Synthesis of a Fe3O4-rGO-ZnO-catalyzed photo-Fenton system with enhanced photocatalytic performance

In this work, we designed a magnetically-separable Fe₃O₄-rGO-ZnO ternary catalyst, ZnO anchored on the surface of reduced graphene oxide (rGO)-wrapped Fe₃O₄ magnetic nanoparticles, where rGO, as an effective interlayer, can enhance the synergistic effect between ZnO and Fe₃O₄. The effects of three operational parameters, namely irradiation time, hydrogen peroxide dosage, and the catalyst dosage, on the photo-Fenton degradation of methylene blue and methyl orange were investigated. The results showed that the Fe₃O₄-rGO-ZnO had great potential for the destruction of organic compounds from wastewater using the Fenton chemical oxidation method at neutral pH. Repeatability of the photocatalytic activity after 5 cycles showed only a tiny drop in the catalytic efficiency.     

光催化-Fenton工艺处理废纸制浆废水

为有效处理废纸制浆废水,采用氙灯照射下的光催化-Fenton技术,研究不同反应器、曝气、草酸钾、H2O2投加方式和废水质量浓度对光-Fenton工艺去除废水中TOC或吸光度的影响.结果表明,提高光照强度可提高TOC去除率;添加适量的草酸钾可提高处理效果;H2O2分两次投加可取得较好的处理效果,大大减少对催化剂的需求;在处理过程中使废水暴露于空气可提高有机物的脱氯效果,但曝气对处理效果并无益处.对于TOC为185 mg/L左右的废纸制浆废水,在[H2O2]=1000 mg/L、[Fe(Ⅱ)]=100 mg/L、pH=3.0、温度为30℃的条件下,经过30 min处理,废水的TOC可去除63%以上.     

UV／Fenton法对高浓度铬黑T染料废水的脱色与矿化

采用UV／Fenton高级氧化技术对偶氮染料铬黑T模拟废水进行了光催化降解,探讨了溶液的pH值、染料浓度、[H2O2]／[Fe^2＋]以及光照强度对脱色和矿化效果的影响．结果表明：UV能够有效地提高脱色速率,在紫外光下照射1h、铬黑T初始浓度为100mg／L时,脱色率可达到95％以上,矿化率可达70％以上,因此UV／Fenton方法对于处理类似铬黑T这种深色度、含芳香烃成分（UV254）的,并且溶解有机碳含量高的偶氮染料废水,在技术上是可行的．     

Degradation of emergent contaminants by UV,UV/H2O2 and neutral photo-Fenton at pilot scale in a domestic wastewater treatment plant

This study focuses on the removal of 22 selected micropollutants in an effluent from a municipal wastewater treatment plant (MWTP) at pilot scale. A reactor of 37 L with five low pressure mercury lamps emitting at 254 nm (UV₂₅₄) was used. The 22 micropollutants include 15 pharmaceuticals, 2 X-Ray contrast medias, 1 corrosion inhibitor and 4 biocides/pesticides. Five of these 22 compounds were used as indicative substances as proposed by the Swiss Federal Office for the Environment (FOEN) (carbamazepine, diclofenac, sulfamethoxazole, benzotriazole and mecoprop).     

Multistage treatment system for raw leachate from sanitary landfill combining biological nitrification–denitrification/solar photo-Fenton/biological processes,at a scale close to industrial – Biodegradability enhancement and evolution profile of trace pollutants

A multistage treatment system, at a scale close to the industrial, was designed for the treatment of a mature raw landfill leachate, including: a) an activated sludge biological oxidation (ASBO), under aerobic and anoxic conditions; b) a solar photo-Fenton process, enhancing the bio-treated leachate biodegradability, with and without sludge removal after acidification; and c) a final polishing step, with further ASBO.     

Fenton和类Fenton反应及其在聚合物合成中的应用

Fenton法是一种高级氧化技术,具有反应快、易操作、氧化速率较高等优点,主要应用于降解废水中有毒或难降解的有机物。近年来关于Fenton及类Fenton反应的研究日益增多。综述了近年来有关Fenton及类Fenton反应泡括Photo—Fenton和光／H2O2／草酸铁络合物体系）的研究进展。一方面,介绍了Fenton、Photo—Fenton和光／H2O2／草酸铁络合物体系的反应机理及影响氧化效果的主要因素;另一方面,由于Fenton反应能产生大量氧化能力强的羟基自由基,可以作为引发剂应用到聚合物合成中。对Fenton及类Fenton反应在聚合物合成领域的应用进行了总结。最后,对Fenton及类Fenton反应在聚合物合成领域的应用前景进行了展望。     

Fenton degradation of 4-chlorophenol contaminated water promoted by solar irradiation

The degradation of 4-chlorophenol (4-CP) contaminated water by Fenton process with or without solar irradiation assistance were investigated. It was found that the COD degradation and mineralization efficiency of 4-CP were more than 90% when a 30 min treatment of solar photo-Fenton oxidation process was applied and under an optimum [H₂O₂]₀/[Fe²⁺]₀ ratio of 40, the COD degradation and mineralization efficiency increased 65% as compared to Fenton oxidation. Meanwhile, the AOS values increased from −0.33 to 2.13 in solar photo-Fenton process while no significant improvement for AOS values was found in Fenton process, implying a higher degree of oxidation for 4-CP in solar photo-Fenton process. In addition, increasing the intensity of solar irradiation seemed to be beneficial for treatment of 4-CP contaminated water. Formation of chloride ion as a result of mineralization of organically bounded chlorine was identified during the treatment of 4-CP solution. Near-stoichiometric accumulation of chlorine was observed during the degradation of 4-CP in both Fenton and solar photo-Fenton processes. However, accumulation rate of chloride ions were much faster in solar photo-Fenton process. The degradation of 4-CP was found to obey a pseudo-first-order reaction kinetics. As compared to Fenton process, the presence of solar light in photo-Fenton process increases the reaction rate by a factor of 6.5 and 15.8 for COD and TOC degradation, respectively. In other words, during the treatment of 4-CP contaminated water, solar photo-Fenton process possesses notably higher mineralization efficiency in a relatively short radiation time as compared to Fenton process, and could enhance the degradation treatment of refractory organic wastewater such as 4-CP in a cost-effective approach.     

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。     

敌百虫农药废水Photo-Fenton处理方法研究

以含敌百虫有机磷农药的溶液为研究对象,采用Photo-Fenton试剂进行氧化降解处理,使其成功转化成为无机磷(PO43-)。实验表明,在pH值=3.0,c(Fe2+)=0.72 mmol/L,c(H2O2)=3 mmol/L的酸性条件下,Photo-Fenton处理方法对敌百虫废水有机磷转化成无机磷的转化率可达70%,这可能是因为Fe3+络合物对光的吸收产生的配合基的作用以及产生羟基自由基(OH.)的速率加快。还对photo-Fenton处理有机磷农药的影响因素进行探讨。     

Synergistic effect of TiO2 and iron oxide supported on fluorocarbon films: Part 2: Long-term stability and influence of reaction parameters on photoactivated degradation of pollutants

The degradation of hydroquinone (HQ) and nalidixic acid (NA) mediated by TiO₂ and iron oxide immobilized on functionalized polyvinyl fluoride films (PVF^f–TiO₂–Fe oxide) in the presence of H₂O₂ under simulated solar light has been examined. The results show that the contribution of homogeneous photo-Fenton oxidation to the initial mineralization process was low. The degradation rates were not dependant of initial pH. Heterogeneous photocatalytic activity of PVF^f–TiO₂–Fe oxide was enhanced by increasing temperature, NaCl addition and by long-term utilization.The PVF^f–TiO₂–Fe oxide surface was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) at different states of utilization. Correlations between the catalyst surface composition and degradation kinetics are discussed. Long-term stability evaluated by repetitive pollutant degradations was outstanding. The presence of TiO₂ seems to (i) limit contact between polymer film and highly reactive radicals in the solution and (ii) act as a charge trap. Moreover, during the photocatalysis mediated by PVF^f–TiO₂–Fe oxide, some leaching of supported iron increased the amount of the top TiO₂ layer exposed to the light increasing the synergistic effects between the two oxides leading to enhanced pollutant degradation.