硫酸钛光度法测定O_3/H_2O_2体系中低浓度H_2O_2

基于在酸性介质中过氧化氢(H2O2)与钛离子(Ti4+)生成橙色络合物的原理,采用硫酸钛光度法测定含强氧化剂(O3)体系中的低浓度H2O2。考察了硫酸钛用量、显色时间、溶液酸度、共存无机离子和氧化剂等因素对测定结果的影响,并在以实际水体(滤后水)为本底的O3/H2O2高级氧化体系中,对DPD法和硫酸钛光度法测定H2O2进行了对比试验。结果表明:与DPD法相比,硫酸钛光度法能有效克服体系中残留氧化剂带来的影响,可作为O3/H2O2高级氧化体系中低浓度H2O2的快速测定方法。     

Fenton试剂处理染料废水的实验研究

选取Fenton试剂高级氧化工艺,以甲基橙染料为模型污染物,通过实验确定其最佳工艺参数（pH范围、过氧化氢和二价铁离子的最佳投加量）,实验结果表明：当pH在3～4,过氧化氢与二价铁离子加入量分别为ImL（质量浓度30％）和2mL（0．0045mol／L）时可以达到最佳效果。     

高级氧化技术在水处理中的研究进展

论述了Fenton法及类Fenton法进行废水处理的工艺原理,对比分析了各类高级氧化技术的优缺点及适用范围,指出高级氧化技术在水处理中具有适用范围广、反应速率快、转化效率高等特点,已成为目前水处理领域的研究热点。     

Fenton法处理有机废水的研究进展

Fenton氧化法是高级氧化技术的代表,主要包括Fenton及类Fenton法、光Fenton法、电Fenton法、超声Fenton法、微波Fenton法等。介绍了难降解有机废水的处理方法及实例,并讨论了应用前景和发展方向。     

高级氧化技术对垃圾渗滤液的处理研究

介绍了高级氧化技术中的臭氧氧化法、Fenton法、湿式催化氧化法、超声波氧化法以及组合工艺处理垃圾渗滤液的研究进展,阐述了这些高级氧化技术的反应机理以及特点,并对高级氧化技术处理垃圾渗滤液研究方向进行了分析,对垃圾渗滤液的有效处理具有积极指导意义。     

高级氧化技术在压裂返排液深度处理中的应用

高级氧化技术对油田压裂返排液中难降解有机污染物的深度处理显示出了较好的效果。文章在阐述高级氧化技术处理油田压裂返排液原理的基础上,简要介绍了油田压裂返排液处理方面的几种高级氧化技术：化学氧化、光催化氧化、电催化氧化、Fenton氧化法、湿式空气氧化、超临界水氧化、超声波氧化,重点讨论了高级氧化技术在油田压裂返排液深度处理中的应用情况,并对其在油田压裂返排液处理方面的发展方向进行了展望。     

热活化过硫酸盐体系中碘离子的转化分析

为控制原水中的碘离子在消毒/氧化过程中生成高致毒性的碘代消毒副产物,通过序批试验分析了热活化过硫酸盐体系中碘离子的转化路径、自由基的产生过程及反应条件。结果表明,热活化过硫酸盐高级氧化体系可以有效促成碘离子转化为对人体无毒无害的碘酸盐。反应过程中,碘离子首先转化为中间产物(次碘酸),进而被氧化为碘酸盐。碘离子在酸性条件下的转化率比在中性和碱性条件下要高,且随过硫酸盐浓度和温度的升高而增大。通过自由基淬灭试验验证了热活化过硫酸盐反应体系中,碘离子向碘酸盐的转化是硫酸根自由基和羟基自由基共同作用的结果,且硫酸根自由基起主要作用。     

变色酯分光光度法测定玻璃中钛的条件选择

本文对变色酸分光光度法测钛的多种影响因素进行了选择实验,并用选定的条件对玻璃中钛进行测定。结果表明,在选定条件下,测定玻璃中钛含量能达到较高的准确度和精密度。     

变色酸分光光度法测定玻璃中钛的条件选择

本文对变色酸分光光度法测钛的多种影响因素进行了选择实验,并用选定的条件对玻璃中钛进行测定。结果表明,在选定条件下,测定玻璃中钛含量能达到较高的准确度和精密度。     

微波消解-磷钼蓝分光光度法测定城市污泥中总磷浓度

建立了微波消解-磷钼蓝分光光度法测定城市污泥中总磷的方法。在微波环境中硝酸-过氧化氢能够将城市污泥中无机磷盐和含磷有机物消解为正磷酸盐,在弱酸性条件下,正磷酸盐在铋盐的催化条件下与钼酸铵-抗坏血酸生成磷钼蓝,于分光光度计波长690nm处进行测定总磷浓度。方法的相对标准偏差0.63%～0.95%,加标回收率为101%～102%,能够满足对城市污泥中总磷浓度的测定要求。     

Measurement of hydrogen peroxide in an advanced oxidation process using an automated biosensor

A hydrogen peroxide biosensor was used to monitor hydrogen peroxide concentrations in a UV/hydrogen peroxide immobilised Fenton advanced oxidation process (AOP). The biosensor is based on gas phase monitoring and thus is more resistant to fouling from the liquid phase constituents of industrial processes. The biosensor is supplied with catalase continually, therefore overcoming any problems with enzyme degradation, which would occur in an immobilised enzyme biosensor. The biosensors response was linear within the experimental range 30-400mg H(2)O(2)l(-1) with a R(2) correlation of 0.99. The hydrogen peroxide monitor was used to monitor residual peroxide in an AOP, operated with a step overload of hydrogen peroxide, with correlation factors of 0.96-0.99 compared to offline hydrogen peroxide determinations by UV spectroscopy. Sparging the sample with nitrogen was found to be effective in reducing the interference from dissolved gases produced with the AOP itself. It is proposed that this biosensor could be used to improve the effectiveness of AOPs via hydrogen peroxide control.     

Fenton法处理垃圾渗滤液

介绍了Fenton法处理垃圾渗滤液的中型试验,其中Fenton氧化在连续搅拌反应器（CSTR）中进行。试验表明,当双氧水与亚铁盐的总投加比一定（H2O2／Fe^2 =3.0)时,COD的去除率随双氧水投加量的增加而增加,但与双氧水在两个氧化槽的投加比例无关。当双氧水的总投加量为0.1mol/L时,COD的去除率可达67．5％,这一结果同样适用于其他垃圾填埋场的晚期渗滤液处理。     

Optimization of hydroxyl radical production using electro‐Fenton method for chemical oxygen demand reduction in diluted palm oil mill effluent

Palm oil mill effluent (POME) is a well‐known highly polluting wastewater due to its extremely high contents of organic matter, suspended solids and nutrients. In this study, we used electro‐Fenton method to treat POME by optimizing OH? generation from hydrogen peroxide (H₂O₂) under low voltage input (1.5–6.0 V). A set of electro‐Fenton system was set up using stainless steel as the anode and graphite as the cathode. Four parameters namely retention times, concentrations of H₂O₂ as well as FeSO₄ catalyst and applied voltages were studied. The results were reflected in the form of removal efficiency of chemical oxygen demand (COD). The optimum conditions to degrade organic matter in POME were found to be in 4 h retention time with the respective H₂O₂ and FeSO₄ catalyst concentrations of 0.05 and 0.10 M, and the power input of 1.5 V. Under such conditions, the maximum COD removal efficiency achieved 94%. The electro‐Fenton treatment was found to have higher efficiency than the conventional Fenton treatment. Without the electrolysis, the COD removal efficiency of the conventional Fenton treatment was only 48%.     

Optimizing linear alkyl benzene sulfonate removal using Fenton oxidation process in Taguchi Method

Linear alkyl benzene sulfonate (LAS), which is the most common used anionic surfactant in detergents manufacturing, can discharge onto water resources through wastewater and causes change in taste and odor, disruption in water treatment processes, aquatics death, and oxygen transfer limitation. Accordingly, this article investigates to optimize LAS removal using Fenton oxidation process in Taguchi Method for the first time. LAS removal using Fenton oxidation was perused experimentally in a lab-scale reactor. In order to save relevant costs, 25 runs were qualified to specify the optimum conditions of Fenton oxidation using Taguchi method by Minitab 16 software. Sampling and testing procedures were executed based on the standard methods for the examination of water and wastewater. The optimum conditions included 900 mg/L hydrogen peroxide, 170 mg/L ferrous ion, pH of 4 and the reaction time of 20 min. Fenton oxidation, as a second order reaction with the rate coefficient of 0.0152 L/mg?min, provided 86.5% efficiency for LAS removal in the optimum conditions. Despite Fenton oxidation appeared as a high efficiency process in LAS removal, low removal efficiency of chemical oxygen demand corresponding with LAS affirmed its partial degradation.     

Trihalomethanes aqueous solutions sono-oxidation

Ultrasonic (US) irradiation, hydrogen peroxide (H(2)O(2)), Fenton's oxidation and the combination of the processes were investigated for destruction and removal of the following trihalomethanes (THMs) compounds from aqueous solutions: CHCl(3), CHBrCl(2), CHBr(2)Cl, CHBr(3), and CHI(3). H(2)O(2) had no significant effect on the THMs sonodegradation. The coupled US and Fenton processes did not affect the CHCl(3), CHBrCl(2), and CHBr(2)Cl sonolysis efficiency. Nevertheless, the sonodegradation of CHBr(3) was enhanced. CHI(3) was degraded by Fenton's oxidation rather than by the US irradiation during the sonication/Fenton treatment. The combination of sonication with H(2)O(2) or Fenton's reagent did not affect the mineralization of the THMs aqueous mixture.     

Use of Fenton reagent to improve organic chemical biodegradability

Fenton reagent has been used to test the degradation of different organic compounds (formic acid, phenol, 4-chlorophenol, 2,4-dichlorophenol and nitrobenzene) in aqueous solution. A stoichiometric coefficient for the Fenton reaction was found to be 0.5 mol of organic compound/mol of hydrogen peroxide, except for the formic acid where a value of approximately one was obtained (due to the direct formation of carbon dioxide). The treatment eliminates the toxic substances and increases the biodegradability of the treated water (measured as the ratio BOD5/COD). Biodegradability is attained when the initial compound is removed.     

Pharmaceutical wastewater degradation: effective and economical treatment using waste-metallic iron shavings

Industrial wastewater generated by a drug manufacturing plant located in Spain was degraded by Fenton oxidation processes, which employ waste-metallic iron shavings as heterogeneous zero-valent iron (ZVI) catalyst and hydrogen peroxide. The effluent comprises a complex mixture of organic substances which are very refractory to common conventional treatments and it is characterized by a low BOD/COD ratio. The stirring speed or the particle size has been found to be the determining factors, greatly influencing the degradation of the organic pollutants present in the wastewater. The influence of the initial hydrogen peroxide concentration has also been evaluated. The optimal conditions for degradation led to total organic carbon (TOC) reductions of up to 60%. The remarkable results of TOC mineralization could also be attributed to the physico-chemical modification of the ZVI during the oxidizing process. This study shows that the ZVI/H₂O₂ system can be considered as an easy, economic and effective alternative solution as a pre-treatment step before biological treatments.     

Fenton and photo-Fenton oxidation of textile effluents

The simultaneous use of Fenton reagent and irradiation for the treatment of textile wastewaters generated during a hydrogen peroxide bleaching process is investigated. The experimental conditions tested during this study provide the simultaneous occurrence of Fenton, Fenton-like and photo-Fenton reactions. The batch experimental results are assessed in terms of total organic carbon reduction. Identification of some of the chemical constituents of the effluent was performed by means of GC-MS. Other pollution related features of the initial effluent-like COD and color were also measured. The main parameters that govern the complex reactive system, i.e., light intensity, temperature, pH, Fe(II) and H2O2 initial concentrations have been studied. Concentrations of Fe(II) between 0 and 400 ppm, and H2O2 between 0 and 10,000 ppm were used. Temperatures above 25 degrees C and up to 70 degrees C show a beneficial effect on organic load reduction. A set of experiments was conducted under different light sources with the aim to ensure the efficiency of using solar light irradiation. The combination of Fenton, Fenton-like and photon-Fenton reactions has been proved to be highly effective for the treatment of such a type of wastewaters, and several advantages for the technique application arise from the study.     

Oxidative decomposition of atrazine by a Fenton-like reaction in a H2O2/ferrihydrite system

The oxidation of atrazine (ATZ) was studied in the presence of hydrogen peroxide (H(2)O(2)) and ferrihydrite at different concentrations and pHs. The rate of ATZ oxidation increased with H(2)O(2) concentration and is independent of pH ranging from 4 to 8. However, at pH 3 an increase of ten times in the rate of ATZ oxidation was observed due to the mineral dissolution. The decomposition rate of H(2)O(2) was three times higher at pH 8 than 3 and increased with increase of both H(2)O(2) and ferrihydrite concentrations. The results indicate that ferrihydrite controls oxidation of ATZ by H(2)O(2) in two different ways: (i) mineral dissolution at low pH allowing the Fenton reaction to proceed in solution and (ii) surface-mediated decomposition of H(2)O(2) producing non-reactive oxygen species in particular at higher pH. Three degradation products (desethylatrazine, desisopropylatrazine, and 2-hydroxyatrazine) were identified and corroborate with a Fenton reaction taking place in solution.     

Use of ultrasound in water treatment

Investigations dealing with the treatment of aqueous systems by physical methods show that ultrasound is an effective reagentless and highly ecological method of water purification of organic pollutants and microorganisms. Its use is particularly effective in combined methods of treatment: ultrasound + ultraviolet irradiation; ultrasound + ultraviolet + ozonization; ultrasound + hydrogen peroxide; ultrasound + Fenton’s reagent, etc. In many cases the combined techniques make it possible to achieve better purification results due to a synergistic effect. The most promising techniques involve the application of high frequency ultrasound (200–500 kHz), simultaneous ultrasound treatment with two frequencies, and the use of hydrodynamic cavitators.