Oakland International Airport in California began separating paper, cardboard and bottles from airport trash in 2003. Since adding food scraps to the list in 2004, it handles 455 tons a year, diverting 37 percent of its waste from landfills, said Rosemary Barnes, the airport spokeswoman. The airport has also cut in half the number of trash pickups each month, helped in small part by the Silver Dragon Cafe, a new restaurant tenant that uses compostable food containers.

Image Darrell Halsell, a custodian, checked recycling chutes at Oakland International Airport in California. Credit... Noah Berger for The New York Times

“I recognize to make a difference, it comes from the top down,” said Lilly Mar-Chee, the restaurant’s owner, who acknowledged it was difficult to decide to spend 10 to 20 percent more for the containers, made from potato starch, while opening a business during the economic downturn. “We are committed to using resources in a sustainable way.”

Even when recycling is available, airport procedures can sometimes make it hard for travelers to use it properly. At Portland International Airport in Oregon, officials discovered that 48,000 to 78,000 recyclable bottles ended up in the trash annually because they had been discarded at security checkpoints.

“The public does a really good job in general, but when we came to the checkpoints there’s all kinds of liquids in the trash,” said Stan Jones, the environmental compliance manager at the airport. The airport installed liquid dumping stations at the checkpoints, allowing travelers to pour out unused liquids and reuse or recycle the bottles. Mr. Jones said liquid collection was an environmental decision with an economic benefit. With more bottles being recycled, trash containers are lighter and fewer custodians are needed to remove them.

“There’s a number of benefits,” he said. “People can empty their bottle and take it through security. The other is we’re getting liquids out of recycling and out of the garbage.”

While a few airports have contacted Portland about following its lead, many more are establishing or refining recycling programs. At Newark Liberty International Airport, all tenants must recycle basic materials, according to Susan M. Baer, director of aviation for the airport’s operator, the Port Authority of New York and New Jersey.

“How you achieve it?” Ms. Baer asked about getting people to think about the environment. “By growing generations of people who want to recycle and making it possible for them to do so.”