海绵铁与火山岩填料A/O生物滴滤池脱氮除磷的中试研究

以火山岩矿物为填料,进行了A/O生物滴滤池脱氮除磷的中试现场试验。通过内部设置缺氧段,采用海绵铁强化除磷的方法,提高了滴滤池的脱氮除磷能力。结果表明,A/O生物滴滤池对TN、NH3-N、TP、COD均有较理想的去除效果,特别是TN和TP;当进水TN、TP质量浓度分别为51.0～56.8 mg/L和4.99～5.32 mg/L时,去除率平均可达79%和84%,比普通生物滴滤池分别高约35%和50%;出水质量浓度分别为12 mg/L和1.0 mg/L左右。出水TN可达城镇污水处理厂污染物排放标准(GB 18918-2002)中一级A排放标准,TP接近一级B排放标准。     

不同碳源条件生物滤池深度脱氮效能及其经济性

通过构建外加碳源+反硝化生物滤池(DNBF)、O_3+DNBF和二级出水掺入原污水+间歇曝气生物滤池(IBAF)3种运行方案,进行了不同碳源条件下反硝化、间歇曝气生物滤池对污水厂二级出水深度脱氮研究,并考察了可行性与经济性。结果表明,方案1和2分别在外加乙酸钠和臭氧投加量为20 mg/L时,出水TN的质量浓度平均分别为13.47 mg/L和13.76 mg/L,TN去除率为32.52%和27.88%;方案3在原污水与二级出水的体积比为1:2时,出水TN的质量浓度平均为13.45 mg/L,TN去除率为39.22%。出水水质均达到GB18918-2002中的一级A标准。方案1的脱氮效能及运行费用最优;方案3可获得定量处理水深度脱氮和原污水协同处置耦合的效果,适用于生物处理扩容及出水提标工程。     

连续曝气生物膜反应器同步脱氮除磷实验研究

为进一步提高生物处理工艺脱氮除磷效果,采用连续曝气生物膜反应器对生活污水进行了实验研究,分析了污染物去除效果和主要影响因素。结果表明,在HRT=3 h的条件下,将DO的质量浓度控制在2 mg/L可取得较好的同步脱氮除磷效果,出水NH_4~+-N、TN、TP的质量浓度和COD分别为2.83、11.9、0.56 mg/L和24.7 mg/L。在HRT=3 h、ρ(DO)=(2±0.2) mg/L的条件下,提高进水碳氮比可进一步优化同步脱氮除磷效果,COD/ρ(TN)=8时,NH_4~+-N、TN、TP去除率分别为92%、77.6%、85.4%。     

循环式活性污泥法工艺运行效果及优化控制方案

介绍了某污水处理厂循环式活性污泥法(CAST)工艺运行情况。生化池由生物选择区及主反应区组成,因此可有效去除COD,出水COD平均为29.5 mg/L,去除率90.7%。提出了以延长回流时间、增强生物选择区污泥混合强度和末端DO含量控制的脱氮除磷优化的控制方案,停止曝气后,增加硝化回流时间0.5～1 h,曝气池末段DO的质量浓度控制在1.5～3.0 mg/L时,系统有较好的TN去除效果,出水TN、NH_4~+-N的质量浓度平均分别为10.1、0.805mg/L,去除率分别为69.9%、96.3%。通过改变除磷药剂投加位置和加药系统自动化改造来优化除磷,节省了药剂费用,实际投加量为1.88 t/d,出水TP的质量浓度平均为0.345 mg/L,去除率93.8%。     

某城镇污水处理厂污染物去除效果研究

以某污水处理厂升级改造工艺(改良A~2/O+MBBR组合工艺+混凝深度处理工艺)为研究对象,对2015年污水处理厂主要进出水水质指标进行分析,发现该污水处理厂主要水质指标COD、TN、NH3-N和TP出水浓度均能稳定达到一级A标准,出水浓度年平均值分别为28.6mg/L、9.5mg/L、1.49mg/L、0.22mg/L,平均去除率分别为96.4%、86.8%、97.3%、97.3%,该污水处理厂污染物去除效果良好,去除率较高。     

改良多级A/O对低C/N生活污水强化除磷效果研究

针对传统多级A/O工艺处理低碳氮比生活污水除磷效果差的问题，通过增设前置厌氧段改良多级A/O工艺，重点研究了除磷效果的可行性。结果表明：在温度为17℃±3℃、流量分配比为100%∶0∶0、水力停留时间为10h、污泥回流比为50%、污泥龄为14天的条件下，系统总体除磷效果较好。其中COD、TP平均去除率分别为89.81%、90.35%，出水平均浓度分别为32.65mg/L、0.49mg/L，均优于GB 18918—2002《城镇污水处理厂污染物排放标准》一级A排放标准。由于受到硝化反硝化的综合影响，对污水中含有的氮素去除效果一般，其中NH₃-N、TN去除率均为50%左右，出水平均浓度为30.32mg/L、30.41mg/L，可通过外加碳源的方式增强反硝化能力，进一步提高系统脱氮效果，出水有望达到一级B标准。改良工艺在保证有机物去除效果的基础上基本实现了脱氮除磷，可为实际生活中处理低C/N生活污水提供参考。     

超滤膜在城市污水深度处理技术中的研究

本文分析了鄂尔多斯市达拉特旗污水处理厂污水中COD、NH4+-N、TP出水浓度水质特征以及经过MBR工艺处理后进出水浓度变化过程,结果表明:该工艺对COD、NH4+-N的平均去除率分别为94.78%、96.88%;试验平均出水COD浓度为31.42mg/L,NH4+-N浓度为1.99mg/L,均达到了《城镇污水处理厂污染物排放标准(GB18918-2002)》的一级A标准,可见该工艺对城市生活污水的有机污染物和氨氮有很好的去除效果。但是试验对污水中TP的平均去除率只有67.00%,平均出水TP浓度为1.84mg/L,远高于国家城市污水排放标准中的TP的排放限值。     

两级A/O工艺处理生活污水脱氮除磷试验

针对传统A2/O工艺存在的泥龄矛盾,将脱氮和除磷分置于前后2套不同的A/O系统中,第一级A/O采用活性污泥法除磷;第二级A/O采用生物膜法脱氮。以生活污水为处理对象进行试验研究。结果表明,在泥龄为6 d、水温为22～28℃,进水NH3-N、TP、COD的质量浓度分别为40～70、2.0～6.0、150～320 mg/L条件下,出水NH3-N、TP、COD的平均质量浓度分别为5.9、1.0、40 mg/L,均达到了城镇污水处理厂污染物排放标准(GB18918-2002)中的一级排放标准,其去除率分别为82.5%、69.7%、83.1%。     

曝气生物滤池后置反硝化效能研究

以甲醇为外碳源,对生活污水进行两级串联O-A曝气生物滤池脱氮及去除COD的试验研究。采用陶粒为填料,向二级滤柱中投加甲醇,确定甲醇的最佳投量,考查该种形式的曝气生物滤池脱氮效果及出水COD浓度是否达标。试验表明,甲醇投量为20mg/L时,曝气生物滤池二级出水COD﹑NH3-N﹑NO3--N﹑TN平均质量浓度分别为49.3﹑3.3﹑1.6﹑5.5mg/L,其去除率分别为85.3%﹑85.7%﹑77.1%﹑82.0%。达到很好的脱氮及去除COD效果。出水水质达到了《城镇污水处理厂污染物排放标准》一级标准中的B级标准。     

生活污水脱氮除磷的工艺设计

以泰州市紫光水业污水处理厂初沉池出水和曝气池的活性污泥制作一定浓度的污泥混合液,通过测定COD、TN、TP、NH3-N等指标发现自制的可移动悬浮式曝气设备脱氮除磷处理效果非常好。进水COD=324.6mg/L,TP=6.04mg/L,NH3-N=49.3mg/L,TN=56.4mg/L,出水COD=28.7mg/L,去除率为91.2%,TP=0.49mg/L,去除率为91.9%,NH3-N=8.02mg/L,去除率为83.7%,TN=12.7mg/L,去除率为77.5%。出水达到了我国《城镇污水处理厂污染物排放标准》(GB18918—2002)。     

Effects of calcination condition on expansion property of MgO-type expansive agent used in cement-based materials

Previous research indicated that the expansion property of MgO-type expansive agent (MEA) depended strongly on the calcining conditions, i.e. kiln temperature and residence time. However, the intrinsic effect of calcination condition on the expansion property of MEA has not been clearly demonstrated. In the present work, the effects of calcination condition on the microstructure, hydration activity, and expansion property of MEA have been investigated, and their correlations are also studied. Results indicate that the microstructure of MEA is the intrinsic factor that controlling its expansion property, which is influenced by the calcination condition. MEA produced under higher temperature and longer residence time has less interior pores, larger crystal size of MgO, and smaller specific surface area, thus resulting in lower hydration activity and slower expansion at early age, but larger “ultimate” expansion at late age. While, a new expansion model of MEA is proposed to explain these results.     

Toughening of polypropylene with styrene/ethylene‐butylene/styrene triblock copolymer: Effects of reactive and nonreactive compatibilization

The effects of the compatibilization on the toughening of polypropylene (PP) by melt blending with styrene/ethylene‐butylene/styrene triblock copolymer (SEBS) in a twin‐screw extruder were investigated. The compatibilizers used were an SEBS functionalized with maleic anhydride, a PP functionalized with acrylic acid, and a bifunctional compound, p‐phenylenediamine (PPD). The effects of the compatibilization were evaluated through the mechanical properties and by the determination of the phase morphology of the blends by scanning electron microscopy. Reactive compatibilized blends show up to a 30‐fold increase in impact strength compared to neat PP, which was likely to have been due to the reaction of the bifunctional compound (PPD) with the acid acrylic and maleic anhydride groups, which rendered both morphological and mechanical stability to these blends. The addition of the PPD to the blends significantly changed their phase morphologies, leading to larger dispersed particles' average diameters, probably due to the morphological stabilization at the initial processing steps during extrusion, with the occurrence of the chemical reactions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1081–1094, 2003     

Material and environmental parameter effects on the leaching of cement pastes: Experiments and modelling

Results already published on the leaching of cement pastes have shown that the kinetics depends sensitively on the material and environment. However and because of the variability of the tested materials and leaching protocols, it is difficult to compare these data and quantify the effect of each parameter. In this paper, a large experimental database on the leaching kinetics of cement pastes is built. Four parameters are investigated: type of cement (portland cement, silica fume cement, slag cement, ternary cement with slag and fly ash); water-to-cement ratio (0.5; 0.4; 0.25), temperature (26 °C; 72 °C; 85 °C) and chemical composition of the leaching solution (pure water, mineralised water, ammonium nitrate solution). Firstly, the database is used to calculate the leaching kinetics of the cementitious materials. Secondly, a simplified model predicting the one-dimensional leaching kinetics for other water-to-cement ratios and temperature up to 85 °C is presented.     

(SrZrO_3)_(10)(SrTiO_3)_(90)缓冲层对PZT结晶及性能的影响

采用Sol-gel法制备了PbZr0.52Ti0.48O3 (PZT)薄膜,并研究了(SrZrO3)10(SrTiO3)90((SZO)10(STO)90)缓冲层对PZT薄膜结晶和性能的影响.X射线衍射(XRD)结果表明:(SZO)10(STO)90缓冲层对PZT薄膜结晶有取向诱导作用,由(SZO)10(STO)90诱导的PZT薄膜有很强的(111)择优取向,缓冲层将PZT薄膜的取向度α由45.0%提高到了90.1%以上;PZT的(111)择优取向提高了薄膜的电性能,使剩余极化强度Pr从26.8 μC/cm2增大到38.8 μC/cm2.     

Photocatalytic degradation of air pollutants — From modeling to large scale application

Indoor as well as outdoor air quality and their limiting values remain a major problem to our present-day society.This paper addresses the modeling of the decomposition process of nitrogen monoxide (NO) on reactive concrete surfaces under the controlled exposition of a UV source. Within this model the external mass transfer of the pollutant and the internal molecule diffusion-reaction were considered. A first-order kinetics equation is derived with respect to the NO concentration and a site-competitive adsorption between NO/NO₂ and water molecules, resulting in a dependence of the reaction kinetics on the relative humidity. Using the proposed model, a reaction rate constant k and an adsorption equilibrium constant K_d can be derived which describe an active paving stone accurately. Experimental results from a self-developed photoreactor with continuous flow mode were used to validate the proposed kinetic expression. Furthermore, the effect of variations in process conditions such as irradiance and relative humidity on the two constants k and K_d is investigated. All modeling work provides a sound foundation for the translation of this process to real outside conditions. In this regard an upcoming project in a Dutch city is described in brief.     

硫氰酸锰及其相关衍生物的合成及化学表征

合成了金属有机配合物非线性光学晶体硫氰酸汞锰，及其相关衍生物，二二甲亚砜合硫氰酸汞锰，乙二醇一甲醚合硫氰酸汞锰，二水合二N，N－二甲基乙酰胺合硫氰酸汞锰，二水合二N－甲基－α－吡咯烷酮合硫氰酸汞锰。采用元素分析，红外光谱以及紫外－可见－近红外透央求我谱分析对其进行了化学表征。     

Design and processing of ZnO doped tricalcium phosphate based materials: Influence of β/α polymorph phase assemblage on microstructural evolution

Tricalcium phosphate (TCP) based biomaterials are excellent candidates in hard tissue engineering due to their similarity to the natural bone composition and outstanding properties. The presence of additives such as (Mg²⁺, Zn ²⁺, F⁻, CO₃²⁻ and/or SiO₄⁻) in solid solution in the structure of TCP, affects the stability of its different polymorphs and therefore the properties of TCP based biomaterials. It is known that the incorporation of zinc in TCP in the non-toxic level stimulates bone growth and its mineralization, hence its interest. Nevertheless its effect on phase assemblage and microstructure evolution has not been clearly established. The main purpose of this study was to synthesize TCP and zinc doped monophasic/biphasic α/β-TCP dense biomaterials, by solid-state sintering process, with different ZnO contents and controlled phase proportions and microstructure on the final material. The effect of ZnO content and sintering temperature on phase assemblage, densification and microstructural evolution has been investigated.     

二环戊二烯在脂环／芳香族环氧树脂中的应用

本文概述了以二环戊二烯及其衍生物为基础的脂环／芳香族环氧树树研究与开发近况；并介绍了这些树脂的主要特性及其在电子工业中的一些应用。     

Optimizing multiple qualities in as‐spun polypropylene yarn by neural networks and genetic algorithms

This investigation considers a quantitative procedure for determining the values of critical process parameters in melt spinning to optimize the qualities of denier, tenacity, breaking elongation, and denier variance in as‐spun polypropylene yarn. An orthogonal array in the Taguchi method defines the minimum set of parameter‐level combinations that are experimentally tested. The significant process parameters, namely the third extruder barrel temperature, spinning temperature, metering pump speed, and take‐up velocity, are identified on the basis of the analysis of variance and F test. After a confirmation experiment is conducted to ensure the reproducibility of the experimental results, the back‐propagation neural network establishes a continuous system linking 10 process parameters and four qualities. The technique for order preference by similarity to an ideal solution can be used to obtain a performance measure for assessing multiple qualities. The genetic algorithm attempts to find parameter values for optimizing the quality performance, including the denier, tenacity, breaking elongation, and denier variance. Finally, the experimental results demonstrate that the smallest denier, largest tenacity, smallest breaking elongation, and second smallest denier variance of as‐spun polypropylene yarn can be achieved with the proposed approach in melt spinning. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2532–2541, 2006     

Selective plasma‐induced grafting of polystyrene onto polyolefin blends

Plasma pretreatment has been used to generate reactive radicals and oxygenated groups on polymer surfaces for graft polymerization. The polymer substrates studied were composed of a polypropylene–polyethylene (PP–PE) copolymer, which was predominantly PP, and also contained blended ethylene–propylene rubber (EPR) as either about 15 or about 60 mol %. A pure PP substrate was also studied for comparison. The grafted polymer was polystyrene (PS). Raman microspectroscopic 2‐dimensional mapping was used to elucidate the role of crystallinity and EPR in the plasma treatment and graft polymerization process. It was found that the plasma pretreatment favored the EPR component of the substrate and the graft yield was related to the EPR content. Crystallinity seemed to have a much less significant effect on the grafting reaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1643–1652, 2003