Patent ID: 7455779

Claim:
A method for minimizing a volume of hazardous waste for disposal comprising: a. contacting a spent sorbent used in a liquid stream decontamination process, the sorbent binding toxic contaminants more strongly relative to non-toxic contaminants, with a first solution selected from at least one of a chloride-containing solution, a nitrate-containing solution, a bicarbonate solution buffered at a pH greater than a point of zero charge of the sorbent, or an alkaline bicarbonate solution, under conditions sufficient to selectively remove relatively weaker bound contaminants from the sorbent resulting in a partially treated sorbent and a first non-hazardous waste stream; b. contacting the partially treated sorbent with at least one hydroxide-containing solution under conditions sufficient to remove relatively stronger bound contaminants from the sorbent, resulting in a regenerated sorbent and a hazardous waste stream containing substantially toxic contaminants, and c. contacting the hazardous waste stream with a minimal volume of a material for binding the toxic contaminants under conditions to retain the toxic contaminants, resulting in a second non-hazardous waste stream and a minimal volume of hazardous waste.