Biofilm carrier screen

A moving bed biofilm reactor comprising,

• a) a tank;
• b) a service platform mounted to a wall of the tank;
• c) a screening body extending downwards from the service platform;
• and,
• d) an effluent pipe in communication between the inside of the screening body and the outside of the tank.

A method of treating water comprising the steps of,

• a) providing a tank with a cover;
• b) providing a plurality of biofilm carriers in the tank;
• c) providing a service box passing through the cover of the tank;
• d) providing a screening body extending downwards from the service box into the tank, the screening body having openings adapted to retain the biofilm carriers in the tank;
• e) providing an effluent pipe in communication between the inside of the screening body and the outside of the tank;
• f) flowing water to be treated into the tank, through the screening body and out through the effluent pipe;
• and,
• g) at some times, forming a seal between the service box and water in the tank.