Hi to the person who started this thread. I work for an engineering company and some people have the job of eliminating odours from buildings and I really don't believe there is an air purifier that your landlord could fit that would stop all smells. Well there is but it would be massively expensive, the kind of system that pharmaceutical or high tech companies use to replace all air in an area within seconds.
My personal view is that you might suffer from a psychological disorder where you think you smell but you actually don't. Do people cover their noses when they talk to you? Do they cough and sniff around you? Do they make comments?