subsystem 12 through recirculation pipe 66 and or from aerobic water purification subsystem 14 through recirculation pipe 68 aerobic water purification subsystem 14 comprises gas diffusers 70 that can be installed on the bottom of aerobic water purification subsystem 14 or above the bottom of aerobic water purification subsystem 14 consistent with the moving bed biofilm reactor mbbr configuration or with the moving bed clarifying reactor mbcr configuration as shown in pct il 2009 000825 respectively when the mbcr configuration is applied gas diffuser outlets 70 are arranged generally between an upper biological treatment turbulence region 72 and a lower solids settling region 74 and provide gas bubbles which move upwardly through wastewater in aerobic water purification subsystem 14 and through a plurality of biomass carriers 18 disposed within upper biological treatment turbulence region 72 and create turbulent motion of wastewater in upper biological treatment turbulence region 72 the gas bubbles typically of pressurized air are supplied to outlets 70 via a gas inlet 76 the outlets 70 may include one or more coarse or fine bubble diffusers and jets sludge 77 s produced in aerobic water purification subsystem 14 is drained by valve 78 treated effluent 80 e leaves aerobic water purification subsystem 14 and reactor 10 via a wedge wire screen 82 coupled to a wastewater outlet in order to prevent carriers 18 from leaving aerobic water purification subsystem 14 it is a particular feature of the present invention that most of.