Apparatus for treating industrial and domestic waste waters

A system for treating industrial and domestic waste sewage, said system comprising:

• a tank;
• a filter positioned in said tank;
• an aerated packed column mounted above said filter in said tank, said column including a bacteria support media having a surface area of approximately 50 ft..sup.2 /ft..sup.3 ;
• inlet means for introducing into said tank screened sewage having suspended solids therein and for passing said sewage downwardly through said column and said filter;
• effluent outlet means at the bottom of said tank for removing effluent from said tank;
• by-pass passage means, including a pump, extending from said effluent outlet means to a lower portion of said tank for recirculating a portion of said effluent back into said tank;
• means connected to said by-pass passage means for diffusing air into the recirculated effluent portion, for causing the air upon entry into said tank to separate in the form of small air bubbles from said recirculated effluent, and for forcing said air bubbles upwardly through said support media to provide oxygen to microorganisms growing on said support media which biologically remove the BOD loading in said sewage;
• and
• means positioned on said tank for receiving and burning floc which rises to the surface of said tank from said support media.