Abstract: A wastewater treatment reactor includes an upper chamber 4 biomass therein and a lower chamber including a combination filtering/aerating unit 6 having a gas inlet 9 and a discharge outlet 10 for purified water. In operation, wastewater enters the upper reactor chamber via delivery pipe 12 and is mixed with biomass. During a filtering mode, the wastewater then enters the porous hollow body 7 defining a membrane unit 6 and is filtered thereby. In an aerating mode, gas travels across the membrane in an opposite direction freeing the membrane of biomass lodged therein. A heat exchanger 16 can be provided for exchanging heat energy between the wastewater input and the purified water output. A control device for regulating gas flow, wastewater flow, and pH may also be provided including pressure, pH and oxygen content measurement. A channel 7a may be provided for adding a cleaning medium and also an absorbent reactor 13 for treating waste air.