Process for the removal of heavy metals from aqueous systems using organoclays
AssigneeRheox, Inc.
InventorsCharles A. Cody, Stephen J. Kemnetz
Life of this patent
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Abstract
This invention relates to a process for removing dissolved heavy metals including lead and radioactive contaminants from contaminated aqueous systems including aqueous soil systems. Such systems have resulted from Department of Defense activities and chemical manufacture, as well as from a large variety of past activities. An organically modified smectite clay, or organoclay, is used to treat these systems. Organoclays are the reaction product of smectite clays and quaternary ammonium compounds. The organoclay is brought in contact with system to be treated where it sorbs the heavy metal in the aqueous system onto the organoclay which sorbed complex is then removed by a variety of methods including flotation and air sparging.
Claims18
A process for removing heavy metal contaminants from aqueous systems containing heavy metals dissolved in ionic form which comprises:
- (a) contacting an aqueous system or washings thereof with an agent consisting of a mixture of one or more smectite clays and one or more quaternary ammonium salts having the formula:
- ##STR5## wherein R.sub.1 comprises a lineal or branched aliphatic hydrocarbon group having 1 to about 30 carbon atoms;
- R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of (a) lineal or branched aliphatic groups having from 1 to about 30 carbon atoms;
- (b) aromatic and substituted aromatic groups;
- and (c) hydrogen and X.sup.- is chloride;
- to form an organically modified smectite clay in the system;
- (b) sorbing heavy metal contaminants on to the organically modified smectite clay to form an organically modified smectite clay/heavy metal complex;
- and
- (c) recovering the organically modified smectite clay/heavy metal sorbed complex from the aqueous system.
A process for removing heavy metals selected from the group consisting of lead and mercury from an aqueous system which contains lead or mercury dissolved in ionic form which comprises:
- (a) contacting an aqueous system or washings thereof containing lead, mercury or both with one or more organically modified smectite clays comprising smectite clay reacted with one or more quaternary ammonium salts having the formula:
- ##STR6## wherein R.sub.1 comprises a lineal or branched aliphatic hydrocarbon group having 1 to about 30 carbon atoms;
- R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of (a) lineal or branched aliphatic groups having from 1 to about 30 carbon atoms;
- (b) aromatic and substituted aromatic groups;
- and (c) hydrogen and X.sup.- is chloride;
- (b) sorbing some or all of the lead or mercury or both onto the organically modified smectite clay to form an organically modified smectite clay complex with said lead or mercury;
- (c) removing said complex from the aqueous system.
Dependencies are inferred from the claim text.