Are air purifiers a good option for keeping my apartment air cleaner?

In the absence of an HRV, the most effective strategy for ensuring healthy air at home is to avoid introducing pollutants in the first place. This means, among other things, avoiding furniture and other articles made of MDF (medium density fiberboard) and other materials that contain urea-formaldehyde. Read more here - 

How to keep Healthy Indoor Air Quality in Homes

As for air purifiers, they don't always work as well as people hope.  The way they operate is quite simple; air is drawn in and passes through a series of filters to remove contaminants, it is then ejected back into the room. They are usually equipped with a pre-filter for larger particles, an activated carbon filter and a HEPA filter (high efficiency particulate air filter).

One of the limitations of air purifiers is that they only filter suspended particles, whereas a large part of the indoor pollutants are deposited on surfaces (floors, furniture, etc.) and become airborne only when they are disturbed. Any air purifier will require regular and rigorous maintenance to maintain their effectiveness.

Finally, portable devices are very limited in the volume of air they can process, which often does not exceed 10 to 20 square meters of floor space. A single portable device will not treat the air of an entire apartment or home the way a centralized system can.