Abstract: The technical field is post-combustion noxious emissions reduction. A post-combustion apparatus 100 mixes noxious gases with a post-combustion gas fuel that burns in air at least at 1950° C., more preferably greater than 2,000° C. in a chamber that mixes the gases 330 and then ignites them on entry into a combustion expansion chamber 360 with a larger sectional surface area ensuring that there is no constriction of the exhaust system from that point in the process to avoid back-pressure. A collection vessel 460, typically using a magnet and water trap is also provided that collects particulate and other magnetic and soluble matter from the exhaust stream.