高熵合金与E-Fenton试剂处理染料废水实验研究

处理染料废水的电芬顿(Electro-Fenton,E-Fenton)技术已经展现出显著的优势。然而,在实际应用中,电极材料的耐用性和腐蚀问题一直是限制其进一步发展的关键因素。为了解决这些问题,并进一步提高降解效率,研究决定采用高熵合金作为阳极,并结合E-Fenton试剂进行实验。目标是以甲基橙为模拟污染物,对染料废水进行降解处理。实验结果显示,在反应进行5 h后,Al_(0.3)CoCrFe_(2)Ni高熵合金的最大腐蚀速率仅为5.94 g/cm^(2)·h。与Al_(0.3)CoCrFe_(1.7)Ni、Al_(0.3)CoCrFe_(1.3)Ni、Al_(0.3)CoCrFe_(0.9)Ni和铁片的腐蚀速率相比,分别降低了44.17%、63.44%、78.06%和84.59%。Al_(0.3)CoCrFe_(2)Ni和Al_(0.3)CoCrFe_(1.7)Ni合金均出现了Fe_(2)O_(3)和Fe_(3)O_(4)的衍射峰。这一研究结果表明,高熵合金与E-Fenton试剂联合处理染料废水的方法,有效地提高了电极材料的耐腐蚀性。这不仅为染料废水的处理提供了新的解决方案,同时也进一步证实了高熵合金在环保领域的应用潜力。

Efficient H_(2)O_(2)Electrosynthesis and Its Electro-Fenton Application for Refractory Organics Degradation

Hydrogen peroxide(H_(2)O_(2))in situ electrosynthesis by O_(2)reduction reaction is a promising alternative to the conventional Fenton treatment of refractory wastewater.However,O_(2)mass transfer limitation,cathodic catalyst selectivity,and electron transfer in O_(2)reduction remain major engineering obstacles.Here,we have proposed a systematic solution for efficient H_(2)O_(2)generation and its electro-Fenton(EF)application for refractory organic degradation based on the fabrication of a novel ZrO_(2)/CMK-3/PTFE cathode,in which polytetrafluoroethylene(PTFE)acted as a hydrophobic modifier to strengthen the O_(2)mass transfer,ZrO_(2)was adopted as a hydrophilic modifier to enhance the electron transfer of O_(2)reduction,and mesoporous carbon CMK-3 was utilized as a catalyst substrate to provide catalytic active sites.Moreover,feasible mass transfer of O_(2)from the hydrophobic to the hydrophilic layer was designed to increase the contact between O_(2)and the reaction interface.The H_(2)O_(2)yield of the ZrO_(2)/CMK-3/PTFE cathode was significantly improved by approximately 7.56 times compared to that of the co nventional gas diffusion cathode under the same conditions.The H_(2)O_(2)generation rate and Faraday efficiency reached125.98 mg·cm^(-2)·h^(-1)(normalized to 5674.04 mmol·g^(-1)·h^(-1)by catalyst loading)and 78.24%at-1.3 V versus standard hydrogen electrode(current density of-252 mA·cm^(-2)),respectively.The high H_(2)O_(2)yield ensured that sufficient OH was produced for excellent EF performance,resulting in a degradation efficiency of over 96%for refractory organics.This study offers a novel engineering solution for the efficient treatment of refractory wastewater using EF technology based on in situ high-yield H_(2)O_(2)electrosynthesis.

Electro-Fenton法的影响因素及研究进展

Electro-Fenton法是一种新型的电催化氧化技术,具有"环境友好"的特点,是一种高级氧化技术(AOPs)。结合国内外Electro-Fenton法的研究近况,阐述Fenton法的作用机理及主要影响因素,主要受pH值、O2流量、温度、电流密度、Fe2+离子浓度、电极间距离、电解质及电极材料等因素影响,结合具体的废水对主要反应参数进行总结,分析作用机理。对Electro-Fenton法的研究发展趋势提出了一些观点。

基于纳米Fe/ACF电极的阴极E-Fenton氧化处理生活污水的研究

成功制备了活性碳纤维负载的纳米铁电极(Fe/ACF),并通过SEM、EDS进行了电极表征.某小区生活污水基于该电极的阴极E-Fenton氧化处理结果表明,在电压1.2 V、中性条件下处理2 h,初始COD由200 mg/L降低到70 mg/L,COD去除率达到65%,出水水质达到国家排放标准GB8978-2000中的一级标准.

Removal of citrate and hypophosphite binary components using Fenton,photo-Fenton and electro-Fenton processes

Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light （photo-Fenton） or electron current （electro-Fenton） was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.

Degradation of acid fuchsine by a modified electro-Fenton system with magnetic stirring as oxygen supplying

The current modified electro-Fenton system was designed to develop a more convenient and efficient undivided system for practical wastewater treatment. The system adopted a cathode portion that employed magnetic stirring instead of common oxygen gas diffusion or gas sparging to supply oxygen gas for the electrolyte solution. Key factors influencing the cathode fabrication and activit） were investigated. The degradation of acid fuchsine with a self-made graphite-polytetrafluorethylene cathode was studied using spectrophotometer. It was found that the cathode generated hydrogen peroxide with high current efficiency and the hydrogen peroxide yield of the cathode did not decay after 10 times reuse. With the Pt anode at a ferrous ion concentration of 0.5 mmol/L, a pH of 3, and using magnetic stirring, dye decolorization could be rapidly accomplished but the destruction of benzene rings and intermediates was fairly difficult. With a Fe anode, dye degradation was more complete.

Kinetic degradation of amoxicillin by using the electro-Fenton process in the presence of a graphite rods from used batteries

This study reports the removal of amoxicillin(AMX)in aqueous media using the electroFenton process in the presence of a graphite cathode recovered from used batteries.The impact of the relevant parameters on the electroFenton process,namely the applied current intensity,the temperature,the initial concentration of AMX and the initial concentration of ferrous ions were investigated.The results showed that the optimal values were:I=600 mA,T=25℃,[AMX]_(0)=0.082 mmol·L^( 1) and[Fe^(2+)]=1 mmol·L^(1),leading to 95%degradation and 74%mineralization.The model parameters of AMX mineralization were determined using nonlinear methods,showing that it follows a pseudosecondorder kinetic.The Energy consumption(EC)calculated under the optimal values was found to be 0.79 kWhg 1,which was of the same order of magnitude of those reported in other findings;while it is noteworthy that the electrodes used in our study are of a lower cost.

Fe^0/Electro-Fenton对邻苯二甲酸二甲酯的降解研究

以纳米零价铁(Fe0)为铁源的Electro-Fenton(Fe0/E-Fenton)对邻苯二甲酸二甲酯(DMP)的降解进行了研究。与Fe2+/E-Fenton体系相比较,Fe0/E-Fenton对DMP的降解效果更好。Fe0/E-Fenton对DMP的降解过程中,相对稳定的溶液pH值和充足的Fe2+量有利于E-Fenton试剂对DMP的降解反应。同时考察了Fe0/E-Fenton反应的初始pH值和纳米Fe0投加量对DMP降解的影响。研究结果表明,当DMP的初始浓度为50 mg.L-1时,溶液的最佳pH值和Fe0的投加量分别为3.0、60 mg.L-1,且DMP溶液在90 min内可以达到完全降解,降解速率符合准一级动力学方程:ln(C0/C)=0.056t-0.072,R=0.996,降解速率常数为0.056 min-1。

Simultaneous utilization of electro-generated O_(2)and H_(2)for H_(2)O_(2)production:An upgrade of the Pd-catalytic electro-Fenton process for pollutants degradation

The Electro-Fenton(EF)process is one of the promising advanced oxidation processes(AOPs)for environmental remediation.The H_(2)O_(2) yield of EF process largely determines its performance on organic pollutants degradation.Conventional Pd-catalytic EF process generates H_(2)O_(2) via the combination reaction of anodic O_(2) and cathodic H;.However,the relatively expensive catalyst limits its application.Herein,a hybrid Pd/activated carbon(Pd/AC)-stainless steel mesh(SS)cathode(PACSS)was proposed,which enables more efficie nt H_(2)O_(2)generation.It utilizes AC,the support of Pd catalyst,as part of cathode for H_(2)O_(2) generation via 2-electron anodic O_(2) reduction,and SS serve as a current distributor.Moreover,H_(2)O_(2) could be catalytically decomposed upon AC to generate highly reactive·OH,which avoids the use of Fe;.Compared with conventional Pd catalyst,H_(2)O_(2) concentration obtained by PACSS cathode is248.2%higher,the O_(2)utilization efficiency was also increased from 3.2%to 10.8%.Within 50 min,26.3%,72.5%,and 94.0%H_(2)O_(2) was decomposed by Pd,AC,and Pd/AC.Fluorescence detection results implied that Pd/AC is effective upon H_(2)O_(2) activation for·OH generation.Finally,iron-free EF process enabled by PACSS cathode was examined to be effective for reactive blue 19(RB19)degradation.After continuous running for 10 cycles(500 min),the PACSS cathode was still stable for H_(2)O_(2)generation,H_(2)O_(2)activation,and RB19 degradation,showing its potential application for organic pollutants degradation without increase in the running cost.

Removal of 17β-Estradiol by Electro-Fenton Process

The Electrochemical advanced oxidation method “Electro-Fenton” has been applied to remove 17β-estradiol (17β)- estra-1,3,5(10)-triéne-3,17-diol) in aqueous-acetonitrile mixture. This endocrine disrupting is a steroid hormone, releases from humans, animals and residual pharmaceuticals into the environmental water and usually causes suspected undesirable effects in aquatic organisms. The degradation of this organic compound by Electro-Fenton process was showed using a carbon felt cathode and platinum anode. The evolution of the concentration during treatment was followed up by high performance liquid chromatography (HPLC). The influence of operating conditions on the degradation of 17β-estradiol by Electro-Fenton step, such as initial concentration and catalyst concentration, has been investi- gated and discussed. We showed that the degradation reaction obeyed apparent first-order reaction kinetics, with absolute rate constant determined as 5.12 × 109 M–1 s–1 by competitive kinetics method taking Benzoic Acid as reference compound. The results confirm the efficiency of the Electro-Fenton process to degrade organic pollutant in aqueous-acetonitrile mixture.

Electro-Fenton法处理某企业羊栖菜废水的实验研究

针对羊栖菜生产废水含盐量高、COD浓度较高、导电性较好等特点,采用electro-Fenton法对其进行处理。探究了该处理过程中初始pH、电流、电压、m(Fe^(2+))∶m(H_2O_2)等对COD去除率的影响。结果表明,最佳运行条件为:pH=3.0,电流20 A,电压15 V,m(Fe^(2+))∶m(H_2O_2)=1∶2,反应经过60 min,此时,COD的去除率为82%。同时,说明了采用Electro-Fenton法处理羊栖菜废水具有反应效率高、运行效果稳定等优点,并且对海带、淡菜等其他海产品加工类废水处理具有指导、借鉴的价值。

Monolithic Mesh-Type Fe-Pd/γ-Al₂O₃/Al Bifunctional Catalysts for Electro-Fenton Degradation of Rhodamine B

A novel Fe-Pd bifunctional catalyst supported on mesh-type γ-Al2O3/Al was prepared and applied in the degradation of Rhodamine B (RhB). The monolithic mesh-type Fe-Pd/γ-Al2O3/Al bifunctional catalyst could be separated from the solution directly and could synthesize H2O2 in situ. The characterization results showed that Fe could improve the dispersion of Pd0, and the electronic interactions between Pd and Fe could increase the Pd0 contents on the catalyst, which increased the productivity of H2O2. Furthermore, DFT calculations proved that the addition of Fe could inhibit the dissociation of O2 and promote the nondissociative hydrogenation of O2 on the surface of Fe-Pd/γ-Al2O3/Al, which resulted in the increasement of H2O2 selectivity. Finally, the in-situ synthesized H2O2 by Pd was furtherly decomposed in situ by Fe to generateOH radicals to degrade organic pollutants. Therefore, Fe-Pd/ γ-Al2O3/Al catalysts exhibited excellent catalytic activity in the in-situ synthesis of H2O2 and the degradation of RhB due to the synergistic effects between Pd and Fe on the catalyst. It provided a new idea for the design of bifunctional electro-Fenton catalysts. Ten cycles of experiments showed that the catalytic activity of Fe-Pd/γ-Al2O3/Al catalyst could be maintained for a long time.

A novel electro-Fenton hybrid system for enhancing the interception of volatile organic compounds in membrane distillation desalination

Membrane distillation(MD)is a promising alternative desalination technology,but the hydrophobic membrane cannot intercept volatile organic compounds(VOCs),resulting in aggravation in the quality of permeate.In term of this,electro-Fenton(EF)was coupled with sweeping gas membrane distillation(SGMD)in a more efficient way to construct an advanced oxidation barrier at the gas-liquid interface,so that the VOCs could be trapped in this layer to guarantee the water quality of the distillate.During the so-called EF-MD process,an interfacial interception barrier containing hydroxyl radical formed on the hydrophobic membrane surface.It contributed to the high phenol rejection of 90.2% with the permeate phenol concentration lower than 1.50 mg/L.Effective interceptions can be achieved in a wide temperature range,even though the permeate flux of phenol was also intensified.The EF-MD system was robust to high salinity and could electrochemically regenerate ferrous ions,which endowed the long-term stability of the system.This novel EF-MD configuration proposed a valuable strategy to intercept VOCs in MD and will broaden the application of MD in hypersaline wastewater treatment.

Three-dimensional heterogeneous electro-Fenton system with reduced graphene oxide based particle electrode for Acyclovir removal

New pollutant pharmaceutical and personal care products(PPCPs),especially antiviral drugs,have received increasing attention not only due to their increase in usage after the outbreak of COVID-19 epidemics but also due to their adverse impacts on water ecological environment.Electro-Fenton technology is an effective method to remove PPCPs from water.Novel particle electrodes(MMT/rGO/Fe_(3)O_(4))were synthesized by depositing Fe3O4 nanoparticles on reduced graphene oxide modified montmorillonite and acted as catalysts to promote oxidation performance in a three-dimensional electro-Fenton(3D-EF)system.The electrodes combined the catalytic property of Fe3O4,hydrophilicity of montmorillonite and electrical conductivity of graphene oxides,and applied for the degradation of Acyclovir(ACV)with high efficiency and ease of operation.At optimal condition,the degradation rate of ACV reached 100%within 120 min,and the applicable pH range could be 3 to 11 in the 3D-EF system.The stability and reusability of MMT/rGO/Fe_(3)O_(4)particle electrodes were also studied,the removal rate of ACV remained at 92%after 10 cycles,which was just slightly lower than that of the first cycle.Potential degradation mechanisms were also proposed by methanol quenching tests and FT-ICR-MS.

改性钯阴极电-芬顿法降解菲那西汀模拟废水

为提高对菲那西汀制药废水的处理效果,采用钛盐光度法、电子顺磁共振法(ESR)和重铬酸钾滴定法等方法对不同电极在电-芬顿法中H2O2产量、·OH生成量和化学需氧量(COD)的影响,并且考察降解菲那西汀的最佳反应条件。结果表明:在电流密度=2.5 mA/cm^2、[Fe^2+]=0.10 mmol/L、pH值=3和[Na2SO4]=0.1 mol/L的操作条件下,H2O2的质量浓度达最大值为6.91 mg/L;改性后的电极比未改性电极具有更高的DMPO-OH相应电流,同时可产生更多的羟基自由基(·OH);经120 min电催化处理后,PNT的去除率达到了81.2%;电-芬顿降解菲那西汀过程符合降解一级反应动力学,动力学常数为0.0493。该结果验证了该电极可以显著提高菲那西汀的降解效能、提升H2O2和·OH产率、缩短反应时间。

气体扩散电极在水处理领域中的研究进展

气体扩散电极(Gas Diffusion Electrode-GDE)作为阴极,通过氧气还原产生过氧化氢(H2O2),在亚铁离子催化剂存在的情况下形成Fenton试剂,从而间接氧化有机污染物,这方面的研究逐步引起人们的重视。本文综述了电极材料、电流密度、pH、催化剂等因素对处理效果的影响,提出了该方法存在的问题并对其发展趋势进行了展望。

活性炭纤维阴极电-芬顿法处理煤气化废水

采用阴极E-Fenton法处理煤气化废水,对比石墨毡和活性炭纤维(ACF)为阴极材料的处理效果,利用傅里叶红外光谱(FT IR)表征处理前后的物质特征;并考察初始pH、电压、Fe2+投加量对处理效果的影响。结果表明,ACF具有较高的表面积,可有效富集反应器中的氧气和有机物,从而取得较好的降解效果。E-Fenton法可破坏废水中的芳香结构或C=C不饱和结构,生成杂环芳烃类产物,未能完全矿化降解废水中的醇和酚羟基、脂环基、羧基、醚,缩醛或缩酮等官能团。ACF为阴极的E-Fenton法优化反应条件为:电解电压10 V,初始pH=3,Fe2+的浓度0.4 mmol/L。在此条件下,COD去除率可达57%。

The progress of catalytic technologies in water purification:A review

Catalytic technologies have been paid increasing attention in refractory pollutants abatement due to its practical and potential values in water purification. As effective and efficient approaches for water purification, Fenton＇s reagent, ozonation, electrochemical and photocatalytic methods have been widely studied and applied in different aspects and have been reviewed by several articles. In recent years, some novel catalytic processes based on above processes have been developed for enhancing the efficiency of removing the organics from water. This review emphasized on the recent development of heterogeneous catalytic ozonation, electrocatalysis in respect of novel electrodes and electro-Fenton method, photoelectrocatalysis process and photoelectron-Fenton in water purification. It was also an attempt to propose general ideas about mechanism and principle enhancing the catalytic efficiency for the degradation and the mineralization of organics in water.

Degradation of 2,4-dichlorophenol with a novel TiO_2/Ti-Fe-graphite felt photoelectrocatalytic oxidation process

Degradation of 2,4-dichlorophenol （2,4-DCP） was studied in a novel three-electrode photoelectrocatalytic （PEC） integrative oxidation process, and the factors influencing the degradation rate, such as applied current, flow speed of O2, pH, adscititious voltage and initial 2,4-DCP concentration were investigated and optimized. H2O2 was produced nearby cathode and Fe^2＋ continuously generated from Fe anode in solution when current and O2 were applied, so, main reactions, H2O2-assisted TiO2 PEC oxidation and E-Fenton reaction, occurred during degradation of 2,4-DCP in this integrative system. The degradation ratio of 2,4-DCP was 93% in this integrative oxidation process, while it was only 31% in E-Fenton process and 46% in H2O2-assisted TiO2 PEC process. So, it revealed that the degradation of 2,4-DCP was improved greatly by photoelectrical cooperation effect. By the investigation of pH, it showed that this integrative process could work well in a wide pH range from pH 3 to pH 9.

FeMo@porous carbon derived from MIL-53(Fe)@MoO_(3) as excellent heterogeneous electro-Fenton catalyst: Co-catalysis of Mo

An ultra-efficient electro-Fenton catalyst with porous carbon coated Fe-Mo metal(FeMo@PC),was prepared by calcining MIL-53(Fe)@MoO_(3).This FeMo@PC-2 exhibited impressive catalytic performance for sulfamethazine(SMT)degradation with a high turnover frequency value(7.89 L/(g·min)),much better than most of reported catalysts.The mineralization current efficiency and electric energy consumption were 83.2%and 0.03 kWh/gTOC,respectively,at lowcurrent(5mA)and small dosage of catalyst(25.0mg/L).The removal rate of heterogeneous electro-Fenton(Hetero-EF)process catalyzed by FeMo@PC-2 was 4.58 times that of Fe@PC/Hetero-EF process.Because the internal-micro-electrolysis occurred between PC and Fe0,while the co-catalysis of Mo accelerated the rate-limiting step of the Fe^(3+)/Fe^(2+) cycle and greatly improved the H_(2)O_(2)utilization efficiency.The results of radical scavenger experiments and electron paramagnetic resonance confirmed the main role of surface-bound hydroxyl radical oxidation.This process was feasible to remove diverse organic contaminants such as phenol,2,4-dichlorophenoxyacetic acid,carbamazepine and SMT.This paper enlightened the importance of the doped Mo,which could greatly improve the activity of the iron-carbon heterogeneous catalyst derived from metal-organic frameworks in EF process for efficient removal of organic contaminants.