Abstract: A backwash system and method for a waste treatment system employ a waste inlet duct extending into an accumulation of microbial growth media particles in a lower region of a tank, with a vertical duct having a duct outlet in an upper region of the tank. A downwardly convergent strainer extends around the vertical duct beneath the duct outlet, with a liquid collector beneath the liquid leakage openings and a liquid outlet from the liquid collector communicating with the exterior of the tank. Compressed air is supplied into the vertical duct to impel the waste water up to the duct outlet and onto the strainer. A solids return duct has an upper end opening through the downwardly convergent strainer and a lower end opening above the accumulation of microbial growth media particles.

Abstract: A waste water treatment apparatus has a treatment tank and a solids retainer baffle downwardly inclined longitudinally of the tank and separating the interior of the tank into an upper region and a lower region. A waste water inlet duct communicating with the lower region of the tank and a treated water outlet duct extends out of the upper region of the tank. An air supply ductwork communicates with air outlets in the lower region of the tank for promoting aerobic digestion in the lower region by microbes on a microbe growth medium between the baffle and the air outlets. Solids from the waste water are retained by the baffle in the lower region while treated waste water is allowed to escape past the lower end of the baffle to the treated water outlet duct.

Abstract: A backwash system and method for a waste treatment system employ a waste inlet duct extending into an accumulation of microbial growth media particles in a lower region of a tank, with a vertical duct having a duct outlet in an upper region of the tank. A downwardly convergent strainer extends around the vertical duct beneath the duct outlet, with a liquid collector beneath the liquid leakage openings and a liquid outlet from the liquid collector communicating with the exterior of the tank. Compressed air is supplied into the vertical duct to impel the waste water up to the duct outlet and onto the strainer. A solids return duct has an upper end opening through the downwardly convergent strainer and a lower end opening above the accumulation of microbial growth media particles.