非均相Fenton催化剂用于降解染料废水的实验研究进展

对非均相Fenton催化剂用于降解染料废水的研究现状作了较为详细的总结和评述,并指出了未来的发展方向。     

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%,CODCr和TOC的去除率分别为78.6%和60.5%。     

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%。     

掺杂Fe~(3+)纳米TiO_2膜光催化降解VOCs

利用玻璃弹簧负载TiO_2膜光催化降解VOCs,以室内空气污染物甲醛、丙酮和甲苯为目标污染物,采用自制反应器,分析了初始浓度、空气湿度和气体流量对甲苯降解效果的影响,考察了三种物质混合的降解效果,对比了在相同条件下单一甲苯和VOCs中甲苯的降解效果。结果表明,气体流速5 L·min~(-1)时,甲苯的降解效率为74.6%,空气湿度为30%时,甲苯降解率为81.6%,初始浓度为0.173 mg·L~(-1)时,甲苯降解率为94%,在这三种情况下,甲苯降解效果较好;对VOCs中甲苯和单一甲苯的降解效果进行对比,发现混合气体中甲苯的降解率在反应205 min后高于单一甲苯。     

染料废水的电催化降解特性研究

采用三维电催化氧化法降解结晶紫（CV）、亚甲基蓝（MB）和罗丹明B(RhB)3种染料废水,通过紫外可见光谱和傅立叶红外光谱初步探究染料的降解特性,并拟合动力学方程。结果表明：MB的COD去除率最大,其次是CV和RhB。各染料分子的苯环、杂环、共轭体系等特征结构均可不同程度地被破坏,且RhB的分子更易被破坏。MB、RhB废水的COD质量浓度符合二级动力学方程,CV废水的COD质量浓度符合一级动力学方程,且MB的COD去除速率比RhB的更高。     

Fe/AC非均相Fenton体系降解废水中苯酚研究

采用浸渍法制备了活性炭载铁(Fe/AC)非均相Fenton催化剂,研究了铁负载量、初始pH值、反应时间和H_2O_2用量对催化剂降解模拟废水中苯酚的影响,结果表明,在苯酚废水体积为50 mL,催化剂铁负载量为7.76%, H_2O_2投加量为4 g/L, pH值为3,反应时间为120 min的条件下,苯酚的降解率约为95%。催化剂的稳定性试验表明,重复使用5次后,该催化剂对苯酚的降解率仍能达60%左右。该催化剂具有良好的活性和较强的稳定性,以及良好的实际应用前景。     

Fe~(2+)-Al~(3+)紫外催化臭氧法降解腈纶废水研究

采用Fe2+-Al3+紫外催化臭氧工艺处理生化后腈纶废水,实现废水中有机组分的有效化和矿化作用,使其达标排放。分析了金属离子和紫外光催化臭氧顺序及协同作用,考察了氨氮及有机物的COD去除率,最后通过p H转化特征和傅里叶红外光谱分析处理前后有机物的形态演化。结果表明,水力停留时间2.0 h时,Fe2+-Al3+和紫外光协同催化臭氧的氧化作用最好,COD去除率达77.4%;氨氮减少缓慢,去除率为8.87%;有机物的去除效率为60%时,BOD/COD提高到0.277,产生大量微生物可接受的小分子有机物。生化后的腈纶废水经工艺氧化后有机物转化为有机酸,溶液p H值降低。经红外光谱分析,影响生物降解性的惰性基团减弱或消失。     

降解壳聚糖与水杨醛改性衍生物对Ca~(2+)、Fe~(3+)的螯合性质

过氧化氢对壳聚糖氧化降解反应适宜条件为:温度70～80℃;pH=4～7;w(H2O2)=5%。对降解产物(CTS′)与水杨醛进行化学改性得相应衍生物S CTS′(H)、S CTS′(Na)和还原产物RS CTS′(H)、RS CTS′(Na)。在pH=10～11的水溶液中对Ca2+的螯合(吸附)能力为RS CTS′(Na)∽S CTS′(Na)>RS CTS′(H)∽S CTS′(H)。同时给出S CTS′(H)在c(HCl)=0 10mol/L的介质中对Fe3+螯合的UV吸收光谱。     

非均相Fenton技术氧化降解废水中N,N-二甲基甲酰胺

采用浸渍法制备了活性炭负载型Fe/C催化剂,并将其作为非均相Fenton催化剂处理废水中的N,N-二甲基甲酰胺(DMF)。探讨了溶液初始p H值、H2O2投加量、催化剂投加量和反应温度等因素对DMF去除率的影响。结果表明,对于DMF浓度为1 000 mg/L的废水,在初始p H值为2.5,H2O2投加量为3.0 g/L,催化剂投加量为6.0 g/L和反应温度为30℃的处理条件下,反应60 min,溶液化学需氧量(COD)的去除率可达到60%以上,且溶液中Fe离子浸出浓度仅为0.7 mg/L。该催化剂具有较好的稳定性,可回收使用,使用5次,溶液COD的去除率仍能达到45%以上。     

正交法探索皂素废水中Fe~(2+)的变化

以黄姜皂素废水为原料,以Fe⁽²⁺⁾的含量为指标,研究进水pH、过氧化氢投加量、反应时间、温度及过氧化氢投加方式对黄姜皂素废水处理效果的影响。结果表明,反应的最佳条件为:进水pH为3. 0,过氧化氢投加量8%,反应时间2 h,温度30℃,过氧化氢投加方式为分三次投加。此时,废水中Fe(2+)的含量为指标,研究进水pH、过氧化氢投加量、反应时间、温度及过氧化氢投加方式对黄姜皂素废水处理效果的影响。结果表明,反应的最佳条件为:进水pH为3. 0,过氧化氢投加量8%,反应时间2 h,温度30℃,过氧化氢投加方式为分三次投加。此时,废水中Fe⁽²⁺⁾的含量达最少值0. 541 6 mg/L。     

Fe_3O_4/三维石墨烯非均相Fenton催化降解酸性红B

采用原位氧化还原法制备了三维石墨烯负载型Fe_3O_4(Fe_3O_4/3D GN)非均相Fenton反应催化剂,对其进行了表征,并用于酸性红B染料废水的Fenton氧化降解。表征结果显示:制备的Fe_3O_4/3D GN具有相互贯通的独特三维网状结构,Fe_3O_4纳米颗粒均匀分散在石墨烯片层中。实验结果表明:Fe_3O_4/3D GN具有较高的催化活性和稳定性。Fe_3O_4/3D GN非均相Fenton催化降解酸性红B的最佳工艺条件为:H2O2投加量0.67 m L/L,催化剂投加量1 g/L,初始溶液pH为6。在此最佳工艺条件下反应30 min,酸性红B染料废水的脱色率达到95.64%。     

粉煤灰负载Fe3+非均相光催化降解苯酚研究

利用粉煤灰负载Fe3+制备异相催化剂,研究了采用该催化剂的UV/Fenton体系对苯酚的降解效果,探讨了催化剂的制备方法对催化效率和稳定性的影响,并研究了反应体系、铁负载量、H2O2投加量和初始pH对苯酚降解效率的影响,考察了催化剂的重复利用性能.研究结果表明:由浸渍法制得的Fe-Al催化剂表现出了较好的稳定性及催化性能,在pH为3,H2O2投加量为5.0mmol/L,催化剂投加质最浓度为0.2 g/L的基准反应条件下,处理500mL初始质量浓度为100 mg/L的苯酚模拟废水,60 min之内对苯酚的降解率达95%以上,并且催化剂重复利用3次后,60 min内对苯酚的降解率仍可达93%以上.     

UV／Fenton处理苯酚废水的研究

采用UV／Fenton联合体系降解苯酚模拟废水,苯酚的初始质量浓度为300mg／L,COD。的初始质量浓度为760mg／L。探讨了pH值、H202（30％）和FeSO4·7H2O投加量、反应时间等因素对苯酚和CODcr去除率的影响。结果表明,UV／Fenton联合体系降解苯酚废水的最佳工艺条件是：溶液pH值为3、H2O2投加量为2．5mL／L、FeS04·7H20投加量为0．020g／L、反应时间为90min。此时,苯酚的去除率为95％,CODcr的去除率为90％。UV／Fenton联合体系能较好地处理苯酚废水。     

Modeling dye degradation kinetic using dark- and photo-Fenton type processes

Dark- and photo-Fenton type processes, Fe²⁺/H₂O₂, Fe³⁺/H₂O₂, Fe⁰/H₂O₂, UV/Fe²⁺/H₂O₂, UV/Fe³⁺/H₂O₂ and UV/Fe⁰/H₂O₂, were applied for the treatment of model colored wastewater containing two reactive dyes, C.I. Reactive Blue 49 and C.I. Reactive Blue 137, and degradation kinetics were compared. Dye degradation was monitored by the means of UV/VIS, adsorbable organic halides (AOX) and total organic carbon (TOC) analysis, thus determining decolorization and dechlorination of triazine structure, as well as mineralization of model colored wastewater. Both dark- and photo-Fenton type processes were proven to be very efficient for color removal; ≥98% was achieved in all cases. Significant improvements in the mineralization of studied dyes were achieved by the assistance of UV light, as it was expected. It was demonstrated that the degradation kinetic of applied dyes depended on the presence of UV light, as well as type of iron catalyst and dye structure. On bases of the obtained experimental results, the mathematical models were developed describing dye degradation kinetics in all studied systems. Since UV light was used in order to enhance the efficiency of dark-Fenton type processes, mathematical model describing dye degradation by UV photolysis providing the values of quantum yields for each of the dye was developed and incorporated in model for photo-Fenton type processes. A sensitivity analysis for the evaluation of importance of each reaction used in mathematical models was also performed.     

Heterogeneous UV-Fenton catalytic degradation of dyestuff in water with hydroxyl-Fe pillared bentonite

In recent years, much attention has been focused on developing heterogeneous catalyst for Fenton or photo-Fenton process to reuse the catalyst and avoid the possible pollution caused by the metal ions in the solution. Through cation exchange reaction, hydroxyl-Fe pillared bentonite (H-Fe-P-B) was successfully prepared as a solid catalyst for UV-Fenton process. Compared with raw bentonite, the content of iron, interlamellar distance and external surface area of H-Fe-P-B increased remarkably. Heterogeneous UV-Fenton catalytic degradation of azo-dye Acid Light Yellow G (ALYG) was investigated in aqueous using UVA (365 nm) light as irradiation source. The effects of H₂O₂ concentration, catalyst dosage, initial pH and temperature on degradation of ALYG were studied in detail. The results demonstrated that the H-Fe-P-B had high catalytic activity. In optimal operation conditions, more than 98% discoloration and 65% TOC removal of 50 mg/L ALYG could be achieved after 120 min treatment. The iron leaching rates of H-Fe-P-B were all below 0.6% in multiple runs in the degradation of ALYG, which indicated that the heterogeneous catalyst had long-term stability and activity. Another advantage of this catalyst was its strong surface acidity, which made the range of pH for heterogeneous UV-Fenton system extended from 3.0 to 9.0. The results indicated that the H-Fe-P-B was a promising catalyst for heterogeneous UV-Fenton system.     

Comparison of a new immobilized Fe3+ catalyst with homogeneous Fe3+–H2O2 system for degradation of 2,4‐dinitrophenol

BACKGROUND: Heterogeneous Fenton catalysts have been used to treat various organic pollutants in an aqueous environment. The present study has investigated the degradation of 2,4‐dinitrophenol (2,4‐DNP), a priority pollutant generated by such industries as pharmaceuticals, pesticides, pigments and dyes. Degradation of 2,4‐DNP (100 mg L^?1) was studied using Fe³⁺ loaded on Al₂O₃ as a heterogeneous catalyst in the presence of H₂O₂, and the efficiency compared with the homogeneous Fe³⁺/H₂O₂ based Fenton‐like process. The effect of different parameters for both processes, such as catalyst loading, H₂O₂ concentration, initial solution pH, initial substrate concentration and temperature were investigated and the optimum operating conditions determined. RESULTS: Under optimal operating conditions of the homogeneous system ([Fe³⁺] 125 mg L^?1; [H₂O₂] 250 mg L^?1; pH 3; room temperature), 92.5% degradation was achieved in 35 min for an initial 2,4‐DNP concentration of 100 mg L^?1. In the case of immobilized Fe (Fe³⁺–Al₂O₃ catalyst), degradation improved to 98.7% under the condition 10 wt% [Fe³⁺–Al₂O₃] 1 g L^?1 catalyst loading; [H₂O₂] 250 mg L^?1; pH 3; at room temperature for the same duration. CONCLUSIONS: This study demonstrated the stability and reusability of the prepared heterogeneous catalyst. This process is a viable technique for treatment of aqueous solutions containing contaminants. Copyright © 2012 Society of Chemical Industry     

Fe3+/La3+共掺杂TiO2光电极对表面活性剂的光电催化降解

采用溶胶-凝胶法制备了Fe3+/La3+共掺杂TiO2/玻璃电极,并将其作为工作电极,以饱和甘汞电极作参比电极,金属Ag片为对电极,0.1 mol/L Na2SO4为支持电解质,建立了三电极光电催化体系,对十二烷基苯磺酸钠配制的表面活性剂废水进行降解.实验表明,Freundlich等温吸附方程能很好地描述Fe3+/La...     

GO/Fe_3O_4/ZnO的制备及其光助Fenton降解苯酚

采用水热法制备了GO/Fe_3O_4/ZnO复合材料,并用SEM、FT-IR、XRD等手段对其进行了表征。以苯酚为降解目标,探讨了GO/Fe_3O_4/ZnO复合材料用量、H_2O_2投加量、苯酚浓度和pH等因素对降解苯酚效果的影响。实验结果表明,在GO/Fe_3O_4/ZnO投加量为200 mg/L,H_2O_2投加量为12 mmol/L,pH=7.2的条件下,利用该复合材料对苯酚质量浓度为88.85 mg/L的油田污水进行光催化Fenton降解,60 min后,苯酚降解率可达98%。     

双波长分光光度法测定自来水中Fe2+和Fe3+的含量

采用双波长分光光度法测定 Fe2 和 Fe3 的方法 ,结果表明 ,在 λ1 =4 0 0 nm,λ2 =5 4 2 nm处 ,显色时间在 6 0 min～ 80 min,p H =4～ 5时能联合测定水中 Fe2 和 Fe3 ,其结果具有较高的精密度和准确度。     

LaCoO_3钙钛矿型催化剂非均相Fenton处理兰炭废水

以苯甲醇为溶剂,采用水热法制备LaCoO_3钙钛矿型催化剂,研究LaCoO_3钙钛矿型催化剂非均相Fenton处理兰炭废水的最佳工艺条件及催化机理。结果表明,在过氧化氢用量3 m L、LaCoO_3钙钛矿型催化剂用量0.2 g、pH=4和反应温度25℃条件下,LaCoO_3钙钛矿型催化剂非均相Fenton处理兰炭废水的COD去除率达到72.7%,通过自由基捕获剂叔丁醇的加入及一级动力学模型研究非均相Fenton过程机理。