非均相UV/Fenton体系氧化降解愈创木酚的研究

以浸渍法制备的Fe3+/γ-Al2O3为催化剂,研究了非均相UV/Fenton体系对木素类模型物愈创木酚的处理效果,并与非均相Fenton体系作比较.实验结果表明,非均相UV/Fenton体系能够有效地降解结构稳定的木素类模型物愈创木酚.在室温、初始pH值为6.3、投加2倍理论量的H2O2和1g/L自制的催化剂(Fe3+与H2O2的摩尔比为1:31.6)、反应60min,初始质量浓度为50mg/L的条件下,愈创木酚的去除率可达到100%.非均相UV/Fenton和非均相Fenton反应90min,愈创木酚的总有机碳去除率分别为94.3%和17.2%,由此可知,紫外光与Fenton试剂存在协同效应,使体系的氧化能力明显增强.愈创木酚的矿化速率慢于去除速率,说明愈创木酚并不是立刻被降解为CO2和H2O,而是先被降解为其他小分子中间产物,最终完全矿化.     

Fenton试剂氧化降解愈创木酚的研究

以木素类模型物愈创木酚为目标化合物,在自制的圆柱形双层玻璃反应器中,考察Fenton试剂对愈创木酚的处理效果,研究了H2O2用量、Fe^2＋用量、愈创木酚溶液初始浓度及pH值、反应时间、紫外光照射等因素对愈创木酚降解的影响。实验结果表明,在室温条件下,当体系pH值为3.0时,加入2倍理论用量的H2O2,Fe^2＋与H2O2的物质的量之比为1∶50,反应60 min后,初始质量浓度50 mg/L的愈创木酚溶液的愈创木酚去除率可达85.1%;当体系中引入紫外光照射后,Fenton试剂的氧化性明显增强,反应速度显著加快,反应进行30 min后愈创木酚可完全去除。     

UV/Fenton法处理制浆造纸废水相关因子筛选

采用Fenton体系氧化-絮凝工艺深度处理制浆造纸废水,对影响氧化效果的pH值、UV辐射、TiO2催化进行了因子分析与筛选。结果表明,因子效应的显著程度顺序为pH>UV>TiO2,其中,pH、UV对废水污染负荷的降低具有显著的积极效应,而TiO2起消极作用。在筛选后的条件下,废水经UV/Fenton体系氧化-絮凝处理后,色度、COD、BOD污染负荷基本去除,达到制浆造纸工业水污染物排放标准。红外光谱分析表明:废水中木素结构被UV/Fenton氧化降解,苯环结构开裂转化为脂肪族羧酸类物质。     

Fenton氧化技术在造纸工业废水处理中的应用与发展

Fenton氧化技术是一种能有效处理难降解有机废水的新型工艺。介绍了Fe2+/H2O2体系的反应机理及影响Fenton氧化反应的因素,对Fenton氧化、Fenton氧化-混凝、吸附-Fenton氧化、UV/Fenton氧化这几种工艺在处理制浆造纸废水方面的应用进行综述,并对其在废水处理中的优势、存在问题和发展趋势进行讨论。     

蛭石类Fenton体系催化降解愈创木基木素模型物的研究

以愈创木酚作为造纸废水中主要污染物愈创木基木素的模型物,以天然蛭石作为类Fenton反应的催化剂,通过扫描电镜-X射线能谱仪、激光粒度分析仪等分析了蛭石的基本性质,考察了蛭石粒径及用量、H₂O₂用量、pH值等因素对蛭石类Fenton体系催化降解愈创木酚效果的影响。结果表明,蛭石中铁元素含量约为13.6%～20.4%;研磨后,蛭石粒径变小,比表面积增大,蛭石仍保持微观层状结构,但表面孔数量增多;在蛭石研磨10 min及其用量2.0 g/L、H₂O₂用量1.3 mmol/L、pH值为3的条件下,反应180 min后,质量浓度50 mg/L愈创木酚的去除率接近100%。     

草酸活化UV/Fenton体系均相催化氧化罗丹明B的研究

以草酸为活化剂,进行了Fenton反应催化氧化有机染料罗丹明B的研究。通过测定罗丹明B溶液吸光度的变化来测定其脱色率。考察了pH值、H 2O2浓度、Fe2＋浓度、草酸浓度等因素对罗丹明B脱色率的影响,确定了优化的反应条件,讨论了UV/Fenton/草酸体系的反应机理。结果表明：UV/Fenton/草酸体系可以提高催化降解罗丹明B的效率,在pH3-4,30%H 2O 2的加入量为0.5mL,5g/L Fe2＋的加入量2mL,150mg/L草酸的加入量为4mL的条件下,有利于染料罗丹明B的氧化,脱色率可达94%以上。     

PVA的Fenton试剂氧化降解

采用Fenton试剂对PVA浆料进行氧化降解,分析了双氧水体积分数、处理温度、时间及pH值对PVA降解率、PVA降解产物黏度及降解产物UV-Vis谱图的影响。结果表明,降解1 g/L PVA浆料的最优工艺为:双氧水0.8 mL/L,H_2O_2与Fe~(2+)物质的量之比10:1,降解温度70℃,pH值3,时间15 min。降解产物的FI-IR图谱表明,PVA降解生成了含有醛、酮基团的物质;Fenton试剂和澄清石灰水的定性判断表明降解产物中含有醛基和二氧化碳。Fenton试剂对聚丙烯酰胺浆料和玉米淀粉浆料同样具有较好的氧化降解作用。     

非均相Fenton反应处理染料废水

非均相Fenton反应能克服均相Fenton反应的诸多不足,使反应在较宽pH值范围内进行,且催化剂可反复使用.通过详细总结和评述了非均相Fenton反应处理印染废水的研究现状,包括有机载体-Fe/H2O2体系、无机载体.Fe/H2O2体系、铁氧化物/2O2和其它金属Fe/2O2等,指出r开发低成本、负载效果好的高催化活性的催化剂载体,进一步提高氧化剂催化部位的活性,以及提高氧化效率等是非均相Fenton反应的发展方向.     

Fenton和光-Fenton反应处理二次纤维制浆废水的研究

采用高效节能的Fenton和光-Fenton技术对二次纤维制浆废水的处理进行对比研究。结果表明，Fenton和光-Fenton技术处理该废水非常有效，在最佳实验条件下（Feton试剂最佳物质的量比为10：1、H2O2用量1678．75mg/L、温度为30％、Fenton和光-Fenton反应体系的最佳pH值分别为2.8和3．0），经过90min的反应。可使二次纤维制浆废水的最大吸光度降低约92％和99％，并可去除87％和95％的CODm减小Fenton试剂比可加快有机物的降解速率；增加H202用量可以增加有机物的降解程度；根据废水C0DG2值计算得到的H2O2理论投加量可以满足降解废水中有机物的需求；光照可提高最佳pH值，显著提高较高pH值体系的有机物降解速率和废水处理效果；光源和光照强度不同，有机物的降解程度不同。     

印染废水的O_3+Fenton+UV/H_2O_2组合氧化处理技术

研究废水处理氧化技术Fenton、O_3、UV/H_2O_2及其组合工艺对印染废水COD_(Cr)的处理效果。结果表明,O_3+Fenton+UV/H_2O_2组合工艺中,反应总时间2h,其中O_3氧化反应30min,Fenton反应1h,UV/H_2O_2反应时间30min。在处理1 L废水时,Fenton反应中加入30%H_2O_2 1 mL,FeSO_4·7H_2O 0.68 g,n(H_2O_2)/n(Fe~(2+))物质的量之比为4:1;UV/H_2O_2反应中,30%H_2O_2投加量为1 mL,废水的COD_(Cr)从504.2 mg/L降至48.9 mg/L,具有较好的处理效果。     

Photoassisted Fenton degradation of polystyrene

Fenton and photoassisted Fenton degradation of ordinary hydrophobic cross-linked polystyrene microspheres and sulfonated polystyrene beads (DOWEX 50WX8) have been attempted. While the Fenton process was not able to degrade these polystyrene materials, photoassisted Fenton reaction (mediated by broad-band UV irradiation from a 250 W Hg(Xe) light source) was found to be efficient in mineralizing cross-linked sulfonated polystyrene materials. The optimal loadings of the Fe(III) catalyst and the H(2)O(2) oxidant for such a photoassisted Fenton degradation were found to be 42 μmol-Fe(III) and 14.1 mmol-H(2)O(2) per gram of the sulfonated polystyrene material. The initial pH for the degradation was set at pH 2.0. This photoassisted Fenton degradation process was also able to mineralize commonly encountered polystyrene wastes. After a simple sulfonation pretreatment, a mineralization efficiency of >99% (by net polymer weight) was achieved within 250 min. The mechanism of this advanced oxidative degradation process was investigated. Sulfonate groups introduced to the surface of the treated polystyrene polymer chains were capable of rapidly binding the cationic Fe(III) catalyst, probably via a cation-exchange mechanism. Such a sorption of the photoassisted Fenton catalyst was crucial to the heterogeneous degradation process.     

Fenton/电-Fenton降解造纸废水中2,4-二氯苯酚的研究

探讨了Fenton/电-Fenton氧化法降解2,4-二氯苯酚影响因素及降解效果。结果显示:Fenton法的最佳工艺条件是pH值为2,3%H2O2投加量为2mL,FeSO4.7H2O投加量为0.30g,去除效率在80%-85%;电-Fenton法的最佳工艺条件是1mol/LNa2SO450mL,电压为5V,pH为4时处理效果最好,去除效率在90%-93%。对比分析研究的结果是Fenton法比电-Fenton法反应速率快、消耗的药品量大、产生的Fe(OH)3沉淀多、去除效果差,但是电耗低。     

Metribuzin degradation by membrane anodic Fenton treatment and its interaction with ferric ion

Metribuzin, a widely used herbicide and a frequently detected pollutant in the environment, was studied as a target compound for membrane anodic Fenton treatment (AFT), a Fenton technology with application potential for on-site treatment of pesticide wastewater. It was found that the degradation kinetics of metribuzin do not obey the AFT model, a previously developed model that fit AFT degradation kinetics of all previously investigated pesticides. The lack of fit for metribuzin data was determined to result from a weak interaction between metribuzin and the ferric ion, resulting in a significant reduction in availability of metribuzin for reaction with hydroxyl radicals during AFT, thus slowing degradation. A revised kinetic model was developed based on the original AFT model with the addition of this interaction. Results demonstrate that the new kinetic model fits metribuzin degradation data quite well at different delivery rates of Fenton reagent and at different temperatures. This weak interaction is also found to exist between ferric ion and several other triazinone/triazine herbicides during membrane AFT. The interaction intensity correlates with the electron-withdrawing/-donating property of substituents on the triazine/triazinone ring. The stronger the electron-donating ability of substituents, the stronger the interaction.     

Fenton氧化处理麦草浆E段漂白废水

采用Fenton氧化处理碱抽提段的漂白废水。实验结果表明,Fenton氧化处理能够很好地降解碱抽提段漂白废水中那些难以被生化降解的有机氯化物和酚类化合物,大部分酚类化合物的去除率超90%,CODCr去除率可达96.1%,Fenton氧化处理可有效地降低漂白废水的毒性和色度,可用于漂白废水的深度处理。Fenton氧化处理的最佳操作条件为:H2O2用量2.0g·L-1,FeSO4用量1.6g·L-1,反应pH值5.0,反应时间90min。     

超声波/光Fenton法联合处理分散玉红染料废水的研究

考察了超声波／光Fenton法联合处理分散玉红染料废水的降解情况．结果表明，超声波对光Fenton试剂处理分散玉红染料废水具有强化作用，在超声条件下，当分散玉红染料质量浓度为100mg／L、pH值为3、Fe^2＋质量浓度为10mg／L、H2O2质量浓度为400mg／L时，反应120in，COD去除率达到90％．     

酸性大红G染色废水的超声波-Fenton降解

以酸性大红G模拟印染废水作为研究对象,对超声波耦合Fenton试剂降解酸性大红G的脱色反应过程进行研究,考察了硫酸亚铁和双氧水用量、废水初始pH值对反应过程及污染物降解的影响。结果表明,当染料质量浓度为100 mg/L时,在Fe2+质量浓度为8 mg/L,H2O2质量浓度为380 mg/L,废水初始pH值为3.0的优化条件下,超声反应120 min,色度和COD去除率分别可达到93.98%和60.9%。紫外-可见光图谱显示,酸性大红G降解过程中,其共轭偶氮双键、苯环、萘环均遭到破坏。酸性大红G的脱色反应过程服从二级反应动力学。     

Advanced oxidation of caffeine in water: on-line and real-time monitoring by electrospray ionization mass spectrometry

High performance liquid chromatography (HPLC), ultraviolet spectroscopy (UV), and total organic carbon (TOC) analyses show that caffeine is quickly and completely degraded underthe oxidative conditions of the UV/H2O2,TiO2/ UV, and Fenton systems but that the organic carbon content of the solution decreases much more slowly. Continuous on-line and real-time monitoring by electrospray ionization mass (ESI-MS) and tandem mass spectrometric experiments (ESI-MS/MS) as well as high accuracy MS measurements and gas chromatography-mass spectrometry analysis show that caffeine is first oxidized to N-dimethylparabanic acid likely via initial OH insertion to the C4=C8 caffeine double bond. A second degradation intermediate, di(N-hidroxymethyl)parabanic acid, has been identified by ESI-MS and characterized by ESI-MS/MS and high accuracy mass measurements. This polar and likely relatively unstable compound, which is not detected by off-line GC-MS analysis, is likely formed via further oxidation of N-dimethylparabanic acid at both of its N-methyl groups and constitutes an unprecedented intermediate in the degradation of caffeine.