System for removing toxic organics and metals from manufacturing wastewater

Claim 1

In an airplane manufacturing operation, which creates a water waste stream or wastewater effluent in which is present certain toxic organics, including phenol, methylene chloride, toluene and other organics, and in which is present certain metals including cadmium, chromium, copper, lead, nickel, silver, zinc and other metals, a method of removing said toxic organics and said metals from said waste stream, comprising the following steps in sequence as defined below: a. adjusting the pH of said waste stream to approximately 5.0; then b. continuously adding iron ions to said waste stream in an effective amount based on the phenol concentration in said stream; then c. continuously adding hydrogen peroxide to said waste stream in an effective amount based on the phenol concentration in said stream, wherein said hydrogen peroxide oxidizes said phenol, such oxidation being catalyzed by said iron ions, and wherein said waste stream is in a flowing condition when both said iron ions and said hydrogen peroxide are added thereto, and further, said hydrogen peroxide is added by using a mixer reactor having a tubular section through which said waste stream passes, said tubular section having an inlet for receiving said waste stream into said mixer reactor after said iron ions are added to said waste stream, and an outlet for delivering said waste stream from said mixer reactor, said mixer reactor further including a static mixer positioned in said tubular section, said mixer reactor still further including means for delivering said hydrogen peroxide into said tubular section at a location immediately upstream of said static mixer, and first vent means for venting said tubular section, said first vent means being located upstream of said location where said hydrogen peroxide is delivered into said tubular section, and second vent means for venting said tubular section, said second vent means being positioned downstream of said static mixer, and after using said mixer reactor; then d. adjusting the pH of said waste stream to within a range of 8.5 to 9.5; followed by e. adding a polymer to said waste stream in an amount based on the concentration of said metals in said stream, wherein said polymer causes flocculation of said metals and produces sludge in said waste stream; then f. clarifying said waste stream by removing said sludge; then g. adjusting the pH of said waste stream to approximately 5.0; then h. continuously adding iron ions to said waste stream in an amount based on the remaining phenol concentration in said stream; then i. continuously adding hydrogen peroxide to said waste stream in an amount based on the remaining phenol concentration in said stream, wherein said hydrogen peroxide oxidizes said remaining phenol, such oxidation being catalyzed by said iron ions, and wherein said waste stream is in a flowing condition when both said iron and said hydrogen peroxide are added thereto, and further, said hydrogen peroxide is added by using a mixer reactor having a tubular section through which said waste stream passes, said tubular section having an inlet for receiving said waste stream into said mixer reactor after said iron ions are added to said waste stream, and an outlet for delivering said waste stream from said mixer reactor, said mixer reactor further including a static mixer positioned in said tubular section, said mixer reactor still further including means for delivering said hydrogen peroxide into said tubular section at a location immediately upstream of said static mixer, and first vent means for venting said tubular section, said first vent means being located upstream of said location where said hydrogen peroxide is delivered into said tubular section, and second vent means for venting said tubular section, said second vent means being positioned downstream of said static mixer, and after using said mixer reactor; then j. adjusting the pH of said waste stream to within a range of 8.5 to 9.5; followed by k. adding a polymer to said waste stream in an amount based on the concentration of any remaining metals in said stream, wherein said polymer causes flocculation of said remaining metals and produces still more sludge in said waste stream; then l. clarifying said waste stream by removing said sludge produced in step (k.) from said waste stream; then m. airstripping said waster stream to remove any remaining toxic organics therefrom.