A fluid mixer apparatus can include an annular ring defining a fluid flow path configured for a first fluid through the annular ring. The annular ring can include one or more fluid inlets circumferentially disposed on an exterior surface of the annular ring, the one or more fluid inlets configured to receive a second fluid different than the first fluid. The fluid mixer apparatus can include a central hub and a plurality of helical airfoils positioned inside the annular ring and connected to both of the annular ring and the central hub. In some examples, each helical airfoil of the plurality of helical airfoils can include: a plurality of perforations in fluid communication with the one or more fluid inlets to introduce the first fluid into the second fluid; and an airfoil surface perturbation positioned adjacent to or rearward of the plurality of perforations.

A system for optimizing flocculation in a liquid waste settling vessel is disclosed having outlet configured to propagate a slurry feed stream flow into a feedwell in a downward direction. A deflector is disposed beneath the feedline outlet. The deflector is configured to intercept the slurry feed stream flow and direct the slurry feed stream in a fan-like shape toward the outer wall of the feedwell where the flow will separate into an upward portion and a downward portion. The upward portion helps create a first mixing zone above the deflector. The downward portion helps create a second mixing zone beneath the deflector.