碳酸氢盐活化的过氧化氢:一种有机废水处理的新技术（英文）

水污染问题已成为影响我国可持续发展的关键问题之一,为有效提高现有污水处理的效率及其回收利用,各种催化氧化技术受到了广泛的关注.目前发展的各类高级氧化技术在实际的应用过程中明显受到了氧化剂的利用率、催化剂的浸出、寿命及成本等问题的严重限制.因此基于新的理念、发展新的催化氧化技术仍然受到广泛的关注.最近几年,利用碳酸氢盐活化过氧化氢,应用于有机废水的降解逐渐受到环境催化领域的关注.碳酸氢盐本身是一种低毒性、广泛存在于环境及生物体系的化学物质,通过它活化过氧化氢产生过碳酸氢盐氧化剂,该氧化剂能够直接氧化有机物.同时,在各种过渡金属催化剂的存在下,通过该过碳酸氢盐可以形成氧化能力更强的各种自由基(如羟基自由基等)及高价态的过渡金属离子参与有机废水的降解.虽然传统认为碳酸盐及碳酸氢盐对高级氧化法降解有机废水不利,原因是认为它们能捕捉羟基自由基,形成氧化能力更低的碳酸根自由基.现有的研究已充分表明,较低浓度的碳酸氢盐能够加快有机废水的氧化降解,而且通常比单独使用过氧化氢效率更高,这些新的发现已明显突破了传统意义上对碳酸氢盐作用的理解.更为重要的是,在微量碳酸氢盐的存在下,其产生的微碱性环境极大地消除了负载型氧化物催化剂在废水降解过程中的金属离子流失、从而极大地延长了催化剂的寿命.该缺点是各种基于过渡金属氧化物催化剂的高级氧化技术难以广泛推广的关键性挑战,原因是随着氧化降解的进行,废水体系由于有机酸的生成而逐渐酸化,进而引发氧化物催化剂的酸溶而流失.在这点上,碳酸氢盐活化过氧化氢系统由于其天然的微碱性环境体现出了其明显的优势.本文即是在本课题组工作基础上,对该领域内国内外研究进展加以总结,以期获得国内外同行的进一步关注.综述的主要内容包括:(1)碳酸氢氧活化过氧化氢的相关知识介绍,(2)均相碳酸氢氧活化过氧化氢降解有机废水的研究进展,(3)基于金属氧化物催化剂的碳酸氢氧活化过氧化氢降解有机废水的研究进展,和(4)碳酸氢盐在其他高级氧化技术中的应用.虽然基于碳酸氢氧活化过氧化氢降解有机废水的研究还处于早期探索阶段,还有很多基础科学问题如降解机理等值得进一步探索,期望通过该综述的介绍能够让同行对碳酸氢氧活化过氧化氢降解有机废水有一个比较全面的了解,进而推动该研究方向的发展,为有机废水的催化处理提供新的机会.     

负载型铜钴氧化物协同催化 H2O2/HCO3-降解苯酚

近年来,环境污染特别是水的严重污染使其治理成为一个极具挑战性的课题.各种污染物复杂的化学成分和催化剂在处理过程中的浸出、寿命及成本等问题是导致众多氧化催化剂难以实际应用的主要原因.相对而言, H2O2是一种活性氧含量高、清洁并可在温和条件下使用的氧化剂,在各种高级氧化技术中受到广泛关注.而碳酸氢盐是一种弱碱性物质,在自然界及水体系中广泛存在,且无明显毒害.它可活化 H2O2,加快其氧化各种有机物,并在废水处理领域开始受到关注.该体系的明显优势在于处理体系始终处于微碱性环境,可以有效避免金属氧化物催化剂在处理过程中由于体系酸化而带来的催化剂流失,从而延长催化剂寿命,降低催化剂成本.
　　本文采用浸渍法制备了一种双金属铜、钴氧化物催化剂及相关的对照催化剂体系,利用碳酸氢盐活化 H2O2用于降解苯酚模拟废水.通过各种空白实验发现,负载于γ-Al2O3表面的钴、铜氧化物催化剂 CuO?Co3O4@γ-Al2O3具有最好的催化降解活性,而 CuO@γ-Al2O3, Co3O4@γ-Al2O3, CuO?Co3O4及 CuO和 Co3O4的物理混合物均表现出较差的催化性能.由此可见,在 CuO?Co3O4@γ-Al2O3催化剂中,铜、钴离子在苯酚降解过程中存在协同效应,这可能与催化剂中钴、铜金属离子的相互作用相关. X射线衍射和 X射线光电子能谱结果表明,反应前后 CuO?Co3O4@γ-Al2O3催化剂中金属的氧化状态并未发生改变,在使用过程中钴离子的浸出率可以忽略,铜离子的浸岀率也仅有0.6 ppm.荧光分析实验和自由基捕获实验表明,只有添加?O2-和?OH的捕获剂能明显抑制降解反应,因而推测该反应体系对有机物的降解是一个自由基氧化过程,起关键作用的可能是?O2-和?OH.     

负载型铜钴氧化物协同催化H_2O_2/HCO_3~–降解苯酚（英文）

近年来,环境污染特别是水的严重污染使其治理成为一个极具挑战性的课题.各种污染物复杂的化学成分和催化剂在处理过程中的浸出、寿命及成本等问题是导致众多氧化催化剂难以实际应用的主要原因.相对而言,H_2O_2是一种活性氧含量高、清洁并可在温和条件下使用的氧化剂,在各种高级氧化技术中受到广泛关注.而碳酸氢盐是一种弱碱性物质,在自然界及水体系中广泛存在,且无明显毒害.它可活化H_2O_2,加快其氧化各种有机物,并在废水处理领域开始受到关注.该体系的明显优势在于处理体系始终处于微碱性环境,可以有效避免金属氧化物催化剂在处理过程中由于体系酸化而带来的催化剂流失,从而延长催化剂寿命,降低催化剂成本.本文采用浸渍法制备了一种双金属铜、钴氧化物催化剂及相关的对照催化剂体系,利用碳酸氢盐活化H2O2用于降解苯酚模拟废水.通过各种空白实验发现,负载于γ-Al_2O_3表面的钴、铜氧化物催化剂CuO-Co_3O_4@γ-Al_2O_3具有最好的催化降解活性,而CuO@γ-Al_2O_3,Co_3O_4@γ-Al_2O_3,Cu O-Co_3O_4及CuO和Co_3O_4的物理混合物均表现出较差的催化性能.由此可见,在CuO-Co_3O_4@γ-Al_2O_3催化剂中,铜、钴离子在苯酚降解过程中存在协同效应,这可能与催化剂中钴、铜金属离子的相互作用相关.X射线衍射和X射线光电子能谱结果表明,反应前后CuO-Co_3O_4@γ-Al_2O_3催化剂中金属的氧化状态并未发生改变,在使用过程中钴离子的浸出率可以忽略,铜离子的浸岀率也仅有0.6 ppm.荧光分析实验和自由基捕获实验表明,只有添加·O_2~-和·OH的捕获剂能明显抑制降解反应,因而推测该反应体系对有机物的降解是一个自由基氧化过程,起关键作用的可能是·O_2~-和·OH.     

分子筛催化剂-亚硫酸盐体系降解水中对乙酰氨基苯酚

过渡金属诱导亚硫酸盐体系产生硫氧自由基是一种新型的高级氧化技术,比常规的高级氧化过程(基于羟基自由基等)有更优越的性能.我们对过渡金属离子活化过硫酸盐和亚硫酸盐的硫氧自由基生成链式反应过程、自由基用于氧化有机污染物的国内外研究现状进行了大致总结,并以SBA-15介孔分子筛为载体,采用浸渍法制备Co-SBA-15固相催化剂,将此固相催化剂用于活化亚硫酸钠,产生强氧化性自由基,以此来降解制药废水中典型污染物对乙酰氨基酚(APAP).通过正交试验,探讨了pH、温度、钴离子与亚硫酸根的比值(简称钴硫比)、气体含氧量等参数对污染物降解效果的影响.对催化剂进行表征,对体系中产生的自由基类型进行检测,结合实验结果和文献资料对降解产物进行了分析,探究了APAP的降解原理.     

过氧化氢生产与利用的新进展

过氧化氢既可用作环境友好的绿色氧化剂,也可用作燃料电池中的太阳能燃料,因而受到越来越多的关注.本文综述了太阳能驱动分子氧氧化水制备过氧化氢及其作为绿色氧化剂和燃料的研究进展.利用太阳能将水的e^-和4e^-氧化与分子氧的e^-还原相结合,使光催化生产过氧化氢成为可能;本文讨论了与e^-和4e^-水氧化选择性及e^-和4e^-氧还原选择性相关的催化反应控制.由于光催化e^-氧化水和e^-还原分子氧的过程都产生过氧化氢,因此该组合的催化效率较高.太阳能光驱动水氧化及分子氧还原生产过氧化氢与过氧化氢催化氧化底物相结合,在该过程中分子氧用作最环保的氧化剂.     

过渡金属基MOF材料在选择性催化还原氮氧化物中的应用

选择性催化还原(SCR)技术是目前应用最广泛的工业脱硝技术,研发具有优良活性和抗毒化性能的催化剂体系是研究学者关注的重点。过渡金属氧化物和金属有机骨架(MOF)材料因其优良的氧化还原性能在脱硝领域受到了广泛关注和研究,且研究学者发现将过渡金属氧化物与MOF材料结合能够进一步提高催化剂的脱硝活性。本文综述了近年来主要应用于NH₃-SCR反应的系列单过渡金属基MOF脱硝催化剂和复合过渡金属基MOF脱硝催化剂的研究进展,阐述了过渡金属基MOF脱硝催化剂抗水抗硫中毒性能和热稳定性的强化方法,并展望了未来过渡金属基MOF脱硝催化剂的主要研究方向:综合利用不同过渡金属氧化物的特点并结合金属氧化物间的强相互作用,制备得到具有优良脱硝活性、抗水抗硫性能和热稳定性的新型过渡金属基MOF脱硝催化剂,进一步通过实验和仿真模拟相结合制备高效过渡金属基MOF脱硝催化剂以满足工业化需求。     

基于尖晶石型铁氧体的高级氧化技术在有机废水处理中的应用

随着我国经济的快速发展和城市化进程的加快,自然水体中的有机污染问题愈加严重。基于自由基反应的高级氧化技术(AOPs)可以高效去除水环境中残留的难生物降解的有机污染物,在催化剂的作用下,高级氧化过程方能有效生成强氧化性的自由基来降解有机污染物。尖晶石型铁氧体(MFe₂O₄(M=Zn, Ni, Co, Cu, Mn))被广泛用作高级氧化过程中驱动自由基生成的催化剂,同时强磁性及高稳定性保证其容易在外加磁场的作用下实现回收和再利用。本文主要综述了基于尖晶石型铁氧体的非均相类芬顿技术、光催化技术及过硫酸盐高级氧化技术在有机废水处理方面的研究进展,着重介绍了不同铁氧体磁性纳米材料在上述3种高级氧化技术中催化降解水体中有机污染物的作用机制以及催化性能增强的途径;最后指出尖晶石型铁氧体在高级氧化技术应用中存在的一些问题,并对其后续研究方向进行展望。     

醇-胺直接脱氢及氧化脱氢偶联酰胺化反应

醇-胺(氨)直接脱氢及氧化脱氢偶联生成酰胺具有原子经济性高和对环境友好等优点,因而受到广泛关注。研究发现,一些过渡金属钌及铑配合物、负载金及银纳米粒子、氧化锰分子筛(OMS-2)以及基于铜、铁化合物的催化体系在醇-胺(氨)直接脱氢或氧化脱氢偶联生成酰胺反应中显示出优良的催化性能。本文首先介绍了PNN-钌、NHC-钌配合物、铑配合物以及负载银原子簇催化的醇-胺(氨)直接脱氢偶联生成酰胺反应的研究进展,然后对负载纳米金粒子、氧化锰分子筛(OMS-2)以及基于铜、铁化合物的催化体系催化的不同氧化剂,包括分子氧、叔丁基过氧化氢以及分子碘氧化的氧化酰胺化反应进行了总结。对各催化剂或催化体系的适用范围和优缺点进行了分析,阐述了主要催化剂或催化体系的催化机理。此外,还对无过渡金属参与的醇-胺氧化酰胺化反应体系进行概述。最后,在总结现有成果的基础上指出了该领域的发展方向。     

基于过硫酸盐活化的微界面电子转移氧化技术

基于过硫酸盐活化的高级氧化技术是当前环境领域的研究热点。然而,环境中广泛存在的基质严重地制约了这一技术的实际应用。最新研究表明,在某些催化剂的作用下,过硫酸盐能够以电子转移的非自由基机制氧化降解污染物,而催化剂主要起电子转移媒介的作用。这一技术不易受水环境中氯离子、碳酸氢根离子等常见阴离子和天然有机物的影响,对目标污染物的氧化去除具有较高的选择性。同时,实验现象初步显示这一技术有望实现污染物的降解而无须使其与氧化剂直接接触,从而能够避免氧化剂和卤素阴离子的作用。本文着重综述了常见电子媒介的类型、电子转移机制的表征方法和常见基质对电子转移过程的影响,提出了这一技术存在的问题并对其应用前景进行了展望。     

MOFs基催化剂活化过硫酸盐在废水处理中的研究进展北大核心CSCD

金属有机框架(MOFs)材料作为一种新兴的多功能材料,因其高的比表面积、可调的孔隙结构、优异的热稳定性和化学稳定性等优势,在催化活化高级氧化水处理领域引起越来越多关注。本综述聚焦于近5年MOFs基催化剂活化过硫酸盐在水处理领域的研究进展。汇总了过硫酸盐活化领域中的各类MOFs基催化剂;介绍了过硫酸盐活化中MOFs基催化剂的常用合成方法;归纳了MOFs基催化剂在活化过硫酸盐过程中的氧化机制;总结了MOFs基催化剂的常见改性方法;最后,对MOFs基催化剂活化过硫酸盐未来研究方向提出了几点建议。有助于加深对MOFs基催化剂活化过硫酸盐降解有机污染物的认识,为开发基于过硫酸盐活化的MOFs基新型非均相催化剂提供理论参考。     

Minireview: Silver-Doped Titanium Dioxide and Silver-Doped Zinc Oxide Photocatalysts

The catalytic oxidation of organic dyes using various systems has been widely reported during the past decade. Photocatalytic methods, heterogeneous processes for the degradation of dyes, are one of the best and efficient oxidation processes to treat industrial wastewater with minimal residual waste. This review describes the improvement in catalytic activity of silver-doped titanium dioxide and silver-doped zinc oxide. The degradation of dyes provides information about the catalytic performance of silver-doped metal oxide. The effects of pH, catalyst concentration, dye concentration, hydrogen peroxide, dissolved oxygen, temperature, irradiation time, and light source have been reviewed along with the degradation mechanism and reaction methodology of organic dyes.     

活性炭和H2O2存在下辉光放电等离子体降解邻苯二胺

活性炭和H2O2存在下辉光放电等离子体降解邻苯二胺;辉光放电等离子体;降解;邻苯二胺;废水处理     

Diamond electrode facilitated electrosynthesis of water and wastewater treatment oxidants

While diamond electrodes have been commonly used to generate ^?OH to treat a variety of persistent water and wastewater micropollutants, mass transfer limitations and the non-selective, short-lived nature of the ^?OH restrict the degradation to the solution at, or near, the electrode surface. However, diamond electrodes can generate oxidizing species that facilitate micropollutant degradation in the bulk water solution. These include persulfate, sulfate radicals, peroxodiphosphate, ferrate, permanganate, reactive chlorine species, hydrogen peroxide, and ozone, which have been reported during electrochemical treatment of water with diamond electrodes. Although still restricted to specialized applications, recent studies, summarized in this review, have proven the electrogeneration of these additional oxidant species to be effective. They have shown the adaptability and potential of diamond electrode-based water treatment to mitigate the presence of micropollutants in water.     

Electrochemical Treatment of Heavy Metal‐containing Wastewater with the Removal of COD and Heavy Metal Ions

The use of electricity to treat water was employed for the first time in the UK a century ago, and since then has been considered a highly reliable method for wastewater treatment. In recent years, the demand for hydrogen gas as a valuable, clean energy source has increased considerably; from this point of view, the electrolysis of wastewater can meet the demand for energy during the process of treating wastewater. In this work, wastewater containing heavy metal ions has been treated by an electrochemical method which not only decreased the chemical oxygen demand value and lowered the number of heavy metals ions but also generated hydrogen throughout the process. A series of experiments were performed under optimum conditions of selected electrode materials, pH values, supply power, and working time. The results obtained indicate that by controlling the key factors of the process, a practical method can be achieved for wastewater treatment which also produces a noticeable amount of green energy. Differential pulse voltammetry measurements were used to determine the properties of an industrial wastewater source before and after treatment, while scanning electron microscopy and energy dispersive X‐ray spectroscopy were applied to investigate the proficiency of the electrode material.     

H2O2在苯酚降解过程中的作用研究

H2O2浓度是影响苯酚降解程度的重要因素之一。实验表明，不同浓度的H2O2在苯酚降解过程中所起的主要作用也不相同。在环状有机物的降解过程中，苯酚往往作为副产物出现，因此，苯酚的降解程度也往往影响到这些环状有机物的降解程度。H2O2在光氧化、光催化氧化和光电催化氧化的条件下均能影响苯酚的降解程度。在后两种条件下，H2O2还影响到用作光催化剂的TiO2的活性。     

Analysis of formaldehyde formation in wastewater using on-fiber derivatization-solid-phase microextraction-gas chromatography-mass spectrometry

A method has been developed for the quantification of the formation of formaldehyde during the advanced oxidation treatment (AOT) of wastewater destined for reuse. This method uses solid-phase microextraction (SPME) with on-fiber derivatization followed by gas chromatography-mass spectrometry (GC-MS) analysis. Based on calculated method detection limits (MDL) and ambient background levels, the method reporting (MRL) limit for formaldehyde was set at 10 microg/L. Precision for formaldehyde using this technique resulted in 23% relative standard deviation (RSD), while the internal standard, acetone-d(6), was only 6%. This method was used to evaluate the formation of formaldehyde in bench scale UV-AOT experiments using natural organic matter (NOM) fortified reagent water and tertiary treated wastewater effluent. Results suggest that the formation of formaldehyde increases in both the reagent water and wastewater matrices with increasing UV exposure and hydrogen peroxide concentrations, with overall higher concentrations of formaldehyde in the wastewater samples. No appreciable amount of formaldehyde formation was observed when UV was applied in the absence of hydrogen peroxide in both matrices tested.     

Self‐assembly of metal–organic framework thin films containing metalloporphyrin and their photocatalytic activity under visible light

With [5,10,15,20‐tetra(4‐carboxyphenyl)porphyrin]Mn(III) and sterically controlled 2,2¢‐dimethyl‐4,4¢‐pyridine as the main raw materials, metal–organic framework thin films containing metalloporphyrin (MnPor‐MOF) with catalytically active sites were built up on functionalized quartz glass surfaces using a layer‐by‐layer self‐assembly method. Retaining active catalytic sites and having a porous reticular structure, the MnPor‐MOF films possessed remarkable photocatalytic activity for oxidative degradation of methylene blue in the presence of hydrogen peroxide under visible‐light irradiation. Most meaningfully, the MnPor‐MOF films were highly stable and simply and conveniently reusable, and are thus a potentially new organic material for photocatalytic wastewater treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

Highly Efficient Photocatalysts and Continuous‐Flow Photocatalytic Reactors for Degradation of Organic Pollutants in Wastewater

One of the most important applications for photocatalysis is engineered water treatment that photodegrades organic pollutants in wastewater at low cost. To overcome the low efficiency of batch degradation methods, continuous‐flow photocatalytic reactors have been proposed and have become the most promising method for mass water treatment. However, most commercial semiconductor photocatalysts are granular nanoparticles with low activity and a narrow active light wavelength band; this creates difficulties for direct use in continuous‐flow photocatalytic reactors. Therefore, a high‐performance photodegradation photocatalyst with proper morphology or structure is key for continuous photocatalytic degradation. Moreover, a well‐designed photocatalytic device is another important component for continuous‐flow photocatalysis and determines the efficiency of photocatalysis in practical water treatment. This review describes the basic design principles and synthesis of photocatalysts with excellent performance and special morphologies suitable for a filtering photocatalysis process. Certain promising continuous photodegradation reactors are also categorized and summarized. Additionally, selected scientific and technical problems that must be urgently solved are suggested.     

New Bacteria Bacillus nitroreducens PLC9 with Hydrogen Peroxide-Degrading Activity with High Survival Rate in Hydrogen Peroxide

Bacteria were isolated from wastewater containing highly concentrated hydrogen peroxide that had been used to clean the pure water delivery system in a semiconductor plant. One bacterium was selected for its high hydrogen peroxide degradation activity. In the presence of 1 % hydrogen peroxide, it degraded 72.5 % in 5 min. It showed 100 % viability after 6 h at 1 % hydrogen peroxide. Even at 3 % hydrogen peroxide, it survived for more than 6 h. This bacterium was named as Bacillus nitroreducens PLC9 since its 16S rRNA showed 100 % similarity with the recently reported new species B. nitroreducens. Purified catalase from B. nitroreducens PLC9 was characterized as a thermo-alkali-stable hydroperoxidase type II catalase, and it is suggested as a new type of catalase based on following: (1) it is stable over a broad pH range (pH?4–11); (2) it is consisted of homodimers with a molecular weight of 66 kDa (total molecular weight, 134 kDa); (3) its activity was not inhibited by 3-amino-1,2,4-triazole; and (4) its N-terminal sequence has never been reported before. Both B. nitroreducens PLC9 and the isolated catalase can be used for efficient degradation of hydrogen peroxide at high concentrations.