微波促进铬(Ⅲ)催化降解甲基橙的研究

重金属与难降解有机污染物形成复合污染物,一些重金属离子也能催化H2O2产生·OH。利用微波加热的热效应和非热效应,以甲基橙溶液为模拟偶氮染料废水,研究了微波功率、微波辐射时间、pH值、Cr（Ⅲ）和H2O2浓度等因素对甲基橙脱色率的影响。研究表明,Cr（Ⅲ）能与H2O2形成类Fenton试剂,产生·OH,在微波的促进作用下,矿化有机物的原理。1 000 mg.L^-1的甲基橙溶液,在H2O2浓度为12.0 mmol.L^-1、5 mmol.L^-1Cr^3＋溶液、pH=3、微波功率700 W下加热5 min,甲基橙脱色率达93%。     

The Role of Fe（Ⅱ） in the Contact Glow Discharge Electrolysis

In this paper, we use methyl violet as a model organic substrate in wastewater to study the effect of Fe（Ⅱ） ion on the contact glow discharge electrolysis （CGDE）. The decoloration rate and the COD （Chemical Oxygen Demand） value have been examined. It is found that the presence of Fe（Ⅱ） ion can accelerate obviously the degradation of methyl violet, because it reacts with H2O2 in the CGDE process to yield hydroxyl radical, just acting as a Fenton-like reagent. Moreover, the optimal conditions for decoloring methyl violet were obtained, by means of an orthogonal experiment, to be [Fe^2＋] =1×10^-3 mol/L, applied voltage of 700 V of and pH = 9.0.     

Recent Advances in Nanomaterial-Based Nanoplatforms for Chemodynamic Cancer Therapy

Triggered by the endogenous chemical energy in the tumor microenvironment (TME), chemodynamic therapy (CDT) as an emerging non-exogenous stimulant therapeutic modality has received increasing attention in recent years. The chemodynamic agents can convert internal hydrogen peroxide (H₂O₂) into the lethal reactive oxygen species (ROS) hydroxyl radicals (^•OH) for oncotherapy. Compared with other therapeutic modalities, CDT possesses many notable advantages, such as tumor-specific, highly selective, fewer systemic side effects, and no need for external stimulation. Nevertheless, mild acid pH, low H₂O₂ content, and overexpressed reducing substance in TME severely suppressed the CDT efficiency. With the rapid development of nanotechnology, some kinds of nanomaterials have been utilized with improved CDT efficiency. In particular, the excellent photo-, ultrasound-, magnetic-, and other stimuli-response properties of nanomaterials make it possible for combination cancer therapy of CDT with other therapeutic modalities, and it has shown superior anti-cancer activity than monotherapies. Therefore, it is necessary to summarize the application of nanomaterial-based chemodynamic cancer therapy. In this review, the various nanomaterials-based nanoplatforms for CDT and its combinational therapies are summarized and discussed, aiming to provide inspiration for the design of better-quality agents to promote the CDT development and lay the foundation for its future conversion to clinical applications.     

Fe／Ce负载型非均相类芬顿系统催化降解孔雀石绿的研究

采用溶胶-凝胶法制备Fe／Ce／改性天然沸石类芬顿催化剂并对孔雀石绿水溶液进行非均相降解研究,考察了其催化特性并研究了催化剂投加量、H2O2投加量、初始pH值、孔雀石绿溶液初始质量浓度和反应时间对孔雀石绿降解效果的影响,并对孔雀石绿降解特性进行动力学分析．结果表明：催化剂投加量3．0g／t,,H2O2的投加量为67．0mg／L,初始pH=8．0,初始孔雀石绿溶液质量浓度为150mg／L,在此条件下,室温反应30min,孔雀石绿溶液脱色率可达97．3％．孔雀石绿溶液的降解速率常数为：k=2．12×106-3．     

FeVO4 as a highly active heterogeneous Fenton-like catalyst towards the degradation of Orange II

The iron vanadate, FeVO₄, was prepared and characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM). It was found that FeVO₄ could effectively catalyze H₂O₂ to generate active hydroxyl radical OH, which was confirmed with electron spin resonance (ESR) spin-trapping technique. Therefore, it was employed as a heterogeneous Fenton-like catalyst in the present contribution, and its catalytic activity was mainly evaluated in terms of the degradation efficiency of Orange II. Compared with the conventional heterogeneous Fenton-like catalysts, α-Fe₂O₃, Fe₃O₄ and γ-FeOOH, FeVO₄ possessed a much higher catalytic activity. The high catalytic activity possibly involved in a special two-way Fenton-like mechanism, that is, the activation of H₂O₂ by both Fe(III) and V(V) in FeVO₄. Moreover, FeVO₄ possessed a wide applicable pH range and its catalytic activity was slightly affected by the solution pH values in the range of 3–8.     

非均相类芬顿催化剂Fe/SBA-15的制备及其催化性能的研究

采用浸渍法制备了负载型Fe/SBA-15催化剂,其与H2O2可构成非均相类芬顿催化剂,采用XRD、N2吸附-脱附分析、IR和TEM等手段对Fe/SBA-15催化剂进行表征。通过降解水中的亚甲基蓝研究催化剂的降解性能,考察催化剂中Fe含量、H2O2初始浓度和溶液初始pH等因素对亚甲基蓝降解率的影响。实验结果表明,Fe/SBA-15催化剂具有介孔结构,孔道均匀,平均孔径为5.534 nm,比表面积为483.5 m2/g;在溶液初始pH=3、H2O2初始浓度20 mmol/L、亚甲基蓝初始浓度2.5 mmol/L,Fe含量为0.9%(w)的Fe/SBA-15催化剂2 g/L、17.5℃和90 min的条件下,亚甲蓝的降解率可达到96.36%;Fe/SBA-15催化剂连续重复使用3次仍具有良好的催化性能。     

基于Fe2V4O13的MHF反应器的构建及其特性研究

近年来,在难降解有机废水的处理技术中,Fenton催化氧化法因具有设备简单、操作容易、条件温和、反应速度快和氧化彻底等特点受到了环境工作者的广泛关注。为了解决悬浮态超细粉体Fenton-like催化剂降解污染物的高效率与其分离、连续重复使用的矛盾,将膜分离和多相Fenton-like催化氧化技术进行耦合,通过液相法制备了一种新的多元多相Fenton-like催化剂Fe2V4O13,构建了一种基于这种催化剂的陶瓷膜MHF反应器。研究结果表明：基于Fe2V4O13的MHF反应器为近似全混流反应器,污染较小。该反应器在连续运行过程中膜通量和降解效率都较稳定,处理量远高于普通Fenton-like反应器。     

采用底渣灰碱-磁改性催化H2O2脱除NO

我国作为煤炭大国,燃煤电厂底渣灰的产量一直居高不下,虽然应用领域广泛但利用率却不高,为了提高其利用率,提出一种高效价廉的处理烟气中NO的新技术,达到“以废治污”的目的。采用碱磁改性的工艺制备底渣非均相类Fenton催化剂,在固定床实验平台上进行快速氧化脱除NO实验研究。通过X射线荧光光谱分析仪(XRF),X射线衍射仪(XRD),扫描电子显微镜(SEM),傅氏转换红外线光谱分析仪(FTIR)等表征方法考察碱磁改性过程对于底渣灰的化学成分、晶体结构、微观形貌及表面官能团的影响。实验研究了反应温度、H2O2溶液质量分数、NO体积分数以及是否通入SO2等反应条件对于NO脱除效率的影响,并通过电子顺磁共振技术(ESR)分析了非均相类Fenton体系脱除NO的机理。结果表明:在最佳反应条件(温度为80 ℃,H2O2为6%,NO为500×10-6,未通入SO2)下NO的脱除效率达到了86%;碱磁改性后电厂锅炉底渣中铁含量明显提升有利于催化反应的进行;晶体的种类没有发生变化但FeOX的强度升高石英的强度降低利于催化反应;底渣的表面变得更加粗糙多孔,内部FeOX明显暴露出来,增加了与H2O2的接触面积;表面有利官能团含量增多,与实验结果相符合;反应温度、H2O2溶液质量分数、NO体积分数和SO2对NO的脱除有很大的影响;·OH自由基的强氧化作用是类Fenton体系脱除NO的主要原因。     

非均相类Fenton法降解硝基苯化工废水的效能及其机制

以实验室制备的3A-Fe型分子筛为催化剂,并利用扫描电镜、能谱分析和XRD技术对催化剂进行了表征。在3A-Fe型分子筛与H₂O₂构建的非均相类Fenton催化体系内对硝基苯的降解效能和机制进行了研究,讨论了体系pH值、H₂O₂的投加量、催化剂投加量、硝基苯废水浓度对硝基苯降解率和反应速率的影响,并初步揭示了硝基苯的降解机理。结果表明：3A-Fe分子筛作为催化剂的类Fenton反应,在pH值2～10之间都具有较好的处理效果;类Fenton体系氧化降解反应过程是一种非均相的界面微观反应;3A-Fe类Fenton催化剂性能优越,对硝基苯废水中硝基苯的去除率为94.1%,COD_Cr和TOC的去除率分别为78.6%和60.5%。     

Fe/AC催化过氧化氢降解双酚A

传统Fenton反应存在对液相pH要求较高、Fe³⁺回收困难以及难以重复使用等问题。基于"活性离子固载化,酸性环境局部化"的设计思路,通过对活性炭(AC)表面酸化改性,制备得到载铁活性炭(Fe/AC)催化剂。研究了Fe/AC制备工艺与其性能之间的关系,结果表明,在载Fe³⁺量44.05 mg·g^-1、煅烧温度200℃的制备工艺下可得到催化活性较高、稳定性好的Fe/AC催化剂。用性能优良的Fe/AC催化H₂O₂降解双酚A(BPA),其较佳催化反应条件为:反应时间60 min、反应温度20℃、溶液pH值为4.0≤pH≤8.0、Fe³⁺/H₂O₂摩尔比为0.007～0.012、30% H₂O₂用量为0.04 ml H₂O₂·(mg BPA)^-1。本工作制备得到的Fe/AC催化剂具有较好的重复使用性能,在实际废水处理领域具有较大的应用前景。