Process for the removal of metals from solution
AssigneeLeuven Research & Development VZW
InventorsAdrien E. J. Cremers, Andre P. A. Maes, Paul G. L. Piegneur
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Abstract
Several metal ions, such as mercury, cadmium, copper, zinc, nickel and cobalt, may be removed from waste waters and similar solutions by treating such solutions with a cation exchanger in the presence of a polyamine. A treatment with clay minerals such as bentonite or montmorillonite in the presence of tetraethylenepentamine is preferred. The solution may be first combined with polyamine and then contacted with the cation exchanger, but in a preferred embodiment, the polyamine and cation exchanger are combined first to form a solid adsorbent and then contacted with the solution.
Claims16
A process of removing metals from an aqueous solution containing ions of at least one dissolved metal therein which is capable of forming stable cationic complexes with polyamines and which has to be removed from said solution, said process comprising the steps of:
- (a) adding to said solution a polyamine selected from the group consisting of ethylenediamine, propylenediamine, triaminotriethylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and tetra-2-aminoethylethlenediamine in order to form stable cationic complexes with the ions of said one metal, said polyamine being added in at least equimolar amount with respect to said metal;
- (b) contacting the solution of step (a) with a cation exchanger selected from the group consisting of synthetic and natural tectosilicates and phyllosilicates, in an amount of 3 to 30 grams of cation exchanger per gram of metal ion to be removed from solution, in order to adsorb said stable cationic metal-polyamine complexes from said aqueous solution onto said cation exchanger, and
- (c) separating said cation exchanger from said aqueous solution after contact.
A process of removing metals from an aqueous solution containing ions of at least one metal dissolved therein which is capable of forming stable cationic complexes with polyamines and which has to be removed from the solution, said process comprising the steps of:
- (a) combining a polyamine selected from the group consisting of ethylenediamine, propylenediamine, triaminotriethylamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and tetra-2-aminoethylethylenediamine with a cation exchanger selected from the group consisting of synthetic and natural tectosilicates and phyllosilicates in order to form a solid adsorbent, said polyamine and said cation exchanger being combined in such a mutual ratio as to ensure that at least an equimolar amount of polyamine is present with respect to said metal when the resulting solid adsorbent is added to said aqueous solution in an amount corresponding to 3-30 grams of cation exchanger per gram of metal ion to be removed from solution;
- (b) contacting said aqueous solution with said solid adsorbent in order to adsorb said metal ion from said solution and form stable cationic polyamine-metal complexes on said cation exchanger in said solid adsorbent, said solid adsorbent being used in an amount corresponding to 3 to 30 grams of cation exchanger per gram of metal ion to be removed from solution;
- and
- (c) separating said solid adsorbent from said aqueous solution after contact.
Dependencies are inferred from the claim text.