Naked Science Forum

Non Life Sciences => Technology => Topic started by: thedoc on 18/03/2014 10:30:01

Title: How is waste recycled?
Post by: thedoc on 18/03/2014 10:30:01
Stuart St.John asked the Naked Scientists:
   
I was wondering whether you have thought of doing/have already done a show about the science involved in recycling?

Most responsible folk these days certainly feel it their duty to separate their cans from their cardboard and their polythene bags from their polyester bottles, but few of us (myself included) know much about what happens to it after it is collected. I have lots of science questions about it, including how different polymer types are separated (are they?) and why on earth crisp manufacturers (among others) are allowed to produce unrecyclable composites (plastic with aluminium film bonded to it)?

Other questions I have include the wider picture of energy usage in recycling - For example, if I have a bit of left-over hot water in the kettle when I finish a 4pt milk carton I often rinse it out with the hot water (thus getting rid of milk residue that would go smelly in summer and making the bottle easier to squash), but there must come a point in cleaning our recycling when the energy we're using to clean it up negates the energy saved by recycling it.

Sorry, this is getting really wordy. I'm sure you get the gist of it. So, could this be an issue to look into at some point?

Cheers for the excellent show (http://www.thenakedscientists.com/HTML/podcasts/)!

Stuart.

What do you think?