三维电极-电Fenton处理硝基苯废水电极材料与影响因素研究

采用三维电极-电Fenton法处理模拟硝基苯废水,选择C-C作为电极极板,研究了该体系的处理效果、电极材料的选择和影响因素。对于200 mg/L硝基苯废水,在pH=3、40 m A/cm2电流密度、0. 5 mmol/L Fe~(2+)、2 g/L电解液、8 cm电极极板间距的试验条件下,硝基苯平均降解率为88%。正交实验结果表明,影响降解效果的显著性依次为pH极板间距电流密度 Fe~(2+)电解质浓度。     

水上介质阻挡放电等离子技术去除双酚A

研究了水上介质阻挡放电法(DBDow)去除水体中双酚A(BPA)的效果与机制,考察了峰值电压、BPA的初始浓度、pH值、电导率等对降解效果的影响。结果表明,随着峰值电压(20、21、22、23、24 kV)的升高,BPA降解率升高,初始浓度为0.684 1 mg/L的BPA在30 min时降解率均超过85%。当峰值电压为24 kV、BPA初始浓度为0.334 0～0.684 1 mg/L、初始电导率为2μS/cm、pH值为7时,随BPA初始浓度的增加,BPA的降解率增大,其中初始浓度为0.684 1 mg/L的BPA降解率在30 min时达到90%。此外,BPA降解率还随pH值的升高而降低、溶液初始电导率的增大而升高。根据GC-MS检测到的中间产物,推测BPA可能的降解途径为:BPA断裂生成4-异丙烷基苯酚自由基,4-异丙烷基苯酚自由基形成2,5-二叔丁基酚以及丙三醇,而丙三醇进一步生成乙二醇。     

电凝聚气浮技术处理采油废水的研究

采用铝电极对采油废水进行电凝聚气浮的试验研究,考察了电流强度、电解时间、pH、极板间距对除油率的影响.结果表明:电流强度和pH对处理效果有显著的影响,中性条件下的处理效果要好于酸性和碱性条件下的,电凝聚气浮对废水的pH有一定的调节作用;在电流强度为 A、极板间距为10 mm的条件下,对初始含油量为500 mg/L、pH值为7.2的模拟采油废水电解气浮20 min后,除油率最高可达89.6%.     

三维电极/电-Fenton法处理苯胺废水影响因素的试验研究

为研究三维电极/电-Fenton法对降解苯胺废水的影响因素,以优化三维电极/电-Fenton法处理苯胺废水的工艺条件,在自制三维电极电解槽中,以苯胺废水为处理对象,分别研究溶液的pH值、Fe~(2+)投加量、电解质(Na_2SO_4)投加量、曝气量四种因素对三维电极/电-Fenton法降解苯胺效果的影响情况。试验结果表明:当电解反应时间达到60min,电解电压为15V,极板间距为8cm时,控制溶液体系的pH值为3.0,Fe~(2+)浓度为0.7mmol/L,电解质投加量为1.8g/L,曝气量为0.8m~3/h,对苯胺和COD的去除率最高可达89.85%和90.69%。三维电极/电-Fenton法处理苯胺废水的效果较好。     

三维电场协同TiO2光催化降解水中双酚A的研究

采用溶胶-凝胶法制备TiO2/Ti膜电极,设计了三维电极电助光催化降解反应装置,并将其用于降解水中的双酚A.结果表明,三维电场协同TiO2光催化氧化技术对双酚A的降解效果较好,反应120 min后降解率可达100%;在本试验条件下,最佳阳极偏电压为8 V;当溶液的电导率较小时,增大电导率有利于对双酚A的降解,但当电导率较大时,对双酚A的降解率反而随电导率的增大而逐渐减小;电助光催化降解双酚A的反应符合表观一级动力学方程.     

隔膜体系阴阳极共同作用电化学法降解水中的甲基橙

本文针对隔膜体系阴阳极共同作用电化学法处理甲基橙废水,在自制的电化学反应器中设置隔膜系统,确定了隔膜体系阴阳极共同作用电化学法处理甲基橙废水的最佳反应条件:进水甲基橙浓度100mg/L,电解质投加量0.02mol/L,电解电压20V,电极板间距4cm,曝气速率2.0L/min,此时阴、阳极室中甲基橙脱色率最高达到90.87%和99.45%。通过数据分析得出阴、阳极室脱色率与能耗的关系式,并对甲基橙降解机理进行了分析。     

复极性三维电极-电芬顿耦合法处理苯酚废水的实验研究

为了降解苯酚废水中有毒有害污染物质,本研究利用复极性三维电极-电芬顿耦合法处理苯酚废水。通过控制p H值、进水苯酚浓度、极板间距、曝气量等因素对苯酚废水处理效果的影响研究得出,当p H值为3、进水苯酚浓度为300mg/L、极板间距为6cm、曝气量为0.8L/min时,复极性三维电极-电芬顿耦合反应器处理苯酚废水的效果最好,对苯酚的去除率可达到92.34%。     

残留电荷对气体放电管冲击放电电压的影响分析

针对气体放电管电极表面残留电荷对冲击放电电压影响问题,讨论残留电荷积累与消散;采用3种不同型号的放电管经过多次4 kV,1.2/50μs开路电压波冲击试验,观测冲击放电电压值的变化趋势,将多次冲击后的放电管施加辉光电压,观测辉光放电电流值的变化趋势,研究残留电荷对气体放电管微观放电的促进作用。实验表明:经过多次4 kV,1.2/50μs开路电压波冲击,放电管在没有明显损坏的情况下,随着冲击次数的增加,放电管残留电荷逐渐增加,导致冲击放电电压值有逐渐减小的趋势,这种趋势在冲击达到30次得到相对稳定。     

可见光助多相电催化法处理苯酚废水的 试验研究

本文针对可见光助多相电催化法处理苯酚模拟废水,制备了活性炭负载N掺杂TiO_2光催化剂作为粒子电极,确定了可见光助多相电催化法处理模拟苯酚废水最佳反应条件,COD浓度为378.5mg·L~(-1),pH值为3.0,电极板间距10 cm,电解质Na2SO4投加浓度1 g·L~(-1),电解电压15 V,曝气量11 L·min~(-1),此时COD去除率为85.12%。对比可见光助多相电催化法、多相电催化法、可见光法对于苯酚处理效果的差异,分析了可见光助多相电催化作用的协同效应与反应机理。可见光助多相电催化法对苯酚模拟废水的降解效果显著,操作简单,通过进一步优化反应条件,可应用于苯酚废水处理工程实践中。     

复极性电-多相催化氧化处理染料废水试验

通过自制的反应器对复极性电-多相催化氧化方法降解处理有机物的规律进行研究。试验确定槽电压、pH、粒子电极活性炭投加浓度、反应时间等因素对体系处理活性艳橙X-GN废水效果的影响。结果表明:当试验条件为槽电压为16V,pH值为6.8,活性炭(粒子电极)投加量为150g/L,曝气量为0.7L/min,电解质投加量为1.2g/L,反应进行60min,复合体系处理活性艳橙X-GN的去除率最高,可达95.85%,此为最佳反应条件。分析结果可知复极性电-多相催化氧化复合的方法降解处理有机物效果较好。     

垂直电极火花放电现象分析

为研究雷电流流过接地极的冲击接地特性,用圆筒中的泥沙代替土壤,研究不同泥沙中垂直电极的冲击特性,得到不同介质的火花放电规律。泥沙击穿电压随泥沙中水含量的增加而降低,盐沙由于导电性增加就不易产生火花放电效应;干沙击穿过程以空气间隙击穿为主,而湿沙击穿以热击穿为主。     

Influence of air humidity and the distance from the source on negative air ion concentration in indoor air

Although negative air ionizer is commonly used for indoor air cleaning, few studies examine the concentration gradient of negative air ion (NAI) in indoor environments. This study investigated the concentration gradient of NAI at various relative humidities and distances form the source in indoor air. The NAI was generated by single-electrode negative electric discharge; the discharge was kept at dark discharge and 30.0 kV. The NAI concentrations were measured at various distances (10-900 cm) from the discharge electrode in order to identify the distribution of NAI in an indoor environment. The profile of NAI concentration was monitored at different relative humidities (38.1-73.6% RH) and room temperatures (25.2+/-1.4 degrees C). Experimental results indicate that the influence of relative humidity on the concentration gradient of NAI was complicated. There were four trends for the relationship between NAI concentration and relative humidity at different distances from the discharge electrode. The changes of NAI concentration with an increase in relative humidity at different distances were quite steady (10-30 cm), strongly declining (70-360 cm), approaching stability (420-450 cm) and moderately increasing (560-900 cm). Additionally, the regression analysis of NAI concentrations and distances from the discharge electrode indicated a logarithmic linear (log-linear) relationship; the distance of log-linear tendency (lambda) decreased with an increase in relative humidity such that the log-linear distance of 38.1% RH was 2.9 times that of 73.6% RH. Moreover, an empirical curve fit based on this study for the concentration gradient of NAI generated by negative electric discharge in indoor air was developed for estimating the NAI concentration at different relative humidities and distances from the source of electric discharge.     

Degradation of 2,4,6-trinitrotoluene by immobilized horseradish peroxidase and electrogenerated peroxide

This paper presents horseradish peroxidase (HRP)-catalyzed removal of 2,4,6-trinitrotoluene (TNT) by an electrochemical packed-bed flow reactor operated in a circulating batch mode with the help of in situ generated hydrogen peroxide. HRP immobilized on the reticulated vitreous carbon electrode was prepared for the cyclic voltammetry of 2,4,6-TNT. Effects of pH and temperature on the TNT electroreduction in 0.2M phosphate buffer saturated with oxygen were examined. HRP immobilized carbon electrode was capable of catalyzing the oxidation and detoxification of 44 microM TNT in aqueous solution under optimized conditions. The removal rate of TNT for the electroenzymatic method was much greater than for electrochemical and biochemical methods. Stoichiometric and kinetic studies indicated that the hydrogen peroxide was utilized more effectively in the electroenzymatic method. Denitrification as intermediate reaction was also investigated.     

Using mesoporous carbon electrodes for brackish water desalination

Electrosorptive deionisation is an alternative process to remove salt ions from the brackish water. The porous carbon materials are used as electrodes. When charged in low voltage electric fields, they possess a highly charged surface that induces adsorption of salt ions on the surface. This process is reversible, so the adsorbed salt ions can be desorbed and the electrode can be reused. In the study, an ordered mesoporous carbon (OMC) electrode was developed for electrosorptive desalination. The effects of pore arrangement pattern (ordered and random) and pore size distribution (mesopores and micropores) on the desalination performance was investigated by comparing OMC and activated carbon (AC). It were revealed from X-ray diffraction and N(2) sorption measurements that AC has both micropores and mesopores, whereas ordered mesopores are dominant in OMC. Their performance as potential electrodes to remove salt was evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests at a range of electrolyte concentrations and sweep rates. It is deduced that under the same electrochemical condition the specific capacitance values of OMC electrode (i.e. 133 F/g obtained from CV at a sweep rate of 1 mV/s in 0.1M NaCl solution) are larger than those of AC electrode (107 F/g), suggesting that the former has a higher desalting capacity than the latter. Furthermore, the OMC electrode shows a better rate capacity than the AC electrode. In addition, the desalination capacities were quantified by the batch-mode experiment at low voltage of 1.2V in 25 ppm NaCl solution (50 micros/cm conductivity). It was found that the adsorbed ion amounts of OMC and AC electrodes were 11.6 and 4.3 micromol/g, respectively. The excellent electrosorptive desalination performance of OMC electrode might be not only due to the suitable pore size (average of 3.3 nm) for the propagation of the salt ions, but also due to the ordered mesoporous structure that facilitates desorption of the salt. Based on the results, it was found that the development of an ordered mesoporous structure and the control of the number of micropores are two important strategies for optimising electrode material properties for electrosorptive deionisation.     

电气化铁路沿线通信机房接地电阻在线监测系统的研究

针对电气化铁路通信机房接地体的特殊运行环境受到的电磁干扰,设计了一套接地电阻在线监测系统。采用变频法测量接地电阻,将辅助电压极置于接地体与辅助电流极之间距离的0.59处,可以精确地测量接地电阻的大小,减少工作量;应用FIR滤波与FFT插值的抗干扰方案,使得沿线机房接地电阻在不断电的情况下实现精确的在线监测。应用该系统对电气化铁路通信机房接地电阻进行了现场实际测量,结果表明,该系统在电气化铁路强电磁干扰环境下能准确测量,可靠工作。     

Degradation of pharmaceutical compound pentoxifylline in water by non-thermal plasma treatment

The decomposition of a model pharmaceutical compound, pentoxifylline, in aqueous solution was investigated using a dielectric barrier discharge (DBD) in coaxial configuration, operated in pulsed regime, at atmospheric pressure and room temperature. The solution was made to flow as a film over the surface of the inner electrode of the plasma reactor, so the discharge was generated at the gas-liquid interface. Oxygen was introduced with a flow rate of 600 sccm. After 60 min plasma treatment 92.5% removal of pentoxifylline was achieved and the corresponding decomposition yield was 16 g/kWh. It was found that pentoxifylline degradation depended on the initial concentration of the compound, being faster for lower concentrations. Faster decomposition of pentoxifylline could be also achieved by increasing the pulse repetition rate, and implicitly the power introduced in the discharge, however, this had little effect on the decomposition yield. The degradation products were investigated by liquid chromatography-mass spectrometry technique (LC-MS). The evolution of the intermediates during plasma treatment showed a fast increase in the first 30 min, followed by a slower decrease, so that these products are almost completely removed after 120 min treatment time.     

利用浅基础作接地装置的探讨

通过比较接地网的网格数量、水平接地带和埋深对跨步电压的影响,定量论述了利用建筑物浅基础做接地装置的可行性。结论:均压措施能有效降低跨步电压;增加接地网的网格数量、水平带数量可以取得和增加接地装置埋深同样的效果;当土壤和基础等客观条件都满足规范要求,利用埋深很浅的钢筋混凝土浅基础梁作接地装置,即使仅有均压措施,也可以预防跨步电压的危害。     

三维电极/电Fenton法去除垃圾渗滤液中的COD

考察了三维电极／电Fenton法对垃圾渗滤液中COD的去除效果及其影响因素,并探讨了COD的降解动力学。结果表明,在涂膜炭填充率为20％、炭水比为0．5、极板间距为10cm、电流密度为57．1mA／cm^2、曝气量为0．2m^3／h、Fe^2＋浓度为1mmoL／L、pH值为4的最佳条件下,电解180min后,对COD的去除率为80．8％,明显高于电Fenton法（58．83％）和三维电极法（69．64％）;三维电杉电Fenton法对垃圾渗滤液中COD的降解符合拟三级反应动力学方程,当原水COD为1634mg／L时,动力学常数k=2．197×10^-8L^2／（mg^2·min）。     

两淮煤系地层主要岩石单轴受压条件下的导电特性试验研究

设计一种岩石受荷条件下的岩石电阻率试验装置。通过试验,发现一种取材方便、效果良好的电极耦合材料——过饱和黏土。试验研究两淮煤系地层主要岩石的导电性随电流、电压、应力的变化特性,并拟合出各岩样较高相关度的电阻率-应力(ρ-σ)回归方程,结果发现:(1)两淮煤田煤系地层岩石在弹性变形范围内,其导电性随着应力的增大而增强(即岩石的电阻率随着应力的增大而降低);(2)软弱砂质泥岩导电性受应力影响的程度大于坚硬的砂岩、闪长岩;(3)岩石电阻率与应力之间存在较好的相关性;(4)在应力一定的条件下,软弱砂质泥岩的导电性随着电压、电流的增强而增强(电阻率降低),坚硬砂岩、闪长岩的导电性基本不受电压、电流的影响。在两淮煤田深井巷道围岩松动圈的高密度电阻率法探测中,将测试得到的巷道围岩视电阻率断面图或电阻率反演断面图与岩石电阻率试验获得的ρ-σ回归方程相结合,分析巷道围岩松动圈的发育状况,取得较好的工程效果。     

辅助电极及电极距离对沉积效果的影响

就电沉积方法修复混凝土裂缝中辅助电极、电极距离对沉积效果的影响进行了试验研究,测定了沉积过程中试件质量增加率、表面覆盖率及裂缝愈合率．通过研究发现,在所选的3种电极中,棱柱状钛网板电极的沉积效果最好,电极距离对沉积效果的影响呈现出一定的规律性．