A wastewater treatment method and apparatus including a denitrification (anoxic) chamber for denitrifying wastewater, an aeration basin with Bio-Wheel for aerating the wastewater, and a membrane device in which sludge particles are separated out of the wastewater, leaving clean discharge water and reusable sludge. Sludge from the membrane chamber floor is sent back to the aeration basin or denitrification chamber or both. Excess sludge is wasted or held for further processing. Preferably, the method and apparatus facilitate both activated sludge and fixed film processes.