Magnetic CuFe2O4 Prepared by Polymeric Precursor Method as a Reusable Heterogeneous Fenton-like Catalyst for the Efficient Removal of Methylene Blue

The heterogeneous Fenton-like catalysts based on CuFe₂O₄ were prepared by polymeric precursor method at several annealing temperatures. The obtained catalysts were respectively characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, point of zero charge measurement, and vibrating sample magnetometer. The Fenton-like catalytic activity was evaluated via the oxidation of methylene blue with H₂O₂. The results show that the CuFe₂O₄ phase content and the particle size increase with the annealing temperatures whereas the surface OH groups and the surface acidity decrease. The prepared powders possess typical ferromagnetic properties which allow them to be easily recovered and reused. These catalysts also present highly catalytic activities for the oxidation of methylene blue, which is principally attributed to the catalysis of the CuFe₂O₄ phase. When the annealing temperature increased, the catalytic performance was reduced, corresponding to the increase of particle size and the decrease of surface OH groups.     

聚苯乙烯/Fe3O4悬浮填料的制备及类芬顿处理愈创木酚模拟废水的研究

均相芬顿(Fenton)处理废水存在化学药剂投加量大、铁泥产生量多的问题,类Fenton是有效的解决途径之一。本课题以羟基修饰的纳米Fe₃O₄(Fe₃O₄-OH)和苯乙烯(St)为主要原料,利用链式加聚反应合成聚苯乙烯(PS)/Fe₃O₄悬浮填料,用于类Fenton处理愈创木酚模拟废水。分别用傅里叶变换红外光谱仪(FT-IR)、热重分析仪(TGA)、超景深显微镜、扫描电子显微镜(SEM)、X射线能谱仪(EDS)对PS/Fe₃O₄悬浮填料进行分析和表征,发现PS/Fe₃O₄悬浮填料具有Fe₃O₄-OH和PS的双层复合结构,其中Fe₃O₄的质量占比为51.6%。对比研究了PS/Fe₃O₄悬浮填料和纳米Fe₃O_4<...     

类Fenton试剂深度处理糖蜜酒精废水

采用单因素试验方法,研究了类Fenton试剂对糖蜜酒精废水深度处理的效果。研究结果表明,类Fenton试剂深度处理糖蜜酒精废水的最佳工艺参数为初始pH=6.0,FeCl3·6H2O的最佳投加量为1000g/m3、3%H2O2的最佳投加量6.7L/m3、慢速搅拌时间为5min。在此条件下,色度和COD的去除率分别为90.35%和77.28%。     

非均相类Fenton催化剂脱汞的实验与机理

采用共沉淀法分别制备Ti、Co、Cu掺杂Fe₃O₄的非均相类Fenton催化剂,在小型实验台架上进行非均相类Fenton反应脱汞的实验研究。利用X射线衍射(XRD)、扫描电子显微镜(SEM)对催化剂的晶体结构和形貌进行了表征。实验考察了掺杂前Fe₃O₄和掺杂后Fe_2.59Ti_0.41O₄、Fe_2.52Co_0.48O₄、Fe_2.44Cu_0.56O₄催化剂的类Fenton脱汞性能,并通过电子顺磁共振技术(EPR)分析了非均相类Fenton脱汞的机理。结果表明:Ti、Cu掺杂后的催化剂具有较高的催化活性, 的强氧化作用是类Fenton脱汞的主要原因。     

Si-FeOOH/H2O2类芬顿降解盐酸四环素废水的效能及其机理

采用碱沉法制备的Si-FeOOH作为非均相类芬顿催化剂,研究其催化降解盐酸四环素废水的效能,考察了催化剂投量、pH、过氧化氢加入量对盐酸四环素降解效能和反应速率的影响。实验结果表明:在催化剂投加量3.0 g·L^-1、H₂O₂投加量9.9 mmol·L^-1、pH为3、室温[(25±1)℃]的条件下,盐酸四环素降解率为90%,一级反应速率常数为0.0504 min^-1。与催化剂FeOOH相比,类芬顿催化剂Si-FeOOH性能更卓越。同时采用探针化合物正丁醇、苯醌,证明了Si-FeOOH /H₂O₂ 催化体系中的氧化活性种主要为羟基自由基(·OH)和超氧自由基(HO₂·), 并推测了其催化反应机理。     

Fe基类Fenton催化剂非均相处理造纸废水

针对传统均相Fenton法深度处理造纸废水中铁泥量大、成本较高等问题,将Fe₂O₃、Al₂O₃、SiO₂、石墨粉采用高温烧结的方式,制备Fe基类Fenton催化剂,并用于非均相Fenton处理造纸废水,可达到节省FeSO₄用量的效果。结果表明,经高温烧结制备的Fe基类Fenton催化剂具有丰富的孔隙结构,在pH值为3、催化剂投加量15 g/L、COD_Cr和H₂O₂质量比1∶0.75、反应时间90 min的条件下,造纸废水COD_Cr去除率为74.8%,且经过10次循环实验仍达70%以上,BOD₅去除率可达67%以上。     

Comparative study of catalytic ozonation and Fenton-like processes using iron-loaded rice husk ash as catalyst for the removal of methylene blue in wastewater

This study intends to compare the effectiveness of catalytic ozonation and Fenton-like processes for the decolorization of methylene blue using iron-loaded rice husk ash as catalyst. In both processes, effect of initial pH, adsorption, hydroxyl radical scavenger, and chemical oxygen demand removal was studied. The results revealed that catalytic processes were found to be pH dependent with the highest activity at pH 3.0. Unlike Fenton-like process, catalytic ozonation also found to be effective at pH 7.0. It is therefore, concluded that catalytic ozonation process is more effective than Fenton-like process near wastewater pH values.     

赤泥基非均相催化剂类Fenton催化降解金橙Ⅱ

采用糖蜜酒精废液协同H2SO4对赤泥进行酸化改性,再经高温焙烧处理,得到赤泥基非均相催化剂（SMA-CA/赤泥）,通过XRD、EDS、N2吸附脱附技术对SMA-CA/赤泥进行了表征,并将其用于金橙Ⅱ的类Fenton催化降解。表征结果显示：经酸化和焙烧,赤泥中的α-FeOOH转变为SMA-CA/赤泥中的α-Fe2O3,且酸化改性使得SMA-CA/赤泥碱含量显著降低;与未添加糖蜜酒精废液酸化改性的赤泥基非均相催化剂相比, SMA-CA/赤泥的孔径增大,大孔分布提高。实验结果表明：在初始溶液pH值为3、H2O2投加量50 mmol/L、金橙Ⅱ质量浓度40 mg/L、反应时间6 h的条件下,金橙Ⅱ去除率达到86.79%;该催化降解过程符合一级动力学模型。     

Hydroxylation of Benzene to Phenol via Hydrogen Peroxide in Hydrophilic Triethylammonium Acetate Ionic Liquid

A new Fenton-like system in a medium of hydrophilic triethylammonium type of ionic liquid(IL) was used for the hydroxylation of benzene to phenol. The triethylammonium acetate([Et<,3>NH][CH<,3>COO]) IL exhibited re- tardation performance for the decomposition of H<,2>O<,2> and protection performance for the further oxidation of phenol, thus the yield and selectivity to phenol were promoted greatly. The acidity of the system was proved to be an impor- tant factor for the selectivity to phenol. The utilization of H<,2>O<,2> and the selectivity to phenol, as well as the Turnover number(TON) of the catalyst were effectively enhanced by a benzene-[Et<,3>NH][CH<,3>COO] bi-phase system. The cata- lyst with [Et<,3>NH][CH<,3>COO] IL was recycled with stable catalytic performance.     

FENTON AND FENTON-LIKE AOPs FOR ALUM SLUDGE CONDITIONING: EFFECTIVENESS COMPARISON WITH DIFFERENT Fe2+ AND Fe3+ SALTS

Currently, organic polymers are adopted in alum sludge (aluminum-coagulated drinking water treatment sludge) conditioning. However, there are important concerns regarding the use of these polymers because of the unknown and long-term effects of the potential release of excess polymer to the surrounding environment when the sludge is landfilled. Therefore, as an initial action, this study aimed at investigating alternative chemical conditioning methods and focused mainly on exploiting Fenton (Fe²⁺/H₂O₂) and Fenton-like (Fe³⁺/H₂O₂) reagents as the conditioner. Experiments have been conducted to test the effectiveness of Fenton's reagent (containing the ferrous salts of chloride, sulfate, or oxalate), Fenton-like reagent (containing ferric salts of chloride and sulfate), and the coagulation method using FeCl₃ for alum sludge conditioning at constant hydrogen peroxide and iron salt concentrations of 125 and 20 mg/g DS (dry solids), respectively. The effectiveness on dewaterability of the alum sludge demonstrated that the maximum reduction (%) of SRF (specific resistance to filtration) and CST (capillary suction time) of 74% and 47%, respectively, can be obtained when Fenton's reagent was adopted for sludge conditioning. Such reduction of 64% for SRF and 38% for CST can be achieved when Fenton-like reagents were applied.