But researchers at the University of New South Wales in Sydney are exploring the possibility of “microfactories”: small, modular machines that can be used together in various combinations to create new materials.

The system is designed to “decentralize” recycling, said Veena Sahajwalla, the director of the university’s Center for Sustainable Materials Research and Technology, who leads the project. “There’s more than enough waste available,” she added, “and there’s more than enough demand.”

Turn disposable cups into sturdy materials.

Disposable coffee cups might seem recyclable, but most are lined with a fine film of plastic that makes them very difficult and expensive to reprocess.

The cups can, however, be mixed with recycled plastic to make various other products, including outdoor benches, vegetable garden planter boxes, coat hangers and even reusable coffee cups.

“Our plan is always to make the waste into products that goes back to the customers we got the waste from in the first place,” said Robert Pascoe, the managing director of Closed Loop, which manufactures new materials from the disposable cups.

Currently, the company recycles about seven million cups per year. Mr. Pascoe said he hoped that one day, the increased use of reusable cups will render the company’s business model unnecessary.

Collect street sweepings and reuse them.

Imagine if the rocks, cans, wrappers and other trash swept from the streets could be sorted, separated and reused. In fact, those items can be sorted in a “detritus processing facility.”