Removal of anionic compounds from water

Claim 1

A method which is capable of removing acid dyes from water which is recycled in manufacturing processes and from wastewater, comprising: (a) adding to recycled water or waste water (1) an amount of a water soluble polymeric cationic assistant roughly corresponding to the amount of acid dyes in said recycled water or said wastewater, said cationic assistant being the reaction product of an alkylating agent containing an aromatic substituent with a cationic polyelectrolyte containing aminoalkyl groups selected from the group consisting of polyethyleneimines, polyvinylamines, the reaction products of ammonia or amines with 1,2-dichloroethane, epichlorohydrin, dichlorohydrin or chlorohydrin ethers of dihydric or polyhydric alcohols, polyamidoamines which are obtained by reacting a dicarboxylic acid of 4-10 carbon atoms with polyalkylenepolyamines possessing 3-10 basic nitrogen atoms in the molecule, polyamidoamines obtained by condensing acrylic or methacrylic ester with diamines or with polyalkylenepolyamines having 3-10 basic nitrogen atoms, polyamidoamines which contain from 20 to 400 parts by weight of grafted-on ethyleneimine per 100 parts by weight of a polyamidoamine, and condensates of urea with bis-aminoethylmethylamine and (2) at least one mineral adsorbent selected from the group consisting of aluminosilicate, chalk, titanium dioxide, bauxite, and calcium sulfoaluminate, the weight ratio of said adsorbent to polymeric cationic assistant ranging from 20:1 to 0.5:1; (b) insolubilizing the acid dyes in said wastewater or recycled water as a result of said treatment; and (c) separating the insolubilized material from said treated water.

Claim 2

A method which is capable of removing acid dyes from water which is recycled in manufacturing processes and from wastewater, comprising: (a) adding to recycled water or waste water (1) an amount of a water soluble polymeric cationic assistant roughly corresponding to the amount of acid dyes in said recycled water or said wastewater, said cationic assistant being the reaction product of an alkylating agent containing an aromatic substituent with a cationic polyelectrolyte containing aminoalkyl groups selected from the group consisting of polyethyleneimines, polyvinylamines, the reaction products of ammonia or amines with 1,2-dichloroethane, epichlorohydrin, dichlorohydrin or chlorohydrin ethers of dihydric or polyhydric alcohols, polyamidoamines which are obtained by reacting a dicarboxylic acid of 4-10 carbon atoms with polyalkylenepolyamines possessing 3-10 basic nitrogen atoms in the molecule, polyamidoamines obtained by condensing acrylic or methacrylic ester with diamines or with polyalkylenepolyamines having 3-10 basic nitrogen atoms, polyamidoamines which contain from 20 to 400 parts by weight of grafted-on ethyleneimine per 100 parts by weight of a polyamidoamine, and condensates of urea with bis-aminoethylmethylamine and (2) at least one mineral adsorbent selected from the group consisting of aluminosilicate, chalk, titanium dioxide, bauxite, and calcium sulfoaluminate, the weight ratio of said adsorbent to polymeric cationic assistant ranging from 20:1 to 0.5:1; (b) insolubilizing the acid dyes in said wastewater or recycled water as a result of said treatment; and (c) separating the insolubilized material from said treated water.