Abstract: Method and apparatus for the treatment of industrial or municipal wastewater including multiple series of alternating aerobic-anaerobic bioreactors in series. Each of such pairs includes fill supporting fixed film microorganisms. The wastewater from primary treatment flows into a first aeration bioreactor and downwardly through the fill where it is contacted by the microorganisms. The effluent is passed to the bottom of an anaerobic bioreactor for passage upwardly past submerged microorganisms affixed to the fill walls. Part of the nutrients in the wastewater are consumed in this first aerobic-anaerobic stage. The wastewater is then passed to a second and third aerobic-anaerobic bioreactor stage. Incremental consumption of organic nutrients, nitrification and denitrification occurs in each stage. Thereafter, it is subjected to tertiary treatment.

Abstract: Apparatus and method for treating liquor (e.g., liquor produced by sewage disposal systems) that is contaminated with dissolved, colloidal and finely divided suspended solids, and also with bacteria and viruses. The apparatus maintains a vertical column of the liquor in a treatment tank. Liquor is continuously introduced into the lower portion of the tank and continuously removed at a level well below the top of the tank. The column is continuously sparged with gas containing ozone whereby gas bubbles progress upwardly to the surface with formation of foam that is received in a confined space above the column. The evolving foam is delivered into the zone of operation of an impeller which collapses the foam bubbles by mechanical shearing and impacting. Liquor derived from the collapsed foam and the evolved gas is collected and discharged. Remaining uncollapsed foam is recycled into the shearing zone.