A radiant burner for treating an effluent gas stream from a manufacturing processing tool includes a plurality of treatment chambers, each treatment chamber having an effluent stream inlet for supplying a respective portion of the effluent gas stream to that treatment chamber for treatment therewithin. In this way, multiple treatment chambers may be provided, each of which treats part of the effluent stream. Accordingly, the number of treatment chambers can be selected to match the flow rate of the effluent gas stream from any particular processing tool. This provides an architecture which is reliably scalable to suit the needs of any effluent gas stream flow rate.