Filtering ain't so easy
Filtering whatever suspended particulates there may be is one thing, but the real problem is that the troublemakers aren't IMHO particulates. By the time they reach your nose, I presume it's all gaseous. Given the flowrates for cabin air exchange, you may need a fairly sizable organic vapor absorbing cartridge. Think lavatory-sized, to be replaced daily if there is a significant sustained presence of volatile organics. Alternatively, have two cartridges, and switch the flow from primary to alternate once you start smelling things. I have never smelled anything in-flight, luckily, only on the ground during engine startup, so I wasn't even aware that organic vapors are an in-flight problem! One learns every day.
Alas, my personal biggest concern would be mold in the evaporators of the air conditioner packs -- both on-plane and ground equipment.