Bimodal cationics for water clarification

Claim 1

A method of coagulating and clarifying waste waters contaminated with oils and suspended inorganic and/or organic solids which comprises the steps: I. Adding to said waste waters an effective amount of a cationic polymer admixture comprising: a. a first water-soluble cationic homopolymer of a vinylic cationic monomer chosen from the group consisting of diallyldimethyl ammonium chloride, dimethylaminoethyl methacrylate and its acid or quaternary salts, methacrylamidoproply trimethyl ammonium chloride and 1-acrylamido-4-methyl piperazine, N-methyl quaternary salt, said homopolymer having a weight average molecular weight ranging between about 2,500-800,000, in admixture with, b. a second water-soluble cationic copolymer of acrylamide and a vinylic cationic monomer chosen from the group consisting of diallyldimethyl ammonium chloride, dimethylaminoethyl methacrylate and its acid or quaternary salts, methacrylamidopropyl, trimethyl ammonium chloride and 1-acrylamido-4-methyl piperazine, N-methyl quaternary salt, said second cationic copolymer having a weight average molecular weight ranging between about 1,000,000-50,000,000, wherein said polymer admixture contains a:b within a weight ratio of about 50:1 to 1:50, and thereby forming a treated waste water, and then, II. vigorously agitating said treated waste water with or without admixture of a dispersion gas, and then, III. allowing phase separation to occur forming a clarified water phase and a coagulated waste phase containing oils and suspended inorganic and/or organic solids, and then, IV. recovering and reusing said clarified water and either recycling said waste phase or discarding or destroying said waste phase.

Claim 2

A method of coagulating and clarifying waste waters contaminated with oils and suspended inorganic and/or organic solids which comprises the steps: I. Adding to said waste waters an effective amount of a cationic polymer admixture comprising: a. a first water-soluble cationic homopolymer of a vinylic cationic monomer chosen from the group consisting of diallyldimethyl ammonium chloride, dimethylaminoethyl methacrylate and its acid or quaternary salts, methacrylamidoproply trimethyl ammonium chloride and 1-acrylamido-4-methyl piperazine, N-methyl quaternary salt, said homopolymer having a weight average molecular weight ranging between about 2,500-800,000, in admixture with, b. a second water-soluble cationic copolymer of acrylamide and a vinylic cationic monomer chosen from the group consisting of diallyldimethyl ammonium chloride, dimethylaminoethyl methacrylate and its acid or quaternary salts, methacrylamidopropyl, trimethyl ammonium chloride and 1-acrylamido-4-methyl piperazine, N-methyl quaternary salt, said second cationic copolymer having a weight average molecular weight ranging between about 1,000,000-50,000,000, wherein said polymer admixture contains a:b within a weight ratio of about 50:1 to 1:50, and thereby forming a treated waste water, and then, II. vigorously agitating said treated waste water with or without admixture of a dispersion gas, and then, III. allowing phase separation to occur forming a clarified water phase and a coagulated waste phase containing oils and suspended inorganic and/or organic solids, and then, IV. recovering and reusing said clarified water and either recycling said waste phase or discarding or destroying said waste phase.