An air treatment appliance is provided which includes an appliance housing and a removable cartridge received therein. The removable cartridge includes a receptacle containing a liquid compound to be aerosolized within an interior thereof and a cap assembly coupled to the receptacle. The cap assembly includes a cap, a venturi insert, and a base attached together without welds or separate fasteners to define an air inlet chamber on one side of the venturi insert, a venturi outlet passage on the other side of the venturi insert in fluid communication with the interior of the receptacle, and an aerosol outlet chamber partitioned from the interior of the receptacle by the base and in fluid communication with an outlet of the cap through which aerosolized compound generated by the venturi insert is discharged during operation.
