System for the Biological Treatment of Water and Corresponding Method

A system for biologically treating wastewater comprising:

• a tank comprising a point of entry for the wastewater to be treated and an exit point for treated wastewater;
• a shaft disposed in the tank;
• a rotating drum having a wall with one or more openings formed therein and supported on the shaft and configured to be partially submerged in the wastewater in the tank where less than one-half of the drum's internal volume contains the wastewater;
• a drive for rotatively driving the drum;
• media configured to support a biofilm disposed in the drum and retained in the drum as the drum is rotatively driven;
• the media occupying a volume of from 30% to 80% of the internal volume of the rotating drum;
• at least one hollow tube disposed in the rotating drum and secured to the wall of the rotating drum, the hollow tube extending generally parallel to the shaft;
• the hollow tube includes one or more orifices formed in a section of the tube;
• and
• wherein the drum and the hollow tube are configured to alternatively fill the hollow tube with air and wastewater in response to the drum being rotatively driven.

A system for biologically treating wastewater comprising:

• a tank having an inlet for receiving wastewater to be treated and an outlet for discharging treated wastewater;
• a shaft disposed in the tank;
• a rotating drum rotatively mounted on the shaft and including a wall having openings therein for permitting wastewater to pass through the openings;
• a drive for rotatively driving the drum;
• biofilm carriers contained in the rotating drum and configured to support biofilm thereon for biologically treating the wastewater in the drum;
• aerators incorporated into the drum for aerating the wastewater in the drum in response to the rotation of the drum;
• the aerators including one or more tubes disposed in the drum and secured to the wall of the drum;
• the one or more tubes including orifices that permit wastewater and air to pass into and out of the one or more tubes;
• and
• the one or more tubes in response to the rotation of the drum, configured to receive air during one portion of a revolution of the drum and to discharge the air from the one or more tubes into the wastewater within the drum during another portion of the revolution of the drum.

A method of biologically treating wastewater comprising:

• directing the wastewater to be treated into a tank and into a rotating drum having a perforated wall and disposed in the tank;
• containing biofilm carriers in the rotating drum;
• rotating the drum and contacting the biofilm carriers with the wastewater in the drum to biologically treat the wastewater therein;
• aerating the wastewater in the drum by employing a plurality of tubes having orifices therein and secured to the wall inside the drum;
• as the drum rotates, filling the tubes passing through an air space above a surface of the wastewater in the drum with air, and thereafter submerging the tubes containing the air in the wastewater in the drum causing the air in the tubes to pass into the wastewater in the drum and in the process filling the tubes with wastewater as the tubes move through the wastewater in the drum;
• and
• directing treated wastewater from the drum and out a treated wastewater outlet in the drum.