Palliser, Janna, Science Scope
Recycling has been around for a long time--people have reused materials and refashioned them into needed items for thousands of years. More recently, war efforts encouraged conservation and reuse of materials, and in the 1970s recycling got its official start when recycling centers were created. Now, curbside recycling programs and recycling centers are common. In 2009, approximately 9,000 curbside recycling programs and 3,000 composting communities existed in the United States (EPA 2010). You can now recycle at home and in airports, schools, and the workplace. But when you throw a can or plastic container into the recycling bin, what happens to it? Where does it go? Recycling helps to reduce waste, but how efficient is it? Are some items more recyclable than others? These questions and others will be addressed in this month's column.
There are several definitions of recycling, but "to adapt to a new use" and "to make ready for reuse" seem to fit best (Merriam-Webster 2011). Recycling turns would-be garbage into another product. A recycling "loop" is created when a consumer purchases a recycled item, instead of the direct line a product would normally take if simply thrown in the trash.
Recycling consists of three basic steps: collection and processing, manufacturing, and purchasing recycled products.
Collection most often occurs curbside at residences, if the service is provided. Other methods include drop-off centers, buy-back centers, and deposit/ refund programs (available in 11 states) (EPA 2011a; Davis 2008). After collection, recyclables are sent to a materials recovery facility where they are cleaned and sorted. As with other commodities, recycled materials are bought and sold at fluctuating prices.
After cleaning and sorting, recyclables move on to the manufacturing stage where they are converted into a product that is either completely or partially made of recycled materials. Newspapers, paper towels, aluminum, plastic, glass soda bottles, steel cans, and plastic laundry detergent bottles are items that often contain recycled material. Recycled materials are also being used in roadway asphalt (glassphalt), carpeting, park benches, and pedestrian bridges (EPA 2011a).
The last step, purchasing recycled products, completes the recycling loop.
In 2009, Americans generated 243 million tons of municipal solid waste (MSW) and recovered 82 million tons of this material (61 million tons were recycled and 21 million tons composted). The recycling rate was about 33.8%. While the amount of trash has increased annually, so have recycling and composting: In 1960, 88.1 million tons of MSW were generated and 5.6 million tons were recycled. In 2009, 243 mil lion tons of MSW were generated and 82 million tons were recycled (EPA 2010).
Of the MSW generated in the United States in 2009, 54.3% was discarded, 33.8% was recovered (recycled), and 11.9% underwent combustion (with energy recovered) (EPA 2010).
What we throw away
Of the 243 million tons of trash generated in 2009, organic materials are the largest component and consist of paper and paperboard (28.2%), food scraps (14.1%), and yard trimmings (13.7%). Other components include plastics (12.3%); metals (8.6%); rubber, leather, and textiles (8.3%); wood (6.5%); glass (4.8%); and other (3.5%) (EPA 2010).
Measured by percentage of generation, products with the highest recovery rates (in 2009) were lead-acid batteries (96%), newspapers (88%), corrugated boxes (81%), office-type papers (74%), major appliances (67%), steel packaging (66%), yard trimmings (60%), commercial printing papers (66%), standard mail (63%), magazines (54%), aluminum cans (51%), and folding cartons (50%). The lowest recycling rate was for polyethylene terephthalate (PET) bottles and jars at 28% (EPA 2010). …