Application of nuclear track membrane in tea filtration

[Background] People keen on tasting tea are plagued by the presence of crushed impurities in the tea soup, such as particles of tea leaf and hairs of tea leaf. [Purpose] The aim is to expand the use of nuclear track membranes (NTMs) for filtration of tea soup. [Methods] Flat membrane filtration equipment with the NTM placed in is used to separate the tea soup. [Results] The colority and turbidity of tea soup after the separation decrease with the intercept aperture. The total volume of residual particles in tea soup decreases with pore size; the peaks of size distribution of particles decrease with the pore size. The flux of NTM is good and decreases with the pore size. After cleaning, membrane flux of 15-μm NTM can be restored to more than 80% of the original. It is found that the membrane can extend the life time and improve economic efficiency by controlling the initial flow rate. [Conclusion] NTM can effectively intercept the particles larger than its pore size in the tea soup. The 15-μm NTM is the best to separate the tea soup with the excellent flux and retention effect during gravity, and 1-μm NTM is the best choice under pressure filtration. (authors)