of Fenton's reagent could enhance the oxidative desulfurization efficiency for diesel fuels and sono-oxidation treatment in combination with Fenton's reagent shows a good synergistic effect. Under our best operating condition for the oxidative desulfurization: temperature 313 K, ultrasonic power 200 W, ultrasonic frequency 28 kHz, Fe2+/H2O2 0.05 mol/mol, pH 2.10 in aqueous phase and reaction time 15 min, the sulfur content in the diesel fuels was decreased from 568.75 μg/g to 9.50 μg/g. 相似文献
12.
Juan L Acero F Javier Benitez Jesus Beltran de Heredia Ana I Leal 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(10):1065-1072
The chemical treatment of cork‐processing wastewater by ozonation, alone and in combination with hydrogen peroxide and UV radiation was investigated. A reduction of the chemical oxygen demand (COD) ranging from 42% to 76% was obtained during ozonation after 3 h of reaction, depending on the experimental conditions. The additional presence of hydrogen peroxide and UV radiation enhanced the efficiency of the ozonation treatment due to the contribution of the OH radicals formed in the decomposition of ozone. Thus, final reductions of the COD higher than 90% and a complete elimination of phenolic compounds and absorbance at 254 nm were achieved in both Advanced Oxidation Processes (AOPs), O3/H2O2 and O3/UV. Therefore the effluent resulting from the ozonation treatments can be reused in the cork‐processing industry. In a second step, the chemical treatment was conducted by means of UV radiation alone and by the action of hydroxyl radicals, which were generated by the following AOPs: UV/H2O2, Fenton's reagent, and photo‐Fenton system. The single photochemical process resulted in 9% of the organic matter present being removed, while the AOPs significantly enhanced this reduction with values in the range 20–75%. Kinetic studies for both groups of treatments were performed, and apparent kinetic rate constants were evaluated. In the ozone‐based experiments, the rate constants ranged from 1846 to 10922 dm3 mol?1 O3 h?1, depending on the operating conditions. In the oxidation experiments using oxidants other than ozone, the rate constants varied between 0.06 and 1.19 h?1. Copyright © 2004 Society of Chemical Industry 相似文献
13.
Giancarlo Cravotto Stefano Di Carlo Massimo Curini Vander Tumiatti Carlo Roggero 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2007,82(2):205-208
Microwave (MW) and high‐intensity ultrasound (US) provide innovative techniques for the degradation of persistent organic pollutants (POPs). When Fenton's reagent is used to treat industrial wastes, organic pollutants are degraded by highly reactive hydroxyl radicals (HO·) that can oxidize almost any organic compound to carbon dioxide and water. These reactions, when carried out under US or MW, are faster and much more efficient. The present work assesses the combined effect of US and MW using a new flow reactor developed in our laboratory. In this 5 L pilot reactor the liquid was pumped in parallel through a modified domestic MW oven and through a cell where it was irradiated with two US generators working at 20 and 300 kHz, while MW irradiation took place in a modified domestic oven. We studied the degradation of 2,4‐dibromophenol (0.1 g L?1 in water) by Fenton's reagent, assessing the contribution of each energy source to the overall effect, and found that MW and US‐300 kHz played the main role. A modest amount of oxidant (6 mL 30% H2O2 per 1 L of polluted water) sufficed to achieve complete degradation within 6 h, at which time organic compounds were no longer detectable. Even if no Fenton's reagent was added, about one half of the pollutant was degraded after 3 h irradiation. Copyright © 2007 Society of Chemical Industry 相似文献
14.
Ya‐Li Song Ji‐Tai Li Hua Chen 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(4):578-583
BACKGROUND: Pollution caused by industrial wastewater has become a common problem for many countries. In particular, dye pollutions from industrial effluents disturb human health and ecological equilibrium. The discharge of highly colored synthetic dye effluents is aesthetically displeasing and can damage the receiving water body by impeding penetration of light. Azo dyes can be reduced to more hazardous intermediates on anaerobic conditions. Therefore, an effective and economic treatment of effluents containing a diversity of textile dyes has become a necessity for clean production technology for textile industries. Herein we wish to report the degradation of Acid Red 88 by the combination of Fenton's reagent and ultrasound irradiation. RESULTS: The results show that the combination of ultrasonic irradiation and Fenton's reagent is effective for the degradation of Acid Red 88 aqueous solution. Furthermore, it can achieve better results than either Fenton's reagent or ultrasound alone. The optimum conditions for the degradation of Acid Red 88 aqueous solution were 1.96 mmol L?1 H2O2, 0.108 mmol L?1 Fe2+, pH 3.0, and ultrasonic irradiation frequency of 40 kHz. A degradation efficiency of 98.6% was achieved within 135 min. CONCLUSION: We have provided an efficient and convenient procedure for the degradation of Acid Red 88 aqueous solution. In the present procedure, the azo linkage of Acid Red 88 is broken and some carbonyl compounds are formed, but the complete mineralization of dye cannot be achieved. Copyright © 2008 Society of Chemical Industry 相似文献
15.
Fenton试剂氧化处理拆弹炸药废水 总被引：5，自引：0，他引：5
实验使用Fenton试剂对炸药废水进行处理。通过考察反应时间、双氧水用量、硫酸亚铁用量、pH以及反应温度对炸药废水TOC去除率的影响,同时应用正交实验设计确定Fenton试剂处理炸药废水的最佳操作条件。结果表明,随着反应时间的延长,TOC的去除率增大．最佳反应时间为70min．之后趋于平衡;当双氧水(30％)用量为70mL／L、FeSO4用量为600rag／L、pH为3、反应温度25℃时去除率最高．达到92．06％。 相似文献
16.
M Mahbubul Hassan Christopher J Hawkyard 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(7):834-841
Combined oxidation with ozone and Fenton's reagent (‘Fentozone’ process) for decolourisation of aqueous dyes was studied and compared with traditional Fenton's reagent. Although the ‘Fentozone’ process was found to be effective at a wide range of pH values, the maximum colour removal was achieved at pH 4. The effect of pre‐ozonation on colour removal efficiency of aqueous dyestuffs in the subsequent treatment with Fenton's reagent was investigated. The reaction kinetics using water‐soluble acid and reactive dyes were also studied. Our experimental results show that pre‐ozonation can considerably accelerate decomposition of dyestuffs in the subsequent treatment with Fenton's reagent. Different concentrations of ferrous sulfate were used to investigate their influences on the removal of colour. The rate of reaction increased with increasing doses of ferrous sulfate. © 2002 Society of Chemical Industry 相似文献
17.
F Javier Benitez Jesus Beltran‐Heredia Juan L Acero F Javier Rubio 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(3):312-320
The oxidation of some chlorophenols: 4‐chlorophenol, 2,4‐dichlorophenol, 2,4,6‐trichlorophenol, 2,3,4,6‐tetrachlorophenol, tetrachlorocatechol (3,4,5,6‐tetrachloro‐2‐hydroxy phenol) and 4‐chloroguaiacol (4‐chloro‐2‐methoxy phenol) has been studied via single photodecomposition produced by polychromatic UV irradiation, oxidation by hydroxyl radicals generated by Fenton's reagent (hydrogen peroxide plus ferrous ions), and degradation by hydroxyl radicals produced by combinations of UV irradiation plus hydrogen peroxide, and UV irradiation plus hydrogen peroxide and ferrous ions (photo‐Fenton system). These organics have been selected as models of chloro‐phenolic derivative pollutants present in wastewaters and groundwaters. The degradation levels obtained in each process are reported. The quantum yields in the single photodecomposition reaction and the rate constants between the chlorophenols and the hydroxyl radicals in the reaction with Fenton's reagent are determined. Finally, the additional contributions to the photodecomposition promoted by the radical reaction in the combined UV/H2O2 and photo‐Fenton systems are also evaluated. © 2001 Society of Chemical Industry 相似文献
18.
19.
Fenton试剂深度处理胃必治制药废水 总被引：7，自引：2，他引：7
胃必治制药废水COD值高且负荷变化大,pH值低,是一种难处理的有机废水。经常规工艺处理后,出水有时仍难达标。采用Fenton试剂对出水进行了氧化降解研究,通过测定废水的COD、UV254值变化以评价氧化的效果,考察了常压下Fenton试剂配比、投加量、氧化时间、温度等因素对制药废水处理效果的影响,初步发现了其氧化规律。在单因素试验的基础上采用正交试验方案,确定最佳工艺条件为:浓度为1mol/L的FeSO4与质量分数为3%的H2O2的体积比为1:2、投加量为150mL/L、反应时间为90min、反应温度为60℃、pH值为3。COD的去除率达到89.50%,出水COD的质量浓度降到了66mg/L以下,达到国家排放标准要求。 相似文献