| 摘要 |
Water contaminated with solids in suspension and microorganisms is purified by addn. of a biguanide polymer or salt thereof, contg. recurring units of formula: -X-NH-C(=NH)-NH-Y-NH-C(=NH)-NH-CN=NH)-NH- (I) where X and Y are each -(CH2)n- or -(CH2)m-, n and m are 3-12; or X and Y are other bridging groups in which, when taken together, the total no. of C atoms directly included between pairs of N atoms is 10-16. The biguanide polymer comprises a mixt. of polymers in which the various polymer chains are of different length and the no. of distinct polymer units: -X-NH-C(=NH)-NH-C(=NH)-NH- and Y-NH-C(=NH)-NH-C-(=NH)-NH- taken together in any polymer chain being 3-80. The terminal gps. of the polymers chains are each chosen from -NH2, -NH-C-(=NH)-NHCN and -NH-C(=NH)-NH-C(=NH)-NR'R2 where R' is H, or opt. substd. (cyclo)aliphatic, araliphatic or aromatic hydrocarbon gp. and R2 is as R' except H. The flocculated and pptd. solids are then sepd. by a flotation technique. Used for purification of household and industrial waters, partic. effluent waters from the paper, chemical, pharmaceutical, petroleum refinery industries. Amt. of polymer used may be as little as 0.001 or even 0.0001%, based on water. |
