A flow-through mixing apparatus for incorporating a dry treatment product into a waste stream. The apparatus comprises a pump for directing a liquid waste from a storage pit/tank, a mixer that receives the liquid waste from the pump, and a valve downstream of the mixer for either recirculating the liquid waste back to the storage pit/tank via a recirculation conduit, or directing the liquid waste to a discharge conduit. The mixer comprising a jet nozzle, a venturi tube and a high-shear assembly. The recirculation conduit establishes a calibration loop for determining the appropriate treatment regimen based on the characteristics of the waste liquid. The recirculation conduit also permits the homogenization of the pit/tank contents prior to addition of the dry treatment product. The dry treatment product introduced in the region of the mixer is subjected high shear forces, thereby incorporating the dry treatment product into the waste stream with increased dispersion and reduced agglomeration.