负载Al_2O_3的活性炭纤维电吸附除盐研究

采用浸渍煅烧法对活性炭纤维进行Al_2O_3负载改性,对改性前后活性炭纤维的微观结构、电化学性能和除盐性能进行分析比较,并探讨了影响其电吸附除盐效果的影响因素,结果表明:改性后活性炭纤维电吸附除盐性能得到极大增强,除盐能力为改性前的2.68倍。且电极具备很好的再生性;其表面出现了絮状和颗粒状的Al_2O_3,比表面积减小,中孔增加,孔径分布更加合理,比电容提高了2.1倍。当电压为2.0 V,极板间距为1 cm,NaCl质量浓度为500 mg/L时,除盐效率可达到64.6%。     

PPES中空纤维纳滤膜的染料脱盐性能研究

采用间歇渗滤恒容操作,考察了杂萘联苯聚芳醚砜(PPES)非对称中空纤维纳滤膜对染料的脱盐性能,并以活性艳蓝染料的盐溶液为分离介质对膜在高温下的分离性能进行了测试分析。结果表明,非对称PPES中空纤维纳滤膜具有良好的染料脱盐性能:在80℃、0.6 MPa下,纳滤膜对活性艳蓝(质量浓度10 g/L)和NaCl(质量浓度2 g/L)的混合溶液渗滤浓缩2倍,经过7个恒容循环操作后,透过液的电导率降至0.1 mS/cm以下。间歇渗透过程中,每个循环后增加反洗操作,有利于提高PPES中空纤维纳滤膜对染料的脱盐效率;以质量分数1.0%的EDTA二钠溶液为反洗液,膜通量恢复率最高可达98.6%。     

Modeling and simulation for direct contact membrane distillation in hollow fiber modules

Direct contact membrane distillation (DCMD) offers an attractive operation for the separation of mixtures at atmospheric pressure with reasonable energy requirement. A new simultaneous heat and mass transfer model in DCMD in a hollow fiber configuration is presented. Flow regime in feed and permeate side, the variations of mean temperature and concentration along the membrane module, the length of the membrane, and various properties of membrane characteristics are taken into account in the present model. A system of nonlinear equations describing the DCMD process is solved numerically for each cell using the FSOLVE coding, which is a built‐in function in MATLAB^® to find the influence of the temperature and velocity of the feed and permeate streams, and the salt concentration of the feed along the module on the permeate flux. The predicted results by the new model show a good accord with a wide range of various experimental results available in the literature. © 2012 American Institute of Chemical Engineers AIChE J, 59: 589–603, 2013     

Membrane-assisted capacitive deionization: Effect of Poly(vinyl alcohol) cross-linking on the properties of ion exchange membranes

Novel composite electrodes were developed for application in membrane capacitive deionization (MCDI). Activated carbon (AC) was dispersed in a solution of poly(vinyl alcohol) (PVA) mixed with polyacrylic acid (PAA) or poly dimethyl diallyl ammonium chloride (PDMDAAC), and cast onto the surface of an AC-based modified graphite electrode, prepared by phase inversion, to form a composite membrane further cross-linked with glutaraldehyde (GA). The effect of the cross-linking on the chemical structure of the PVA-based membranes was determined by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. Cyclic voltammetry was conducted to examine the specific capacitance of the composite electrodes. Desalination experiments were then performed with MCDI unit cells to study the effect of cross-linking on the desalination efficiency. It was proved that after optimization, the synthesized composite electrodes exhibited one and a half times higher NaCl removal capacity and three times higher adsorption rate as compared to that of a conventional CDI cell using commercial ion exchange membranes (IEMs) with almost the same energy consumption. The enhanced desalination performance was attributed to the optimized properties of the selected polymers and the improved adhesion of IEMs to the electrodes. This research paves the way for the application of new materials in MCDI processes for improved water desalination.     

纤维滤料与石英砂过滤海水的对比试验

预处理在海水淡化过程中占有重要地位,在海水淡化的预处理工艺中,过滤过程一般不可省略,目前海水过滤工艺中应用最多的仍是传统的石英砂滤料,存在滤速低、易堵塞、过滤周期短等缺点。本文采用纤维球和彗星式纤维滤料进行直接过滤海水试验,通过与石英砂滤料对比,考察纤维滤料在海水过滤净化中的使用效果。试验结果表明：对于石英砂滤料,当滤速为15 m/h时,过滤出水浊度小于5.0 NTU;当滤速增大到20 m/h时,过滤水头损失快速增高,过滤周期仅为2 h。对于纤维滤料,当滤速为20 m/h时,过滤出水水质稳定,出水浊度小于2.0 NTU,过滤周期可达50 h以上。相对于石英砂滤料,纤维滤料在比表面积、过滤阻力、截污能力等方面都优于传统滤料,更适用于海水的高效净化处理。     

环境友好型多功能海水缓蚀剂的研制及性能研究

为同时解决碳钢与铜材在海水中的腐蚀问题,将聚天冬氨酸、苯并三唑等5种原料按一定的质量比复配成多功能海水缓蚀剂。利用失重法和电化学法研究了海水缓蚀剂在海水中对A3碳钢及H62黄铜的缓蚀性能。结果表明,当海水缓蚀剂用量为150 mg/L时,对碳钢与黄铜在海水中的腐蚀均有良好的抑制作用,碳钢缓蚀率达到95.17%,黄铜缓蚀率达到93.67%。该海水缓蚀剂具有优良的生物降解性能,28 d后生物降解率达到82.6%。     

马莲河苦咸水淡化中试项目

中试项目处理水量20 m3/h,采用一级两段式反渗透(RO)处理系统,段内加压。运行结果表明,反渗透工艺可有效去除苦咸水中的各种有害离子,水回收率达到84%以上。处理后的淡化水各项水质指标均显著优于生活饮用水卫生标准(GB 5749-2006)和饮用净水水质标准(CJ 94-2005)的相应标准值。     

冲厕海水SBBR处理工艺中悬浮填料的选型

悬浮填料作为微生物赖以栖息的场所,是批式生物膜反应器的关键技术之一。基于冲厕海水水质特性,提出SBBR处理冲厕海水用悬浮填料的选型原则：密度应接近海水,比表面积较大,水力学和理化特性优良。筛选三种悬浮填料进行了挂膜试验,结果表明,改性聚丙烯柱状填料更适合用于冲厕海水处理。     

海水淡化的热处理工艺技术综述

综述了海水淡化的主要热处理工艺：多级闪蒸(MSF)、多效蒸发(MED)和压气蒸馏(VC)。     

固相萃取法与GC-FPD联用分析海水中13种有机磷

有机磷农药的广泛使用导致其不可避免地进入到环境中,不仅会影响生态环境,而且还会通过食物链富集进入到人体中,对人类健康造成影响.建立了固相萃取与GC-FPD联用的方法,并成功用于海水样品中敌敌畏等13种有机磷的分析.在中性条件下,100 mL水样经过HLB固相萃取小柱富集后,以二氯甲烷为洗脱溶剂进行洗脱,以HP-5柱为分...