Not directly CCS Biology related but since sustainability is the theme du jour I thought I'd post this here in the hope that somebody might learn something. At UC Berkeley I worked with a lot of students on recycling projects as they investigated an interesting variety of topics from the economics of single stream versus mutliple stream recycling to the contribution of the homeless to the recycling industry. The message I came away with is that recycling is a complicated, constantly changing and sometimes counter intuitive industry.
For example single stream recycling (where all recycling is collected in one bin) is becoming increasingly popular because collection costs are lowest and new technology allows some quite efficient sorting of materials at the depot. However recycling agencies discovered that the less restrictive you make the instructions - the more you collect. ie if you say 'All plastics' you collect a lot more (of ALL kinds of plastics) than if you say only 'Plastics #1 and #2' and if you say something like 'Only #1PETE and #2HDPE blow molded plastic jugs and bottles' you collect least of all because people get confused and end up chucking a lot more in the garbage. But the truth is that in many areas there is ONLY a market for the aforementioned #1 and blow molded#2. So they collect everything but then end up chucking away everything else so that they can get more of #1 and #2. Confused? Try persuading your friends that in most cases they are better off throwing away plastics (at least of #3 and greater), even if their recycling company collects them, because putting them in the recycling devalues the value of the recycling.
This does differ a bit from place to place and depends on your local collection agency and what the local market is for recycling products. I was reminded of this because New Scientist had an article this week on 'Dumb eco-questions you were afraid to ask' that covers a few of these recycling issues. Including the popular, and much debated pizza box question. I'm not sure why they call them dumb though, most of these are pretty good questions.
Coincidentally Popular Mechanics had an article on 'Recycling Myths: Popular Mechanics Debunks 5 Half Truths about Recycling' this month which contains some useful ecomomic information about the recycling industry.