纳米催化电解法处理磺胺二甲基嘧啶废水

为了解决磺胺类抗生素废水处理的难题,利用新型纳米催化电解技术处理并探讨其最佳处理条件及效果.以模拟磺胺二甲基嘧啶废水为研究对象,采用新型纳米催化电解技术处理,讨论电解时间、电压、pH、电解质浓度对磺胺二甲基嘧啶废水的处理效果.得出废水处理的最佳技术条件为:废水pH为13、电解电压为6 V、NaCl电解质浓度为1.5%.在此条件下,COD_(Mn)的去除率为86.98%,磺胺二甲基嘧啶的去除率为90.21%.该工艺对磺胺二甲基嘧啶废水的处理效果较好.

纳米催化电解技术在市政污水处理中的应用和展望

纳米催化电解技术是市政污水处理领域的新型处理技术。通过分析纳米催化电解技术的原理和影响因素,结合在厦门污水处理厂中水回用、尾水消毒和污泥减量处理中应用的典型工程案例,阐述了该技术的适用性和可行性,并展望了其未来的发展方向。

基于纳米催化电解的市政污水深度处理及污泥处置研究

以厦门市杏林污水处理厂为例,研究NCE在市政污水深度处理及污泥处置中的可行性及适用性,为市政污水处理及污泥处置领域的技术优化开发提供技术支持。结果表明,1)采用"NCE+砂滤"技术,在20 V、200 A的最佳电解运行参数下,出水可达到GB/T 18920-2002城市绿化水质要求,运行能耗约为0.56 k Wh/t,其中电解机能耗约为0.1 k Wh/t。采用"NCE+MBR+RO"技术,出水可作为工业企业的中水进行循环利用;2)采用NCE作为污泥处置的前处理技术,在13.2 V、900 A的最佳运行条件下,可将万吨污水产泥量从传统方法的9.6 t降至5.2 t左右,通过NCE电解后回流的浓缩池上清液,可生化性能得到更好地改善,其BOD/COD比可由0.32提升至0.43。与传统污泥脱水技术相比,具有环境和经济效益。

纳米催化电解法处理磺胺甲噁唑废水

利用纳米催化电解法处理磺胺甲噁唑废水,研究pH、盐度、电解电压、电解时间等因素对处理磺胺甲噁唑的影响。结果表明,对于浓度为80 mg/L的磺胺甲噁唑废水,最佳的电解条件是pH=13,盐度为15‰,电解电压为6 V。在此条件下,CODMn的去除率达到76%,磺胺甲噁唑的去除率为83%,说明纳米催化处理对此类难以生物降解的抗生素具有很好的去除效果,为该类废水的处理提供了一种可行的方法。

电化学氧化耦合纳米催化微电解技术处理腈纶废水的静态实验研究

以抚顺腈纶厂生化池出水为研究对象,以CODCr和NH3-N去除率为考察指标,对电化学氧化耦合纳米催化微电解技术处理腈纶废水进行了静态实验研究。结果表明,电化学氧化耦合纳米催化微电解技术受电流强度、水力停留时间和电解质投加量三个因素的影响,对NH3-N有良好的处理效果,NH3-N去除率达90%以上;但对CODCr的处理效果不佳,只受水力停留时间的影响比较显著,当水力停留时间为10 min时,出水CODCr浓度能满足GB 8978-1996中一级排放指标(CODCr≤100 mg.L-1)。为进一步的动态实验奠定了基础。

纳米催化微电解海水的杀菌效果及斜带石斑仔鱼对其适应性的研究

水质的调控是决定养殖生产成败的一个关键因素,目前已有化学和物理等水处理方法被应用到水产种苗和养殖生产,对改善水产养殖的生长环境具有一定效果,但这些方法仍存在各种不同的弊端。本文通过纳米催化微电解技术对海水杀菌效果的研究,以期确定该仪器的最低完全杀菌的处理当量;利用不同的处理当量了解斜带石斑鱼(Epinephelus coioides)仔鱼对水体中游离氯的耐受范围,并在石斑鱼的苗种培育生产中进行了可行性的实验。研究结果表明:该技术对海水的消毒杀菌效果非常显著,处理当量在1.06 W.h/t以上时,杀菌效果可达到100%,该当量处理每吨海水的用电成本约为0.053分;斜带石斑仔鱼可耐受的最高处理当量为4.08 W.h/t,该当量已达到完全杀菌的效果,且持续抑菌效果良好,因此该处理当量可应用到石斑鱼苗种的实际生产中。利用纳米催化微电解海水产生游离氯的消毒作用,以灭活养殖环境水体中的病原生物,达到净化水体,抑制病原性疾病的目的,在水产动物种苗与养殖生产中具有一定的推广运用价值,且具较好的环保功效。

电化学氧化处理腈纶废水的研究

研究了电化学氧化法与纳米催化微电解联合技术处理腈纶厂生化池废水,运用国标试验方法对COD,NH_3-N,色度和pH等4项指标进行分析。结果表明,当氯化钠的投加质量分数为0.3%、电流为9A、循环时间为3.5 h时,COD由227 mg/L降低到46 mg/L,去除率达79.7%;NH_3-N质量浓度由117mg/L降低到9mg/L,去除率达92.3%;色度由32倍降到4倍,去除率达87.5%。实验表明电化学氧化法与纳米催化微电解联合技术在有机废水处理领域有广泛的应用前景。

Nanotube array-like WO_3/W photoanode fabricated by electrochemical anodization for photoelectrocatalytic overall water splitting

Photoactive WO3is attractive as a photocatalyst for green energy evolution through water splitting.In the present work,an electrochemical anodic oxidation method was used to fabricate a photo‐responsive nanotube array‐like WO3/W(NA‐WO3/W)photoanode from W foil as a precursor.Compared with a reference commercial WO3/W electrode,the NA‐WO3/W photoanode exhibited enhanced and stable photoelectrocatalytic(PEC)activity for visible‐light‐driven water splitting with a typical H2/O2stoichiometric ratio of2:1and quantum efficiency of approximately5.23%under visible‐light irradiation from a light‐emitting diode(λ=420nm,15mW/cm2).The greatly enhanced PEC performance of the NA‐WO3/Wphotoanode was attributed to its fast electron–hole separation rate,which resulted from the one‐dimensional nanotube array‐like structure,high crystallinity of monoclinic WO3,and strong interaction between WO3and W foil.This work paves the way to a facile route to prepare highly active photoelectrodes for solar light transfer to chemical energy.

In situ growth of minimal Ir-incorporated CoxNi1-xO nanowire arrays on Ni foam with improved electrocatalytic activity for overall water splitting

Exploration of cost-effective electrocatalysts for boosting the overall water-splitting efficiency is vitally important for obtaining renewable fuels such as hydrogen.Here,earth-abundant CoxNi1-xO nanowire arrays were used as a structural framework to dilute Ir incorporation for fabricating electrocatalysts for water splitting.Minimal Ir-incorporated CoxNi1-xO nanowire arrays were synthesized through the facile hydrothermal method with subsequent calcination by using Ni foam(NF)as both the substrate and source of Ni.The electrocatalytic water-splitting performance was found to crucially depend on the Ir content of the parent CoxNi1-xO nanowire arrays.As a result,for a minimal Ir content,as low as 0.57 wt%,the obtained Ir-CoxNi1-xO/NF electrodes exhibited optimal catalytic activity in terms of a low overpotential of 260 mV for the oxygen evolution reaction and 53 mV for the hydrogen evolution reaction at 10 mA cm?2 in 1 mol L–1 KOH.When used as bifunctional electrodes in water splitting,the current density of 10 mA cm–2 was obtained at a low cell voltage of 1.55 V.Density functional theory calculations revealed that the Ir-doped CoxNi1-xO arrays exhibited enhanced electrical conductivity and low Gibbs free energy,which contributed to the improved electrocatalytic activity.The present study presents a new strategy for the development of transition metal oxide electrocatalysts with low levels of Ir incorporation for efficient water splitting.

High photocatalytic activities of zinc oxide nanotube arrays modified with tungsten trioxide nanoparticles

Well‐aligned zinc oxide(ZnO)nanotube arrays loaded with tungsten trioxide(WO3)nanoparticles were synthesized by a process involving chemical bath deposition in combination with pyrolysis.The prepared ZnO–WO3composites were characterized by X‐ray diffraction,energy dispersive spectrometer,field emission scanning electron microscopy,X‐ray photoelectron spectroscopy,photoluminescence spectroscopy,Fourier transform infrared spectroscopy and UV–vis diffuse reflectance spectroscopy.The photocatalytic activities of the ZnO–WO3composite photocatalysts with different WO3contents for the degradation of the herbicide chlorinated phenoxyacetic acid(MCPA‐Na)under simulated sunlight irradiation were systematically evaluated.It was found that the WO3content had a great effect on the photocatalytic activity of the ZnO–WO3composites.The composite with3%WO3showed the highest photocatalytic activity,with a degradation rate of chlorinated phenoxyacetic acid of98.5%after200min with20mg of photocatalyst.This photodegradation rate was about twice that of the pristine ZnO nanotube array.The recombination of photogenerated electrons and holes was increasingly suppressed with the addition of WO3to ZnO.The high relative content of defects on the surface of the ZnO–WO3composites was beneficial to their photocatalytic activity in the degradation of chlorinated phenoxyacetic acid.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.

Controllable synthesis of well-ordered TiO_2 nanotubes in a mixed organic electrolyte for high-efficiency photocatalysis

Well-ordered TiO 2 nanotube arrays (TNAs) were fabricated by electrochemical anodization in a mixed organic electrolyte consisting of ethylene glycol and glycerol. The morphology, structure, crystalline phase, and photocatalytic properties of TNAs were characterized by using TEM, SEM, XRD and photodegradation of methylene blue. It was found that the morphology and structure of TNAs could be significantly influenced by the anodization time and applied voltage. The obtained tube length was found to be proportional to anodization time, and the calculated growth rate of nanotubes was 0.6 m/h. The microstructure analysis demonstrated that the diameter and thickness of the nanotubes increased with the increase of anodization voltage. The growth mechanism of TNAs was also proposed according to the observed relationship between current density and time during anodization. As expected, the obtained TNAs showed a higher photocatalytic activity than the commercial TiO 2 P25 nanoparticles.

Cobalt-vanadium bimetal-based nanoplates for efficient overall water splitting

The development of effective and low-cost catalysts for overall water splitting is essential for clean production of hydrogen from water.In this paper,we report the synthesis of cobalt-vanadium（Co-V）bimetal-based catalysts for the effective water splitting.The Co_2V_2O_7·xH_2O nanoplates containing both Co and V elements were selected as the precursors.After the calcination under NH_3atmosphere,the Co_2VO_4and Co/VN could be obtained just by tuning the calcination temperature.Electrochemical tests indicated that the Co-V bimetal-based materials could be used as active hydrogen evolution reaction（HER）and oxygen evolution reaction（OER）catalyst by regulating their structure.The Co/VN showed good performance for HER with the onset potential of68 mV and can achieve a current density of 10 mA cm^（-2）at an overpotential of 92 m V.Meanwhile,the Co_2VO_4exhibited the obvious OER performance with overpotential of 300 mV to achieve a current density of 10 mA cm^（-2）.When the Co_2VO_4and Co/VN were used as the anode and cathode in a twoelectrode system,respectively,the cell needed a voltage of1.65 V to achieve 10 mA cm^（-2）together with good stability.This work would be indicative to constructing Co-V bimetalbased catalysts for the catalytic application.