Abstract: The present invention provides a process for treating waste water in a reactor in order to remove contaminants, including: mixing the waste water with a biomass, the biomass for consuming a quantity of the contaminants or adsorbing the contaminants; dosing the waste water with a micronized zeolitic material; mixing the zeolitic material with the biomass; allowing solids to settle from the waste water; and discharging resultant effluent, wherein a significant portion of the micronized zeolite material has a grain size less than or equal to 100 &mgr;m.