Method for waste treatment of organic strippers containing metals
AssigneeTandy Corporation
InventorJames A. Brown
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Abstract
A method for treating liquid wastes containing photoresist polymers and heavy metals is disclosed. The method includes adding to the liquid wastes an aqueous solution of water soluble FE.sup.+3 and Al.sup.+3 salts at a pH in the range of from about 0.1 to 1.0, and a water soluble salt of Mg.sup.+2 or Ca.sup.+2. The ratio of the amount of the Fe.sup.+3 and Al.sup.+3 to the amount of the Mg.sup.+2 or Ca.sup.+2 is in the range of from 2 to 3 moles to 1 to 3 moles. A precipitate containing the heavy metals and photoresist polymers is formed.
Claims4
A method of treating liquid wastes containing photoresist polymers and heavy metals, comprising the steps of:
- treating said liquid wastes with an aqueous solution comprising a water soluble Me.sup.+3 salt wherein Me.sup.+3 is selected from the group consisting of Fe.sup.+3 and Al.sup.+3, and wherein at least a portion of said Me.sup.+3 comprises Al.sup.+3 ;
- and a water soluble Me.sup.+2 salt wherein Me.sup.+2 is selected from the group consisting of Mg.sup.+2 and Ca.sup.+2 ;
- and an acid to result in a pH of said aqueous solution in the range of from about 0.1 to about 1.0;
- wherein the amount of said Me.sup.+3 to the amount of said Me.sup.+2 is in the ratio of from about 2 to about 3 moles Me.sup.+3 to from about 1 to about 3 moles Me.sup.+2 ;
- wherein a precipitate is formed which contains said heavy metals and said photoresist polymers.
Dependencies are inferred from the claim text.