Method for inhibiting aluminum-based deposition in water systems

Claim 3

A method as recited in claim 1 wherein said number average molecular weight (Mn) of said copolymer is between about 2,000-10,000.

Claim 4

A method as recited in claim 1 wherein said water soluble copolymer is added to said aqueous medium in an amount of about 0.1-500 parts polymer based upon 1 million parts of said aqueous medium.

Claim 5

A method as recited in claim 1 wherein said repeat unit (a) comprises acrylic acid or water soluble salt form thereof.

Claim 6

In a cooling water system of the type in which from 0.1-500 ppm of a deposit control agent are admitted to said cooling water system and wherein Al +3 species is present in said cooling system water in a range of from about 0.5-10 ppm Al +3 (as Al +3 ), wherein said Al+ 3 species is admitted to said cooling water system from a clarified effluent water makeup source which has been contaminated by a clarifier upset, the improvement comprising also admitting to said cooling water an effective amount of a water soluble copolymer I comprising repeat unit moieties (a) and (b) wherein said repeat unit moiety (a) comprises the structure: ##STR6## and wherein repeat unit moiety (b) comprises the structure: ##STR7## wherein x and y are integers and the ratio of x:y is in the range of about 10:1 to 1:5, R 1 is H or lower alkyl (C 1 -C 3 ), R 2 is OH, or OM, M is H or a water soluble cation, said copolymer I having a number average molecular weight (Mn) between about 1,000 to 1,000,000, and also being admitted to said water in an amount of from about 0.1-500 ppm, to control deposition and fouling by said Al+ 3 species.

Claim 7

In a cooling water system of the type in which from 0.1-500 ppm of a deposit control agent are admitted to said cooling water system and wherein Al +3 species is present in said cooling system water in a range of from about 0.5-10 ppm Al +3 (as Al +3 ), wherein said Al+ 3 species is admitted to said cooling water system from a clarified effluent water makeup source which has been contaminated by a clarifier upset, the improvement comprising also admitting to said cooling water an effective amount of a water soluble copolymer I comprising repeat unit moieties (a) and (b) wherein said repeat unit moiety (a) comprises the structure: ##STR6## and wherein repeat unit moiety (b) comprises the structure: ##STR7## wherein x and y are integers and the ratio of x:y is in the range of about 10:1 to 1:5, R 1 is H or lower alkyl (C 1 -C 3 ), R 2 is OH, or OM, M is H or a water soluble cation, said copolymer I having a number average molecular weight (Mn) between about 1,000 to 1,000,000, and also being admitted to said water in an amount of from about 0.1-500 ppm, to control deposition and fouling by said Al+ 3 species.

Claim 8

A method as recited in claim 5 wherein said deposit control agent comprises a member selected from the group consisting of polyacrylic acid, polymethacrylic acid, sulfonated styrene/maleic anhydride copolymers, polyacrylamides, isopropenylphosphonic acid polymers and copolymers, acrylic acid/hydroxylated lower alkyl acrylate polymers, diisobutylene/maleic anhydride copolymers and acrylic acid/acrylamido-2-methylpropane sulfonic acid copolymers.

Claim 9

A method as recited in claim 6 wherein said repeat unit (a) of copolymer I comprises acrylic acid or water soluble salt form thereof, and the number average molecular weight of said copolymer I being between about 2,000-10,000.