| abstract |
1,146,384. Flocculating agents. DOW CHEMICAL CO. 1 June, 1967 [1 June, 1966], No. 25415/67. Heading C1C. Sewage sludge is dewatered with a mixture of a major proportion of an amino-condensation polymer of M.W. less than 500,000 and a cationic vinyl-addition polymer of M.W. greater than 1,000,000. Amino-condensation polymers are polyalkylene polyamines, polyalkylene polyimines, melamine, urea and (guanidine/formaldehyde resins. Vinyl-addition polymers are homopolymers and copolymers of N-vinylpyridine, vinyl-benzyl trimethyl ammonium chloride, aminoethyl acrylate hydrochloride, N-methyl amino ethyl acrylate, N,N-dimethylaminoethyl methacrylate, N,N-dimethylaminomethyl-N-acrylamide. N,N-dimethyl-aminoethyl-N-acrylamide. |