聚硅铝系列絮凝剂的制备表征及其应用

制备了聚硅铝系列絮凝剂 ,利用透射电镜 (TEM)和准弹性激光散射 (PCS)进行了粒径分布和结构表征 ,发现聚硅铝系絮凝剂具有与硫酸铝和聚合氯化铝不同的结构形态 ,聚硅硫酸铝 (PASS)聚集体之间的距离与颗粒直径成线性关系。通过对原水的混凝处理对比 ,发现聚硅铝絮凝剂在降低浊度、去除有机物和某些元素方面具有显著优势。其中PASM和PASFⅢ对重金属和放射性元素的去除效果最好 ,尤其是经PASFⅢ处理后水中残留铝的去除率为 1 5 .3 % ,解决了使用铝盐增高铝含量的难题。经济分析也表明聚硅铝系絮凝剂价格低廉 ,具有良好的应用前景     

蚯蚓抗菌肽EABP-1的分离纯化及部分性质

经硫酸铵沉淀、超滤和阳离子交换分离 ,得到了一蚯蚓抗菌肽EABP 1,该肽的最大紫外吸收在 2 77.16nm ,SDS PAGE结果表明其Mr≈ 2 0× 10 3,精确的分子量没有确定 .最小抑菌浓度 (ρMIC)实验表明 ,EABP 1对鹑鸡肠球菌(Enterococcusgallinarum)、绿脓杆菌 (Pseudomonaspyocyanea)、鲍氏不动 (Acinetobacterbaumanii)、土生克雷伯 (Kleb siellaterrigena)的 ρMIC为 11.4μg/mL ,对粪肠球菌 (Enterococcusfaecalis)的 ρMIC为 2 2 .8μg/mL ,对真菌白色念株菌(Candidaalbicans)没有表现为完全的抑制作用 .图 1表 1参 10     

Adsorption of formaldehyde vapor by amine-functionalized mesoporous silica materials

The amine-functionalized mesoporous silica materials were prepared via the co-condensation reaction of tetraethoxysilane and three types of organoalkoxysilanes： 3-aminopropyl-trimethoxysilane, n-（2-aminoethyl）-3-aminopropyltrimethoxysilane, and 3-（2-（2- aminoehtylamino）ethylamino） propyl-trimethoxysilane. Cetyltrimethylammonium bromide was used as a template for forming pores, Specific surface area and pore volume of the amine-functionalized mesoporous silica materials were determined using surface area and pore size analyzer. Fourier transform infrared （FTIR） spectroscope was employed for identifying the functional groups on pore surface. In addition, the amine-functionalized mesoporous silica materials were applied as adsorbents for adsorbing formaldehyde vapor. FTIR spectra showed the evidence of the reaction between formaldehyde molecules and amine groups on pore surface of adsorbents. The equilibrium data of formaldehyde adsorbed on the adsorbents were analyzed using the Langmuir, Freundlich and Temkin isotherm. The sample functionalized from n-（2-aminoethyl）-3-aminopropyltrimethoxysilane showed the highest adsorption capacity owing to its amine groups and the large pore diameter.     

纳米聚硅酸铝锌絮凝剂的制备及表征简

在SiO₂含量为3%，pH为3，活化时间为85 min，（Al+Zn ）/Si摩尔比为1.5，Al/Zn摩尔比为2，表面活性剂硬脂酸钠加入量为0.1%，超声频率为40 Hz，超声时间为60 min的最佳制备条件下制备出液体PSAZS絮凝剂，用超声法制成纳米级Nano-PSAZS，用环境扫描电子显微镜（ESEM）和智能型傅里叶变换红外光谱（FT-IR）等仪器进行分析。结果表明，硅有助于絮凝剂分子链的延伸，有助于生成更大分子的聚合物；铝盐和锌盐的加入到聚硅酸中，并不是简单的混合，而是发生了缩聚和配位反应，有助于生成链网状结构，能更好地发挥吸附架桥和网捕卷扫作用。同时Nano-PSAZS陈化时间为24 h时的结构有利于絮凝效果的发挥。     

A baseline study characterizing the municipal solid waste in the State of Kuwait

This paper provides a new reference line for municipal solid waste characterization in Kuwait. The baseline data were collected in accordance with the Standard Test Method for the Determination of the Composition of Unprocessed Municipal Solid Waste (ASTM). The results indicated that the average daily municipal waste generation level is 1.01 kg/person. Detailed waste stream surveys were conducted for more than 600 samples of municipal solid waste (MSW). The waste categories included paper, corrugated fibers, PET bottles, film, organic matter, wood, metal, glass, and others. The results indicated that organic waste dominated the characterization (44.4%), followed by film (11.2%) and then corrugated fibers (8.6%). Analysis of variance (ANOVA) was used to investigate the influence of season and governorate on waste composition. A significant seasonal variation was observed in almost all waste categories. In addition, significant differences in proportions between the current level and 1995 baseline were observed in most waste categories at the 95% confidence level.     

The presence of zinc in Swedish waste fuels

Zinc (Zn) is a chemical element that has gained more attention lately owing to its possibility to form corrosive deposits in large boilers, such as Waste-to-Energy plants. Zn enters the boilers in many different forms and particularly in waste, the amount of Zn is hard to determine due to both the heterogeneity of waste in general but also due to the fact that little is yet published specifically about the Zn levels in waste. This study aimed to determine the Zn in Swedish waste fuels by taking regular samples from seven different and geographically separate waste combustion plants over a 12-month period. The analysis shows that there is a relation between the municipal solid waste (MSW) content and the Zn-content; high MSW-content gives lower Zn-content. This means that waste combustion plants with a higher share of industrial and commercial waste and/or building and demolition waste would have a higher share of Zn in the fuel. The study also shows that in Sweden, the geographic location of the plant does not have any effect on the Zn-content. Furthermore, it is concluded that different seasons appear not to affect the Zn concentrations significantly. In some plants there was a clear correlation between the Zn-content and the content of other trace metals.     

好氧颗粒污泥表征技术研究进展

随着好氧污泥颗粒化技术的兴起,好氧颗粒污泥成为研究的热点之一。各国学者对好氧颗粒污泥应用了不同的表征手段,文章对好氧颗粒污泥的物理性质表征方法、物化性质表征方法、生化性质表征方法、性能参数表征方法以及PCR、FISH、DGGE等现代分子生物学技术在好氧颗粒污泥研究中的应用进行了综述。     

MAMA双功能螯合剂前体的合成及结构表征

双功能螯合剂在放射性药物的研究、合成、应用,特别是在生物分子的放射性标记方面发挥着极为重要的作用.本文采用简易方法合成了MAMA双功能螯合剂前体,N-(2"-对甲氧苄巯乙基)-2-[(2'-对甲氧苄巯乙基)氨基]乙酰胺,并通过Uv-vis、IR、1HNMR、MS以及元素分析等对其结构组成进行了确证;同时,利用Gaussian 03W程序对其进行了结构优化描述,并计算了相应的分子能量.此外,对制备得到的前体进行了稳定化处理,将其转化为盐酸盐形式,并用IR、1HNMR等进行了检验,确定了此处理是合理可行的.     

低温燃烧合成纳米Ni掺杂TiO2光催化剂的表征及活性研究

采用低温燃烧合成法制备了Ni掺杂TiO₂光催化剂,通过紫外-可见漫反射光谱(UV-Vis DRS)、X射线粉末衍射(XRD)、激光散射、热重-差示扫描量热分析(TG-DSC)等方法对催化剂的光吸收特性、晶相组成、粒度分布、升温过程中化学变化等进行了表征,以亚甲基蓝为模型污染物考察了催化剂在可见光下的光催化活性.结果表明,相对P25而言,Ni掺杂TiO₂的光吸收带边红移,当Ni/Ti原子比为0.4时,催化剂的带隙宽度为2.3eV,对应的吸收带边为564nm;催化剂晶型以锐钛矿TiO₂为主,随Ni掺杂量增大,NiTiO₃比例升高;催化剂粒径主要分布在50～150nm之间,占总量的96.9%;升温过程中催化剂在445.2℃发生晶型转化,出现锐钛矿和NiTiO₃晶体.催化剂显示出较高的催化活性,在可见光作用150min后最高可使93.9%的亚甲基蓝分解,活性高于P25.     

DNAPL distribution in the source zone: effect of soil structure and uncertainty reduction with increased sampling density

This paper focuses on parameters describing the distribution of dense nonaqueous phase liquid (DNAPL) contaminants and investigates the variability of these parameters that results from soil heterogeneity. In addition, it quantifies the uncertainty reduction that can be achieved with increased density of soil sampling. Numerical simulations of DNAPL releases were performed using stochastic realizations of hydraulic conductivity fields generated with the same geostatistical parameters and conditioning data at two sampling densities, thus generating two simulation ensembles of low and high density (three-fold increase) of soil sampling. The results showed that DNAPL plumes in aquifers identical in a statistical sense exhibit qualitatively different patterns, ranging from compact to finger-like. The corresponding quantitative differences were expressed by defining several alternative measures that describe the DNAPL plume and computing these measures for each simulation of the two ensembles. The uncertainty in the plume features under study was affected to different degrees by the variability of the soil, with coefficients of variation ranging from about 20% to 90%, for the low-density sampling. Meanwhile, the increased soil sampling frequency resulted in reductions of uncertainty varying from 7% to 69%, for low- and high-uncertainty variables, respectively. In view of the varying uncertainty in the characteristics of a DNAPL plume, remedial designs that require estimates of the less uncertain features of the plume may be preferred over others that need a more detailed characterization of the source zone architecture.