Patent ID: 8080163

Claim:
A method of treating waste water, comprising: providing an influent stream of waste water containing solids and at least one dissolved contaminant; subjecting said influent stream to primary treatment to remove some of the solids therefrom and to produce a first treated stream; subjecting said first treated stream to secondary treatment to remove additional solids therefrom to produce a second treated stream; adding metal salt reagents to said second treated stream to produce a third treated stream; subjecting said third treated stream to tertiary treatment to produce a purified effluent stream, wherein said tertiary treatment includes passing said third treated stream over media surfaces; generally continually regenerating metal salt reagents on the media surfaces while flowing said third treated stream over the media; separating at least some of said at least one dissolved contaminant as solid contaminants and at least some of the metal salt reagents from said third treated stream in said tertiary treatment, wherein the separated solid contaminants and the at least some of the metal salt reagents are contained in a waste stream, and wherein at an initial point in time the purified effluent stream has a first contaminant concentration of said at least one dissolved contaminant; and, recycling the waste stream back into said influent stream at a point upstream of said primary treatment, and wherein subsequent to the recycling, at a subsequent point in time, the purified effluent stream has a second contaminant concentration of said at least one dissolved contaminant that is lower than the first contaminant concentration of said at least one dissolved contaminant.