涂膜耐候钢大气暴露及锈层结构的研究

涂膜JT345耐候钢在青岛、沈阳、北京等地大气环境下曝晒2年,表现出良好的耐腐蚀性能,采用电子探针、X射线衍射等对大气挂片锈层形貌、结构、组成进行了分析,发现JT345耐候钢表面锈层主要由γ-FeOOH、α-FeOOH和Fe3O4组成.改性涂层处理可加速耐候钢表面生成致密保护性锈层,该锈层中富集大量的Cr、Cu、P等.     

涂膜下铝合金的丝状腐蚀

对铝合金汽车轮毂在海南万宁试验站进行为期24个月的棚下 和户外暴露试验,发现涂膜下铝合金发生丝状腐蚀。对涂膜下铝合金 丝状腐蚀的几个特点、类型、形成过程和影响因素进行了分析和讨 论。     

纳米TiO2薄膜在不同陶瓷表面的负载及其光催化性能研究

利用2种不同表面处理的陶瓷作为载体,用溶胶凝胶法在其表面进行了纳米TiO2光催化薄膜的负载.采用X射线衍射法(XRD)、X射线光电子能谱仪(XPS)和扫描电镜(SEM)对薄膜的粒径、横断面及表面组成进行了表征和分析,结果表明,TiO2的平均粒径约为15 nm,釉面陶瓷TiO2薄膜分布均匀,膜厚约为300 nm;无釉陶瓷TiO2薄膜分布不均,膜层不明显;2种载体中的一些基质离子在TiO2薄膜有渗透.苯酚的降解实验表明,以2种不同表面处理的陶瓷为载体的TiO2薄膜对苯酚的降解均符合一级反应动力学,就催化活性而言,TiO2/釉面陶瓷＞TiO2/无釉陶瓷,分析认为基质渗透的Ca2 有降低TiO2光催化活性的作用;该薄膜对实际生产多菌灵废水具有催化降解作用.重复降解实验20次,TiO2/釉面陶瓷和TiO2/无釉陶瓷对苯酚的去除率仅分别降低9%和6%.     

Synthesized magnetic nanoparticles coated zeolite for the adsorption of pharmaceutical compounds from aqueous solution using batch and column studies

The contamination of fresh water with pharmaceutical and personal care products (PPCPs) has risen during the last few years. The adsorption of some PPCPs namely, Diclofenac-Na, Naproxen, Gemfibrozil and Ibuprofen from aqueous solution has been studied, magnetic nanoparticles coated zeolite (MNCZ) has been used as the adsorbent. Batch adsorption experiment was conducted to study the influences of different adsorption parameters such as contact time, solution pH and PPCPs concentrations in order to optimize the reaction conditions. The removal was favored at low pH values. Thus, as pH turns from acidic to basic conditions these compounds were less efficiently removed. The initial concentration does not appear to exert a noticeable effect on the removal efficiency of the studied PPCPs at low concentrations, but it showed less removal efficiency during high concentration of PPCPs especially for Ibuprofen. The removal of Diclofenac-Na was independent on time, while the contact time was of significant effect on the adsorption of Naproxen, Gemfibrozil and Ibuprofen even though these compounds were removed up to 95% during 10 min using MNCZ. From the isotherm adsorption study, the adsorption of PPCPs studied on MNCZ was best fitted with Freundlich isotherm equation. Pseudo-second order model providing the best fit model with the experimental data. Column adsorption study was conducted to compare the removal efficiency of MNCZ with other processes used at drinking water treatment plants (DWTPs), MNCZ showed high removal efficiency (>99%) than other used processes at DWTPs.     

水滑石类材料的制备及在水污染治理中的应用

简要介绍了目前国内外水滑石类材料的各种制备方法,包括共沉淀法、焙烧还原法、离子交换法等。同时总结了其作为催化剂和离子交换剂在修复阴离子污染水体、印染废水脱色、重金属去除等方面应用。     

硅藻泥包埋纳米零价铁处理含铬废水的研究

采用环境友好型矿物材料硅藻泥(Diatom Mud)包埋纳米零价铁(nZVI)得到复合材料(D-nZVI),分别用XRD、SEM和TEM对样品分析表征.同时,通过考察D-nZVI中硅藻泥的用量、投加量、含Cr(VI)废水浓度、p H值、处理时间等对Cr(VI)去除率的影响,进一步研究了反应动力学等.结果表明,在25℃的条件下,D-nZVI中硅藻泥的用量为20%时,D-nZVI对Cr(VI)的去除效率要高于nZVI.p H值较低时D-nZVI的处理效果更好,并且含Cr(VI)废水的浓度越高,去除率越低,投加量增多和反应时间越长,Cr(VI)的去除率越高.当D-nZVI的用量为16 g·L-1,Cr(VI)废水浓度为10 mg·L-1,p H=3时,Cr(VI)的去除率达99%.从SEM和TEM样品分析结果可以看出,硅藻泥表面有很多小而均匀的小孔,较好地包埋或附着在纳米零价铁的表面上,起到了很好的抗氧化作用,为D-nZVI吸附、还原和共沉淀降解Cr(VI)提供了有力依据.     

包膜尿素对水田土壤排放NH3、NOx、CO2影响的研究

为了研究包膜尿素对水田土壤排放NH3、NOx和CO2的影响,采用水稻盆栽的方法,探讨了在水稻不同生育期内不同种类包膜尿素对水田土壤排放NH3、NOx和CO2的影响。结果表明,包膜尿素处理对水田土壤排放NH3、NOx和CO2均具有抑制作用,与普通尿素相比,包膜尿素LP40、LPSS、BB、SC60 NH3的挥发总量降低了5.4%~19.3%,NOx的挥发总量降低了8.1%~23.4%,CO2的挥发总量降低了1.6%~13.0%;施用包膜尿素能够抑制水田土壤NH3、NOx和CO2的排放。     

铝污泥酸化提取液改性沸石的除磷特性及机制

为了提高沸石的除磷能力并降低改性成本,以给水厂铝污泥为铝源,采用酸化提取液合成层状双氢氧化物(LDHs)覆膜于沸石表面制备改性沸石,分别测定原沸石、Al-Zn改性沸石及铝污泥改性沸石的表面特性和化学组分,分析等温吸附及吸附动力学特性,探讨铝污泥改性沸石的除磷性能及除磷机制.结果表明,最佳酸化提取条件为60 min、150 r·min~(-1)和p H1. 0,该条件下1 g铝污泥(干重)可提取77 mg的铝;改性沸石的饱和吸附容量和解吸性能较原沸石显著提高,尤其是铝污泥改性沸石,其理论最大吸附量从30. 24 mg·kg~(-1)提升至170. 40 mg·kg~(-1);改性使得沸石对磷酸盐的主要吸附类型由物理吸附向化学吸附转变.以铝污泥为铝源改性沸石能有效地提高其对磷酸盐的吸附能力及再生能力,在降低磷浓度过高引发的水体富营养化风险的同时,实现以废治废的目的.     

覆膜滤料过滤性能分析

覆膜滤料以其高效低阻、透气性好等特点备受关注。选取4种典型的覆膜滤料,通过静态和动态过滤实验分析其阻力和效率特性,进而对覆膜滤料的过滤性能进行综合分析。结果表明:在清洁阶段,4种覆膜滤料的喷吹周期和残余阻力差异较大,粉尘剥离率平均值为83.2174%,最大偏差为2.32%;在稳定阶段,4种覆膜滤料的清灰周期、残余阻力差异减小且趋于稳定,残余阻力增长率接近且偏差均在5%以内,剥离率平均值为95.4485%,最大偏差仅0.55%。可以看出,稳定阶段覆膜滤料的种类对于阻力增长率和粉尘剥离率影响不大。通过细颗粒物过滤实验可知,评价覆膜滤料对PM2.5的过滤效果需要综合考察滤料清洁阶段和稳定阶段,可为覆膜滤料应用和评价提供指导。     

Performance of activated carbon coated graphite bipolar electrodes on capacitive deionization method for salinity reduction

• Graphite bipolar electrodes act as an appropriate bed for the CDI process. • Activated carbon Coating improves the application of the electrodes. • CDI is an environmentally friendly method to apply for brackish water. • Initial concentration is the most important parameter in the CDI method. • CDI process in a batch-mode setup needs more development. This research investigates a capacitive deionization method for salinity reduction in a batch reactor as a new approach for desalination. Reductions of cost and energy compared with conventional desalination methods are the significant advantages of this approach. In this research, experiments were performed with a pair of graphite bipolar electrodes that were coated with a one-gram activated carbon solution. After completing preliminary tests, the impacts of four parameters on electrical conductivity reduction, including (1) the initial concentration of feed solution, (2) the duration of the tests, (3) the applied voltage, and (4) the pH of the solution, were examined. The results show that the maximum efficiency of electrical conductivity reduction in this laboratory-scale reactor is about 55%. Furthermore, the effects of the initial concentration of feed solution are more significant than the other parameters. Thus, using the capacitive deionization method for water desalination with low and moderate salt concentrations (i.e., brackish water) is proposed as an affordable method. Compared with conventional desalination methods, capacitive deionization is not only more efficient but also potentially more environmentally friendly.