title: [Pollution prevention and control of aqueous extract of astragali radix processed with ZrO2 inorganic ceramic membrane micro-filtration].
abstract: OBJECTIVE
  To study the measures for preventing and controlling the pollution of aqueous extract of Astragali Radix proceeded with inorganic ceramic membrane micro-filtration, in order to find effective measures for preventing and controlling the membrane pollution.
  
  
  METHODS
  The resistance distribution, polymer removal and changes in physical and chemical parameters of the zirconium oxide film of different pore diameters were determined to analyze the state or location of pollutants as well as the regularity of formation. Meanwhile, recoil and ultrasonic physical measures were adopted to strengthen the membrane process, in order to explore the methods for preventing and controlling the membrane pollution.
  
  
  RESULTS
  When 0.2 microm of ZrO2 micro-filtrated aqueous extract of Astragali Radix, the rate of pollution was as high as 44.9%. The hole blocking resistance and the concentration polarization resistance were the main filtration resistances, while the surface deposit resistance decreased with the increase in the membrane's hold diameter; after micro-filtration, the liquid turbidity significantly reduced, with slight changes in both pH and viscosity. The 0.2 microm ZrO2 micro-filtration membrane performed better than the 0.05 microm pore size membrane in terms of conductivity. The 0. 2 microm and 0.05 microm pore diameter membranes showed better performance in the removal of pectin. The ultrasonic measure to strengthen membranes is more suitable to this system, with a flux rate up by 41.7%.
  
  
  CONCLUSIONS
  The membrane optimization process adopts appropriate measures for preventing and controlling the membrane pollution, in order to reduce the membrane pollution, recover membrane performance and increase filtration efficiency.
authors: Laboratory of Separation Engineering for Chinese Medicine Compound, Nanjing University of Traditional Chinese Medicine, Nanjing 210029, China. linmeip@yahoo.com.cn
authors: Lin-Men
authors: LM
authors: Pan
authors: Min-Yan
authors: MY
authors: Huang
authors: Li-Wei
authors: LW
authors: Guo
mesh_terms: D027883:Astragalus Plant / Q000737:chemistry; D027885:Astragalus propinquus; D002516:Ceramics / Q000737:chemistry; D004340:Drug Contamination; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D005374:Filtration / Q000379:methods*; D008567:Membranes, Artificial; D013678:Technology, Pharmaceutical; D015040:Zirconium / Q000737:chemistry
chemical_list: D004365:Drugs, Chinese Herbal; D008567:Membranes, Artificial; C027492:Huang Qi; D015040:Zirconium; C028541:zirconium oxide