Renovation of waste water

Claim 1

A process for the renovation of waste water containing a plurality of contaminants including suspended solids, dissolved organic material, nitrogenous material including organic nitrogen-, ammoniacal nitrogen-, nitrite nitrogen- and nitrate nitrogen-containing materials, phosphate material, odor-imparting materials, turbidity-providing materials and bacteria, which comprises: passing said waste water to a first reaction zone, removing a part of said suspended solids, dissolved organic materials, nitrogenous material, phosphate material and turbidity-providing materials by subjecting said waste water to a primary treatment in said first reaction zone, said first reaction zone being constituted by a first single upright tank and said primary treatment comprising: separating said first tank into a first vertically-extending zone extending the height of the tank and a second vertically-extending zone extending through the tank to a location adjacent to and vertically spaced from the lower end of the tank and in fluid flow communication with said first zone at the lower end of the tank and in fluid flow communication with said first zone at the lower end thereof only, establishing a liquid level in each of said zones and a flow path of liquid through said first tank downwardly through said first zone and upwardly through said second zone, feeding said waste water to said first zone adjacent the liquid level therein, mixing said fed waste water with a recycled mixture of suspended solids and liquid at said first zone liquid level in such a manner as to form a rotating body of liquid in said first zone to subject said waste water to centrifugal forces to concentrate suspended solids in the liquid in said first zone, accumulating said concentrated suspended solids in the bottom of said first tank, flowing liquor in said flow path from said first zone and into and upwardly through said second zone to separate treated liquid from said accumulated solids for discharge from said primary treatment by withdrawal from said first tank at the downstream end of said flow path treated liquid having a decreased suspended solids- and dissolved organic material-content, anaerobically decomposing at least a portion of said accumulated solids at the bottom of said first tank, removing accumulated solids from the accumulation thereof substantially at the rate of mixing of suspended solids and waste water, and recycling said removed accumulated solids to said first zone as said recycled mixture of suspended solids and liquid, passing the effluent from said primary treatment from said first reaction zone to a second reaction zone, removing from said effluent from said primary treatment phosphate material and substantial quantities of suspended solids, dissolved organic material, nitrogenous material and turbidity-providing materials by subjecting said effluent from said primary treatment to an adsorption-biooxidation treatment utilizing activated carbon and microorganisms in said second reaction zone, removing from said effluent from said adsorption-biooxidation treatment substantial quantities of phosphate material, suspended solids, dissolved organic material, nitrogenous material and turbidity-providing materials and substantially completely said bacteria and odor-imparting material by subjecting said effluent from said adsorption-biooxidation treatment to chemical treatment in said third reaction zone, said chemical treatment being effected in two separate treatment steps, the first chemical treatment step being carried out in a second single upright reaction tank and comprising: separating said second reaction tank into a first vertically-extending zone extending upwardly from the bottom of the tank for part of the height thereof, a second vertically-extending zone extending upwardly from the bottom of the tank the height of the first zone and in fluid flow communication with said first zone at the upper end only thereof, and a third vertically-extending zone extending upwardly from the upper extremity of the first and second zones in fluid flow communication with said first and second zones, establishing a liquid level in said second tank and a flow path of liquid through said second tank downwardly through said third and first zones respectively out of fluid flow communication therewith and upwardly through said first and third zones respectively, establishing and maintaining a rotating fluidized bed of chemical sludge in said first zone, mixing said effluent from said adsorption-biooxidation treatment with said chemical coagulant, feeding said mixture by gravity along said flow path from the upstream end thereof tangentially into the lower end of said first zone, passing said mixture through said rotating fluidized bed of chemical sludge in said first zone, chemically coagulating said phosphate materials in said fluidized bed, passing treated liquid along said flow path through said third zone, passing chemical sludge from said fluidized bed into said second zone to achieve separation of said treated liquid from chemical sludge, discharging treated liquid having a decreased phosphate-materials content from said third zone at the downstream end of said flow path, and accumulating said passed chemical sludge in said second zone, said second chemical treatment step being carried out in third single upright reaction tank and comprising: separating said third reaction tank into a first vertically-extending zone extending upwardly from the bottom of the tank extending the height of the tank and a second vertically-extending zone extending the height of the tank in fluid flow communication with said first zone at the lower end thereof only, establishing a liquid level in each of said zones and a flow path of liquid through said third tank downwardly through said first zone and upwardly through said second zone, feeding the effluent from the second tank to said first zone at the liquid level therein, feeding a gaseous mixture of ozone and oxygen into said first zone at the lower end thereof, allowing said gaseous mixture to rise in said first zone countercurrently to said effluent flowing in said flow path, absorbing ozone and oxygen from said gaseous mixture in said effluent in said first zone, passing said effluent having gases absorbed therein from said first zone to said second zone, oxidizing contaminants in said effluent with said absorbed oxygen and ozone in said second reaction zone, filtering solids formed in said second zone from the treated liquid adjacent the downstream end of said flow path, and withdrawing treated liquid having a decreased contaminants content from the downstream end of said flow path, and recovering renovated waste water substantially free from said contaminants from said third reaction zone, fluid flow of waste water from one reaction zone to another and within each reaction zone being achieved solely by a combination of gravitational forces and airlift forces whereby said primary treatment, adsorption-biooxidation treatment and chemical treatment are fluidly interconnected for continuous flow of waste water from one treatment to the next.