Old electical goods

I guess it depends on your commune.
Mine will collect things like that several times a year.
However, if you buy new ones, the seller has to take the old one from you free of charge though that's only useful for you if you have the items delivered.

If you're living in the Brussels area (may be true for other areas too) the dustbin people will come once a year free of charge to collect any stuff you want to throw away. Maximum 20 cubic metres.
In Brussels you should contact Bruxelles Propriété, you'll find them on the web.

http://www.recupel.be/homepage.html?lang=3