Comparable Evaluation of Iron‐based Coagulants for the Treatment of Surface Water and of Contaminated Tap Water

Abstract

The aim of this study was to investigate the efficiency of various commercially‐available coagulants based on iron, such as ferric or ferrous salts, or polyferric sulfate (PFS), for the treatment of surface (river) water in order to become drinkable. These coagulants were evaluated, considering the removal of suspended solids (SS), of natural organic matter (NOM) and of the residual iron concentration. Furthermore, the kinetics of flocculation was studied by using a Photometric Dispersion Analyzer (PDA), comparing the different flocculation rates. The optimum operational conditions, i.e. coagulant dosage, pH value, duration, and intensity of (initial) rapid‐mixing rate, were determined for the examined cases. The results indicated that certain trivalent iron coagulants [Ferrisol‐123 (based on FeClSO₄) – Ferrisol‐Cl‐130 (based on FeCl₃)] showed higher efficiency, than the divalent [Ferrosol‐9 (based on a mixture of FeSO₄ and FeCl₂), presenting higher SS and NOM removal, higher flocculation rates, and lower residual iron concentration.     

PDA包覆铝粉及其在HTPB中的分散稳定性

通过原位多巴胺(DA)聚合法在铝粉表面包覆聚多巴胺(PDA),制备了Al@PDA复合颗粒;采用SEM表征不同DA质量浓度下Al@PDA的表面形貌。用XRD测试铝粉包覆前后的晶型;采用XPS分析Al@PDA的表面元素组成;通过沉降法研究了铝粉和Al@PDA在HTPB中的分散稳定性;通过制备固化胶并切片取样观察固体颗粒在HTPB中的分散情况。结果表明,当DA质量浓度为3.5g/L时对铝粉的包覆效果最好,在铝粉表面形成牢固的PDA薄膜;包覆前后Al的晶型没有改变;XPS在Al@PDA表面检测到的C-OH、C=O组分和π-π共轭结构证实了PDA包覆层的存在。沉降24h后Al-HTPB体系出现分层,而Al@PDA-HTPB体系仍然颜色均一,表明Al@PDA在HTPB中的分散稳定性明显优于原料铝粉。     

基于传感器的PDA高速数据采集分析系统

为实现对现场各种物理量的传感器数据进行采集,开发了PDA高速数据采集与分析系统,设计了几种接入PDA系统的数据采集方式。     

Systemized organic functional group controls in polydiacetylenes and their effects on color changes

A variety of organic functional groups have been successfully installed into polydiacetylenes (PDAs) and applied to the color change‐controlled system of PDA sensors. Ten diacetylene compounds possessing different functionalities and lengths were systemically synthesized and fully characterized using spectroscopic methods. The polymerized vesicle solution with these compounds showed different temperatures required to induce a color change (from blue to red) depending on the functionalities installed on 10,12‐pentacosadiynoic acid (PCDA) molecules. In addition, the results reported here reveal that the intermolecular interactions of PCDA molecules and the intermolecular distance play a key role to the color of PDA system. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45011.     

Fabrication of a new type of organic-inorganic hybrid superlattice films combined with titanium oxide and polydiacetylene

We fabricated a new organic-inorganic hybrid superlattice film using molecular layer deposition [MLD] combined with atomic layer deposition [ALD]. In the molecular layer deposition process, polydiacetylene [PDA] layers were grown by repeated sequential adsorption of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet polymerization under a substrate temperature of 100°C. Titanium oxide [TiO₂] inorganic layers were deposited at the same temperatures with alternating surface-saturating reactions of titanium tetrachloride and water. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the nanohybrid films. The transmission electron microscopy analysis of the titanium oxide cross-linked polydiacetylene [TiOPDA]-TiO₂ thin films confirmed the MLD growth rate and showed that the films are amorphous superlattices. Composition and polymerization of the films were confirmed by infrared spectroscopy. The TiOPDA-TiO₂ nanohybrid superlattice films exhibited good thermal and mechanical stabilities.     

工业X射线机现场实时遥控装置研制

介绍了一种工业X射线机现场实时遥控装置。该装置采用PLC(可编程控制器)采集射线机控制箱的信息,通过无线数据通讯方法,在PDA(无线掌上电脑)上实现遥控功能,实时远程显示X射线机的工作状态,从而实现遥控射线机高压开关,使操作人员远离X射线现场进行操作,从而达到保护操作人员安全、提高工作效率的目的。     

PDA微机三维配管工程设计软件的应用与体会

介绍PDA三维配管设计软件的功能特点 ;结合硝酸尾气治理项目工程设计中使用的体会 ,对PDA软件提出了改进建议。     

高分子型阳离子破乳剂对文明寨油田调驱原油的破乳性能研究

由于文明寨油田处于高含水开采阶段,使聚合物驱油技术大规模推广。但同时,也明显增大了聚驱含油污水处理难度。本文根据文明寨油田的原油特点,用二甲基二烯丙基氯化铵(DMDAAC)和丙烯酰胺(AM)合成出一种带有阳离子基团的线型水溶性高聚物(以下简称PDA),采用室内瓶试法为文明寨油田筛选出性能较好的破乳剂。结果表明:在PDA和破乳剂LGS-2的浓度分别为40m g/L和60m g/L,脱水温度60℃进行复配时,脱水速度最好,界面颜色清澈。但是这种传统的破乳剂评价方法不能将原油脱水和污水净化有机结合,且与现场实际脱水工艺有差距,最后提出建议,应该使用油水相实验方法进行破乳性能评价。     

An analysis of a pulse combustion drying system

The paper presents a theoretical and experimental analysis of a pulse combustion spray drying system. Measurements of the velocity flow field inside the drying chamber and extensive tests on drying and water evaporation were carried out for various feed rates and operating parameters of the pulse combustor. Each test included the analysis of temperature distribution in the dryer, evaporation level and sprayed material structure. LDA and PDA techniques were employed to determine the character of pulsating flow in the chamber, amount of water evaporated and to perform a profound analysis of spray structure. Experimental results show an intensive and efficient drying process. An attempt was made to perform theoretical predictions of velocity and temperature distribution in the drying chamber. The CFD technique was used to calculate time-dependent flow in the chamber. Results show vanishing velocity, pressure and temperature oscillations along the length of the drying chamber. Temperature oscillations decline faster than oscillations of pressure and velocity. Satisfactory agreement between calculations and experimental results was found in certain regions of the drying chamber. Discrepancies might be caused by simplification of the system geometry and flow pattern which were assumed to perform calculations in reasonable time.     

江西省防汛PDA应用系统设计

防汛PDA系统采用B/S和C/S相结合的构架方式,通过GPRS网络平台,能够清晰而灵活的显示出各种防汛工作所需的信息,为防汛工作者提供了全方位的移动指挥办公手段.