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.     

好氧颗粒污泥用于膜污染的控制

膜生物反应器在运行过程中容易引起严重的膜污染,从而限制了膜生物反应器在实际废水处理工程中的应用.从污泥特性角度分析了好氧颗粒污泥的特点和减缓膜污染的原因,并且与活性污泥比较,提出好氧颗粒污泥减缓膜污染的优势,为膜污染的控制提出了新的思路和方法.     

环境雌激素生物效应的作用机制研究进展

环境雌激素(environmental estrogens,EEs)种类繁多,来源多样且分布广泛,大量工业添加剂、食品添加剂和农药类物质已被证实具有雌激素活性。EEs对人体生殖、神经、免疫等系统的生物毒性已经引起了公众的普遍关注。近年来的研究表明,EEs不仅结合雌激素核受体(nuclear estrogen receptor,n ER),还可以活化雌激素膜受体(membrane estrogen receptor,m ER),干扰正常的雌激素信号通路。本文总结了EEs通过n ER、m ER介导的多种雌激素基因组和非基因组信号途径及其产生的生物学效应,综述了在其毒理学作用机理基础上发展的环境样品的雌激素活性评估和EEs混合物的联合作用研究,以期为该类污染物的筛查、风险评估和进一步的机制研究提供参考。     

Prenatal diagnosis of severe combined immunodeficiency with defective synthesis of HLA molecules

The immunodeficiency associated with a defective expression of HLA molecules is an autosomal recessive disorder leading to death during childhood. We have performed prenatal diagnosis for six fetuses at risk for this disease by membrane immunofluorescence on blood lymphocytes and monocytes, using specific monoclonal antibodies for HLA class I and II molecules. Two pregnancies have been found to be affected. The diagnosis has been confirmed on each abortus by the study of the membrane expression of HLA class I and II molecules on blood lymphocytes and monocytes, and on thymic and splenic cells. The four other cases were found to be normal both during pregnancy and after birth. The detection of the defect as early as the 20th week of gestation allows selective termination.     

超滤法处理清洗乳化液废水的应用研究

采用自制超滤膜设备对上海拖拉机内燃机公司油嘴油泵 清洗乳化废水进行了实验室试验，和近一年的生产性应用，结果表明，清洗乳化液废水经超滤处理，ＣＯＤｃｒ去除率为８５％－９１％，油的去除率为９９．４％－９９．９％，出水添加适量新清洗剂后可以回用于生产。     

化工生产中的清洁工艺

简述了清洁生产产生的背景及其重要意义，从改进工艺（聚乙烯醇生产工艺改革），改变生产原料（以乙烯取代乙炔作为合成有机中间体的原料），应用生物技术（两步发酵法生产维生素Ｃ）和改变反应设备（离子膜法生产氢氧化钠）等４个方面说明清洁工艺在化工生产领域取得的实际成效。     

膜分离稀土废水预处理中钙镁去除的研究进展

稀土废水成分复杂,硬度高,利用膜法处理时,进膜之前必须进行预处理.介绍了降低稀土废水硬度传统的和新型的方法.经过分析得出,根据具体水质情况,选择适当的互补处理方法,稀土废水完全可达到膜分离装置进水水质要求.     

膜电除尘器-静电除尘新技术

膜电除尘器是将炭纤维或硅纤维编织膜作为集尘极的新式电除尘器,它克服了传统电除尘器存在的一些缺点,进一步提高了除尘效率,降低了电除尘器的造价,同时能去除粉尘中的酸性盐.介绍了膜电除尘器的结构、特点及除尘性能,并指出了进一步研究的方向.     

好氧生物处理污染水体的供氧技术

针对好氧生物处理污染水体需要充足的溶解氧，阐述了氧传递原理、传统供氧技术（机械供氧，鼓风供氧、氧载体供氧）和新型供氧技术（射流曝气供氧、膜供氧）。指出氧载体供氧和膜供氧技术具有广阔的应用前景。从材料，工艺及应用等方面详细介绍了膜供氧技术的研究进展，并对其发展前景进行了展望。     

膜—生物反应器特性影响因素研究

通过对外压管式膜组件与曝气池构成的好氧膜生物反应器的研究，分别考究膜组件的操作压力，膜面流速以及活性污泥混合液的污泥浓度，溶解性有机特的含量和温度等对膜通量的影响。