Comparison of fenton and photo-fenton processes for livestock wastewater treatment

In this study, the photochemical degradation of livestock wastewater was carried out by the Fenton and Photo-Fenton processes. The effects of pH, reaction time, the molar ratio of Fe(2 +)/H(2)O(2), and the Fe(2 +) dose were studied. The optimal conditions for the Fenton and Photo-Fenton processes were found to be at a pH of 4 and 5, an Fe(2 +) dose of 0.066 M and 0.01 M, a concentration of hydrogen peroxide of 0.2 M and 0.1 M, and a molar ratio (Fe(2 +)/H(2)O(2)) of 0.33 and 0.1, respectively. The optimal reaction times in the Fenton and Photo-Fenton processes were 60 min and 80 min, respectively. Under the optimal conditions of the Fenton and Photo-Fenton processes, the chemical oxygen demand (COD), color, and fecal coliform removal efficiencies were approximately 70--79, 70--85 and 96.0--99.4%, respectively.     

Fenton法处理垃圾渗滤液MBR-NF浓缩液

采用Fenton法处理MBR-NF浓缩液,考察了FeSO4·7H2O投加量、n(H2O2)/n(Fe2+)投加比、初始pH对渗滤液MBR-NF浓缩液处理效果的影响,并在最佳实验条件下,探讨浓缩液富里酸(FA)、亲水性有机物(HyI)组分在Fenton氧化前后组成的变化。研究结果表明,在FeSO4·7H2O投加量为0.055 mol/L、n(H2O2)/n(Fe2+)投加比为4、初始pH为7.58时,对COD、腐植酸(UV254)、色度(CN)的去除率分别为79.6%、93.7%和97.8%。Fenton氧化后,浓缩液中有机物组分含量发生了较大变化,腐植酸含量下降,HyI成为渗滤液溶解性有机物主要成分。紫外-可见光谱表明,Fenton法对FA去除效果较好,而对HyI氧化效果较差;傅立叶红外光谱显示,经Fenton氧化后,FA的结构发生了明显变化,而HyI则变化不明显。     

Fenton氧化法深度处理抗生素废水二级出水

采用Fenton氧化法对青霉素和土霉素混合废水二级处理出水进行深度处理,通过正交和单因素实验研究了废水初始反应pH值、H2O2投加量、Fe2+/H2O2摩尔比及反应时间等因素对废水处理效果的影响。实验结果表明,Fenton氧化法处理的最佳反应条件为:初始pH值4、H2O2(30%)投加量50 mL/L、Fe2+/H2O2摩尔比1/20和反应时间60 min,处理后出水COD小于120 mg/L,COD去除率在75%以上,急性毒性(HgCl2毒性当量)小于0.07 mg/L,满足《发酵类制药工业水污染物排放标准》(GB21903-2008)表2标准要求。     

Fe(III)–EDDS complex in Fenton and photo-Fenton processes: from the radical formation to the degradation of a target compound

The present work compares the efficiency of homogenous Fenton and photo-Fenton processes in the presence of Fe(III)–EDDS complex under different experimental conditions. 4-tert-Butylphenol (4-t-BP), which is one of the endocrine disrupting chemicals, was used as a model pollutant to investigate the Fenton and photo-Fenton application. The efficiency of homogenous photo-Fenton process was significantly much higher than homogenous Fenton process, which is due to the rapid formation of Fe²⁺ under UV irradiation of the iron complex and the photochemical formation of HO^? from the photolysis of the complex Fe(III)–EDDS. Through the degradation of 4-t-BP, the effect of Fe(III)–EDDS concentration, H₂O₂ concentration, pH, and oxygen was investigated in both processes. Such trend was also correlated with pH calculating the polychromatic Fe²⁺ quantum yield formation at pH 4.0, 6.0, and 8.6. The results showed that at high Fe(III)–EDDS and H₂O₂ concentrations, a negative effect was found. By the way, the Fenton process was found to be enhanced at basic pH. These results can be very useful for the use and optimization of such iron complex in water treatment process as function of different physico-chemical conditions.     

Fenton氧化法对磺胺类抗生素的降解动力学

采用Fenton氧化法同时降解水溶液中磺胺吡啶(SPY)、磺胺二甲基嘧啶(SMZ)和磺胺甲噁唑(SMX)。系统考查了初始H2O2浓度、Fe2+浓度、pH对3种磺胺类抗生素降解性能的影响。结果表明,3种磺胺抗生素被完全降解的最佳Fenton氧化条件是:H2O2浓度为2.0 mmol/L,Fe2+浓度为0.10 mmol/L,pH为3.0~3.5,反应时间为20 min。Fenton试剂对3种磺胺类抗生素的降解符合一级反应动力学,速度常数为0.0318~0.2002 min-1。     

微波-Fenton对沼液中抗生素和激素的高级氧化

采用微波强化Fenton氧化处理系统,研究H2O2浓度、Fe2+浓度、初始pH、微波辐射时间和微波辐射功率对沼液中喹乙醇、土霉素、四环素及金霉素降解效果的影响.结果发现,采用微波强化Fenton氧化降解沼液中抗生素与激素的最优条件是:H2O2浓度为40 mg/L、Fe2+浓度为12 mg/L、初始pH为4、微波辐射时间为2 min、微波辐射功率为中火(445W),沼液中喹乙醇、土霉素、四环素、金霉素和COD的去除率分别达到67％、93％、91％、88％和46％.在水浴条件下,与单独微波辐射和单独Fenton相比,微波强化Fenton氧化有明显的优越性.     

含吡啶有机废水物化预处理工艺

对含吡啶有机废水进行分类收集,分质处理,确定了蒸发脱盐-微电解-芬顿氧化预处理工艺路线。实验表明,蒸发脱盐阶段,pH值为5时,COD去除率达62.77%;微电解阶段,pH值为4、反应时间为2.5 h时,COD去除率达24.49%;Fenton试剂氧化阶段,pH值为4,30%H2O2投加量为3.5 ml/L,Fe2+与H2O2摩尔比为1∶20,反应时间为2.5 h时,COD去除率达30.41%。经预处理,废水B/C比从0.075上升至0.48,3种特征吡啶的去除率均达到95%以上。     

Fenton-超声联合处理金刚烷胺制药废水

近年来,流感常用药盐酸金刚烷胺的产量不断增大,然而,其生产过程中产生的废水由于得不到有效处理,引起较大污染。以盐酸金刚烷胺生产过程中产生的胺化废水和溴化废水为原水,利用Fenton-超声联合工艺进行处理,主要研究反应时间、初始pH、H2O2投加量和H2O2/Fe2+的投加比和声能密度等操作条件对于金刚烷胺制药废水处理效果的影响。实验结果表明,优化处理条件下,Fenton-超声联合工艺对金刚烷胺制药废水中TOC去除效果最高达到65.6%。超声和Fenton的联合产生了良好的协同效果,Fenton-超声联合工艺对金刚烷胺制药废水的处理效果比单独超声和单独Fenton处理效果之和高18%,大大提高了废水中有机物的去除效果。     

Fenton氧化法深度处理甲醛废水

采用Fenton氧化法深度处理经生化降解后的甲醛废水,结果表明,Fenton氧化法深度处理甲醛废水是可行的,在合适的反应条件下,降解初始COD为150 mg/L左右的甲醛废水,COD去除率达30%以上;Fe2+与H2O2的投加比例、投加量及投加方式、反应温度、pH、反应时间对处理效果都有不同程度的影响。     

Parathion degradation and its intermediate formation by Fenton process in neutral environment

The purpose of this study is to investigate parathion degradation by Fenton process in neutral environment. The initial parathion concentration for all the degradation experiments was 20 ppm. For hydrogen ion effect on Fenton degradation, the pH varied from 2 to 8 at the [H₂O₂] to [Fe²⁺] ratio of 2-2 mM, and the result showed pH 3 as the most effective environment for parathion degradation by Fenton process. Apparent degradation was also observed at pH 7. The subsequent analysis for parathion degradation was conducted at pH 7 because most environmental parathion exists in the neutral environment. Comparing the parathion degradation results at various Fenton dosages revealed that at Fe²⁺ concentrations of 0.5, 1.0 and 1.5 mM, the Fenton reagent ratio ([H₂O₂]/[Fe²⁺]) for best-removing performance were found as 4, 3, and 2, resulting in the removal efficiencies of 19%, 48% and 36%, respectively. Further increase in Fe²⁺ concentration did not cause any increase of the optimum Fenton reagent ratio for the best parathion removal. The result from LC-MS also indicated that hydroxyl radicals might attack the PS double bond, the single bonds connecting nitro-group, nitrophenol, or the single bond within ethyl groups of parathion molecules forming paraoxons, nitrophenols, nitrate/nitrite, thiophosphates, and other smaller molecules. Lastly, the parathion degradation by Fenton process at the presence of humic acids was investigated, and the results showed that the presence of 10 mg L⁻¹ of humic acids in the aqueous solution enhanced the parathion removal by Fenton process twice as much as that without the presence of humic acids.     

Fenton氧化降解垃圾渗滤液中COD的动力学研究

对絮凝预处理后的垃圾渗滤液进行Fenton氧化处理。通过微分法对Fenton氧化的反应级数进行求解,确定其反应级数为2,并初步建立了Fenton氧化的动力学模型,即1/c=1/c0+kt,由此建立起来的降解的动力学模型与实验数据相吻合;在4个实验基准条件下———初始COD浓度为960 mg/L、pH值4、H2O2投加量0.4 mol/L、nH2O2/nFe2+3∶1,探讨了其中某一变量对反应速率的影响。实验水样为絮凝反应出水,进水COD浓度为912～960 mg/L,出水COD浓度为80～112 mg/L,COD去除率在87%～92%之间,表明Fenton试剂能够有效地处理垃圾渗滤液。     

Application of Fenton, photo-Fenton, solar photo-Fenton, and UV/H2O2 to degradation of the antineoplastic agent mitoxantrone and toxicological evaluation

In the present study, selected advanced oxidation processes (AOPs)—namely, photo-Fenton (with Fe²⁺, Fe³⁺, and potassium ferrioxalate—FeOx—as iron sources), solar photo-Fenton, Fenton, and UV/H₂O₂—were investigated for degradation of the antineoplastic drug mitoxantrone (MTX), frequently used to treat metastatic breast cancer, skin cancer, and acute leukemia. The results showed that photo-Fenton processes employing Fe(III) and FeOx and the UV/H₂O₂ process were most efficient for mineralizing MTX, with 77, 82, and 90 % of total organic carbon removal, respectively. MTX probably forms a complex with Fe(III), as demonstrated by voltammetric and spectrophotometric measurements. Spectrophotometric titrations suggested that the complex has a 2:1 Fe³⁺:MTX stoichiometric ratio and a complexation constant (K) of 1.47 × 10⁴ M^–1, indicating high MTX affinity for Fe³⁺. Complexation partially inhibits the involvement of iron ions and hence the degradation of MTX during photo-Fenton. The UV/H₂O₂ process is usually slower than the photo-Fenton process, but, in this study, the UV/H₂O₂ process proved to be more efficient due to complexing of MTX with Fe(III). The drug exhibited no cytotoxicity against NIH/3T3 mouse embryonic fibroblast cells when oxidized by UV/H₂O₂ or by UV/H₂O₂/FeOx at the concentrations tested.     

微电解-Fenton深度处理制药废水影响因素与参数控制

采用铁炭微电解-Fenton联合工艺深度处理制药废水生化出水,探讨了初始pH、曝气量、反应时间等因素对微电解出水Fe2+和Fe3+变化规律、COD降解速率以及后续Fenton氧化效果的影响,为优化微电解-Fenton氧化联合工艺提出了微电解间歇加酸的理论。间歇加酸可提高微电解系统中COD降解速率和Fe2+含量,使后续Fenton氧化无需投加FeSO4·7H2O即可达到较好的COD去除效果。结果表明,当初始pH=2.5,曝气量为0.6 m3/h,间歇加酸30 min/次,微电解反应2 h,出水投加1 mL/L的H2O2进行Fenton氧化2 h,COD总去除率可达81.33%;间歇加酸30 min/次可将微电解反应2 h出水Fe2+浓度从50 mg/L提高至151 mg/L,COD降解速率从10.6 mg COD/(L·h)提高至22.2 mg COD/(L·h)。     

Factors affecting degradation of dimethyl sulfoxide (DMSO) by fluidized-bed Fenton process

In this study, the target compound is dimethyl sulfoxide (DMSO), which is used as a photoresist stripping solvent in the semiconductor and thin-film transistor liquid crystal display (TFT-LCD) manufacturing processes. The effects of the operating parameters (pH, Fe²⁺ and H₂O₂ concentrations) on the degradation of DMSO in the fluidized-bed Fenton process were examined. This study used the Box-Behnken design (BBD) to investigate the optimum conditions of DMSO degradation. The highest DMSO removal was 98 % for pH 3, when the H₂O₂ to Fe²⁺ molar ratio was 12. At pH 2 and 4, the highest DMSO removal was 82 %, when the H₂O₂ to Fe²⁺ molar ratio was 6.5. The correlation of DMSO removal showed that the effect of the parameters on DMSO removal followed the order Fe²⁺?>?H₂O₂?>?pH. From the BBD prediction, the optimum conditions were pH 3, 5 mM of Fe²⁺, and 60 mM of H₂O₂. The difference between the experimental value (98 %) and the predicted value (96 %) was not significant. The removal efficiencies of DMSO, chemical oxygen demand (COD), total organic carbon (TOC), and iron in the fluidized-bed Fenton process were higher than those in the traditional Fenton process.     

Influence of operational key parameters on the photocatalytic decolorization of Rhodamine B dye using Fe2+/H2O2/Nb2O5/UV system

The present research deals with the development of a new heterogeneous photocatalysis and Fenton hybrid system for the removal of color from textile dyeing wastewater as Rhodamine B (RhB) solutions by using Fe²⁺/H₂O₂/Nb₂O₅ as a photocatalytic system. The application of this photocatalytic system for the decolorization of dye contaminants is not reported in the literature yet. Different parameters like dye concentration, Nb₂O₅/Fe²⁺ catalyst amount, pH, and H₂O₂ concentration have been studied. The optimum conditions for the decolorization of the dye were initial concentration of 10 mg L^?1 of dye, pH 4, and Nb₂O₅/Fe²⁺ catalyst concentration of 0.5 g L^?1/50 mg L^?1. The optimum value of H₂O₂ concentration for the conditions used in this study was 700 mg L^?1. Moreover, the efficiency of the Nb₂O₅/photo-Fenton hybrid process in comparison to photo-Fenton alone and a dark Fenton process as a control experiment to decolorize the RhB solution has been investigated. The combination of photo-Fenton and Nb₂O₅ catalysts has been proved to be the most effective for the treatment of such type of wastewaters. The results revealed that the RhB dye was decolorized in a higher percent (78 %) by the Nb₂O₅/photo-Fenton hybrid process (Fe²⁺/H₂O₂/Nb₂O₅/UV) than by the photo-Fenton process alone (37 %) and dark Fenton process (14 %) after 120 min of treatment. Moreover, the Nb₂O₅ catalyst as a heterogeneous part of the photocatalytic system was demonstrated to have good stability and reusability.     

Fenton氧化活性深蓝染料B-2GLN的动力学

为了考查H2O2/Fe2+的摩尔比和H2O2的初始剂量、pH值以及活性深蓝染料B-2GLN(RDB B-2GLN)的初始浓度对活性深蓝染料B-2GLN降解过程的影响,采用在线分光光度法对活性深蓝染料B-2GLN的Fenton氧化过程进行了研究,探讨了其动力学过程,并利用气相色谱-质谱联用分析降解中间产物。结果显示,采用Fenton氧化降解水溶液中活性深蓝染料B-2GLN,在H2O2的剂量为2.635 mmol/L,pH值为2.7,H2O2/Fe2+的摩尔比为37.80和活性深蓝染料B-2GLN的初始浓度16 mg/L的条件下,得到300 s后活性深蓝染料B-2GLN的最大色度去除率为85.04%。水溶液中活性深蓝染料B-2GLN与·OH的反应速率常数为2.62×1011L/(mol·s)。活性深蓝B-2GLN染料的分子结构被Fenton试剂分解而未被完全矿化,同时对活性深蓝染料降解产物进行了分析。在线分光光度法是研究染料色度去除率的一种精确、快速与可行的方法。     

4种高级氧化法处理高浓度正丙醇废水的动力学比较

研究了1%和10%(V/V)模拟正丙醇废水在UV/TiO2体系、UV/H2O2体系、Fe2+/H2O2体系和UV/TiO2/Fe2+/H2O2体系等4种工艺条件下的降解动力学过程,对比了降解动力学特点及工艺参数对动力学常数的影响,优化工艺参数。结果表明,UV/TiO2体系和Fe2+/H2O2体系的降解过程可分为零级反应阶段和一级反应阶段,转折点分别在反应开始后2 h和氧化剂浓度为6.7 g/L,UV/H2O2体系和UV/TiO2/Fe2+/H2O2体系分别符合零级反应和一级反应规律;相同工艺参数条件下,6 h反应后,组合工艺UV/TiO2/Fe2+/H2O2体系在处理效率达85%,比前3个体系分别高52.0%、8.3%和32.0%,与UV/TiO2体系和Fe2+/H2O2体系的处理效率之和持平,其协同效应提高了速率常数,在目标物浓度降低时依然可维持较高降解速率。而目标物浓度提高10倍后,UV能量利用率提高35.5倍,氧化剂用量是Fe2+/H2O2体系的1/7.1。     

Fenton-混凝法处理苯胺废水

农药生产过程中产生的苯胺废水,COD浓度高、生物毒性强、可生化性差,一般生化方法很难处理。研究了Fenton与PAC联用处理苯胺废水。结果表明,Fenton氧化处理苯胺废水在最佳条件为pH=6、m（H2O2）/m（COD）=1.8、n（H2O2）/n（Fe2＋）=8时,COD和色度去除率分别为78.4%和92.3%。Fenton氧化后废水B/C值由0.037提高到0.324。最佳条件下联用PAC,在投加量为320 mg/L时COD与色度去除率分别为83.6%和94.8%,并且处理时间显著缩短,实际应用中可减少水力停留时间和构筑物体积。     

TiO2纳米管催化活性再生处理技术简

采用H₂O₂、Fe₂（SO₄）₃和Fenton溶液对失活的TiO₂纳米管进行再生处理，重点考察了3种溶液的浓度和处理时间等对再生效果的影响，初步分析了经处理后TiO₂纳米管催化活性得到再生或增强的机理。结果表明，经H₂O₂溶液处理后TiO₂催化活性能得到有效再生，经Fe₂（SO₄）₃和Fenton溶液处理后其催化活性不仅得到再生，还能显著增强，这与H₂O₂和Fenton的强氧化作用，及进入TiO₂纳米管的Fe³⁺的阻止电子-空穴对再复合作用有关。     

Fenton and Fenton-like oxidation of pesticide acetamiprid in water samples: Kinetic study of the degradation and optimization using response surface methodology

The aims of this study were (a) to evaluate the degradation of acetamiprid with the use of Fenton reaction, (b) to investigate the effect of different concentrations of H₂O₂ and Fe²⁺, initial pH and various iron salts, on the degradation of acetamiprid and (c) to apply response surface methodology for the evaluation of degradation kinetics.