滤膜的表面分离层可能拥有1µm左右的微孔结构，故称之为“纳滤”。因其具有纳米级孔径且带有电荷性的特殊过滤性能，故而迅速取代了传统的离心分离、真空浓缩、多效蒸发等工艺。
纳滤的截流分子量从200-10000Dalton可选，因而该过程能耗低，不会破坏生物活性，浓缩倍数高，所以在食品工业、饮料工业、生物医药、发酵工业、乳品工业中纳滤技术已得到越来越广泛地应用。
目前，膜分离技术在抗生素中的应用主要是在抗生素发酵液的澄清，产品的浓缩脱盐以及废液中抗生素的浓缩回收等几个方面。
现代抗生素的生产一般首先是通过澄清和溶剂萃取从发酵液中加以分离，在对萃取液进行真空蒸发制得。但发酵液中抗生素含量一般较少，浓度较低，且含有大量其它杂质，常规提取和浓缩方法存在着有机溶剂用量大，浓缩能耗高，破坏生物活性，产品回收率低，操作环境差等不足。
纳滤浓缩技术的采用可有效避免以上不足，提高抗生素类产品品质，降低生产成本，成为生物医药生产中的高效分离手段。

The nano superficial filteration process has about 1 µm of the pore structure; therefore it is called he nano filters ". Because it has the nano level aperture and has the performance of electric filteration, it rapidly substituted the traditional centrifugal separation, the vacuum concentration, multiple-effect evaporates and so on .
The nano filters the current the molecular amount may elect from 200-10000 Dalton, thus this process energy consumption is low, and cannot destroy the biology life, the concentration multiple is high, therefore in the food industry, the drink industry, the biology medicine, the fermentation industry, the dairy product industry the nano filters the technology has been applied more and more widely.
At present, membrane separation technology is mainly used in the clarification of antibiotic fermentation liquid, concentration and desalination of the product, and concentration and recovery of the antibiotics in the waste liquid and so on.
Now, in general, the produce of antibiotic is firstly extracted by clarification and solvent, and is separated from fermentation liquid and at last do the vacuum evaporation of the liquid extraction. But the content of the antibiotic in the fermentation is low, the density is low too, and it contains a lot of other impurities, the routine method of extraction and concentration has the shortages of great organic solvent consumption, high concentration energy consumption, low product recovery rate, poor operation environment and so on.
The use of nano filteration concentration technology can avoid above shortages validly improve the quality of the antibiotic series,low the production cost,it is high effective separation method in the production of the big medicine.