Stabilization of waste material

Abstract

A process and apparatus for stabilizing waste material, preferably of the type that has been subjected to an initial treatment process, is disclosed and includes a main reaction tank into which the waste material is pumped after having been mixed with a suitable oxidizing agent. In the main reaction tank the mixture undergoes a chemical oxidation reaction and is then discharged through the top of the tank. A significant portion of the mixture so discharged is mixed with new waste material and an additional amount of the oxidizing agent and the new mixture is circulated back through the main reaction tank where the oxidation reaction continues; the remaining portion of the mixture is circulated through a secondary reaction tank similar to the first. Pressure is maintained in the secondary reaction tank by a suitable mechanism so that the oxidation reaction continues at a relatively high rate and the oxidized mixture is discharged as stabilized sludge through the top of the tank to a suitable sludge dewatering apparatus. In one particular embodiment of the invention, the mechanism maintaining the pressure in the secondary reaction tank includes a pump running in opposition to the direction of sludge flow but at a pressure insufficient to stop the flow.

Dependencies are inferred from the claim text.