高频超声波降解4-氯酚的反应机理及试验研究

探讨了高频超声波（1.7MHz)降解4-氯酚的反应过程和反应机理，研究了高频超声波降解4-氯酚的效果及4-氯酚的初始浓度，高级氧化方法（AOPs)等因素对降解效果的影响。试验结果表明，高频超声波降解4-氯酚为一级反应，超声波空化效应在降解过程中起主导作用。超声波与其他氧化方法联用可大大提高降解效率。具有良好的工业应用前景。     

高级氧化技术降解环烷酸的研究进展

针对原油及油砂洗脱废水中的环烷酸所具有的酸性、毒性、腐蚀性等特点，介绍了多种降解环烷酸的高级氧化技术，包括Fenton氧化法、臭氧氧化法、光催化氧化法、超临界氧化法、微波辐照法等。评述了高级氧化技术降解环烷酸的最新进展和发现，分析了各种技术的处理效果，并总结了各种技术的优缺点。最后，提出了处理石油行业环烷酸废水的一些思路，为现阶段石油行业环烷酸废水的处理提供了参考。     

超声波技术降解水中氯代有机物的研究进展

介绍了超声波技术的基本原理，概述了超声波和各种超声联用（超声波与紫外光、过氧化氢、臭氧、Fenton试剂等联用）技术降解氯代有机物的效果和影响因素，总结了氯代有机物降解机理与动力学的研究进展，并在此基础上提出了今后超声波及其联用技术降解水中氯代有机物的研究方向。     

Technology review and evaluation of different chemical oxidation conditions on treatability of PFAS

Per‐ and polyfluoroalkyl substances (PFAS) are a class of stable compounds widely used in diverse applications. These emerging contaminants have unique properties due to carbon–fluorine (C–F) bonds, which are some of the strongest bonds in chemistry. High energy is required to break C–F bonds, which results in this class of compounds being recalcitrant to many degradation processes. Many technologies studied that have shown treatment effectiveness for PFAS cannot be implemented in situ. Chemical oxidation is a demonstrated remediation technology for in situ treatment of a wide range of organic environmental contaminants. An overview of relevant literature is presented, summarizing the use of single or combined reagent chemical oxidation processes that offer insight into oxidation–reduction chemistries potentially capable of PFAS degradation. Based on the observations and results of these studies, bench‐scale treatability tests were designed and performed to establish optimal conditions for the formation of specific free radical species, including superoxide and sulfate radicals, via various combinations of oxidants, catalysts, pH buffers, and heat to assess PFAS treatment by chemical oxidants. The study also suggests the possible abiotic transformations of some PFAS when chemical oxidation is or was used for treatment of primary organic contaminants (e.g., petroleum or chlorinated organic compounds) at a site. The bench‐scale tests utilized field‐collected samples from a firefighter training area. Much of the available data related to chemical oxidation of PFAS has only been reported for one or both of the two more commonly discussed PFAS (perfluorooctane sulfonic acid and/or perfluorooctanoic acid). In contrast, this treatability study evaluates oxidation of a diverse list of PFAS analytes. The results of this study and published literature conclude that heat‐activated persulfate is the oxidation method with the best degradation of PFAS. Limited reduction of reported PFAS concentrations in this study was observed in many oxidation reactors; however, unknown mass of PFAS (such as precursors of perfluoroalkyl acids) that cannot be identified in a field collected sample complicated quantification of how much oxidative destruction of PFAS actually occurred.     

四溴双酚A降解技术的研究进展

综述了微生物、物理和化学降解技术等几种主要的四溴双酚A（TBBPA）降解技术的研究进展。阐述了各种降解技术的机理和优缺点。指出今后重点的研究方向是：根据不同的反应机理和生长特性分离出微生物降解TBBPA的优势菌种，探索将TBBPA彻底碳化的工艺条件;优化高级氧化法降解TBBPA的反应条件，使之更适于工程应用;将还原法与微生物降解技术或高级氧化法相结合，先将TBBPA快速还原成双酚A，再进一步彻底碳化成CO2和H2O。     

Fenton法氧化降解聚乙烯醇的机制

为深入了解Fenton法氧化降解聚乙烯醇（PVA）的机制，通过考察反应过程中COD、BOD5、总有机碳及pH等随反应时间的变化，研究了聚乙烯醇Fenton氧化降解过程的特点，结果表明，当PVA被Fenton试剂氧化时，可生成大量CO2，同时生成酸性中间产物。进一步分析认为，当Fenton试剂中H2O2不足景时PVA氧化的中间产物以醛为主，而当H2O2足量时醛会被继续氧化生成有机酸，最终COD去除率达到80％。     

高级氧化技术处理水中人工甜味剂的研究进展

介绍了几个国家在地表水、污水处理厂进出水等水环境中检测出的人工甜味剂的含量,简介了人工甜味剂对人体的危害,综述了基于臭氧氧化和紫外光照射的高级氧化技术处理水中人工甜味剂的研究进展,剖析了人工甜味剂的降解产物和降解路径以及在降解过程中的矿化效果和毒性变化,对后续的研究方向进行了展望。     

高级氧化法处理甲基叔丁基醚的研究进展

综述了采用常规氧化、光强化氧化以及超声波辅助氧化等高级氧化技术降解甲基叔丁基醚（MTBE）的降解机理及研究进展。并介绍了MTBE与醚类、苯系物以及可吸附卤化物共存的复合污染物的氧化降解研究进展。指出今后研究的重点是利用光、声、电能量的摄入来降低氧化剂加入量,提高矿化程度以减少毒性较大的叔丁基团的含量,研发更易于固液分离、稳定性更高和寿命更长的高效催化剂及共存体系将是持续热点。     

Assessment of the Whole Environmental Degradation of Oxo-Biodegradable Linear Low Density Polyethylene (LLDPE) Films Designed for Mulching Applications

The current paper is aimed at understanding the environmental fate of linear low density polyethylenes (LLDPE) films designed for mulching purposes and loaded with different pro-degradant additives. These were analyzed, upon exposure to natural sunlight for a period intended to mimick a general crop season in the mediterranean region. The selected samples underwent a relatively low extent of degradation as monitored by carbonyl index, molecular weight variation, extractability by solvent, changes in the onset of the decomposition temperature and crystallinity. The tendency to biodegradation of outdoor exposed LLDPE was then assessed under different environmental compartments including soil medium, aqueous medium as well as in axenic culture of white-rot fungus Phanerochaete chrysosporium. That fungus is known to be effective in the degradation of recalcitrant organic materials and plastic items. During the soil burial biodegradation test, lasted for 27?months, samples specimen were withdrawn at time intervals and characterized by means of structural and thermal analysis. These analytical assessments allowed to monitor any progress of oxidative degradation as a direct effect of the incubation in an active microbial environment. Analogous characterizations were carried out at the end of the biodegradation tests in aqueous medium and in P. chrysosporium axenic cultures. Data presented here are in keeping with the initial abiotic oxidation via a free radical chain reaction promoted by a pro-degradant additive acting on hydroperoxides and peroxide moieties present initially in the polymer bulk. This step was followed by a free radical cascade reactions leading to degradation once the oxidation started under relatively mild conditions (sunlight exposure). During the incubation step in soil, the abiotically degraded samples underwent significant variation in the level of oxidation and degradation with respect to the detected starting values. Indications were gained on the synergistic effect of a random fashion microbial metabolization coupled to biotically mediated oxidation of the original abiotically fragmented samples. Similar results were obtained in the biodegradation tests carried out in the aqueous media and in presence of P. chrysosporium axenic cultures. These evidences are suggesting the role of natural occurring microorganisms in promoting both partial oxiditation and degradation of LLDPE samples in combination with contextual mineralization process of the oxidized fragments.     

Investigation of the ozonolysis of ethylenebisdithiocarbamate-fungicides in model solutions

A study of the effectiveness of ozonation for the removal of nabam (disodium ethylenebisdithiocarbamate) from aqueous solutions was carried out. Nabam is the parent compound of a commonly used group of fungicides. The process of nabam degradation was followed in terms of several parameters such as nabam concentration, chemical oxygen demand (COD), sulphate ion concentration as a measure of the relative degree of mineralization of nabam, and the pH value of the solution. Ozonation accelerates the decomposition of nabam with the formation of sulphates and nitrates as final products. The intermediate decomposition products of nabam are more resistant to degradation by ozone than the parent compound. The amounts of ozone which are used in wastewater treatment plants for disinfection may be sufficient to remove both nabam and its decomposition products, at a low level of contamination, but if the concentration of nabam is too high the intermediate decomposition products can still be present. Lowering the pH of the medium favours the oxidation of nabam.     

Sonophotocatalytic Degradation of Chitosan in the Presence of Fe(III)/H2O2 System

The degradation of chitosan by means of ultrasound irradiation and its combination with homogeneous photocatalysis (photo-Fenton) was investigated. Emphasis was given on the effect of additive on degradation rate constants. 24 kHz of ultrasound irradiation was provided by a sonicator, while an ultraviolet source of 16 W was used for UV irradiation. To increase the efficiency of degradation process, degradation system was combined with Fe(III) (2.5 × 10⁻⁴mol/L) and H₂O₂ (0.020–0.118 mol/L) in the presence of UV irradiation and the rate of degradation process change from 1.873 × 10⁻⁹−6.083 × 10⁻⁹ mol^1.7 L s⁻¹. Photo-Fenton process led to complete chitosan degradation in 60 min with the rate increasing with increasing catalyst loading. Sonophotocatalysis in the presence of Fe(III)/H₂O₂ was always faster than the respective individual processes. A synergistic effect between ultrasound and ultraviolet irradiation in the presence of Fenton reagent was calculated. The degraded chitosans were characterized by X-ray diffraction (XRD), gel permeation chromatography (GPC) and Fourier transform infrared (FT-IR) spectroscopy and average molecular weight of ultrasonicated chitosan was determined by measurements of intrinsic viscosity of samples. The results show that the total degree of deacetylation (DD) of chitosan change, partially after degradation and the decrease of molecular weight led to transformation of crystal structure. A negative order for the dependence of the reaction rate on total molar concentration of chitosan solution within the degradation process was suggested. Results of this study indicate that the presence of catalyst in the reaction medium can be utilized to reduce molecular weight of chitosan while maintaining the power of irradiated ultrasound and degree of deacetylation.     

微电解—Fenton试剂氧化—A/O工艺处理制药废水

采用微电解—Fenton试剂氧化—A/O组合工艺处理高浓度制药废水。实验结果表明:经微电解—Fenton试剂氧化工艺预处理后,COD去除率可达50%~60%,BOD5/COD提高到0.3以上;预处理后的废水与清洗废水和生活污水混合,采用生化法进一步处理,出水COD小于100 mg/L,BOD5小于20 mg/L,ρ(NH3-N)小于50 mg/L,SS小于70 mg/L,满足GB 8978—1996《污水综合排放标准》中的三级排放标准。     

高级氧化技术再生吸附剂的研究进展

对高级氧化技术再生吸附剂的研究现状进行了综述,重点介绍了光催化氧化技术、Fenton氧化技术、活化过硫酸盐氧化技术和臭氧氧化技术4种方法再生吸附剂的应用,分析了4种氧化技术用于吸附剂再生的机理,指出了各种再生方法存在的不足,并对后续的研究方向进行了展望。     

Use of Oxidation Onset Temperature Measurements for Evaluating the Oxidative Degradation of Isotatic Polypropylene

The widespread use of polymeric materials in many applications requires polymers that are weather resistant. The aim of this study is to examine the usefulness of oxidation onset temperature measurements as a tool for evaluating oxidative degradation of isotatic polypropylene. Differential scanning calorimetry was used to measure the oxidation onset temperature in formulations of isotatic polypropylene containing different concentrations of light and thermal stabilizers after aging in a Weather-Ometer. Oxidation onset temperature gave better results than oxidation induction time for evaluating the degradation of isotatic polypropylene during aging in a Weather-Ometer. However, both tests showed a poor correlation with the appearance of cracks seen by optical microscopy.     

阴离子对Fenton氧化降解聚乙烯醇的影响

研究了亚铁盐中NO3-、SO42-、Cl-、Br-等阴离子对Fenton氧化降解高浓度聚乙烯醇(PVA)效果的影响。实验结果表明:酸性条件下具有氧化性的阴离子NO3-或能被氧化形成具有氧化性物质的离子Cl-、Br-对Fenton氧化降解PVA有协同促进作用,且氧化性越强越容易促使PVA大分子链断裂;含NO3-、Cl-、Br-和SO42-的Fenton氧化降解PVA,COD去除率分别为70.05%、70.60%、72.40%和87.90%。采用COD去除率相差不大、产物分子量较小的硝酸亚铁、氯化亚铁、溴化亚铁中的一种作为Fenton试剂催化降解PVA较适宜。     

超声协同Fenton法处理有机废水的研究进展

超声协同Fenton法是利用超声的空化效应及自由基效应强化Fenton法对废水的处理效率,实现两者对废水中有机污染物的协同降解。概述了超声与Fenton法处理废水的协同机制。综述了废水pH、催化剂和H₂O₂投加量、超声功率、温度等工艺条件的优化研究,催化剂的研发以及共存物质的影响研究等方面的进展。指出开发新型高效、可重复利用、廉价易得的催化剂是提高超声协同Fenton法降解有机污染物效率的关键,还可将超声、Fenton法或超声协同Fenton法与其他的氧化法或生化方法相结合,寻找更加安全、高效、低成本的新途径。     

微波-改性活性炭-Fenton试剂氧化法降解水中2,4-二氯酚

以经Fe2（SO4）3溶液浸渍改性的活性炭作催化剂、Fenton试剂作氧化剂，采用微波-改性活性炭-Fenton试剂氧化法降解水中的2，4-二氯酚。考察了改性活性炭加入量、H2O2与Fe^2＋摩尔比、Fenton试剂加入量、微波功率和2，4-二氯酚溶液初始pH对2，4-二氯酚降解效果的影响。在改性活性炭加入量1．0g／L、n（H2O2）：n（Fe^2＋）=16．7（H2O2加入量6．0mmol／L、Fe^2＋加入量0．36mmol／L）、Fenton试剂加入量为6．36mmol／L、微波功率600W、微波辐射时间10min、2，4-二氯酚溶液初始pH为6．0的条件下，2，4-二氯酚降解率和TOC去除率分别可达98．7％和84．0％。     

几种焦化废水深度处理技术的比较

分别采用Fenton试剂氧化法、固定床离子交换树脂吸附法和流化床磁性树脂吸附法对某焦化厂焦化废水生化工艺出水进行深度处理.试验结果表明:Fenton试剂氧化法处理后出水COD去除率最高达75.4％,色度去除率达89.1％;固定床离子交换树脂吸附法COD去除率为49.4％,色度去除率为96.5％;流化床磁性树脂吸附法COD去除率为58.2％,色度去除率为90.2％.Fenton试剂氧化法COD去除率较高,固定床离子交换树脂吸附法和流化床磁性树脂吸附法色度去除率较高.综合考虑,Fenton试剂氧化法具有更高的工程应用价值.     

Practical Perspectives of 1,4‐Dioxane Investigation and Remediation

1,4‐Dioxane (dioxane) is a contaminant of emerging concern that is classified by the U.S. Environmental Protection Agency as a likely human carcinogen. Dioxane has been used as a minor or major ingredient in many applications, and is also generated as an unwanted by‐product of industrial processes associated with the manufacturing of polyethylene, nonionic surfactants, and many consumer products (cosmetics, laundry detergents, shampoos, etc.). Dioxane is also a known stabilizer of chlorinated solvents, particularly 1,1,1‐trichloroethane, and has been commonly found comingled with chlorinated solvent plumes. Dioxane plumes at chlorinated solvent sites can complicate site closure strategies, which to date have not typically focused on dioxane. Aggressive treatment technologies have greatly advanced and are clearly capable of achieving lower parts per billion cleanup criteria using ex situ advanced oxidation processes and sorption media. In situ chemical oxidation has also been demonstrated to effectively remediate dioxane and chlorinated solvents. Other in situ remedies, such as enhanced bioremediation, phytoremediation, and monitored natural attenuation, have been studied; however, their ability to achieve cleanup levels is still somewhat questionable and is limited by co‐occurring contaminants. This article summarizes and provides practical perspectives on dioxane analysis, plume stability relative to other contaminants, and the development of investigation tools and treatment technologies.     

含硝基苯类化合物废水处理技术研究进展

综述了近年来处理含硝基苯类化合物废水的物理法（包括吸附法和溶剂萃取法）、化学法（包括电化学法、铁碳微电解法、超声波氧化法和臭氧氧化法及复合技术）和生物法的研究进展。指出将现有的处理技术高效整合并降低成本是今后处理含硝基苯类化合物废水的研究方向和重点。