Embodiments herein provide waste abatement apparatuses and methods for treating waste solutions derived from depleted or used plating solutions, such as from an electroless deposition process or an electrochemical plating process. The waste abatement systems and processes may be used to treat the waste solutions by lowering the concentration of, if not completely removing, metal ions or reducing agents that are dissolved within the waste solution. In one embodiment of a demetallization process, a waste solution may be exposed to a heating element (e.g., copper coil) contained within an immersion tank. In another embodiment, the waste solution may be exposed to a catalyst having high surface area (e.g., steel wool or other metallic wool) within an immersion tank. In another embodiment, the waste solution may be flowed through a removable, catalytic conduit (e.g., copper tubing) having an internal catalytic surface.