In my constant quest to recycle everything and cut out weekly rubbish bag to next to nothing I have discovered that you can send your BRITA filters back to Brita for recycling. You have to send 6 at a time but it is Freepost.
Send to the following address : Brita Recycling, FREEPOST NAT 17876, Bicester, OX26 4BR.
Just thought other MNetters might like to know this!