Abstract A composition and method for the bactericidal treatment of water with oligodynamic metal ions. The composition comprises a particulate silver yielding material and a particulate filler material which is intermixed with the silver yielding material. The silver yielding material comprises a highly porous carrier having a hardness which is greater than that of elemental silver and a layer of elemental silver on the surfaces of the carrier, and the filler material comprises a material, such as charcoal, having a hardness which is less than that of elemental silver. The composition is utilized in accordance with the method of the invention by passing a stream of water through a quantity of the composition to cause the particles of silver yielding material to mechanically interact with each other to release silver into the water. The particles of filler material, intermixed with the silver yielding material, buffer this mechanical interaction to provide a relatively slow release of silver from the composition which can be effectively controlled so that the composition and method can be effectively used in substantially closed systems, such as swimming pool systems.
A composition for the bactericidal treatment of a stream of water comprising: a. a particulate silver yielding material comprising: i. a carrier which has a particle size of between approximately 4 and 20 mesh, a surface area of greater than approximately 150 square inches per gram, and a Mohs scale hardness of greater than 2.5 and which is substantially insoluble in water having a pH of between 5 and 9; ii. a layer of elemental silver on the surfaces of said carrier, said silver being between approximately 1% and 10% by weight of said silver yielding material; and iii. the mechanical interaction between adjacent particles of said silver yielding material causing a release of elemental silver into said stream when it is passed therethrough; b. a particulate filler material intermixed with said silver yielding material, said filler material being substantially insoluble in water having a pH of between 5 and 9, said filler material having a particle size of between approximately 4 and 20 mesh and a Mohs scale hardness of less than 2.5, the volumetric ratio of said filler material to said silver yielding material being between approximately 1:1 and 5:1; and c. said filler material reducing the rate at which elemental silver is released from said composition to produce a controlled release of said elemental silver when said stream is passed therethrough.
Claim 2
Dependent Claim
224 words
A composition for the bactericidal treatment of a stream of water comprising: a. a particulate silver yielding material comprising: i. a carrier which has a particle size of between approximately 4 and 20 mesh, a surface area of greater than approximately 150 square inches per gram, and a Mohs scale hardness of greater than 2.5 and which is substantially insoluble in water having a pH of between 5 and 9; ii. a layer of elemental silver on the surfaces of said carrier, said silver being between approximately 1% and 10% by weight of said silver yielding material; and iii. the mechanical interaction between adjacent particles of said silver yielding material causing a release of elemental silver into said stream when it is passed therethrough; b. a particulate filler material intermixed with said silver yielding material, said filler material being substantially insoluble in water having a pH of between 5 and 9, said filler material having a particle size of between approximately 4 and 20 mesh and a Mohs scale hardness of less than 2.5, the volumetric ratio of said filler material to said silver yielding material being between approximately 1:1 and 5:1; and c. said filler material reducing the rate at which elemental silver is released from said composition to produce a controlled release of said elemental silver when said stream is passed therethrough.
Claim 3
Dependent Claim
13 words
In the composition of claim 1, said carrier further characterized as being activated.
Claim 4
Dependent Claim
10 words
In the composition of claim 2, said carrier comprising alumina.
Claim 5
Dependent Claim
10 words
In the composition of claim 1, said carrier comprising alumina.
Claim 6
Dependent Claim
11 words
In the composition of claim 4, said filler material comprising charcoal.
Claim 7
Dependent Claim
21 words
In the composition of claim 1, said silver yielding material and said filler material being of substantially the same particle size.
Claim 8
Dependent Claim
14 words
The composition of claim 1 further characterized as being substantially free from silver salts.