摘要 |
An integrated filter for removing impurities from a fluid stream. The filter includes a first element adapted to remove at least some of the impurities by physical adsorption, and a second element adapted to remove at least some of the impurities by electrokinetic adsorption. Either or both of the first element and the second element further may be adapted to remove at least some of the impurities by sieving. The first element generally may be composed of loose particles or granules, or the first element may be composed of a porous block of an adsorbent, wherein the block is permeable to fluids and has interconnected pores therethrough. The second element generally is composed of a porous, charge-modified fibrous web which includes fibers prepared from a thermoplastic polymer. For example, the thermoplastic polymer may be a polyolefin. As another example, the porous, charge-modified fibrous web may be a nonwoven web, such as a meltblown or microfiber glass web. Alternatively, both the first and second elements may be in the form of a sheet. |