I think "recycling" is a strong and growing keyword online, especially with the green buzz we are finding ourselves in. Unfortunately, the 2nd keywords you've paired them with, dont quite make sense for the industry. Personally, I have never looked up a recycling plant online, as they make it very simple where Ive lived (you put out the recycling with the trast, and the city trucks take it away).
Interestingly enough there is a good Recycling domains coming up on NameJet - the end of those auctions should give you a realstic starting point to consider value from on these domains.
Currently:
RecyclingTechnologies.com - $80 with 14 Bidders (2 1/2 days left remaining)
Justin