国内外海水反渗透膜技术发展现状

综述了国内外海水反渗透淡化膜所经历的3个发展阶段,对反渗透膜组件、材料发展状况进行了总结。还综述了目前新型无机、无机杂化以及有机复合反渗透海水淡化膜材料、性能的研究进展,介绍了代表未来反渗透膜发展方向的碳纳米管、分子筛、石墨烯等无机纳米粒子在反渗透海水淡化膜中的应用,总结了反渗透膜市场主流国内外厂家,简要介绍了我国“十二·五”期间海水淡化专项科技规划,并对反渗透膜技术未来发展进行了展望。     

Preozonation Effects on the Reduction of Reverse Osmosis Membrane Fouling in Water Reuse

The purpose of this bench-top study was to demonstrate the feasibility and effect of applying ozone and ozone/peroxide upstream of reverse osmosis (RO) membranes as a means of controlling organic fouling during reuse applications. A series of ozone or ozone/peroxide doses was applied to surface water and a membrane bioreactor (MBR) filtrate using a HiPOx® reactor skid, with ozone-to-dissolved organic carbon ratios of approximately 0.25 to 1.75. Results from the flat-sheet testing indicate that both ozone- and ozone/peroxide-treated waters, even at the lowest ozone dose of 1.5 mg/L, fouled the membranes less than the MBR filtrate and surface control waters while both treated and control waters maintained consistent levels of salt rejection throughout the tests.     

有机化学实验绿色化的探讨

本文引入了绿色化学的新观念,把绿色化学融合到有机化学实验教学中.设计了两个微型有机化学合成试验,与传统的实验相比较,达到了将实验中造成的环境污染降低到最低限度的目的,同时还培养学生的绿色意识.     

Treatment of Prehydrolysis Liquor from Pulp Mill using a Biological Route Followed by Reverse Osmosis

A new method, comprised of a biological treatment followed by membrane separation, has been suggested for the treatment of spent prehydrolysis liquor (PHL) from a rayon grade pulp mill. First, the PHL was treated biologically using the torula utilis strain for the conversion of sugar into yeast. Reductions of 57 % in the amount of total reducing sugar (TRS) and about 46 % in COD were achieved in the biological treatment step. A “shifting order type” rate equation, where the order shifts from (m–n) at high concentrations to m at lower concentrations, was found to predict the total reducing sugar with high accuracy. An ultracentrifuge was used to separate out the yeast formed during the biological treatment. The clarified biologically treated liquor was subjected to reverse osmosis (RO) to remove all the remaining solutes. The permeate obtained was observed to be of disposable/reusable grade (negligible COD and less than 0.9 mg/L sugar). An attempt was made to predict the permeate flux during reverse osmosis (RO) using an osmotic pressure model. Modified osmotic pressure and concentration polarization models were utilized for the estimation of the osmotic pressure of different concentrations of the PHL's solute constituents. Three different concentration parameters (TRS, COD, and Brix) were chosen to estimate the osmotic pressures. The prediction of the permeate flux by the combination of these models was found to be in good agreement with experimental flux values.     

有机化学教学中关于“学”的思考

教学活动是教与学的统一。教师不但要重视教法的改进,还要加强对学生学法的指导。有机化学理论分散、内容庞杂、反应繁多,学生普遍反映易懂难记。教师应指导学生注重理论基础的学习,抓住内在规律,从正反两方向记忆反应,重视习题训练,经常进行知识的分类、比较、归纳、总结,有效提高有机化学的学习效果。     

氯代铬酸吡啶盐在有机合成中的应用

氯代铬酸吡啶盐作为一种温和的、选择性的氧化剂,用于有机合成中,其效果是明显的,应用范围也越来越大。     

反渗透法浓缩葡萄糖溶液过程数学模拟和实验研究

报道在不同的进料浓度和操作压力下用反渗透法浓缩葡萄糖溶液实验研究，再建立新的模拟卷式反渗透过程的数学模型并进行最优参数估计。结果表明，反渗透法能够替代常规的蒸发操作浓缩葡萄糖浓液，且理论计算的渗透通量和渗透液浓度与实验结果相当一致。     

反渗透技术在金泰氯碱化工废水处理中的应用

文章主要介绍了反渗透工艺原理,及金泰动力分厂工业污水处理应用的依据,对运行中出现的问题进行了有益的探讨     

Parameters affecting backwash variables of RO membranes

The optimal setup of backwash (BW) cleaning methods was determined by analyzing the parameters affecting BW flux: accumulated volume during the process, and permeate salinity. An investigation was carried out on the parameters affecting BW flux and accumulated volume based on existing data and the 2D time-dependent FEM model developed in a previous study. According to this model, the absence or presence of feed velocity and applied pressure relates to Case 1 or Case 2 of BW cleaning methods, respectively. The main parameters affecting BW flux and accumulated volume are BW time t_BW and feed concentration C_f. Effects of membrane thickness, salt and water diffusivities, and feed velocity on BW flux are negligible within ± 10% change. Results show that BW flux based on Case 1 is higher than fluxes of Case 2. This result provides a clear advantage of BW cleaning methods to Case 1 over Case 2 methods. Permeate salinity increases with C_f and t_BW and decreases with desalination time t_RO and feed pressure P_f. A preferable BW cleaning method resulting from this study is a cleaning method based on Case 1 for t_RO > 20 min, at a t_BW as short as possible and C_f around 31 kg/m³.     

非对称性聚合物微孔膜研究进展

综述了近年来在微孔膜的非对称性结构控制方面的研究进展,重点介绍了添加剂种类和摩尔质量、聚合物组成和制膜工艺等对微孔膜非对称结构的影响。     

关于有机合成化学课程改革的探讨

从现代有机合成的发展和学生的实际出发,在对有机合成课程的现状进行剖析的基础上,合理处理教材,由浅入深、循序渐进、与时俱进。采取具体措施进行有机合成课程教学改革,启发学生的创造性思维,培养学生提出问题、分析问题、解决问题的能力。     

超临界二氧化碳在有机合成中的应用

介绍了超临界二氧化碳应用于有机合成的新成果及新动向 ,尤其在催化氢化、醛化、自由基反应、氧化反应、傅 -克烷基化反应和酶催化反应方面 ,它在绿色化学反应方面具有很大的潜在优势     

反渗透技术在废水处理中应用的研究进展

反渗透技术是一种高效、易操作的液体分离技术,同传统的废水处理方法相比具有处理效果好,可实现废水的循环利用和对有用物质回收等优点。文章简要介绍了反渗透技术的基本原理,重点介绍了反渗透技术在垃圾渗滤液、矿区污水、钢铁工业废水、电厂废水处理中的应用研究进展状况。并讨论了反渗透膜技术的预处理、反渗透膜污染及清洗和反渗透技术的发展前景。     

反渗透脱盐水处理技术在沙特南方省水泥公司水泥生产线上的尝试与探索

由中材国际总包的沙特南方省水泥公司5000t/d熟料水泥生产线,采用了反渗透脱盐水处理技术处理当地苦咸水,这是有别于国内项目的重要部分之一。文章介绍了该项目从进、出水质设计控制指标,我国及美国《反渗透水处理设备》标准中对水质的要求及饮用水水质标准,水处理工艺流程,设备选型及水处理药品建议。工程运行效果表明:该项目的水处理系统获得成功,处理后的水质能完全达到设计要求。     

Economic benefits of membrane technology vs. evaporator

European Union food ingredients production operations face operating cost challenges. Ingredient production steps frequently incorporate product recovery steps employing centrifugation, rotary vacuum filtration, evaporation and spray drying demanding high energy inputs.Product and process waste streams contain small molecular weight components that can be concentrated, desalted or, in some applications, fractionated with membrane filtration technology.Substantial capital and operating cost benefits together with selective separations can be derived by use of low energy consumption membrane technology as a complete stand alone process step or in conjunction with evaporation enabling product recovery and water for reuse.Reverse osmosis membrane technology can offer greater than 75% reduction in operating cost when compared with 5 multi-effect evaporation with thermal vapour re-compression process. Mechanical vapour recompression evaporators offer the lowest operating cost, similar to membrane technology, but with a considerably higher capital investment.Many companies which employ evaporation as a standard de-watering step in the manufacture of products such as dairy food ingredients, sugars, sweeteners, beverages, organic acids, renewable source bio-fuels, etc., can potentially reduce their carbon foot print with membrane technology.     

典型有机化学实验的绿色化研究

将绿色合成新技术应用于有机化学实验教学,通过对烯烃溴化实验、己二酸合成实验、肉桂酸合成实验的绿色化改进,减少或消除了实验产生的污染,提高了反应产率,缩短了实验时间,实现了实验流程的绿色化。因此,逐步推广绿色有机化学实验,是化学实验教学改革的重点,也是解决环境污染的重要手段。     

新型抗沉降有机蒙脱土的制备

针对蒙脱土在PA6/MMT复合材料连续聚合反应体系中存在的沉降问题,采用十六烷基三甲基溴化铵(CTAB)为插层剂、乙醇等为助插层剂,讨论了插层剂用量、反应温度、机械搅拌与超声波处理的时间比以及反应液pH值对制备有机蒙脱土的影响,确定了有机改性的最佳工艺条件。粒径分析表明,有机蒙脱土在己内酰胺中粒径变小,比表面积增大;沉降对比实验表明,有机蒙脱土在熔融己内酰胺中可长时间不沉降,可满足工业连续生产的需要。     

Preparation and characterization of thermally crosslinked chlorine resistant thin film composite polyamide membranes for reverse osmosis

Currently, polyamide reverse osmosis membranes are highly effective for desalination, industrial process water, and home drinking water. However, they have poor resistance to strong oxidants especially chlorine due to chain cleavage of aromatic polyamide. In general, aromatic polyamide RO membranes are essentially random copolymers consisting of the linear and crosslinked structures. The amide ring is sensitive to attack by chlorine because it is an electron-rich region. Therefore, the activated carbon or sulfite addition processes are essential to remove the chlorine in the separation processes. Many research groups have studied to improve the chlorine-resistance RO membrane having hydrophilic groups (− SO₃H and − COOH) or nitro groups (− NO₂) such as electron acceptors. In this study, thin film composite polyamide RO membranes were prepared by interfacial polymerization method including cross-linking agents having hydroxyl groups to improve the chlorine-resistance. The chlorine-resistance of polyamide RO membrane was influenced by the thermal cross-linking conditions (temperature and time) and cross-linking density of polyamide membranes.     

浅析有机化学在高分子材料合成中的应用

有机化学是高分子材料专业的一门重要的专业基础课,结合多年来高分子材料专业和有机化学的教学实践,本文从高分子单体的合成、高分子材料的改性、高分子合成新技术三个方面举例探讨了有机化学知识对高分子材料合成的重要作用。     

浅谈有机合成中的中国人人名反应

简单介绍了有机合成化学中黄鸣龙反应、陆[3+2]环化反应、史一安不对称环氧化反应等几个中国人人名反应。