Optimising operating conditions in an abatement apparatus

A method of optimising operating conditions in an abatement apparatus (10, fig. 1) to treat an effluent stream from a process by determining carbon monoxide (CO) concentration produced by the apparatus and adjusting operating parameters accordingly. The CO concentration may be measured in the exhaust of the apparatus and potentially by means of an infrared spectrometer (130, fig. 1). Adjusted operating parameters may include fuel/oxidant ratio, oxidant supply or fuel supply. The method of changing by increasing or decreasing either the fuel/oxidant ratio or oxidant supply may involve reversing the change if CO concentration increases as a result, or retaining the change if concentration decreases. There may also be a CO threshold and manipulation of either fuel/oxidant ratio or fuel supply may involve reversing the change if it drives CO concentration away from this threshold or retaining a change if it drives the concentration towards the threshold amount. An apparatus for the method is also claimed.