高分子材料耐候性试验测试方法概述及评价指标的选择

高分子材料耐候性试验测试及其评价一直是材料科学与工程方面的一个重要研究课题,本文主要介绍当前高分子材料耐候性测试中常用的几种方法,并比较这些耐候性试验方法的优缺点;同时介绍进行高分子材料耐候性试验时性能变化评价指标和终止指标的选择.     

微生物絮凝剂作用下厌氧颗粒污泥的形成及特性

以3个同样的UASB(R1、R2、R3)处理COD浓度为5 500~6 500 mg.L-1的废水,在相同的工艺条件下,采用每7 d投加1次方式,R1中每次投加7.5 g CaCl2和400 mL微生物絮凝剂MBF21,R2中每次投加140 mg阳离子PAM,R3作为对照,进行厌氧颗粒污泥培育试验,以考察微生物絮凝剂MBF21对培育厌氧颗粒污泥的促进作用.结果表明,经过67 d的运行,R1、R2、R3中均培育出厌氧颗粒污泥,对应的平均粒径分别为1.18、1.21、0.76 mm,平均粒径增长速率分别为15.37、15.82、9.10μm.d-1,比产甲烷活性SMA(COD-CH4/VSS.t)值分别为0.740、0.657、0.558 g.(g.d)-1,VSS/SS分别为0.667、0.629、0.607,SVI值分别为14.7、13.1、20.4 mL.g-1,湿污泥密度分别为1.061、1.064、1.054 g.cm-3,强度系数ζ分别为92.1、93.5、84.7.电镜扫描发现R1和R2中的颗粒污泥比对照组R3中的颗粒污泥更密实,在形成成熟颗粒污泥过程中,3个反应器均呈现相似规律,即污泥表面由丝状菌占优逐渐向杆菌、球菌占优方向转化.本研究证明了微生物絮凝剂MBF21在促进厌氧污泥颗粒化过程中,在提高颗粒污泥物理性能方面接近阳离子PAM,在提高颗粒污泥生理、生化性能方面优于阳离子PAM.     

Adsorption characteristics of humic acid-immobilized amine modified polyacrylamide/bentonite composite for cationic dyes in aqueous solutions

Humic acid-immobilized amine modified polyacrylamide/bentonite composite (HA-Am-PAA-B) was prepared and used as an adsorbent for the adsorption of cationic dyes (Malachite Green (MG), Methylene Blue (MB) and Crystal Violet (CV)) from aqueous solutions. The polyacrylamide/bentonite composite (PAA-B) was prepared by intercalative polymerization of acrylamide with Nabentonite in the presence of N,N0-methylenebisacrylamide as a crosslinking agent and hexamethylenediammine as propagater. PAA-B was subsequently treated with ethylenediammine to increase its loading capacity for HA. The surface characterizations of the adsorbent were investigated. The adsorbent behaved like a cation exchanger and more than 99.0% removal of dyes was detected at pH range 6.0–8.0. The capacity of HA-Am-PAA-B was found to decrease in the following order: MG > MB > CV. The kinetic and isotherm data were interpreted by pseudo-second order rate equation and Freundlich isotherm model, respectively. Experiments were carried out using binary solute systems to assess the competitive adsorption phenomenon. The experimental isotherm data for each binary solute combination of MG, MB and CV were analyzed using Sheindrof-Rebhun-Sheintuch (SRS) (multicomponent Freundlich type) equation.     

高分子材料用于我国大气环境严酷度比较的研究

在大气环境腐蚀性分类分级的研究中,利用高分子材料来评价大气环境严酷度的研究并不多见。因此,尝试了利用高分子材料的老化模型来定量评价大气环境的严酷度。结果表明,广州、琼海、拉萨3个自然暴晒试验点中,琼海和拉萨的严酷度接近,约为广州的1．2倍左右。     

活性污泥絮体的性状及其沉降性能的探讨

活性污泥法是最常见的污水处理工艺。该方法的关键是形成了活性污泥絮体。而这些絮体的性状,如表面性质(胞外聚合物、表面电荷、疏水性)和形态结构(粒径、孔隙率、分形维数)将影响后续固液分离过程的效率。目前一系列研究活性污泥絮体性状的实验测试方法已经建立。了解污泥表面基本信息,探究污泥絮体形态结构特征,充分认识污泥沉降性能与污泥絮体的物理、化学、生物因素的相关联系,可为改善固液分离效果提供新的信息和视角;并为活性污泥系统的参数设计,实际运行调控提供理论依据。     

榆树皮提取液絮凝作用的实验研究

研究了榆树皮提取液的絮凝性能,其结果表明Fe3+可以显著地提高榆树皮提取液对硅藻土悬浊液的絮凝活性。当质量浓度10 g/L的榆树皮提取液用量为0.3 mL,质量浓度16 g/L的FeCl3溶液(溶质以FeCl3.6H2O计)加入量为0.7 mL,沉降时间为3 min,pH值为5～11时具有良好的絮凝效果,对模拟废水的絮凝率可达97.2%,低浓度河水86.4%。当榆树皮提取液用量为0.6 mL,FeCl3溶液加入量为1.4 mL时,对高浊度生活污水絮凝率可达92.7%。     

单分子荧光技术与聚合物单链物理性质的研究

对以荧光关联光谱、荧光光子计数直方图技术、单分子荧光成像、单分子荧光散焦成像等单分子荧光技术为主要研究手段开展的关于聚合物单分子链物理化学性质的研究工作进行了总结与介绍,重点介绍了本实验室在聚电解质单链构象转变及抗衡离子分布、表界面聚合物单链动态性质、空间受限状态下聚合物单分子链及单分子链段的平动扩散、转动运动的研究工作。研究结果表明,单分子荧光技术在研究高分子单链物理化学方面具有很大的潜力,发展新的技术与方法能够大力促进我们对于高分子体系微观结构与性质的理解与认识。     

Hydrolyzed AI（Ⅲ） clusters： Speciation stability of nano-All3

Pure nano-Al13 and aggregates at various concentrations were prepared to examine the particle size e ect of coagulation with inorganic polymer flocculant. The property and stability of various species formed were characterized using Infrared, 27Al-NMR, photo correlation spectroscopy (PCS), and Ferron assay. Results showed that concentration and temperature exhibited di erent roles on the stability of Al13. The quantity of Alb species analyzed by ferron assay in the initial aging period corresponded well with that of Al13, which has been confirmed in a dimension range of 1–2 nm by PCS. Al13 solutions at high concentrations (0.5–2.11 mol/L) were observed to undergo further aggregation with aging. The aggregates with a wide particle size distribution would contribute to the disappeared/decreased Al13 basis on the 27Al-NMR spectrum, whereas a part of Al13 would still remain as Alb. At low concentrations, Al13 solution was quite stable at normal temperature, but lost its stability quickly when heating to 90°C.     

壳聚糖改性高分子絮凝剂对焦化废水Zeta电位的影响研究

采用混凝过程对焦化废水进行了深度处理研究,研究了壳聚糖改性高分子混凝剂的剂量、p H值对焦化废水浊度去除率和Zeta电位的影响。结果表明在混凝过程中壳聚糖改性高分子絮凝剂剂量为200mg/L,p H值为7的最佳条件下浊度去除率比色度去除率更好,它们分别是94.44%和66.67%。焦化废水混凝后絮凝体的Zeta电位显示该最佳条件下混凝后絮凝体的Zeta电位最大。     

对硝基酚在超高交联吸附树脂NDA-701上的脱附行为研究

通过碱当量选择、脱附动力学以及固定床吸附-脱附实验,研究了对硝基酚在自制的超高交联吸附树脂NDA-701上的脱附行为,考察了2个温度下不同碱当量比(MNaOH/4-NP)对树脂脱附率的影响;研究了3个脱附温度和3种MNaOH/4-NP值情况下NDA-701的脱附动力学性能;考察了NDA-701的固定床吸附性能和不同脱附...