A fluid decontamination apparatus, comprising: a body (10, 40, 210, 212, 214) defining an enclosure that enables fluid flow therethrough, the body (10, 40, 210, 212, 214) having opposing ends (26, 50); and an outlet aperture for discharging the fluid flow from the enclosure, the inlet and the outlet apertures configured to direct the fluid flow through the enclosure; characterized by: an inlet aperture (16, 42, 46, 64) coupled to a contaminated fluid source and coupled to the body (10, 40, 210, 212, 214) for introducing a fluid flow into the enclosure, the inlet aperture (16, 42, 46, 64) configured to generate hydrodynamic cavitation upon exiting the inlet aperture (16, 42, 46, 64) within the enclosure; and a three dimensionally open structured metal foam substrate disposed within the enclosure proximate to the inlet aperture such that the hydrodynamic cavitation generated by the inlet aperture (16, 42, 46, 64) enters the 3DOS substrate and extends in a continuous manner therein, the 3DOS substrate having an openness ranging from 3.9 pores per centimeter (ppc) to 19.7 ppc (10 pores per inch (ppi) to 50 ppi) and having a relative density between 2% and 15% relative to the density of the solid material making up the 3DOS substrate, the 3DOS structure is structured such that the hydrodynamic cavitation is maintained and hydrodynamic cavitation continues through the 3DOS substrate, to enable destruction of toxic species and unwanted organic compounds contained in the contaminated fluid. a body (10, 40, 210, 212, 214) defining an enclosure that enables fluid flow therethrough, the body (10, 40, 210, 212, 214) having opposing ends (26, 50); and an outlet aperture for discharging the fluid flow from the enclosure, the inlet and the outlet apertures configured to direct the fluid flow through the enclosure; characterized by: an inlet aperture (16, 42, 46, 64) coupled to a contaminated fluid source and coupled to the body (10, 40, 210, 212, 214) for introducing a fluid flow into the enclosure, the inlet aperture (16, 42, 46, 64) configured to generate hydrodynamic cavitation upon exiting the inlet aperture (16, 42, 46, 64) within the enclosure; and a three dimensionally open structured metal foam substrate disposed within the enclosure proximate to the inlet aperture such that the hydrodynamic cavitation generated by the inlet aperture (16, 42, 46, 64) enters the 3DOS substrate and extends in a continuous manner therein, the 3DOS substrate having an openness ranging from 3.9 pores per centimeter (ppc) to 19.7 ppc (10 pores per inch (ppi) to 50 ppi) and having a relative density between 2% and 15% relative to the density of the solid material making up the 3DOS substrate, the 3DOS structure is structured such that the hydrodynamic cavitation is maintained and hydrodynamic cavitation continues through the 3DOS substrate, to enable destruction of toxic species and unwanted organic compounds contained in the contaminated fluid. an inlet aperture (16, 42, 46, 64) coupled to a contaminated fluid source and coupled to the body (10, 40, 210, 212, 214) for introducing a fluid flow into the enclosure, the inlet aperture (16, 42, 46, 64) configured to generate hydrodynamic cavitation upon exiting the inlet aperture (16, 42, 46, 64) within the enclosure; and a three dimensionally open structured metal foam substrate disposed within the enclosure proximate to the inlet aperture such that the hydrodynamic cavitation generated by the inlet aperture (16, 42, 46, 64) enters the 3DOS substrate and extends in a continuous manner therein, the 3DOS substrate having an openness ranging from 3.9 pores per centimeter (ppc) to 19.7 ppc (10 pores per inch (ppi) to 50 ppi) and having a relative density between 2% and 15% relative to the density of the solid material making up the 3DOS substrate, the 3DOS structure is structured such that the hydrodynamic cavitation is maintained and hydrodynamic cavitation continues through the 3DOS substrate, to enable destruction of toxic species and unwanted organic compounds contained in the contaminated fluid.