In at least one aspect, a controlled decomposition oxidation (CDO) system is provided for abating perfluorocarbons (PFCs) that includes (1) an upstream portion including a first conduit adapted to convey a gaseous waste stream; (2) a thermal reaction chamber having an inlet coupled to the first conduit, a catalyst bed adapted to abate PFCs, and an outlet; and (3) a downstream portion including a second conduit having a first end coupled to the outlet of the thermal reaction chamber and having a portion, downstream from the first end, positioned proximate to the first conduit. The second conduit is adapted to convey a gaseous waste stream heated within the thermal reaction chamber to enable a transfer of heat energy from the second conduit to the first conduit so as to pre-heat the gaseous waste stream in the first conduit. Numerous other aspects are provided.