Method and apparatus for upgrading wastewater treatment plants

Claim 1

PROCESS FOR THE TREATMENT OF WASTEWATER INCLUDING CARBONACEOUS AND NITROGENOUS POLLUTANTS COMPRISING THE STEPS OF, A. REMOVING SETTLEABLE AND FLOATABLE SOLIDS TO OBTAIN PRESETTLED WASTEWATER, B. SUPPLYING SAID PRESETTLED WASTEWATER AT A PAREDETERMINED RATE TO A BIOLOGICAL TREATMENT UNIT, C. SAID BIOLOGICAL TREATMENT UNIT EMPLOYING PARTIALLY SUBMERGED ROTATABLE BIOLOGICAL CONTACTORS HAVING SURFACE AREA FOR THE GROWTH AND MAINTENANCE OF ORGANISMS, D. ROTATING SAID BIOLOGICAL CONTACTORS AT A PREDETERMINED PERIPHERAL VELOCITY TO ALTERNATELY EXPOSE SAID SURFACE AREA TO WASTEWATER AND AN OXYGEN CONTAINING ATMOSPHERE, E. SAID PREDETERMINED RATE AND PERIPHERAL VELOCITY BEING CHOSEN TO BIOCHEMICALLY OXIDIZE SAID CARBONACEOUS AND NITROENOUS POLLUTANTS IN SAID BIOLOGICAL TREATMENT UNIT, F. SUPPLYING WASTEWATER INCLUDING MATURE ORGANISMS FROM SAID BIOLOGICAL TREATMENT UNIT TO A DENITRIFYING UNIT, G. SAID DENITRIFYING UNIT EMPLOYING DENITRIFYING ORGANISMS SUPENDED IN THE WASTEWATER TO CONVERT THE NITROGEN

Claim 15

A method for substantially upgrading the pollutant removal capability of wastewater treatment plants that include a primary treatment means for the removal of settleable and floatable solids from said wastewater, an activated sludge processing tank and a final clarifier, said method including the steps of providing a biological treatment unit including a plurality of partially submerged rotatable biological contactors having surface area for the growth and maintenance of organisms between said primary treatment means and said processing tank, supplying wastewater including carbonaceous and nitrogenous pollutants from said primary treatment means to said biological treatment unit at a predetermined rate, rotating said contactors at a predetermined peripheral velocity to alternately expose said surface area to wastewater an an oxygen containing atmosphere, said predetermined rate and peripheral velocity being chose to biochemically oxidize carbonaceous and nitrogenous pollutants in said biological treatment unit, supplying the effluent from said biological treatment unit, including mature organisms sloughed off from the surface area of said contactors and oxidized nitrogenous pollutants to said processing tank, operating said processing tank to grow denitrifying organisms suspended in said wastewater, said denitrifying organisms utilizing oxygen from said oxidized nitrogenous pollutants for respiration and sloughed off mature organisms as an energy source to convert the nitrogen content of a substantial portion of said oxidized nitrogenous pollutants to nitrogen gas, supplying the effluent from said processing tank to said final clarifIer, removing solids in the form of sludge from said wastewater in said final clarifier, wasting a first portion of said sludge and recirculating a second portion of said sludge to said processing tank without said recirculated sludge passing through said biological treatment unit, whereby said denitrifying organisms are grown in said processing tank without the addition of an external carbonaceous energy source.

Claim 16

A method for substantially upgrading the pollutant removal capability of wastewater treatment plants that include a primary treatment means for the removal of settleable and floatable solids from said wastewater, an activated sludge processing tank and a final clarifier, said method including the steps of providing a biological treatment unit including a plurality of partially submerged rotatable biological contactors having surface area for the growth and maintenance of organisms between said primary treatment means and said processing tank, supplying wastewater including carbonaceous and nitrogenous pollutants from said primary treatment means to said biological treatment unit at a predetermined rate, rotating said contactors at a predetermined peripheral velocity to alternately expose said surface area to wastewater an an oxygen containing atmosphere, said predetermined rate and peripheral velocity being chose to biochemically oxidize carbonaceous and nitrogenous pollutants in said biological treatment unit, supplying the effluent from said biological treatment unit, including mature organisms sloughed off from the surface area of said contactors and oxidized nitrogenous pollutants to said processing tank, operating said processing tank to grow denitrifying organisms suspended in said wastewater, said denitrifying organisms utilizing oxygen from said oxidized nitrogenous pollutants for respiration and sloughed off mature organisms as an energy source to convert the nitrogen content of a substantial portion of said oxidized nitrogenous pollutants to nitrogen gas, supplying the effluent from said processing tank to said final clarifIer, removing solids in the form of sludge from said wastewater in said final clarifier, wasting a first portion of said sludge and recirculating a second portion of said sludge to said processing tank without said recirculated sludge passing through said biological treatment unit, whereby said denitrifying organisms are grown in said processing tank without the addition of an external carbonaceous energy source.