Sadly no, not in one uncut shot without mel anyway that I know of.
However, after trying a setup like you described, before I pass along my solution, are you really tied to your story of the falling dust first?
Because if you could get rid of that one collision, then things MAY be easier for you if you MUST do this all in one shot.
I ask because I think you may need to do this using a simple editing technique called a "cutaway".
TRIAL AND ERROR:
The first thing I tried was setting up your situation as you have it now, with the exception of when the dust fell to the floor for the first collision, I setup an event that killed the particle dust, and IMMEDIATELY spawned new particles with a conserve of 0 so they appear to the camera as the same piece of dust.
Then I created ANOTHER collision event with a new name that was setup like you had it originally and that seemed to work ok........ sortof.
The SECOND thing that worked PERFECTLY was to not show the falling dust at all.
Simply emit the dust from the floor geometry as a surface emitter with a conserve of 0 and an initially high rate till the floor filled up with dust then I killed the rate.
Then all I had to do was use only ONE collision event with the vacum-head geo and the particles dissapeared like they were supposed to.
(see my Maya 8.5 Unl. attachment for this example)
Of all of this, I believe the BEST solution for you would be to use a cutaway.
This is simply what it sounds like:
One rendered sequence is of the dust falling.
One sequence is a super-quick 1-2 second cutaway of the vacum cleaner beauty shot.
Then, render a final sequence for the part with the vacum head moving & killing particles.
This way you only have to deal with one collision at a time.
Lemme know if ANY of this gibberish helped
Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS