Ceramic membrane fouling mechanisms and control for water treatment

● The fouling is summarized based on ceramic membrane performance and pollutants. ● The current research methods and theoretical models are summarized. ● The membrane fouling control methods and collaborative technology are reviewed. Membrane separation, as an important drinking water treatment technology, has wide applications. The remarkable advantages of ceramic membranes, such as chemical stability, thermal stability, and high mechanical strength, endow them with broader prospects for development. Despite the importance and advantages of membrane separation in water treatment, the technique has a limitation: membrane fouling, which greatly lowers its effectiveness. This is caused by organics, inorganic substances, and microorganisms clogging the pore and polluting the membrane surface. The increase in membrane pollution greatly lowers purification effectiveness. Controlling membrane fouling is critical in ensuring the efficient and stable operation of ceramic membranes for water treatment. This review analyzes four mechanisms of ceramic membrane fouling, namely complete blocking, standard blocking, intermediate blocking, and cake filtration blocking. It evaluates the mechanisms underlying ceramic membrane fouling and summarizes the progress in approaches aimed at controlling it. These include ceramic membrane pretreatment, ceramic membrane surface modification, membrane cleaning, magnetization, ultrasonics, and nanobubbles. This review highlights the importance of optimizing ceramic membrane preparation through further research on membrane fouling and pre-membrane pretreatment mechanisms. In addition, combining process regulations with ceramic membranes as the core is an important research direction for ceramic membrane-based water treatment.     

滤膜过滤 微波干燥法快速测定水中悬浮物

采用滤膜过滤微波干燥技术,建立了水中悬浮物的快速测定方法。以0.45μm硝酸乙酸纤维素(CN-CA)滤膜为过滤介质,采用变功率连续加热模式,空白湿滤膜在10 min内恒重(900 W/5 min+500 W/5 min),附有悬浮物的湿滤膜在13 min内恒重(900 W/8 min+500 W/5 min)。选择不同质量浓度的高岭土标准样品和不同类别的实际样品进行方法性能测试,结果表明,该方法检出限为5 mg/L,相对标准偏差(RSD)为2.7%~7.1%,相对误差为2.0%~5.0%,采用该方法与采用标准方法《水质悬浮物的测定重量法》(GB 11901—89)测定实际样品的结果吻合。该方法显著缩短了水中悬浮物测定的分析时间,精密度和准确度能够满足分析要求,可用于地表水及一般工业排放废水中悬浮物质量浓度的快速测定。     

室内空气净化技术

概述了室内空气污染的类型 ,全面介绍了目前各种室内空气净化技术及其进展 ,并且分析了各技术的优缺点。此外 ,提出将膜分离与光催化技术相结合 ,能克服当前各种技术的局限性的构想。这一组合技术可能成为今后该领域研究的一个重要方向     

生物膜接触氧化法处理苯胺废水

以AN3菌和硝化类细菌构成的复合生物膜降解苯胺 ,研究挂膜过程中苯胺代谢产物的变化情况、生物膜内异养菌与硝化类细菌生态分布情况 ,以及水质条件对苯胺代谢速率的影响 .结果表明 ,挂膜期间苯胺中的氮首先被降解成氨 ,然后进一步生成亚硝酸根或硝酸根 .反应器内的稳定生物膜主要由AN3菌构成 ,但靠近出水位置生物膜中的硝化类细菌密度较进水位置高 10 0倍以上 .生物膜代谢的最佳pH值范围是 6 9— 7 5 .重金属离子 ,尤其是Hg2 ,通常会对生物膜的代谢活性产生抑制作用     

含油废水处理研究

简要概述了含油废水的特征,介绍了盐析法、絮凝法、电解法、吸附法、浮选法等常规处理含油废水方法及其相应的不足之处,同时介绍了四个处理含油废水的典型流程,并指出了这些传统处理流程的特点及不足之处,重点介绍了微滤、超滤和反渗透等膜分离技术处理含油废水的研究及进展,最后综合阐述了膜分离技术处理含油废水的优点,并指出膜分离技术处理含油废水的研究方向。     

膜法富氧助燃技术在节能和环保中的应用

主要介绍了该高新技术在玻璃窑、注汽炉、加热炉、热媒炉、燃煤炉、燃油及燃气炉等方面的典型应用,一般均具有显著的经济效益和社会效益,不但显著节能、增产,而且改善燃烧效率,延长炉龄,环保达标,通常几个月就能收回全部投资。     

SMBR不同特性膜处理城市内河道水对比试验研究

用一体浸没式膜生物反应器(SMBR)不同特性膜处理上海市城市内河道水,结果表明,SMBR对氨氮含量较高的富营养化河水,氨氮的去除率在90%以上,但对COD的平均去除率仅为50%.比较两种膜的运行性能,亲水性膜在运行通量和通量恢复能力上,均比疏水性膜优越.两种膜的出水水质几乎没有差异.     

Effect of components in activated sludge liquor on membrane fouling in a submerged membrane bioreactor

Introduction The membrane bioreactors (MBRs) have shown many advantages over conventional activated sludge processes, which apply membrane modules instead of the secondary settle tank to make a better separation of the solids and liquid and have been grea…     

改性聚偏氟乙烯中空纤维超滤膜处理乳化液废水

应用改性聚偏氟乙烯中空纤维超滤膜处理乳化液废水(COD浓度100~300 g/L、含油量30~100 g/L),考察了在不同压力、温度及流速条件下,膜处理能力的变化,并研究了清洗方法对膜性能的恢复效果。结果表明,在组合预处理条件下,乳化液废水的COD去除率可达95%以上,油去除率可达99%以上,采用金属清洗剂可使膜的透过量恢复率达97%以上。该项研究为膜处理技术用于乳化液废水处理奠定了基础。     

富氧助燃技术减少NOx排放

富氧助燃技术是最新节能环保技术,可以用于各种燃料和多种窑炉.不但显著节能、增产,而且能延长炉龄,环保达标,通常几个月就能收回全部投资.富氧燃烧能有效地降低NOx的排放量,在环境问题得到日益重视的今天富氧助燃技术具有显著的经济意义和社会意义.先介绍其节能和环保的机理,然后再介绍有关典型工艺流程、技改要点和典型应用实例.并对热力型NOx的生成进行了探讨.