电磁催化臭氧氧化在难降解废水升级改造中的应用

针对设计规模105 m3/d的某污水处理厂需升级改造至GB 18918-2002一级A排放标准的工程,分析了面临的难题,认为主要是COD的达标。通过中试,验证了电磁(EM)催化臭氧氧化工艺对难降解有机废水深度处理的可行性。并在此基础上,进行了升级改造,实际运行结果表明,在进水COD平均为66.68 mg/L、O3投加量为20 mg/L时,EM催化臭氧氧化工艺可将COD降至平均为41.92 mg/L,平均去除率为36.4%。出水COD稳定达到GB 18918-2002一级A排放标准。

电磁催化氧化法去除油田废水COD中试研究

对采用电磁EM高级催化氧化法去除羊三木区块油田外排废水COD进行中试研究。中试过程依据试验装置的进水量以及臭氧投放量分4个阶段进行,连续监测4个阶段的进出水水质,对监测数据进行对比分析研究。中试结果表明:采用电磁EM高级催化氧化法对油田外排废水进行处理,处理装置进水COD含量在60~80 mg/L,出水COD含量稳定控制在40 mg/L以下,COD平均去除率达到45%以上,处理结果达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。采用此方法对羊三木区块油田外排废水进行处理,可以达到环保要求。

电磁催化氧化法去除油田废水COD中试研究

采用电磁EM高级催化氧化法，对去除羊三木区块油田外排废水COD进行深度处理中试研究。中试过程分4个阶段进行，连续监测4个阶段的进出水水质，对监测数据进行对比分析研究。中试结果表明，采用电磁EM高级催化氧化法对油田外排废水进行处理，处理装置进水COD含量在60～80mg／L之间，出水COD含量稳定控制在50mg／L以下，处理结果达到《城镇污水处理厂污染物排放标准》（GB18918-2002）一级A标准。采用此方法对羊三木区块油田外排废水进行深度处理，可以达到环保要求。

MBBR+臭氧电磁催化氧化用于污水处理厂提标扩建

焦作市工业集聚区万方污水处理厂总规模为5×10~4m^3/d,分两期建设。一期于2009年7月建成投产,处理量为2.5×10~4m^3/d,进水以生物制药废水为主,采用水解酸化+A^2O工艺,设计出水水质执行《城镇污水处理厂污染物排放标准》(18918—2002)一级B标准。目前实施二期提标扩建工程,总规模达到5×10~4m^3/d,出水执行一级A标准,提标扩建工程采用生化池投加悬浮填料工艺(MBBR)、增加精密过滤和臭氧电磁催化氧化等措施,改造后出水水质达标。

反硝化深床滤池/电磁催化臭氧氧化用于污水厂升级改造

山东某10×10~4m^3/d规模污水处理厂,原设计出水水质执行一级B标准。进水水质严重偏离设计水质,导致出水COD及TN达标困难。随着环保要求的提高,需升级改造至出水水质达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。经过中试论证后,最终采用"反硝化深床滤池+电磁催化臭氧氧化"深度处理工艺。升级改造工程完成后,出水各项指标均达到一级A排放标准。

臭氧电磁氧化+炭砂滤池处理汽车园生产废水

针对汽车园生产废水成分复杂、可生化性较差的特点,选择臭氧电磁高级催化氧化+炭砂滤池深度处理工艺进行处理。臭氧电磁高级催化氧化可降低色度和去除难降解有机物,介绍了炭砂滤池可通过滤层截留、活性炭吸附与生物降解的共同作用,有效去除SS、有机物和NH_3^-N等污染物。实际运行结果表明,采用臭氧电磁氧化+炭砂滤池技术,COD、NH_3^-N和SS去除率可达96.0%、97.1%和98.2%,出水COD≤20 mg/L,BOD_5≤4 mg/L,SS、NH_3^-N、TP、TN的质量浓度分别≤4、≤1.0、≤0.3、≤10 mg/L,色度≤10 NTU,达到DB 12/599-2015排放要求。总处理成本0.76元/t。

某污水处理厂提标改造中高级氧化工艺选型分析

随着天津市地方标准《天津市城镇污水处理厂污染物排放标准》(DB12/599-2015)的发布,天津市内各污水处理厂均面临提标改造问题。由于部分城镇污水处理厂进水混有一定比例的工业废水,因此原水组成较为复杂、难降解有机物浓度较高,这对污水厂提标改造中COD_(Cr)达标造成了较大困难。文章以天津市某污水处理厂为例,对芬顿法、臭氧氧化法等COD_(Cr)深度处理工艺进行对比分析,结果表明,采用臭氧电磁催化氧化工艺在工程投资及运行成本上均具有一定优势。

臭氧电磁高级催化氧化去除难降解有机物的研究

臭氧电磁高级催化氧化技术是一种新型的水处理技术，适用于去除溶解性难生物降解有机物。采用该技术处理某化工区综合污水处理厂的尾水，中试结果表明，在进水COD为70～110mg／L、臭氧投加量为25mg／L的条件下，出水COD在45mg／L以下，处理成本为0．41元／m^3，证明该技术是可行的。另外，试验结果还显示，曝气生物滤池作为臭氧电磁高级催化氧化工艺的后续工艺，其对COD的进一步去除效果并不明显。

电磁(EM)催化高级氧化用于桥东污水处理厂升级改造

石家庄桥东污水处理厂于2006年建成投产，处理水量为50×10^4m^3／d，进水中60％为制药和化工废水，原设计出水水质执行《污水综合排放标准》（GB8978--1996）的二级标准。2008年实施了升级改造工程，出水BOD5、氨氮、总氮、SS和总磷等达到了《城镇污水处理厂污染物排放标准》（GB18918--2002）的一级A标准，但COD约为70mg／L、色度为120倍。为此，进行了第二次升级改造，采用电磁（EM）催化高级氧化工艺，出水COD≤50mg／L、色度≤15倍，达到了排放标准，臭氧投加量为12—14mg／L，吨水处理成本增加0．18元／m^3。

Effect of Magnetic Field on Properties of AuPt Particles Magneto- electrodeposited on Carbon Paper

AuPt nano particles are bi-functional catalysts for Oxygen Reduction Reaction （ORR） and Oxygen Evolution Reaction （OER） that were taken place on air electrodes in lithium air batteries. Magnetic field has been applied during electrodeposition for the preparation of AuPt particles. With the increase of the magnetic flux density under constant current density, the grain size decreases from - 1μm to 200nm and the activity of the AuPt catalyst increases. The magnetic field oriented vertical to the electric field has a promotion effect on increasing the catalytic ability of AuPt/carbon electrode. By pulse plating, the grain size decreases to about 100nm. By adjusting parameters of the electric field and the magnetic field, controllable in-situ preparation of AuPt catalyst with various morphology and catalytic activity could be achieved.

某高排放标准污水处理厂提标改造工程设计及运行分析

某污水处理厂提标改造工程设计规模15万m^3/d,出水执行天津市地方标准《城镇污水处理厂污染物排放标准》(DB12/599-2015)A标准,项目设计主体工艺采用"改良bardenpho+磁混凝澄清池+深床滤池+臭氧电磁催化高级氧化+紫外线消毒"的处理工艺,运行实践表明,工艺运行效果良好,出水可稳定达到设计要求,并给出了工艺流程及设计参数,以为类似高排放标准污水处理厂精细化设计与运行提供参考。

Co0.85Se magnetic nanoparticles supported on carbon nanotubes as catalyst for hydrogen evolution reaction

Co0.85Se magnetic nanoparticles supported on carbon nanotubes were prepared by a one‐step hydrothermal method.The saturation magnetization and coercivity of the MWCNTs/Co0.85Se nanocomposites increased due to a decrease in the Co0.85Se nanoparticle size in the MWCNTs/Co0.85Se nanocomposites and an increase in the distance between the Co0.85Se nanoparticles,which increased the specific surface area,thereby benefiting the electrocatalytic performance of the catalyst.Moreover,the MWCNTs/Co0.85Se nanocomposites exhibited an excellent hydrogen evolution reaction performance owing to the presence of MWCNTs,which enhanced the mass transport during the electrocatalytic reactions.Furthermore,in an acid solution,the 30 wt%MWCNTs/Co0.85Se composite catalyst exhibited a current density of 10 mA cm^‒2 at a small overpotential of 266 mV vs.RHE,a small Tafel slope of 60.5 mV dec^‐1,and good stability for HER.

LSDA+U study on the electronic and anti-ferromagnetic properties of Ni-doped CuO and Cu-doped NiO

Doping is an effective way to improve the activity of photocatalysts.The effect of doping on the magnetic properties of some photocatalysts that are easily recycled was studied using the local spin density approximation(LSDA)+U method on typical divalent metal oxide semiconductors CuO,NiO,Ni‐doped CuO,and Cu‐doped NiO.It is found that the influence of Ni doping on the spatial structure of CuO and that of Cu doping on the spatial structure of NiO are negligible because of the similar radii of Ni2+and Cu2+.The valence band and conduction band for Ni‐doped CuO are clearly spin‐split,corresponding to a net effective magnetic moment ofμeff=1.66μB.This may improve the photocatalytic efficiency and raise the recycle rate of photocatalysts.In the Cu‐doped NiO system,the presence of Cu3d states near to the Fermi level increases the width of the valence band and narrows the band gap with respect to that in pure NiO.Beyond the Cu3d states,within the band gap,appear two energy levels around the Fermi level,which may effectively separate the electron‐hole pair and also lead to enhanced absorption of visible light and infrared light.It can be concluded that the observed changes in the band structure may be helpful for improving the activity of photocatalysts and the doped systems have net magnetic moments,meaning that they are easily recycled and can be reused.

Electrocatalytic oxidation of hydrazine on magnetic bar carbon paste electrode modified with benzothiazole and iron oxide nanoparticles: Simultaneous determination of hydrazine and phenol

A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was developed. The DPB was firstly self‐assembled on the Fe3O4NPs, and the re‐sulting Fe3O4NPs/DPB composite was then absorbed on the designed MBCPE. The MBCPE was used to attract the magnetic nanoparticles to the electrode surface. Owing to its high conductivity and large effective surface area, the novel electrode had a very large current response for the electrocat‐alytic oxidation of hydrazine. The modified electrode was characterized by voltammetry, scanning electron microscopy, electrochemical impedance spectroscopy, infrared spectroscopy, and UV‐visible spectroscopy. Voltammetric methods were used to study the electrochemical behaviour of hydrazine on MBCPE/Fe3O4NPs/DPB in phosphate buffer solution （pH = 7.0）. The MBCPE/Fe3O4NPs/DPB, acting as an electrochemical sensor, exhibited very high electrocatalytic activity for the oxidation of hydrazine. The presence of DPB was found to reduce the oxidation potential of hydrazine and increase the catalytic current. The dependence of the electrocatalytic current on the hydrazine concentration exhibited two linear ranges, 0.1–0.4 μmol/L and 0.7–12.0 μmol/L, with a detection limit of 18.0 nmol/L. Additionally, the simultaneous determination of hydrazine and phe‐nol was investigated using the MBCPE/Fe3O4NPs/DPB electrode. Voltammetric experiments showed a linear range of 100–470 μmol/L and a detection limit of 24.3 μmol/L for phenol, and the proposed electrode was applied to the determination of hydrazine and phenol in water samples.

The possible implications of magnetic field effect on understanding the reactant of water splitting

Electrochemical water splitting consists of two elementary reactions i.e.,hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Developing robust HER and OER technologies necessitates a molecular picture of reaction mechanism,yet the reactants for water splitting reactions are unfortunately not fully understood.Here we utilize magnetic field to understand proton transport in HER,and hydroxide ion transport in OER,to discuss the possible implications on understanding the reactants for HER and OER.Magnetic field is a known tool for changing the movement of charged species like ions,e.g.the magnetic‐field‐improved Cu^(2+)transportation near the electrode in Cu electrodeposition.However,applying a magnetic field does not affect the HER or OER rate across various pH,which challenges the traditional opinion that charged species(i.e.proton and hydroxide ion)act as the reactant.This anomalous response of HER and OER to magnetic field,and the fact that the transport of proton and hydroxide ion follow Grotthuss mechanism,collectively indicate water may act as the universal reactant for HER and OER across various pH.With the aid of magnetic field,this work serves as an understanding of water might be the reactant in HER and OER,and possibly in other electrocatalysis reactions involving protonation and deprotonation step.A model that simply focuses on the charged species but overlooking the complexity of the whole electrolyte phase where water is the dominant species,may not reasonably reflect the electrochemistry of HER and OER in aqueous electrolyte.

Magnetic field assisted electrocatalytic oxidation of organic pollutants in electroplating wastewater

To degrade the organic compounds in the electroplating wastewater,magnetic field was tentatively introduced into electrocatalytic oxidation on Ti-PbO2 anode.The magnetic field assisted electrocatalytic oxidation can promote anion movement and the generation of active species,resulting more organic compounds to be oxidized and degraded.Oxidation parameters such as treatment time,current density and initial pH of the wastewater were systematically discussed and optimized.The mineralization of organic compounds is improved by over 15% under a magnetic density of 22 mT while the current density is 50 A/m2,pH is 1.8 and the reaction time is 1.5 h.The results indicate that the magnetic field assisted electrocatalytic oxidation has considerable potential in electroplating wastewater treatment.

Magnetic and Relativistic Effects in Uranium Catalysts and the Movement of Charged Particles under the Effect of Electric and Magnetic Fields

We first received and examined X-ray spectroscopy of uranium catalyst. We studied magnetic and relativistic effects in uranium catalysts, and the movement of charged particles under the effect of a uniform electric field and uniform magnetic field. We proposed the mechanism of the motion of charged particles under the influence of a uniform electric field and a uniform magnetic field.

Detection of Hydrogen Peroxide Photogenerating from a Hypocrellin B Derivative

In order to f urther improve the photosensitizing activity of hypocrellin B(HB), the complex o f 5,8 di Br HB with Al 3+ was designed and synthesized in high yield. Th e complex of aluminium ion with 5,8 di Br HB is a new water soluble perylene quinonoid derivative with enhanced absorption over HB in the phototherapeutic wi ndow (600-900 nm). Electron paramagnetic resonance (EPR) measurement and 9,10 diphenyl anthracene bleaching methods were used to investigate the photosensiti zing activity of [Al 2(5,8 di Br HB)Cl 4] n in the prese nce of oxygen. Singlet oxygen, superoxide anion radical, hydroxyl radical can be generated by [Al 2(5,8 di Br HB)Cl 4] n photosensit ization. The results showed that the production of hydroxyl radical ( · OH) by [Al 2(5,8 di Br HB)Cl 4] n photosensitization comes from the Fenton Haber Weiss reaction and the decom position of DMPO 1O 2 adduct. Formation of H 2O 2 as one of main intermedi ates in the photogeneration of hydroxyl radical was detected by using the cataly zed oxidation of the DPD reagent by the POD enzyme method. Moreover, the experim ents of EPR spin trap and catalase enzyme excluded the effect of organoperoxide on DPD oxidization. These results further support the proposed mechanism of · OH formation.

Nanomagnetic CoPt truncated octahedrons:facile synthesis,superior electrocatalytic activity and stability for methanol oxidation

Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent electrocatalytic performance of both activity and stability for methanol oxidation reaction （MOR）. The mass and specific activities of CoPt TONPs is 8 and 6 times higher than that of standard commercial Pt/C, respectively. After accelerated durability test （ADT）, the loss of electrochemical surface area （ECSA） for CoPt TONPs is only 18.5%, which is significantly less than that of commercial Pt/C （68.2%）, indicating that CoPt TONPs possess much better stability than commercial Pt/C in the prolonged operation. The Curie temperature of CoPt TONPs down to 8 nm is as high as 350 K with weak ferromagntism at room temperature （RT）, which is greatly valuable for recycling in the eletrocatalytic applications.

Influence of PEG 6000 on gallium oxide(Ga_2O_3) polymorphs and photocatalytic properties

Three different nanorod-like gallium oxides with mono/poly-crystalline nature(α, β, and α/β-Ga2O3) were prepared by regulating the amount of polyethylene glycol(PEG) 6000 in the range of 0.2–0.8 g proportionally via a hydrothermal method combined with further calcination. The bandgap of the products, given by UV-Vis diffuse reflectance spectra(UV-Vis DRS), was in the order of α-Ga2O3 > α/β-Ga2O3 > β-Ga2O3. To further investigate the photocatalysis performance of the catalysts, the decomposition of rhodamine B(Rh B) by Ga2O3 under UV light illumination(λ < 387 nm) was presented and complete degradation could be achieved within 30 min, a result that showed the highest efficiency. The photocatalytic oxidation mechanism is further discussed and prominently related to the active species: hydroxyl radical(·OH) and superoxide radical(O·-2), which were confirmed by electron paramagnetic resonance(EPR).