PROCESS AND APPARATUS FOR THE BIOLOGICAL TREATMENT OF AQUEOUS WASTE IN A PURE OXYGEN-ACTIVATED SLUDGE/OZONE SYSTEM

摘要

A process is provided for the biological treatment of aqueous waste in a pure oxygen activated sludge/ozone disinfection system as well as apparatus to accomplish the process. In this process, the off-gas from an ozone disinfection tank, after removal of residual ozone, is blended with the pure oxygen stream needed to supply the requirements of activated sludge treatment basin and ozonation zone. This blending of two streams is carried out either in pipe line or in a specially built (and baffled) vessel. The combined stream is then compressed and split into two portions. One portion of the gas is diverted to the activated sludge treatment plant. The rest of the gas is dried to a dew point level and then fed to ozone generator. The discharge from the ozone generator contains a small percentage of ozone and is routed to the ozone disinfection tank. An alternate of the system, compresses the off-gas first and then combines it with pure oxygen stream. A two bed desiccant type dryer should preferably be employed for the drying of the gas stream upstream of the ozone generator. A required amount of pure oxygen will be used to purge the inactive bed of the dryer. The wastewater first flows into an oxygenation basin, whereby through the action of microorganisms in the presence of an oxygen rich gas, the organics in the wastewater are converted (oxidized) into harmless compounds. The wastewater is discharged into a settling basin, where the biomass settles to form activated sludge which is returned to the oxygenation basin. The clarified liquid from the settling basin overflows into an ozone contact tank where the ozonated gas is introduced to disinfect the water stream.