Coupling mechanism of activated carbon mixed with dust for flue gas desulfurization and denitrification

To clarify the effect of coking dust, sintering dust and fly ash on the activity of activated carbon for various industrial flue gas desulfurization and denitrification, the coupling mechanism of the mixed activated carbon and dust was investigated to provide theoretical reference for the stable operation. The results show that coking dust had 34% desulfurization efficiency and 10% denitrification efficiency; correspondingly, sintering dust and fly ash had no obvious desulfurization and denitrification activities. For the mixture of activated carbon and dust, the coking dust reduced the desulfurization and denitrification efficiencies by blocking the pores of activated carbon, and its inhibiting effect on activated carbon was larger than its own desulfurization and denitrification activity. The sintering dust also reduced the desulfurization efficiency on the activated carbon while enhancing the denitrification efficiency. Fly ash blocked the pores of activated carbon and reduced its reaction activity. The reaction activity of coking dust mainly came from the surface functional groups, similar to that of activated carbon. The reaction activity of sintering dust mainly came from the oxidative property of Fe₂O₃, which oxidized NO to NO₂ and promoted the fast selectively catalytic reduction (SCR) of NO to form N₂. Sintering dust was activated by the joint action of activated carbon, and both had a coupling function. Sintering dust enhanced the adsorption and oxidation of NO, and activated carbon further promoted the reduction of NO_x by NH₃; thus, the denitrification efficiency increased by 5%-7% on the activated carbon.     

Fe2O3/TiO2负载膨胀珍珠岩光催化降解罗丹明B

为获得高效催化活性的光催化材料,研究不同煅烧氛围对材料在可见光下催化性能的影响,以膨胀珍珠岩（EP）为载体,采用溶胶-凝胶法,在不同煅烧氛围（O₂和/或NH₃）下制备Fe₂O₃/TiO₂负载EP的光催化复合材料〔Fe₂O₃-TEP（O₂）、Fe₂O₃-TEP（NH₃）、Fe₂O₃-TEP（O₂,NH₃）、Fe₂O₃-TEP（NH₃,O₂）〕,采用EDS（X-射线色散能谱）、BET（比表面积及孔径分析）、XRD（X射线衍射）、SEM（扫描电子显微镜）、XPS（X射线光电子能谱）等对复合材料进行表征,并研究了其在可见光下对罗丹明B的光催化降解效果.结果表明:①复合材料成功负载了Ti、Fe元素,负载的TiO₂以锐钛矿型存在,Fe₂O₃的掺杂增强了TiO₂对可见光的响应能力;②不同的煅烧氛围明显影响复合材料的晶粒尺寸、比表面积和光催化性能,其中,Fe₂O₃-TEP（O₂,NH₃）的光催化性能最好,4 h后罗丹明B降解率达到87.59%,Fe₂O₃-TEP（NH₃,O₂）、Fe₂O₃-TEP（O₂）和Fe₂O₃-TEP（NH₃）4 h后对罗丹明B的降解率则分别为65.02%、62.48%和47.48%;③在试验条件下,复合材料的光催化反应符合一阶反应动力学方程,Fe₂O₃-TEP（O₂,NH₃）、Fe₂O₃-TEP（NH₃,O₂）、Fe₂O₃-TEP（O₂）和Fe₂O₃-TEP（NH₃）相应的降解速率常数分别为0.008 3、0.004 3、0.004 3和0.002 7 min-1.研究显示,通过溶胶-凝胶法所制备的复合材料（Fe₂O₃-TEP）经煅烧后所得矿相均一;Fe₂O₃掺杂TiO₂可形成Ti—O—Fe键,减小TiO₂固有的禁带宽度;复合材料光催化性能也受到煅烧氛围的影响,先O₂后NH₃煅烧条件下所得材料的光催化性能最佳.      

BiOCl/SiO2/Fe3O4复合材料可见光催化去除水中亚甲基蓝

以FeCl_3·6H_2O、FeCl_2·4H_2O、(C_2H_5)_4SiO_4、Bi(NO_3)_3·5H_2O、KCl为主要原料,采用化学共沉淀法和水热法制备了BiOCl/SiO_2/Fe_3O_4光催化剂,并对其进行EDS、TEM、XRD、FT-IR、UV-Vis表征,最后通过亚甲基蓝降解实验,研究了催化剂在合成过程中pH及催化剂投加量对其光催化性能的影响.结果表明,在pH=6、催化剂初始投加量为0.5 g·L~(-1)时,对亚甲基蓝的可见光催化效果最佳,光照120 min后对10 mg·L~(-1)的亚甲基蓝溶液的脱色率达到93.2%.BiOCl/SiO_2/Fe_3O_4经过简单的无水乙醇和水洗后,可高效重复利用4次.综合表明,BiOCl/SiO_2/Fe_3O_4是一种在处理染料废水中具有应用前景的磁性光催化剂.     

冶金尘泥混合垃圾燃烧飞灰熔融重构固化重金属的研究

针对冶金固废组分复杂且难以高附加值利用的特性,结合当前垃圾燃烧飞灰重金属污染现状,通过将两者混合进行熔融固化及成分重组,研究了重金属固化及浸出毒性.结果表明:随着温度升高,固化渣出现明显结块,且燃烧过程中矿物发生重组,Zn、Cu、Pb和Cr取代硅酸盐中Ca~(2+)、Al~(3+)等离子而被固熔于网状基体中,生成了Cu_6Zn_4Al_2O_4、FeCr_2O_4、Cd_(0.75)Zn_(0.25)Fe_2O_4、Zn(AlO0.5Fe1.5)O4、MgCr0.4Fe1.6O4及Cu0.5Zn0.5Fe2O4等物质;且随着温度升高,Ca-Fe-Si-O体系形成一种耐热硅酸盐稳定相CaFe_3(SiO_4)2OH,由于其覆盖或包裹住含有重金属的晶体,从而延缓并阻止了灰渣分解及重金属的浸出,降低了重金属对环境的污染.     

含氟氯类危险废物焚烧灰渣的熔融特性研究

为了解决低熔点含氟氯类危险废物（简称＂危废＂）在回转窑焚烧炉内燃烧时,灰渣熔化导致窑内结圈的问题,实验采用氧化物分析纯（SiO2、Al2O3、CaO、Fe2O3、Al2O3）和NaCl、KCl、NaF分析纯来模拟危废炉渣组分,研究了危废焚烧炉灰渣的熔融特性,并采用神经网络预测危废灰渣的熔融温度.结果表明,SiO2、Al...     

Co-adsorption of gaseous benzene, toluene, ethylbenzene, m-xylene (BTEX) and SO2 on recyclable Fe3O4 nanoparticles at 0-101% relative humidities

We herein used Fe3O4 nanoparticles(NPs) as an adsorption interface for the concurrent removal of gaseous benzene, toluene, ethylbenzene and m-xylene(BTEX) and sulfur dioxide(SO2), at different relative humidities(RH). X-ray diffraction, Brunauer–Emmett–Teller, and transmission electron microscopy were deployed for nanoparticle surface characterization.Mono-dispersed Fe3O4(Fe2O3·Fe O) NPs synthesized with oleic acid(OA) as surfactant, and uncoated poly-dispersed Fe3O4 NPs demonstrated comparable removal efficiencies.Adsorption experiments of BTEX on NPs were measured using gas chromatography equipped with flame ionization detection, which indicated high removal efficiencies(up to(95 ± 2)%) under dry conditions. The humidity effect and competitive adsorption were investigated using toluene as a model compound. It was observed that the removal efficiencies decreased as a function of the increase in RH, yet, under our experimental conditions, we observed(40 ± 4)% toluene removal at supersaturation for Fe3O4 NPs, and toluene removal of(83 ± 4)% to(59 ± 6)%, for OA-Fe3O4 NPs. In the presence of SO2, the toluene uptake was reduced under dry conditions to(89 ± 2)% and(75 ± 1)% for the uncoated and coated NPs, respectively, depicting competitive adsorption. At RH 100%,competitive adsorption reduced the removal efficiency to(27 ± 1)% for uncoated NPs whereas OA-Fe3O4 NPs exhibited moderate efficiency loss of(55 ± 2)% at supersaturation.Results point to heterogeneous water coverage on the NP surface. The magnetic property of magnetite facilitated the recovery of both types of NPs, without the loss in efficiency when recycled and reused.     

四氧化三铁/聚乙烯亚胺纳米颗粒的制备及除磷性能的研究

采用化学共沉淀法,以聚乙烯亚胺(PEI)为改性剂,制备了聚乙烯亚胺改性的纳米四氧化三铁复合材料(Fe3O4/PEI).Zeta电位、透射电镜和FTIR表征结果显示,PEI修饰提高了纳米Fe3O4在水中的分散性和稳定性,同时也增强了其表面正电荷,从而提高了Fe3O4对水中磷酸根的去除能力.在磷酸根初始浓度为50 mg·L~(-1),Fe3O4/PEI投加量为200 mg,p H=3,温度为25℃的条件下,Fe3O4/PEI对100 m L磷酸根的吸附去除率达到91%.吸附过程在3 h内达到平衡.吸附等温数据表明,该吸附过程符合Langmuir吸附等温方程,可决系数R2达到0.99,最大吸附量为29.88 mg·L~(-1).Fe3O4/PEI复合材料重复利用性好,在第5次吸附-解析后还能保持对磷酸根75%以上的吸附去除率.磷的解析效率随着p H增加而增加,在p H=13时,解析效率达到65%.     

铜在壳核结构磁性颗粒上的吸附:效能与表面性质的关系

为了揭示吸附剂的吸附效能与其组成、结构及表面性质之间的关系,本研究对两种壳核结构磁性颗粒Fe_3O_4/Mn O2与Fe-Mn/Mn O2的形貌特征、表面性质进行了系统表征,并对铜在磁性颗粒表面的吸附行为与机制进行了详细研究.表征结果表明磁核Fe_3O_4与Fe-Mn具有相似的尖晶石类晶体结构,包覆Mn O2后,晶体结构均未发生明显变化.但Mn的引入,增强了磁核与外壳间的结合作用,Fe-Mn比Fe_3O_4包覆MnO_2的量更多、更均匀,进而使Fe-Mn/Mn O2具有更高的比表面积与更低的等电点.吸附实验结果表明,Fe-Mn的最大铜吸附容量33.7 mg·g-1(pH 5.5)高于Fe_3O_4的17.5 mg·g-1(pH 5.5);包覆MnO_2以后,铜吸附性能显著增强,Fe-Mn/MnO_2最大铜吸附容量升高至58.2 mg·g-1(p H 5.5),为Fe_3O_4/MnO_2的2.6倍,且优于多数文献报道的磁性吸附剂.机制研究表明铜在Fe_3O_4/Mn O2与Fe-Mn/MnO_2的表面发生了特性吸附,形成了内层表面络合物.综上所述,磁性颗粒的吸附效能与其组成成分、形貌结构及表面性质之间具有显著的相关性.     

水合氧化铝负载的磁性核/壳结构Fe3O4@SiO2纳米颗粒对水中磷的去除及再利用

在磁铁矿纳米颗粒表面包被硅壳后再包被水合氧化铝,制备了具备核壳结构的磁性纳米颗粒除磷吸附剂(磁性氧化铝),通过XRD、TEM、VSM、BET比表面积测定进行了表征.XRD和TEM结果显示了核壳结构的存在,其饱和磁化强度达56.00 emu·g~(-1),比表面积达47.27 m~2·g~(-1).Langmuir模型计算的磷最大吸附量为12.90 mg·g~(-1),且在25℃和50℃下均保持稳定,反应快速,40min磷去除率达96%以上.磁性纳米吸附剂对磷的吸附与pH关系密切,在p H为5~9时磷去除率达90%以上.采用实际污水实验,最佳投量为1.25 kg·t~(-1).吸附-脱附-再生实验结果表明,磷吸附率随循环次数增加稍有下降,吸附的磷可以通过1 mol·L~(-1)的NaOH脱附,脱附率为90%左右,且吸附剂可以进行再生,具有反复利用和回收磷资源的潜力.     

MnFe2O4磁性纳米棒非均相Fenton催化降解水中四环素的研究

采用水热合成法成功制备出MnFe₂O₄磁性纳米棒（s-MnFe₂O₄）,并考察了商品化的Fe₃O₄、MnFe₂O₄和合成的s-MnFe₂O₄纳米棒这3种磁性纳米颗粒作为非均相Fenton催化剂降解水中四环素抗生素的性能.同时,采用X射线衍射（XRD）、透射电镜（TEM）、N₂吸附-脱附、振动样品磁强计（VSM）及X射线光电子能谱（XPS）等技术对催化剂的理化性质进行了表征.非均相Fenton催化降解四环素的结果表明,s-MnFe₂O₄具有最高的催化活性,反应180 min,四环素的去除率可以达到87.6%,TOC的去除率达到47.5%.自由基捕获试验证实了羟基自由基（·OH）是非均相Fenton氧化过程中的主要活性物种.s-MnFe₂O₄磁性纳米棒的高催化活性归因于其表面拥有较高含量的Mn³⁺和Fe²⁺物种,它们的存在能加速界面电子的转移效率,从而促进·OH的生成.合成的s-MnFe₂O₄催化剂具有良好的稳定性,循环使用6次,四环素的去除率仅从87.6%降低到80.2%,且氧化过程中活性组分的流失很少.     

Fe2O3/MIL-53(Al)催化类芬顿氧化性能及其作用机制研究

以MIL-53(Al)和铁盐为原料,采用浸渍-焙烧的方法,制备了Fe_2O_3/MIL-53(Al)类芬顿催化剂.通过扫描电子显微镜(SEM)、射透射电子显微镜(TEM)、X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)及X射线光电子能谱仪(XPS),对Fe_2O_3/MIL-53(Al)、MIL-53(Al)及Fe_2O_3 3种材料的理化性质进行了表征.以亚甲基蓝为相关材料催化类芬顿反应氧化性能的指示剂,考察了Fe_2O_3/MIL-53(Al)、MIL-53(Al)及Fe_2O_3 3种材料催化类芬顿反应的活性.探讨了Fe_2O_3/MIL-53(Al)催化活性强化的相关作用机制.研究结果表明,Fe_2O_3/MIL-53(Al)的物化结构特征是以赤铁矿为主的纳米Fe_2O_3颗粒均匀、离散地分布在MIL-53(Al)之上,纳米Fe_2O_3颗粒尺寸大多集中在1～5 nm.与未负载纳米Fe_2O_3相比,其分散性和颗粒尺寸都展现出潜在优越性.Fe_2O_3/MIL-53(Al)材料催化类芬顿反应降解水溶液中亚甲基蓝的效果是未负载纳米Fe_2O_3的4.8倍(以反应速率常数计),且TOC去除率亦有明显优势.自由基猝灭实验结果表明Fe_2O_3/MIL-53(Al)催化类芬顿降解污染物的主要活性氧类物质为羟基自由基.MIL-53(Al)孔结构发达、孔分布均匀及孔尺寸较小且均一等结构特征,导致负载其中的Fe_2O_3具有孔道负载量大、颗粒分布离散且均匀、颗粒粒径小且均一等特点,从而强化了纳米Fe_2O_3催化类芬顿反应氧化降解水中污染物的性能.     

Fe3O4@SiO2-Chitosan的制备及其对水中Cu2+的吸附效能研究

以SiO_2包覆Fe_3O_4,戊二醛为交联剂,交联壳聚糖(Chitosan, CTS),制得Fe_3O_4@SiO_2-Chitosan复合磁性纳米粒子.以Fe_3O_4和Fe_3O_4@SiO_2为对照,采用X射线衍射、透射电镜和傅立叶红外光谱对其进行表征分析,并测定了投加量、pH值、吸附时间和温度等因素对Cu~(2+)吸附效果的影响,从动力学、热力学以及再生回用性能评价等方面对其吸附性能进行了探究.结果表明Fe_3O_4@SiO_2-Chitosan对Cu~(2+)的吸附过程符合准二级吸附动力学模型和Langmuir模型,为自发、放热、优惠型的单分子层化学吸附.在pH为6.0, 298 K下达到最大吸附量154.8 mg·g~(-1),吸附解吸4次后吸附容量变化不大,说明Fe_3O_4@SiO_2-Chitosan具有较高的吸附容量,可作为处理含铜废水和回收铜的高效吸附剂.     

常规金属离子对Fe3O4磁性纳米颗粒悬浮和沉降的影响

水体中的有机质、无机盐及酸碱度是影响纳米材料迁移转化的主要因素.考察了Na~+、Mg~(2+)、Ca~(2+)、Sr~(2+)和Ba~(2+)对Fe_3O_4磁性纳米材料(Magnetic Nanoparticles,MNPs)的沉降作用.结果表明,Fe_3O_4MNPs的沉降作用是水体pH、金属离子化合价、离子强度共同影响的结果.整体上,碱土金属离子较Na~+更能加速Fe_3O_4MNPs的沉降.当pH为5.0时,浓度低于1.0 mmol·L~(-1)的Na~+、Mg~(2+)和Ca~(2+)有助于Fe_3O_4MNPs的悬浮;当浓度大于1.0 mmol·L~(-1)时,较强的离子强度促使Fe_3O_4MNPs团聚,发生沉降.当pH为9.0时,碱土金属离子较Na~+更能促使Fe_3O_4MNPs聚沉.因此,纳米颗粒在水体中的扩散和聚沉需要综合考虑金属离子种类和浓度.     

One-step preparation of a novel graphitic biochar/Cu0/Fe3O4 composite using CO2-ambiance pyrolysis to activate peroxydisulfate for dye degradation

Herein,a one-step co-pyrolysis protocol was adopted for the first time to prepare a novel pyrogenic carbon-Cu⁰/Fe₃O₄ heteroatoms (FCBC) in CO₂ ambiance to discern the roles of each component in PDS activation.During co-pyrolysis,CO₂ catalyzed formation of reducing gases by biomass which facilitated reductive transformation of Fe³⁺ and Cu²⁺ to Cu⁰ and Fe₃O₄,respectively.According to the a...     

纳米Fe3O4/CeO2-H2O2非均相类Fenton体系对3,4-二氯三氟甲苯的降解

以浸渍法制备的新型纳米Fe3O4/Ce O2为催化剂,3,4-二氯三氟甲苯(3,4-DCBTE)为目标污染物,在Fe3O4/Ce O2-H2O2非均相类Fenton体系中对目标污染物的降解进行研究,考察催化剂的催化效果和温度、p H、H2O2投加量等因素对催化剂催化效果的影响.结果表明,以纳米Fe3O4/Ce O2作为催化剂的非均相类Fenton体系对3,4-二氯三氟甲苯的处理效果极佳;随着温度的升高,纳米Fe3O4/Ce O2的催化效果不断提高;在偏酸性环境中,p H越低催化效果越好,p H=2时反应去除效率可达96.67%;随着H2O2投加量的增加,3,4-二氯三氟甲苯的降解效率先提高后降低,投加量为15 mg·L-1时去除效果最好可达99.47%;随着催化剂投加量的增加,同样出现了处理效果先升高后降低的现象,投加量为0.5 g·L-1时催化效果最好可达99.64%.在以纳米Fe3O4/Ce O2为催化剂的非均相类Fenton体系中,3,4-二氯三氟甲苯的降解符合一级反应动力学,反应所需活化能较低只需30.26 k J·mol-1.     

Effect of Al2O3 doping on the structure and performance of an Al2O3/Fe2O3 catalyst for mercury oxidation

In this study,the thermal stability of a Fe_2 O_3 catalyst for mercury oxidation was significantly improved by doping with Al_2 O_3.After 1 hr,the catalyst doped with 10 wt.% Al_2 O_3 still exhibited a mercury conversion efficiency of 70.9%,while the undoped sample even lost its catalytic activity.Doping with Al_2 O_3 retarded the collapse of the catalyst mesoporous structure during high-temperature calcination,and the doped samples maintained a higher specific surface area,smaller pore size,and narrower pore size distribution.Transmission electron microscope images revealed that after calcination at 350℃,the average size of the catalyst grains in Fe_2 O_3 was 23.4 nm;however,the corresponding values for 1%Al_2 O_3/Fe_2 O_3,3%Al_2 O_3/Fe_2 O_3,and 10%Al_2 O_3/Fe_2 O_3 were only 13.3,7.1,and 4.7 nm,respectively.Results obtained from X-ray diffraction and thermogravimetry coupled with differential scanning calorimetry confirmed that doping with Al_2 O_3 also retards the crystallization of the catalysts at high temperature,constraining catalyst grains to a smaller size.     

纳米四氧化三铁/过碳酸钠降解DDTs及降解产物

以滴滴涕(DDTs)为降解对象,采用基于纳米Fe_3O_4/过碳酸钠的新型非均相类芬顿试剂进行处理,考察了纳米Fe_3O_4投加量、过碳酸钠投加量和初始pH值对水中DDE、DDD、o,p′-DDT和p,p′-DDT4种DDTs去除率的影响.同时,采用响应面法进行多因素实验设计,利用二次多项式和逐步回归法拟合了DDTs降解率与实验条件之间的关系,并对实验条件进行了优化.结果表明,纳米Fe_3O_4和过碳酸钠单独处理对DDTs降解率的最大值均小于60%,两者联合处理可大幅度提高DDTs降解率,表明两者对于DDTs降解存在较好的协同作用,纳米Fe_3O_4/过碳酸钠体系在碱性条件下可以有效降解水样中的DDTs.在纳米Fe_3O_4投加量为8.0 g·L~(-1)、过碳酸钠投加量为1.5 g·L~(-1)、溶液初始pH值为11的条件下,DDE、DDD、o,p′-DDT和p,p′-DDT的降解率分别为95.5%、84.3%、96.8%和87.5%,与模型预测值接近.自由基猝灭实验结果表明,羟基自由基是降解过程中主要的活性物质.GC/MS检测结果表明,DDTs脱氯生成DDE和DDD,随后DDE和DDD进一步降解生成DDMU、o,p′-TDE、DDNU、DDMS及DBP等物质.     

Sulfur evolution in chemical looping combustion of coal with MnFe2O4 oxygen carrier

Chemical looping combustion （CLC） of coal has gained increasing attention as a novel combustion technology for its advantages in CO2 capture. Sulfur evolution from coal causes great harm from either the CLC operational or environmental perspective. In this research, a combined MnFe2O4 oxygen carrier （OC） was synthesized and its reaction with a typical Chinese high sulfur coal, Liuzhi （LZ） bituminous coal, was performed in a thermogravimetric analyzer （TGA）-Fourier transform infrared （FT-IR） spectrometer. Evolution of sulfur species during reaction of LZ coal with MnFeaO40C was systematically investigated through experimental means combined with thermodynamic simulation. TGA-FTIR analysis of the LZ reaction with MnFe2O4 indicated MnFe2O4 exhibited the desired superior reactivity compared to the single reference oxides Mn304 or Fe203, and SO2 produced was mainly related to oxidization of H2S by MnFe2O4. Experimental analysis of the LZ coal reaction with MnFe2O4, including X-ray diffraction and X-ray photoelectron spectroscopy analysis, verified that the main reduced counterparts of MnFe2O4 were Fe304 and MnO, in good agreement with the related thermodynamic simulation. The obtained MnO was beneficial to stabilize the reduced MnFe2O4 and avoid serious sintering, although the oxygen in MnO was not fully utilized. Meanwhile, most sulfur present in LZ coal was converted to solid MnS during LZ reaction with MnFe2O4, which was further oxidized to MnSO4. Finally, the formation of both MnS and such manganese silicates as Mn2SiO4 and MnSiO3 should be addressed to ensure the full regeneration of the reduced MnFe2O4.     

核-壳表面磁性印迹聚合物的制备及其对水中双酚A的特异性去除

采用表面印迹技术制备了核-壳结构的磁性分子印迹聚合物(Fe3O4@SiO2-MIPs),在外磁场作用下该吸附剂很容易实现固-液分离.采用X-射线衍射(XRD)、扫描电镜(SEM)和傅里叶变换红外光谱(FT-IR)对产物的结构进行了表征.通过平衡吸附实验与斯卡查德(Scatchard)分析证实了Fe3O4@SiO2-MIPs对双酚A的吸附选择性.Freundlich模型拟合吸附等温线的相关系数R2=0.995 2;准二级动力学模型很好地拟合了吸附动力学,相关系数R2达到了0.999 9.在弱酸性条件下,制备的印迹材料表现出高吸附效率和快速的吸附动力学,达到90%的去除率仅需40 min;各种离子的存在不影响双酚A的吸附率;与非印迹聚合物(Fe3O4@SiO2-NIPs)比较,Fe3O4@SiO2-MIPs对湖水中加标的双酚A表现出显著的亲和性;7次的重复使用而性能没有明显下降证明了Fe3O4@SiO2-MIPs的可重复使用性.     

纳米四氧化三铁对2,4-D的脱氯降解

采用纳米四氧化三铁(Fe3O4)降解水溶液中的2,4-二氯苯氧乙酸(2,4-D),考察了2,4-D初始浓度、纳米Fe3O4投加量、溶液pH和温度等因素对2,4-D降解率的影响.结果表明,纳米Fe3O4对2,4-D有显著的降解效果,初始浓度为10 mg/L的2,4-D, 48 h内降解率可达48%.纳米Fe3O4对2,4-D的降解是一个还原脱氯过程,反应体系中氯离子浓度随2,4-D浓度降低而升高.LC/MS分析表明,2,4-D降解的主要产物是苯酚,其他中间产物是2,4-二氯苯酚(2,4-DCP)、4-氯苯酚(4-CP)和2-氯苯酚(2-CP).溶液中2,4-D的降解符合准一级反应动力学,产物4-CP、2,4-DCP和苯酚的反应速率常数K分别为0.0043、0.0026和0.0032 h -1.环境条件对降解效率有显著影响,2,4-D初始浓度在0～10 mg/L、纳米Fe3O4投加量0～300 mg/L的范围内,2,4-D降解率随初始浓度和纳米Fe3O4投加量的增加而增大;pH对2,4-D的脱氯降解有显著影响,在pH为3.0时,纳米Fe3O4对2,4-D的还原脱氯效果最好;温度升高,可以提高脱氯反应速率.