| 摘要 |
A material having an electronegatively charged surface, e.g diatomaceous earth, charcoal, perlite, sand, asbestos, cellulose pulp, fuller's earth, or mixtures thereof, is given at least a partial coating of an alkyleneimine polymer, a polyalkylene polyamine having a molecular weight of at least 1000, or a polymer of vinyl benzyl trimethyl ammonium chloride, and the coated product is an improved filter aid material. The material preferably contains from 0.01 to 0.5 weight per cent of the polymer and a preferred polymer is polyethyleneimine. The above filter aid material may be used for removing suspended matter from gaseous or liquid media, e.g. air or water, and is used as a pre-coat material on a filter septum, or is formed into a slurry with the contaminated liquid before being submitted to filtration. This filter aid material is particularly useful in removing suspended matter containing micro-organisms from fluid media. In an example, diatomaceous earth is coated with a polyethylenepolyamine polymer (mol. weight about 200,000) by stirring a slurry of this material in an aqueous solution of the polymer for 30 minutes, dewatering, reslurrying and dewatering three times, using de-ionized water, and then drying for 24 hours at ambient temperature.ALSO:A material having an electronegatively charged surface, e.g diatomaceous earth, charcoal, perlite, sand, asbestos, cellulose pulp, fullers earth, or mixtures thereof, is given at least a partial coating of an alkyleneimine polymer, a polyalkylene polyamine having a molecular weight of at least 1000, or a polymer of vinyl benzyl trimethyl ammonium chloride, and the coated product is an improved filter aid material. The material preferably contains from 0.01 to 0.5 weight per cent of the polymer and a preferred polymer is polyethyleneimine. The above filter aid material may be used for removing suspended matter from gaseous or liquid media, e.g. air or water, and is used as a pre-coat material on a filter septum, or is formed into a slurry with the contaminated liquid before being submitted to filtration. This filter aid material is particularly useful in removing suspended matter containing micro-organisms from fluid media. In an example, diatomaceous earth is coated with a polethylenepolyamine polymer (Mol. Wt. about 200,000) by stirring a slurry of this material in an aqueous solution of the polymer for 30 minutes, dewatering, reslurrying and dewatering three times using deionized water, and then drying for 24 hrs at ambient temperature. |
