环境内分泌干扰物双酚A的降解研究进展

双酚A是一种典型的环境内分泌干扰物,其负面作用随着使用的扩大而日益受到人们的重视。介绍了双酚A的理化性质、应用情况、生物毒性及污染现状,概述了国内外学者对双酚A降解方法与技术（物理法、化学法、生物法等）的研究及影响因素的探讨,并提出了未来研究的主要方向。     

水环境内分泌干扰物双酚A的降解研究进展

双酚A是一种典犁的环境内分泌干扰物,其负面作用随着使用的扩大而日益受到人们的重视.介绍了双酚A的理化性质、应用情况、生物毒性及污染现状,概述了国内外学者对双酚A降解方法与技术(物理法、化学法、生物法等)的研究及影响因素的探讨,并提出了未来研究的主要方向.     

高级氧化技术降解双酚A的研究进展

对高级氧化技术降解污水中一种内分泌干扰物双酚A（BPA）的作用机理和研究现状进行了综合评述。针对高级氧化技术中最重要的5种技术,即芬顿氧化及光-芬顿氧化、电化学氧化、光分解及光氧化、超声辐射和光催化氧化,详述了各种氧化技术的作用机理、降解效果以及影响因素等。还对这5种高级氧化技术今后可能的发展方向做了初步展望,鉴于各种高级氧化技术降解BPA的条件不同,通过合理设计多种高级氧化技术复合作用并建立优化模型,开发低能耗、高效率以及广泛适用于内分泌干扰物及持久性有机污染物的处理技术。     

Fe/AC非均相Fenton体系降解废水中苯酚研究

采用浸渍法制备了活性炭载铁(Fe/AC)非均相Fenton催化剂,研究了铁负载量、初始pH值、反应时间和H_2O_2用量对催化剂降解模拟废水中苯酚的影响,结果表明,在苯酚废水体积为50 mL,催化剂铁负载量为7.76%, H_2O_2投加量为4 g/L, pH值为3,反应时间为120 min的条件下,苯酚的降解率约为95%。催化剂的稳定性试验表明,重复使用5次后,该催化剂对苯酚的降解率仍能达60%左右。该催化剂具有良好的活性和较强的稳定性,以及良好的实际应用前景。     

铁酸锌负载碳纳米管结合微波催化降解双酚A

碳纳米管是一种新型吸附材料,具有比表面积大、吸附容量大且质轻、强度高、导电性强等优点。而铁酸锌由于其结构具有较高的光催化活性、气敏性和光敏感性等特点,是高频带理想的磁性吸波材料。文章旨在结合微波诱导催化技术,利用微波水热法将铁酸锌负载在碳纳米管上合成新型催化剂,增强微波吸收能力,并探讨ZnFe_2O_4/MWCNTs结合微波的催化降解能力。结果表明,ZnFe_2O_4/MWCNTs催化剂的最佳合成条件为Fe∶Zn=2∶1,Fe~(3+)0.03 mol/L,MWCNTs 0.5 g,微波水热合成压力1.5 MPa,微波水热合成时间30 min。并且,以ZnFe_2O_4/MWCNTs为催化剂结合微波催化降解能使溶液中的BPA迅速降解且减少副产物的产生。     

腐殖酸共存条件下双酚A的纳滤分离效果研究

双酚A(BPA)是一种痕量的危害性极大的环境内分泌干扰物质,主要考察了在天然有机物(腐殖酸)存在的条件下,pH、离子强度、操作压力对纳滤分离水中BPA的效果.结果表明,用纳滤膜去除水中BPA是完全可行的,其截留率达94%以上;当溶液的pH值大于BPA的pKa(10.1)时,去除效果最好;离子强度增大,BPA的截留率会降低:操作压力对纳滤去除BPA的影响较小.     

活性炭负载Fe~(3+)催化臭氧氧化水中双酚A

采用浸渍法在活性炭上负载铁制备催化剂Fe/AC,用于催化臭氧氧化水中内分泌干扰物双酚A(BPA),研究了Fe/AC/O3体系的协同效应,探讨了Fe/AC投加浓度、臭氧浓度和BPA初始浓度等工艺参数的作用规律,并分析了Fe/AC/O3体系在不同pH值下的催化反应机制。结果表明,在Fe/AC/O3体系下,反应60 min后,BPA和COD的去除率分别为97.44%和69.47%,效果明显优于臭氧体系的70.15%、30.89%和活性炭体系的14.69%、7.53%之和,具有明显的协同作用;Fe/AC/O3体系降解BPA符合一级反应动力学,当Fe/AC的投加浓度为5.0 g/L,臭氧浓度为15.0 mg/L,BPA初始浓度为50.0 mg/L时,Fe/AC/O3体系降解BPA的反应速率常数为0.05972 min-1;其反应机制受溶液pH值的影响,在酸性条件下是吸附和臭氧直接氧化共同作用,而在碱性条件下以·OH间接氧化为主,活性炭上负载的Fe3+促进了·OH的生成,大大提高了BPA的反应效率和矿化率。     

高铁酸钾的制备及其去除微污染水中双酚A能力的研究

探讨了次氯酸盐氧化法制备的高纯度高铁酸钾对微污染水中双酚A(BPA)的降解效果以其影响因素。结果表明,采用次氯酸盐氧化法自制的高铁酸钾的质量分数可以稳定在90%以上;在pH为5、7.1和9时,高铁酸钾降解BPA效果较好,降解率分别为95.4%、99.0%和98.5%;BPA降解率与高铁酸钾投加量之间的关系符合Slogistic模型,高铁酸钾的投加量越大,BPA去除率越高,但m(K2FeO4):m(BPA)大于5时,去除率增长缓慢。高铁酸钾去除微污染水中BPA的优化pH在5~9,K2FeO4与BPA的质量浓度比应当控制在5~6,优化反应时间为10 min。     

类Fenton试剂ZnFe_2O_4的制备及其光催化降解双酚A的性能研究

通过水热法制备了Zn Fe2O4催化剂,使用扫描透射电镜、能量分散谱仪和X射线衍射仪等表征手段分析其微观形貌、化学组成和晶体类型;研究了其对双酚A(BPA)废水的光催化降解性能,考察H2O2投加量、催化剂循环使用次数对催化降解效果的影响。结果表明,所制备的Zn Fe2O4为木屑状、具有微孔结构的立方尖晶石型材料;单一Zn F2O4在紫外光激发下对BPA废水具有光催化降解能力,反应120 min,BPA降解率为81.6%;在添加H2O2后,系统催化性能得到提升,反应90 min,BPA降解率高达98.5%;优化的H2O2投入浓度为1 mmol/L。所制备Zn Fe2O4有稳定的催化能力,可循环利用。     

Catalytic wet peroxide oxidation of phenol with a Fe/active carbon catalyst

A Fe on activated carbon catalyst has been prepared and tested for phenol oxidation with H₂O₂ in aqueous solution at low concentration (100 mg/L). Working at 50 °C, initial pH 3 and a dose of H₂O₂ corresponding to the stoichiometric amount (500 mg/L) complete removal of phenol and a high TOC reduction (around 85%) has been reached. Oxidation of phenol gives rise to highly toxic aromatic intermediates which finally disappear completely evolving to short-chain organic acids. Some of these last showed to be fairly resistant to oxidation being responsible for the residual TOC. In long-term continuous experiments the catalyst undergoes a significant loss of activity in a relatively short term (20–25 h) due to Fe leaching, this being related with the amount of oxalic acid produced. Deactivation may also be caused by active sites blockage due to polymeric deposits on whose formation some evidences were found. Washing with 1N NaOH solution allows to recover the activity although complete restoration was not achieved.     

Reaction pathway of the catalytic wet air oxidation of phenol with a Fe/activated carbon catalyst

Catalytic wet air oxidation (CWAO) of phenol with molecular oxygen using a home-made Fe/activated carbon catalyst at mild operating conditions (100–127 °C; 8 atm) has been studied in a trickle-bed reactor. Ring compounds (hydroquinone, p-benzoquinone and p-hydroxybenzoic acid) and short-chain organic acids (maleic, malonic, oxalic, acetic and formic) have been identified as intermediate oxidation products. CWAO experiments using each one of these intermediates as starting compound have been carried out (at 127 °C and 8 atm) in order to elucidate the reaction pathway. It was found that phenol is oxidized through two different ways. It can be either para-hydroxylated to hydroquinone, which is instantaneously oxidized to p-benzoquinone or para-carboxylated to p-hydroxybenzoic acid. p-Benzoquinone is majorly mineralized to CO₂ and H₂O through oxalic acid formation whereas p-hydroxybenzoic acid gives rise to short-chain acids. Only acetic acid showed to be refractory to CWAO under the operating conditions used in this work. The catalyst avoids the presence of ring-condensation products in the reactor effluent which were formed in absence of it. This is an additional important feature because of the ecotoxicity of such compounds.     

Fe2O3/AC催化剂上对甲基苯硫酚的水相催化氧化偶联

以对甲基苯硫酚为模型底物，空气为氧化剂，来研究硫醇水相催化氧化偶联制备二硫醚。以活性炭为载体，采用等体积浸渍法制备了一系列负载型氧化物催化剂，并考察了其在对甲基苯硫酚氧化偶联制备对甲苯二硫醚反应中的催化性能。反应结果表明，活性炭负载的铁氧化物具有最佳催化性能。采用N₂物理吸附、X射线衍射、X射线光电子能谱和透射电镜等表征手段对活性炭负载的铁氧化物催化剂进行了表征。表征结果表明，铁氧化物为高度分散在活性炭上的Fe₂O₃物种。以Fe₂O₃/AC为催化剂，当催化剂焙烧温度为400℃，Fe负载量为5%，在50℃下反应30min时，对甲苯二硫醚的收率高达97.4%；该催化剂循环使用5次后活性无明显下降。     

Catalytic wet oxidation of H2S to sulfur on Fe/MgO catalyst

The room temperature wet catalytic oxidation was conducted in a batch reactor with Fe/MgO catalyst. Fe/MgO catalyst was prepared by the dissolution–precipitation method. XRD and temperature-programmed reductions (TPR) indicate that Fe oxide in the Fe/MgO is finely dispersed in the MgO support. The high H₂S removal capacities of Fe/MgO can be explained by the finely dispersed iron oxide MgO. The H₂S removal capacities of Fe/MgO are dependent on oxygen partial pressure (1.0 g H₂S/g_cat in air and 2.6 g H₂S/g_cat in oxygen). The valence state analysis of Fe/MgO catalyst suggests that the H₂S oxidation on Fe/MgO can occur by a redox couple reaction, reducing Fe³⁺ into Fe²⁺ by H₂S and oxidizing Fe²⁺ to Fe³⁺ by O₂.     

Catalytic wet peroxide oxidation over mixed (Al–Fe) pillared clays

Mixed (Al–Fe) pillared clays are very efficient solid catalysts for oxidation of organic compounds in water by hydrogen peroxide. We have shown that in rather mild experimental conditions (atmospheric pressure, T≤70°C) and with a low excess (20%) of hydrogen peroxide, phenol was rapidly converted, mainly to CO₂, without significant catalyst leaching. The (Al–Fe) pillared clay catalyst (called FAZA) can be used several times without any change of its catalytic properties. According to the low leaching observed and a previous Mössbauer spectroscopy study, the iron species appear to be strongly bonded to the aluminium pillars.     

筛板塔Fe/Cu湿式催化氧化脱除H2S气体制硫磺的实验

阐述了筛板塔Fe/Cu湿式催化氧化脱除H₂S气体制硫磺流程,考察了操作空塔气速、液气比、起始pH值和H₂S入口浓度对H₂S脱除效率的影响及鼓风量、液柱高度对Fe^3＋氧化再生的影响;并进行了综合实验。结果表明,含120g/L的Cu²⁺、70g/L的Fe²⁺及70g/L的Fe³⁺的吸收体系即能对体积分数为1000×10^－6的H₂S废气近100％稳定脱硫,流程简短、能耗低,体系除消耗O₂外,过程不消耗原料,不产生二次污染,体系无降解问题。     

Cu-silicalite-1 catalyst for the wet hydrogen peroxide oxidation of phenol

The aim of the present work is to study the heterogeneous wet hydrogen peroxide catalytic oxidation (WHPCO) of phenol using copper bearing Silicalite-1 type zeolite, prepared by direct hydrothermal synthesis. The catalysts used for this study were three: one (Na)Cu-Silicalite-1 and two (H)Cu-Silicalite-1 prepared by different ion exchange methods. The results on catalytic activity for phenol abatement and hydrogen peroxide consumption of these materials are presented. The copper leaching during the reaction was evaluated for all samples. A comparison with the catalytic activity and stability of a Cu-Silicalite-1 material prepared by ionic exchange method is presented.     

Au/Fe2O3催化剂上CO选择氧化反应性能的研究

采用共沉淀法、沉积-沉淀法和浸渍法制备了1.5%Au/Fe2O3催化剂,考察了不同方法制备的Au/Fe2O3催化剂对富氢气体中CO选择氧化反应性能的影响。结果表明,浸渍法制得的催化剂在40℃~60℃时CO的转化率为100%;共沉淀法与沉积-沉淀法制得的催化剂在80℃以下CO的转化率均为100%;沉积-沉淀法制得的催化剂在100℃时CO的转化率依然高于95%。上述三种催化剂CO氧化反应的选择性均高于40%,且在CO完全转化时选择性在50%以上。     

Fe/Al_2O_3催化剂催化氧化兰炭废水

采用浸渍法制备Fe/Al_2O_3催化剂,采用BET、XRD和穆斯堡尔谱等进行结构和性能表征。以自制Fe/Al_2O_3为催化剂,应用催化湿式过氧化氢氧化技术处理COD为6 742 mg·L-1的兰炭废水,通过建立正交实验确定最佳实验条件,结果表明,在p H=4、过氧化氢添加量9.6 m L、反应时间150 min和反应温度80℃条件下,兰炭废水COD去除率达66.30%。对催化氧化后的废水进行GC-MS分析,确定最终氧化产物主要为乙酸。表明自制Fe/Al_2O_3催化剂具有优良的催化效果,并使大分子难降解有机污染物分解为易生化的小分子污染物,甚至被完全分解矿化。     

微波诱导Fe3O4/AC催化氧化降解邻苯二甲酸二甲酯

为了有效地提高活性炭在微波场中的催化活性和分离性,采用化学共沉淀法制备了磁性四氧化三铁/活性炭（Fe₃O₄/AC）催化剂,并结合微波辐射技术用于催化氧化降解水中邻苯二甲酸二甲酯（DMP）。利用BET、扫描电镜/能谱（SEM/EDS）、X射线衍射（XRD）、X射线光电子能谱（XPS）、红外光谱（FTIR）和振动样品磁强计（VSM）等手段对催化剂的微观结构、形貌和磁性能进行了表征。研究了不同反应体系对DMP的降解率及反应动力学的影响,探讨了催化剂用量、微波辐射功率和溶液初始pH等因素对微波诱导Fe₃O₄/AC催化氧化降解DMP的影响,考察了催化剂的重复使用性能。结果表明,所制备的铁氧化物主要以Fe₃O₄为主,并已成功负载于活性炭上。Fe₃O₄/AC具有超顺磁性,饱和磁化强度为21.2emu/g,可通过外加磁场作用快速地从溶液中分离出来。微波诱导催化反应体系对DMP的降解率大于单独吸附或单纯微波辐射反应体系,且反应速率均符合一级反应动力学。催化剂用量越多,降解率越高;微波辐射功率的增加可以提高降解效率;溶液初始pH对DMP的降解率影响非常显著,随着pH的增大,降解率明显提高。Fe₃O₄/AC具备良好的催化活性及稳定性,循环使用5次后DMP的降解率仍保持在83.5%。通过气相色谱-质谱联用仪（GC-MS）分析,推断DMP在微波诱导Fe₃O₄/AC催化体系中的降解主要包括水解、异构化、羟基化、甲酸甲酯基的脱落和苯环三取代及苯环开环等5个途径。