Belfast Freegle is a group for getting rid of things you don't want and acquiring things other people don't want:
Here's the blurb:
Throwing something away? STOP! If you live in the Belfast area, please offer your reusable items to group members. Keep it out of landfill. Recycle it! Items must be legal, appropriate, and given for free. Items can't be lent, swapped or sold.