超声波强化γ-Al_2O_3催化臭氧氧化法降解2,4-二硝基苯酚

采用超声波强化γ-Al_2O_3催化臭氧氧化法降解模拟废水中的2,4-二硝基苯酚,考察了超声波对降解反应的强化作用及γ-Al_2O_3加入量、臭氧流量、超声波功率等对2,4-二硝基苯酚降解的影响.实验结果表明:2,4-二硝基苯酚在超声波强化γ-Al_2O_3催化臭氧氧化作用下的降解过程符合一级表观动力学;在2,4-二硝基苯酚质量浓度为20.00 mg/L、γ-Al_2O_3催化剂加入量为1.5g/L、臭氧流量为61 mg/min、超声波功率为300 W、反应时间为60 min时,2,4-二硝基苯酚的降解率达96.4%.     

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。     

超声波-铁粉协同降解五氯酚

通过超声波-铁粉联合体系协同降解废水中的五氯酚(PCP).实验结果表明:降解120 min后,PCP去除率可达90.4％；在该体系中铁粉被逐渐腐蚀成Fe2+,随降解时间的延长,Fe2+浓度逐渐增加；体系中的Fe2+可以促进·OH的产生,并且可以与超声空化作用下产生的H2O2发生Fenton试剂氧化反应降解PCP；超声波...     

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％。     

化工园区生化出水氯代烃污染物的臭氧氧化降解

以化工园区污水处理厂生化出水为背景水样,考察了臭氧氧化对2,4,6-三氯酚、氯苯、1,2-二氯苯、对硝基氯苯、四氯酞酸5种特征氯代烃污染物的降解效果,并对其降解动力学进行了分析。实验结果表明:臭氧对2,4,6-三氯酚和氯苯的降解效果最好,反应30 min时的去除率均接近100%,其次为1,2-二氯苯和对硝基氯苯,反应30 min时的去除率分别为95.7%和36.0%,最差为四氯酞酸,反应30 min时的去除率仅为8.9%;臭氧对2,4,6-三氯酚和对硝基氯苯的降解符合零级动力学方程,对氯苯和1,2-二氯苯的降解符合一级动力学方程,对四氯酞酸的降解符合二级动力学方程。     

Fenton试剂降解氯酚类物质的研究进展

概述了Fenton试剂对氯酚类物质的降解效果及其作用机理,讨论了氯代酚中氯的含量及氯的位置对Fenton试剂降解氯酚类物质难易程度的影响.得出Fenton试剂可以有效地降解氯酚类物质,同时氯代酚中所含氯的数量及氯所处的位置对其降解速率有较大的影响.     

低温湿式空气氧化法处理废碱液的研究

对采用低温湿式空气氧化法处理炼油和乙烯废碱液进行了研究。考察了停留时间对废碱液中硫化物的氧化、氧化产物的形态、COD和酚去除率的影响，反应温度对废碱液中污染物氧化反应的影响。试验结果表明，废碱液的脱臭效果很好，S^2-的氧化产物以S2O3^2-和SO4^2-2种形式共存；酚、COD的去除率及S^2-的氧化反应停留时间影响小，受反应温度影响明显；废碱液的S^2-的酚浓度相当时，COD去除率一 般低于40％， 废碱液的S^2-浓度远大于酚浓度时，废碱液的COD去除率为40％－70％；废碱液中酚的质量浓度大于20000mg/L时才有回收价值。     

电-Fenton法对五氯酚的降解研究

研究了电化学方法对五氯酚的降解过程.分别以石墨和铂分别作为阴极和阳极,对电解电压、电解质浓度和pH等影响因素进行了优化.在优化条件下,剂量的Fe3+或Fe2+都能够较大程度地增加五氯酚的处理效果,表明活性中间体H2O2的存在和Fenton试剂的产生.在该电-Fenton体系下,对五氯酚处理过程中氯离子释放量和五氯酚浓度降低之间的关系进行了分析,并以GC/MS对处理中间过程和最终过程的物质进行了分析鉴定,提出了相应的降解机理和途径.反应动力学分析表明,反应初始阶段呈一级反应动力学过程,后续阶段出现对一级动力学过程的偏移.     

稀土Gd掺杂SnO2-Sb涂层阳极电催化氧化甲基橙

采用溶胶-凝胶法，以无机盐SnCl4·5H2O，Sb2O3，Gd（NO3）3为前驱体，制备了稀土Gd掺杂SnO2-Sb涂层阳极。以稀土Gd掺杂SnO2-Sb为阳极电催化氧化处理甲基橙溶液，考察了电解质浓度、电流密度、溶液的pH、溶液温度及稀土Gd掺杂对甲基橙降解率的影响。实验结果表明：稀土Gd掺杂SnO2-Sb涂层阳极对甲基橙具有较好的降解效果。在电解质NaCl质量浓度为4g/L、电流密度为0．06A／cm2、甲基橙溶液的pH为3、溶液温度为25℃条件下，氧化降解1．0h甲基橙降解率为92．21％，氧化降解2．5h甲基橙降解率为99．15％。     

超声波协同电化学氧化降解苯胺的研究

采用超声波协同电化学氧化法处理苯胺溶液，考察了超声时间、苯胺浓度、溶液pH、电解电压、电解质浓度等因素对苯胺降解率的影响。试验结果表明：在超声波与电化学联合作用下，苯胺降解率随降解时间的延长而提高，苯胺浓度无论是低还是高，声电联合作用完全去除苯胺只需30min左右，电化学单独作用完全去除苯胺约需要120min；苯胺初始浓度较低时，其降解率较高；随着pH的增大，苯胺降解率先降低后提高，pH为10左右苯胺降解率最高；电解质Na2SO4的浓度对苯胺降解率影响不大；电解电压在4～12V范围内，苯胺降解率随电压升高而提高，电压为16V时，其降解率下降。     

Recent trends in the decomposition of chlorinated aromatic hydrocarbons by ultrasound irradiation and Fenton's reagent

Over the past few years, a large number of studies have been conducted on the use of ultrasound for decomposition of harmful organic pollutants, particularly chlorinated aromatic hydrocarbons (CAH) in wastewater. The published reports cover a variety of applications, including both ultrasonic treatment alone and in combination with other methods, e.g., advanced chemical oxidation processes. This article presents a review of recent work on ultrasonic-based methods of CAH decomposition, with emphasis on the applications of ultrasound alone and in combination with Fenton's reagent, as attractive advanced oxidation systems. In the first part of this review, the basic principles of sonochemical treatment are presented, followed by a review of the applications of ultrasound alone for CAH degradation. In the second part, the mechanisms of CAH degradation with Fenton's reagent and its application for CAH degradation are summarized. In the final part, studies on the applications of ultrasound together with Fenton's reagent are reviewed. The reported results suggest that a combination of ultrasound and Fenton's reagent is more attractive for practical application than the use of either method separately. Further studies, however, are required in this area because the reaction mechanism and the relationship between the reaction rates and process parameters for such a combined process are not yet well established.     

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。     

Photochemical oxidation of p-chlorophenol by UV/H2O2 and photo-Fenton process. A comparative study

In this study, photochemical advanced oxidation processes (AOPs) utilizing the combinations of UV/H2O2 and the photo-Fenton reaction (UV + classical Fenton reaction) were investigated in lab-scale experiments for the degradation of p-chlorophenol. The study showed that the photo-Fenton process, (a mixture of hydrogen peroxide and ferrous or ferric ion), was the most effective treatment process under acidic conditions and produced a higher rate of degradation of p-chlorophenol at a very short radiation time. It accelerated the oxidation rate by 5-9 times the rate for the UV/H2O2 process. The reaction was found to follow the first order, the reaction was influenced by the pH, the input concentration of H2O2 and the amount of the iron catalyst and the type of iron salt. The experimental results showed that the optimum conditions were obtained at a pH value of 3, with 0.03 mol/l H2O2, and 1 mmol/l Fe(II) for the UV/H2O2/Fe(II) system and 0.01 mol/l H2O2 and, 0.4 mmol/l Fe(III) for the UV/H2O2/Fe(III) system. The reactions were accompanied by the generation of Cl- which reached its maximum value at a short reaction time when using the photo-Fenton process. Finally a rough comparison of the specific energy consumption shows that photo-Fenton process reduced the energy consumption by at least 73 to 83% compared with the UV/H2O2 process.     

羟胺强化Fenton反应降解水中氯酚

针对传统Fenton体系Fe（Ⅲ）累积和pH适用范围过窄等缺点，采用羟胺（HA）强化的HA-Fenton体系，以对氯苯酚（4-CP）为目标污染物进行降解实验，考察了Fe（Ⅱ）投加量、H2O2投加量、HA投加量和溶液pH等工艺条件对4-CP去除率的影响。实验结果表明：HA-Fenton体系适用于酸性和弱酸性条件，最佳pH范围为3.0~4.0；在溶液pH为3.0、Fe（Ⅱ）投加量为5.0 μmol/L、H2O2投加量为0.4 mmol/L、HA投加量为0.20 mmol/L的最适条件下，反应10 min， 4-CP去除率达64.25 %。     

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.     

氯系阻燃剂四氯双酚A的毒性及降解技术研究进展

作为目前广泛使用的氯系阻燃剂,四氯双酚A(TCBPA)在运输、使用和处理的过程中会不可避免地释放到环境中,并通过各种途径进入人体,产生危害。简介了TCBPA的基本性质和制备,阐述了其环境分布及毒性,并总结了其降解技术的研究进展,最后对该领域未来的研究方向进行了展望。指出:应当进一步研究TCBPA微生物降解的机理和分子基础,并引入光催化、高级氧化等其他降解技术;同时,开发新型环境友好的阻燃剂不失为一种根源上的解决方式。     

Mechanism of Microbial Degradation of Slow-Release Fertilizers

Methyleneureas are condensation products of urea and formaldehyde of different molecular mass and solubility; they are used in large amounts both as resins, binders, and insulating materials for industrial applications, as well as a slow-release nitrogen fertilizer for greens, lawns, or in bioremediation processes. In the present study, the microbial breakdown of these products was investigated. The nitrogen was released as ammonia and urea, and the formaldehyde released immediately oxidized via formiate to carbon dioxide. The enzymatic mechanism of metabolization of methyleneureas was studied in microorganisms isolated from soil, which were able to use these compounds as the sole source of nitrogen for growth. A strain of the Gram-negative bacterium Ralstonia paucula (formerly Alcaligenes sp. CDC group IVc-2) completely degraded methylenediurea and dimethylenetriurea to urea, ammonia, formaldehyde, and carbon dioxide. The enzyme initiating this degradation (methylenediurease) was purified and turned out to be different from the previously described enzyme from Ochrobactrum anthropi with regard to its regulation of expression and physicobiochemical properties. Fungal degradation of methyleneureas may occur via the formation of organic acids, thus leading to a nonenzymatic degradation of methyleneureas, which are unstable under acidic conditions.     

链霉菌(Streptomyces sp.)对吡啶的降解特性

从焦化废水的活性污泥中分离出对溶液中吡啶具有降解效果的链霉菌（Streptomyces sp．），考察了吡啶初始质量浓度、初始pH、降解温度、振荡速度等对吡啶降解效果的影响，初步探讨了该菌降解吡啶的动力学与机理。实验结果表明，该菌对吡啶有很强的耐受力，能以吡啶为惟一碳源和氮源生长。链霉菌在初始pH=8、降解温度30℃、振荡速度100r／min的条件下培养7d后，吡啶的质量浓度从250mg/L降至6．6mg/L，吡啶降解率达97．4％。该菌对吡啶的降解反应符合一级动力学方程，初始质量浓度为100mg／L时的吡啶降解速率常数为0．4011d^-1。紫外一可见光谱分析表明，吡啶经该菌降解后的特征环被破坏。     

Thermal Stability and Degradation of Chitosan Modified by Acetophenone

N-(Methylphenylmethylidenyl) chitosan (MPMC) polymer was synthesized by chemical modification of chitosan. The chemical structure of the modified polymer was characterized by IR, ¹H NMR and elemental analysis. Thermogravimetric reveals that the thermal stability of chitosan polymer is greater than MPMC polymer. The activation energies of thermal degradation of chitosan and MPMC polymers determined using Arrhenius relationship. Thermal degradation of MPMC polymer was studied and the products of degradation were identified by GC–MS technique. It seems that the mechanism of degradation of MPMC polymer is characterized by elimination of low-molecular weight radicals. Combination or recombination of H^· or OH⁻ with these radicals and random scission mechanism along the backbone chain are the main source of the degradation products.