异相Fenton催化水污染控制

高级氧化技术(AOPs)是当前水处理研究领域的热点问题。异相Fenton催化氧化是一种极具代表性的高级氧化技术,其反应过程中产生的羟基自由基(·OH)等活性氧物种可以无选择性地攻击有机污染物,将有机大分子逐步分解为小分子物质,从而达到高效去除废水中有毒有害污染物的目的。相比均相Fenton反应,它具有pH响应范围广、不产生铁泥、催化剂可循环利用等优点。然而,由于固相催化剂的本征特性和局限性,当前所研究的异相Fenton催化剂仍存在中性条件下活性低、过氧化氢(H₂O₂)利用率低、Fe(Ⅲ)/Fe(Ⅱ)转化速率不高等问题,难以实现异相Fenton催化在环境修复领域的大规模应用。本文综述了不同活性氧物种参与的异相Fenton反应机理,总结了多种异相Fenton催化剂及其在有机污染物控制方面的应用,为继续开展异相Fenton催化水污染控制研究提供参考。     

非贵金属催化电极Ni/C@CF的制备及绿色类Fenton性能

传统芬顿(Fenton)法利用Fe²⁺催化H₂O₂产生具有强氧化性的羟基自由基(·OH),可以高效氧化降解水中有机污染物,但其操作pH范围窄(pH≈3)和易产生铁絮凝沉淀的缺点限制了其应用发展.原子氢H*作为一种单电子供体,可以将电子快速转移到H₂O₂中,生成·OH,适用于广泛的pH值,没有铁污泥产生,是一种新型高效绿色芬顿法.然而,原子H*更易相互结合形成H₂,极不稳定,因此,探索合适的电催化剂对H*绿色Fenton的应用起着至关重要的作用.本文以炭黑作为载体,通过液相还原法制备了具有催化活性高、性能稳定的Ni/C@碳毡(Ni/C@CF)非贵金属电催化材料,制备的Ni纳米粒子均匀分散在炭黑上.以此电极材料为阴极,构建绿色Fenton催化体系,能够催化H₂O和H+生成H*,进而催化H₂O₂产生·OH,高效降解去除水中抗生素污染物.通过调节制备方法、电压、溶液pH值及外加氧化剂量,确定了该体系...     

高级氧化和可见光照射协同作用下Bi2WO6对有机污染物降解的催化活性增强(英文)

随着工业化社会的不断发展,环境问题日益严重。尤其是工业废水问题一直是催化降解领域的研究热点。光催化与高级氧化工艺(AOPs)耦合技术因为具有高效、无选择性、处理条件温和等特点,被认为是一种高效的有机污染物降解技术。本文以十六烷基三甲基溴化铵(CTAB)表面活性剂作为模板,采用简单的水热法制备了钨酸铋(Bi₂WO₆)纳米花。通过X射线衍射(XRD)、傅里叶红外光谱(FTIR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)和紫外-可见漫反射光谱(DRS)技术对其微观形貌、晶相、表面化学元素状态和光学性质进行了表征。为了研究钨酸铋(Bi₂WO₆)纳米花的催化性能,在不同催化体系下降解有机污染物罗丹明B (Rh B),实验发现,于vis/过硫酸盐(PMS)/Bi₂WO₆体系下,40 min内对Rh B的去除率高达96.39%,明显优于PMS/Bi₂WO₆ (40 min内去除率为38.7...     

基于零价铝的氧化/还原技术在水处理中的应用

利用零价金属(ZVMs)处理环境污染物一直是环境治理领域的研究热点,其中以零价铁(ZVI)的研究最为广泛。近年来,零价铝(ZVAl)因其具有比ZVI更低的氧化还原电位(E⁰(Al³⁺/Al⁰)=-1.662 V, E⁰(Fe²⁺/Fe⁰)=-0.44 V)及其两性性质(反应pH可以拓展到碱性)而开始受到关注。目前环境领域关于ZVAl的研究主要集中于两类:以零价铝/氧/酸(ZVAl/O₂/H⁺)体系为核心的氧化体系和以零价铝/无氧(ZVAl/anaerobic)体系为核心的还原体系,其中前者因原位产生过氧化氢构成类Fenton氧化体系而备受关注。研究已发现,基于ZVAl的氧化/还原技术可有效去除酚类、偶氮染料、有机卤化物等有机污染物和Cr(Ⅵ)、As(Ⅲ)等无机污染物,且超声、微波、外加多金属氧酸盐(POM)、Fe²⁺等辅助手段对该技术有一定辅助效果。本文分别就基于ZVAl的氧化体系和还原体系,对其反应机理及去除水中污染物的国内外最新研究进展进行了综述和展望,以期促进ZVAl水处理技术的发展。铝作为地壳中最丰富的金属元素,ZVAl不存在像ZVI高pH值时产生沉淀的问题,相信随着ZVAl表面氧化膜这一制约因素的逐渐解决,其在水处理领域将有更广泛的应用。     

Fenton及Photo-Fenton非均相体系降解有机污染物的研究进展

Fenton及photo-Fenton氧化法是一种有效的应用于环境污染物处理领域的高新氧化技术之一,对Fenton试剂的固定化可以减少铁离子的二次污染,提高催化能力和光利用率,及扩展pH等优势。本文综述了近年来Fenton及photo-Fenton非均相体系氧化降解有机污染物的研究状况。引用文献57篇。     

电-Fenton及类电-Fenton技术处理水中有机污染物

传统Fenton技术是一种广泛用于水体里有机污染物降解的高级氧化技术(advanced oxidation technologies, AOTs)。它利用Fenton试剂Fe²⁺与H₂O₂反应生成具有强氧化性的羟基自由基(^·OH),从而降解有机污染物。基于相似的机理,过渡金属离子(Fe²⁺、Co²⁺和Ag⁺等)也可与过硫酸盐反应生成氧化能力较强的硫酸根自由基(SO₄^·-),而被称之为类Fenton技术。传统Fenton技术存在Fe²⁺投加量多,产生的铁污泥多等缺点,因此,有学者将Fenton技术与电化学技术结合,使Fe²⁺在阴极得以持续再生,这就是广为关注的电-Fenton技术。同样地,类Fenton技术也遇到与传统Fenton技术相似的问题。借鉴电-Fenton技术的成功应用,基于硫酸根自由基的类电-Fenton技术应运而生。本文在介绍电-Fenton和类电-Fenton技术原理的基础上,概括了电-Fenton和类电-Fenton技术的主要类型及其改进方法,并就值得深入研究的问题和热点趋势进行了展望。     

基于铁化合物的异相Fenton催化氧化技术

异相Fenton催化氧化技术是一种非常有效的处理难生物降解有机污染物的方法,它可以在温和的条件下实现反应。作为均相Fenton的发展,异相Fenton具有容易分离并再利用和更宽的适用范围等优点。该文主要综述了常见的含铁物质作为异相Fenton催化剂降解有机污染物的发展,这些催化剂包括零价铁、氧化铁、羟基氧化铁、水铁矿和其他铁化合物等。全面介绍了Fenton反应的不同机理,包括自由基机理和高价铁机理。重点讨论了提高异相Fenton催化剂活性的发展,并指出催化剂的效率受其表面氧化态、比表面积、过渡金属掺杂种类和晶相等许多因素的影响。概述了提高异相Fenton催化剂催化效率的不同方法,包括减小催化剂尺寸到纳米尺度、将催化剂负载于高比表面积载体上、引入过渡金属(如Ti、Co、Mn、Cr和V)到催化剂结构中。另外,一类新颖的异相Fenton催化剂铁氧体受到特别的关注,这是由于它高的催化活性和稳定性。最后,对异相Fenton催化氧化技术的发展进行了展望。我们认为理想的异相Fenton催化剂要具有高的催化活性和H2O2利用率、良好的稳定性、宽pH应用范围和易于回收利用等特点。     

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。     

多相芬顿催化水处理技术与原理

多相芬顿催化水处理技术是一种有效的降解水中有机污染物的方法。相比均相芬顿反应,它具有可循环利用、pH响应范围宽、不产生铁泥以及易于固液分离等优点。本文主要综述了经典芬顿反应机制、多相芬顿催化反应机制以及基于传统机理所发展起来的多相芬顿/类芬顿催化剂。总结了现存多相芬顿催化体系所存在的中性条件下活性低、催化剂稳定性差以及过氧化氢利用率低等瓶颈问题。重点介绍了针对这些问题所开发出的新型多相芬顿催化体系,包括单一铜反应中心催化体系和金属双反应中心催化体系。我们认为双反应中心催化体系实际上已经突破了经典芬顿反应概念,从电子分布极化理论出发,创造性地构建出具有电子高密度中心和低密度中心,实现了过氧化氢高效选择性还原和污染物高效氧化降解,解决了经典芬顿反应在实际水处理中的技术瓶颈问题。     

零价铝/铁饱和凹凸棒复合材料活化氧化剂降解4-氯酚的研究

零价铝是高级氧化技术中极具潜力的一种非均相催化剂,然而其表面固有的致密氧化膜影响其电子传递而限制其应用.本文将一种铁饱和的商品化粘土凹凸棒(FeATP)与微米零价铝(mZVAl)球磨复合制得mZVAlFeATP复合材料,并探究其对H₂O₂、过硫酸盐及过一硫酸盐(PMS)活化降解4-氯酚(4-CP)效果. mZVAl-FeATP对PMS具有最佳活化性能,因此系统探究了mZVAl-FeATP/PMS体系的氧化性能与相关机理.结果表明,该体系在p H 3.00～9.00间均能快速降解4-CP,主要活性物质为SO₄^·-,·OH和¹O₂也参与反应. mZVAl作为电子供体,不仅还原mZVAl-FeATP表面吸附态Fe(Ⅲ)生成Fe(Ⅱ)用于活化PMS,还可促进Fe(Ⅲ)/Fe(Ⅱ)循环.除了4-CP,该体系对不同有机污染物在不同水质条件下均有着良好的氧化降解性能,具有较好的应用普适性; mZVAl-FeATP还可通过二次球磨再生恢复其催化活性.综上,该工作不仅克服了...     

Enhanced Peroxymonosulfate Activation by NixCo1-xOOH for Efficient Catalytic Oxidation of Organic Pollutants

Peroxymonosulfate(PMS) has received increasing attention as viable technology for recalcitrant organics removal from polluted waters. Although promising, alternative heterogeneous catalysts with stable structure, strong hydrophilicity, environmental friendliness and excellent catalytic performance are highly desirable to facilitate the wide industrialization of PMS. In this work, Ni doped CoOOH catalyst was employed as PMS activator. Ni dopant had a significant influence on the morphology, structure and catalytic performance of CoOOH. NiojCoo.gOOH exhibited the best catalytic performance. Reaction rate ofNio.2Coo.8OOH was 2, 4, and 4.4 times that of CoOOH, CoFe2O4 and CO3O4, respectively. Moreover, Ni。2C00.8OOH/PMS system had potential application to organic pollutants and displayed a great catalytic activity over a broader pH value(e.g., 4-10). More importantly, Ni doping accelerated the transfonnation of Co(Ⅲ) and Co(Ⅱ) and formed active species CoOH^+ and NiOH^+ which were responsible to the enhancement of PMS activation.OH, SO4^-:O2^- and 1^O2 were detected, indicating both non-radical and radical processes in the Nio.2Coo.8OOH/PMS system. These findings provide a promising alternative to mixed-metal oxyhydroxides catalysts for PMS activation, demonstrating a great potential in environmental remediation and wastewater treatment.     

CuFe2O4@GO nanocomposite as an effective and recoverable catalyst of peroxymonosulfate activation for degradation of aqueous dye pollutants

An effective and recoverable CuFe₂O₄@GO catalyst for PMS activation was synthesized and the underlying catalytic mechanism was revealed in this study.     

Co-Fe/SBA-15与过一硫酸盐联用非均相催化降解水中染料罗丹明B

由于硫酸根自由基(SO4?-)的强氧化性,基于SO4?-的高级氧化技术受到人们的高度关注.采用过渡金属活化过一硫酸盐(PMS)产生SO4?-用以分解有机物,反应体系简单,反应条件温和,且不需要额外的能量供给,因此,成为人们优先选用的方法,其中,采用高效、环境友好的非均相过渡金属催化剂活化PMS处理难降解有机物成为研究热点.本文研究了非均相CoFe/SBA-15-PMS体系对水中难降解染料罗丹明B(RhB)的降解.以SBA-15为载体, Co(NO3)2·6H2O和Fe(NO3)3·9H2O为前驱物,采用一步等体积浸渍法制备了CoFe/SBA-15,通过X射线衍射(XRD)、N2吸附-脱附、扫描电镜(SEM)、能谱(EDS)、透射电镜(TEM)和振动样品磁强计(VSM)等对其进行了表征.考察了焙烧温度、Co与Fe的负载量对CoFe/SBA-15催化性能的影响和该催化剂的重复使用性能,还考察了RhB降解动力学及催化剂CoFe/SBA-15投加量、氧化剂PMS投加量和反应物(RhB和PMS)初始浓度对其性能的影响,探讨了RhB的降解机理.结果表明：对于催化剂CoFe/SBA-15,合成焙烧后在SBA-15上负载的Fe、Co化合物主要是CoFe2O4复合物,它作为催化剂的活性中心负载在SBA-15的孔道内外.制备的焙烧温度对CoFe/SBA-15催化性能几乎无影响,但对Co浸出影响显著.与SBA-15相比,催化剂10Co9.5Fe/SBA-15-700(Co和Fe负载量分别为10 wt%和9.5 wt%,焙烧温度700 oC)的比表面积、孔体积和孔径均减小,分别为506.1 m2/g,0.669 cm3/g和7.4 nm,但仍然保持SBA-15的有序六方介孔结构.该催化剂以棒状体的聚集态存在,聚集体直径大于0.25μm,其磁化强度为8.3 emu/g,因此,可通过外磁铁容易地从水中分离.相比之下,10Co9.5Fe/SBA-15-700具有最佳的催化性能和稳定性,可使RhB的降解率达到96%以上, Co的浸出量小于32.4μg/L.在CoFe/SBA-15和PMS共存下, RhB的降解符合一级动力学方程, RhB降解速率随CoFe/SBA-15和PMS投加量的增加和初始反应物浓度的减小而提高.淬灭实验结果表明,在CoFe/SBA-15, PMS和RhB水溶液体系中,存在的主要活性自由基为SO4?-,它是由CoFe/SBA-15活化PMS产生的,对RhB的降解起决定性的作用. RhB降解过程的UV-vis结果表明, RhB的降解途径主要是蒽环打开, SO4?-优先攻击RhB的有色芳香烃环,然后RhB进一步分解为小分子有机物. CoFe/SBA-15循环使用10次仍能保持高催化活性和稳定性,在每次反应中RhB的降解率均大于84%, Co和Fe的浸出量均分别小于72.1和35μg/L. CoFe/SBA-15作为高效、环境友好的非均相催化剂可有效地活化PMS产生SO4?-降解水中RhB,具有实际应用的潜力.     

Degradation of 4-nitrophenol by electrocatalysis and advanced oxidation processes using Co3O4@C anode coupled with simultaneous CO2 reduction via SnO2/CC cathode

Herein, we prepared novel three-dimensional (3D) gear-shaped Co₃O₄@C (Co₃O₄ modified by amorphous carbon) and sheet-like SnO₂/CC (SnO₂ grow on the carbon cloth) as anode and cathode to achieve efficient removal of 4-nitrophenol (4-NP) in the presence of peroxymonosulfate (PMS) and simultaneous electrocatalytic reduction of CO₂, respectively. In this process, 4-NP was mineralized into CO₂ by the Co₃O₄@C, and the generated CO₂ was reduced into HCOOH by the sheet-like SnO₂/CC cathode. Compared with the pure Co0.5 (Co₃O₄ was prepared using 0.5 g urea) with PMS (30 mg, 0.5 g/L), the degradation efficiency of 4-NP (60 mL, 10 mg/L) increased from 74.5%–85.1% in 60 min using the Co0.5 modified by amorphous carbon (Co0.5@C). Furthermore, when the voltage of 1.0 V was added in the anodic system of Co0.5@C with PMS (30 mg, 0.5 g/L), the degradation efficiency of 4-NP increased from 85.1%–99.1% when Pt was used as cathode. In the experiments of 4-NP degradation coupled with simultaneous electrocatalytic CO₂ reduction, the degradation efficiency of 4-NP was 99.0% in the anodic system of Co0.5@C with addition of PMS (30 mg, 0.5 g/L), while the Faraday efficiency (FE) of HCOOH was 24.1 % at voltage of −1.3 V using the SnO₂/CC as cathode. The results showed that the anode of Co₃O₄ modified by amorphous carbon can markedly improve the degradation efficiency of 4-NP, while the cathode of SnO₂/CC can greatly improve the FE and selectivity of CO₂ reduction to HCOOH and the stability of cathode. Finally, the promotion mechanism was proposed to explain the degradation of organic pollutants and reduction of CO₂ into HCOOH in the process of electrocatalysis coupled with advanced oxidation processes (AOPs) and simultaneous CO₂ reduction.     

CuFe2O4@GO nanocomposite as an effective and recoverable catalyst of peroxymonosulfate activation for degradation of aqueous dye pollutants

Recently, heterogeneous activation of peroxymonosulfate (PMS) to oxidatively degrade organic pollutants has been a hotspot. In the present work, copper ferrite-graphite oxide hybrid (CuFe₂O₄@GO) was prepared and used as catalyst to activate PMS for degradation of methylene blue (MB) in aqueous solution. A high degradation efficiency (93.3%) was achieved at the experimental conditions of 20 mg/L MB, 200 mg/L CuFe₂O₄@GO, 0.8 mmol/L PMS, and 25 °C temperature. Moreover, CuFe₂O₄@GO showed an excellent reusability and stability. The effects of various operational parameters including pollutant type, solution pH, catalyst dosage, PMS dosage, pollutant concentration, temperature, natural organic matter (NOM), and inorganic anions on the catalytic degradation process were comprehensively investigated and elucidated. The further mechanistic study revealed the Cu(II)/Cu(I) redox couple on CuFe₂O₄@GO played the dominant role in PMS activation, where both hydroxyl and sulfate radicals were generated and proceeded the degradation of pollutants. In general, CuFe₂O₄@GO is a promising heterocatalyst for PMS-based advanced oxidation processes (AOPs) in wastewater treatment.     

亚微米级Cu0/Fe3O4复合物多相催化过一硫酸盐降解有机污染物

过一硫酸盐催化活化技术因其可产生强氧化性活性氧化物种,可快速氧化降解并矿化有机污染物的优异性能而备受关注.本文成功制备了亚微米级Cu0/Fe3O4复合物,发现其能多相催化过一硫酸盐产生单线态氧降解有机污染物.首先,以CuCl2·2H2O,FeCl2·4H2O和FeCl3·6H2O为铜源和铁源,水合肼为还原剂,采用水热法在180oC反应24 h制备了亚微米级磁性Cu0/Fe3O4复合物.表征结果显示,所制材料为Cu0和Fe3O4的复合物,颗粒大小约为220 nm;单一相Cu0和Fe3O4晶体粒径分别为33.8和106.2 nm,而Cu0/Fe3O4复合物中Cu0和Fe3O4晶体粒径分别减为20.8和31.9 nm.这表明Cu0和Fe3O4复合降低了Cu0和Fe3O4晶体粒径,有利于Cu0和Fe3O4的分散.BET测试结果表明,Cu0/Fe3O4复合物比表面积为4.6 m2/g,与Cu0颗粒的(4.2 m2/g)相当,但远小于Fe3O4的(15.6 m2/g).制备的Cu0/Fe3O4复合物可有效催化过一硫酸盐产生单线态氧降解罗丹明B、亚甲基蓝、金橙II、苯酚和对氯酚.当Cu0/Fe3O4复合物的用量为0.1 g/L,过一硫酸盐浓度为0.5 mmol/L和初始pH为7时,Cu0/Fe3O4复合物可在30 min内完全降解20μmol/L的罗丹明B、亚甲基蓝、金橙II以及0.1 mmol/L的苯酚和对氯酚.对比试验显示,在相同条件下,Cu0和Fe3O4颗粒分别可以降解28%和20%的罗丹明B.这表明Cu0/Fe3O4复合物中的Cu0和Fe3O4晶体在催化过一硫酸盐降解污染物的反应中具有协同作用,这主要来源于Cu0/Fe3O4复合物中Cu0和Fe3O4的晶体粒径变小和更好的分散.采用分光光度法测定了降解反应液中铜和铁离子的溶出量.当Cu0/Fe3O4复合物的用量为0.1 g/L,过一硫酸盐浓度为0.5 mmol/L和初始pH为7时,反应60 min后,降解液中铜和铁离子的浓度分别为0.22和0.1 mg/L,仅占复合物中总铜和总铁量的1.1%和0.2%,表明Cu0/Fe3O4复合物具有较强的化学稳定性.所制Cu0/Fe3O4复合物具有超顺磁性,借助磁场实现快速分离回收,可循环利用五次,表明其优越的催化稳定性.通过加入乙醇和叠氮化钠,考察了Cu0/Fe3O4复合物催化活化过一硫酸盐体系中的活性氧化物种.发现100 mmol/L乙醇的加入对污染物的降解无明显影响,而加入同等量的叠氮化钠可完全抑制污染物的降解,表明Cu0/Fe3O4复合物催化活化过一硫酸盐产生的主要活性氧物种为单线态氧.采用电子顺磁共振谱进一步证实了单线态氧的生成.基于以上研究,Cu0/Fe3O4复合物催化活化过一硫酸盐的机理为Cu0/Fe3O4作为一个电子媒介加速过一硫酸盐和污染物之间的电子转移,从而导致污染物被快速降解.该反应机理不同于常见的金属催化过一硫酸盐产生硫酸根和羟自由基的反应机理.我们推测,电导性优良的Cu0在此催化反应中起着关键性作用.本催化方法可作为一种绿色的氧化技术用于环境污染物的氧化降解处理.     

Surface sulfur vacancies enhanced electron transfer over Co-ZnS quantum dots for efficient degradation of plasticizer micropollutants by peroxymonosulfate activation

Peroxymonosulfate (PMS) activation in heterogeneous processes is a promising water treatment technology. Nevertheless, the high energy consumption and low efficiency during the reaction are ineluctable, due to electron cycling rate limitation. Herein, a new strategy is proposed based on a quantum dots (QDs)/PMS system. Co-ZnS QDs are synthesized by a water phase coprecipitation method. The inequivalent lattice-doping of Co for Zn leads to the generation of surface sulfur vacancies (SVs), which modulates the surface of the catalyst to form an electronic nonequilibrium surface. Astonishingly, the plasticizer micropollutants can be completely degraded within only tens of seconds in the Co-ZnS QDs/PMS system due to this type of surface modulation. The interfacial reaction mechanism is revealed that pollutants tend to be adsorbed on the cobalt metal sites as the electron donors, where the internal electrons of pollutants are captured by the metal species and transferred to the surface SVs. Meanwhile, PMS adsorbed on the SVs is reduced to radicals by capturing electrons, achieving effective electron recovery. Dissolved oxygen (DO) molecules are also easily attracted to catalyst defects and are reduced to O₂^??, further promoting the degradation of pollutants.     

The electrochemical advanced oxidation processes coupling of oxidants for organic pollutants degradation: A mini-review

In this mini-review, the homogeneous and heterogeneous EAOPs-oxidant processes were summarized. The reaction mechanisms of different EAOPs combined with different oxidants are elucidated in detail, as well as the synergistic effect for improving the treatment efficiency.     

Combustion synthesis of mesoporous CoAl2O4 for peroxymonosulfate activation to degrade organic pollutants

A mesoporous cobalt aluminate (CoAl₂O₄) spinel is synthesized through a combustion method and adopted for the activation of peroxymonosulfate (PMS) to degrade organic pollutants. Multiple characterization procedures are conducted to investigate the morphology and physicochemical properties of the CoAl₂O₄ spinel. Due to its mesoporous structure, large surface area, and high electrical conductivity, the obtained CoAl₂O₄ exhibits remarkable catalytic activity for Rhodamine B (RhB) degradation. Its RhB degradation rate is 89.0 and 10.5 times greater than those of Co₃O₄ and CoAl₂O₄ spinel prepared by a precipitation method, respectively. Moreover, the mesoporous CoAl₂O₄ spinel demonstrates a broad operating pH range and excellent recyclability. The influence of several parameters (catalyst amount, PMS concentration, initial pH, and coexisting inorganic anions) on the oxidation of RhB is evaluated. Through quenching tests and electron paramagnetic resonance experiments, sulfate radicals are identified as the predominant reactive species in RhB degradation. This paper provides new insights for the development of efficient, stable, and reusable cobalt-based heterogeneous catalysts and promotes the application of persulfate activation technology for the treatment of refractory organic wastewater.     

CATALYTIC WET PEROXIDE OXIDATION OF HYDROQUINONE WITH Co（II）/ACTIVE CARBON CATALYST LOADED IN STATIC BED

Catalysts based on Co（II） supported on active carbon were prepared and loaded in static bed. The hydroquinone would be degraded completely after treated by Catalytic wet peroxide oxidation method with Co（II）/active carbon catalyst. After activate treatment, the active carbon was immerged in cobaltous nitrate solution, then put into a drying oven, Co（II） could be loaded on the micro-surface of carbon. Taking the static bed as the equipment, the absorption of active carbon and catalysis of Co（II） was used to reduce activation energy of hydroquinone. Thus hydroquinone could be drastically degraded and the effluent can be drained under the standard. Referring to Fenton reaction mechanism, experiment had been done to study the heterogeneous catalyzed oxidation mechanism of Co（II）. The degradation rate of hydroquinone effluent could be achieved to 92% when treated in four columns at H2O2 concentration 10%, reaction temperature 40 ℃, pH 5 and reaction time 2.5h.