11.3.4: Explain the concept of recycling.

Recycling & Remanufacturing

Recycling is the separation, collection, processing, marketing, and reuse of the unwanted material. Remanufacturing is the rebuilding of a product to specifications of the original manufactured product using a combination of reused, repaired, and new parts. Both are increasingly used in industry as ways to promote more sustainable industrial processes.

Recycling

Recycling involves the breaking down of the components used in the creation of plastics, papers, aluminum, and glass, and preparing them for use in a future application. Formal programs to encourage recycling are common in developed countries, though rates vary widely. Around 65 percent of solid waste is recycled in Germany but only 19 percent in Japan. Recycling in the United States increased from 10 percent in 1985 to 34 percent in 2015. Formal recycling programs are not in place in most developing countries, though informal recycling is common. Pickers comb through landfills and resell what they find.

Recycling in Europe and Other Developed Countries

Recycling in the United States

Since 1990, the percentage of recycling has increased (green line) and the waste generated per person has stayed about the same (red line).

Materials that would otherwise be “thrown away” are collected and sorted, in four principal ways:

• Curbside programs. Recyclables can often be placed at the curb in a container separate from the non-recyclable trash at a specified time each week, either at the same or different time as the other trash. The trash collector usually supplies homes with specially marked containers for the recyclable items.

• Drop-off centers. Drop-off centers are sites, typically with several large containers placed at a central location, for individuals to leave recyclable materials. A separate container is designated for each type of recyclable material, and the containers are periodically emptied by a processor or recycler but are otherwise left unattended (Figure 11-72).

• Buy-back centers. Commercial operations sometimes pay consumers for recyclable materials, especially aluminum cans, but also sometimes plastic containers and glass bottles. These materials are usually not processed at the buy-back center.

• Deposit programs. Glass and aluminum containers can sometimes be returned to retailers. The price a consumer pays for a beverage may include a deposit fee of 5¢ or 10¢ that the retailer refunds when the container is returned.

Recycling and Composting Tent at an Outdoor Festival, Washington, DC

Pause & Reflect 11.3.4

When you have takeout or fast food, are the containers for food and beverages recyclable? Do you and your friends recycle them? If not, how could the rate of recycling be improved?

Remanufacturing

The percentage of materials recovered by recycling varies widely by product. Materials are manufactured into new products for which a market exists. Four major manufacturing sectors account for more than half the recycling activity—paper mills, steel mills, plastic converters, and iron and steel foundries.

Sources of Solid Waste Before and After Recycling, 2015

The left side shows the share of different sources of waste. The right side shows the share remaining after some of the waste has been recycled.

Common household items that contain recycled materials include newspapers and paper towels; aluminum, plastic, and glass soft-drink containers; steel cans; and plastic laundry detergent bottles. Recycled materials are also used in such industrial applications as recovered glass in roadway asphalt (“glassphalt”) and recovered plastic in carpet, park benches, and pedestrian bridges.

The principal inputs into manufacturing include recycled paper, plastic, glass, and aluminum:

• Paper. Most types of paper can be recycled. Newspapers have been recycled profitably for decades, and recycling of other paper, especially computer paper, is growing. Rapid increases in virgin paper pulp prices have stimulated construction of more plants capable of using waste paper. The key to recycling is collecting large quantities of clean, well-sorted, uncontaminated, and dry paper.

• Plastic. Different plastic types must not be mixed, as even a small amount of the wrong type of plastic can ruin the melt. Because it is impossible to tell one type from another by sight or touch, the plastic industry has developed a system of numbers marked inside triangles on the bottom of containers. Types 1 and 2 are commonly recycled, and the others generally less frequently.

• Glass. Glass can be used repeatedly with no loss in quality and is 100 percent recyclable. The process of creating new glass from old is extremely efficient, producing virtually no waste or unwanted by-products. Though unbroken clear glass is valuable, mixed-color glass is nearly worthless, and broken glass is hard to sort (Figure 11-74).

• Aluminum. The principal source of recycled aluminum is beverage containers. Aluminum cans began to replace glass bottles for beer during the 1950s and for soft drinks during the 1960s. Aluminum scrap is readily accepted for recycling, although other metals are rarely accepted.

Recycling Glass, Pennsylvania