RECYCLING IS NOT the most glamorous work, and it's generally not the sort of thing that politicians and environmentalists discuss when they discuss "green jobs." But for the right person, it's an opportunity as endless as anything dreamed up by Silicon Valley.

Alan Bachrach is the right kind of person. As a director of recycling for Waste Management Corp., North America's largest recycler of household waste, he has a professional, profit-driven interest in recycling. If there are those who feel shame for working in an industry that handles other people's waste, Alan Bachrach isn't one of them. He loves it.

We meet early in the visitor's area of Waste Management's new recycling plant in Houston. Bachrach's eyes don't focus on me, but rather on what's on the other side of a plate-glass window and two stories down: swiftly moving Class A rapids of plastic bottles, cardboard, and paper, riding up and down conveyors, over and under, around and around, until they emerge as perfectly sorted hay-bale-sized blocks of bottles, cardboard, and paper, tied together with steel ties.

Waste Management's single-stream recycling plant sorts between 600,000 and 700,000 pounds of recycling per day. That's roughly the weight of an Airbus A380 jet — measured out in newspapers, plastic milk jugs, beer cans, and shoe boxes. When I ask for an estimate of just how many households those pounds represent, Alan tells me that, on average, a Houston family generates 50 pounds of single-stream recycling per month.

"You ready to take a walk?" Alan asks me with a child-like gleam. We walk outside and around the building, to an enclosed receiving area where a truck is tipping a load of recycling onto the concrete floor. Single-stream recycling hisses more than it clanks, mostly due to the fact that 70 percent of it is paper — junk mail, newspaper, office paper. A front-end loader of the sort most people are accustomed to seeing dig in the dirt at construction sites rolls up and digs into this mass of well-intentioned waste, picks it up, and dumps it into a device that feeds the stuff onto conveyors.

WE ENTER INTO the Walmart-size space that I saw from above, and I swear, the first thing that comes to mind is Willy Wonka's chocolate factory: conveyors of trash rush upward and release their cargo into spinning stars that toss it about in a manner that I can only describe as joyful, like popcorn jumping in a frying pan. Some continues along, some drops away. I see detergent and shampoo bottles zipping by, and I see milk bottles dropping, from points unknown, into a giant cage.

We climb a stairway to what Alan calls the "pre-sort." Here two workers stand over a high-speed conveyor that carries freshly arrived, unsorted recycling. One of them reaches out and grabs a brown plastic bag from the blur, and just as quickly it disappears, sucked up by a large vacuum tube positioned directly above them. Then he does it again. "Not everybody can hack this job," Alan leans over to say, nodding at the speeding, blurry line. "Some people get dizzy, throw up."

One of the sorters grabs a hunk of something — it happens so fast I can't tell what — and drops it down a square chute. "The other job is to pull out big pieces of plastic and trash," he adds and points me farther along to the spinning stars I saw from below.

The conveyor feeds into the stars and newspaper bounces and froths atop them like white water on churning waves. The stars — they're made of a specialized plastic that wears well — are spaced at intervals to allow plastic, glass, and aluminum to fall down onto another line. The newspaper, meanwhile, dances right across the stars and emerges on the other end, separated. Meanwhile, below, the material that dropped through the stars, including more paper, is conveyed into yet more stars, spaced at smaller intervals that convey out even more paper — in smaller sizes — while the plastics, glass, and cans continue to fall away. It's a cascade, each step angled steeper than the last, and at each level paper and plastic are separated.

Below, aluminum cans are literally ejected from the system by a device that creates an electrical current that repulses metals. The glass, meanwhile, is removed by several processes that take advantage of the obvious fact that glass is heavier than paper. Think of it this way: If you place a beer bottle next to a pile of newspaper coupons, and aim a hair dryer at both, you'll likely be left with only a beer bottle. That's a rough approximation of the physics that Waste Management uses to separate the two materials.

WE CLIMB MORE stairs, moving ever higher into the system. There's no more paper up this high. Now it's all about separating the different kinds of plastics. "This is my guys' favorite one," Alan tells me, and he nods at a yellow device that hangs over a blur of bottles. It contains 200 sensors that shine infrared light onto the trash passing beneath them. When the light reflects off, say, a red Tide detergent bottle, nothing happens. But if the light reflects off a clear Coca-Cola bottle, the computer records exactly where it is on the precisely timed conveyor.

Through the clamor, I hear irregular, sharp pops of compressed air, like tiny gun bursts. A few feet from the sensors, I see an Aquafina bottle stagger backward onto another conveyor, followed by a Coke bottle. The computer knows exactly where the bottles are, and how long it takes for them to arrive at the air guns. I can see the nozzles, now, tiny needle tips capable of sending an empty bottle flying. According to Alan, this one machine, its sensors and air guns, replaces six to 10 manual sorters.

Still, infrared light sensors, for all of their sophistication, have limitations. One of them, according to Alan, is that "they can't sort white polyethylene bottles from colored polyethylene bottles." In layman's terms, that's the process of sorting a red Tide detergent bottle from a white Minute Maid orange juice bottle. But have no fear: "We have the most sophisticated equipment available: a person." Sure enough, three human beings stand over a conveyor, grabbing the white bottles and tossing them down chutes. At their best, people can handle perhaps 45 "sorts" per minute — not bad, but certainly not nearly the hundreds that an array of air guns and sensors can handle.

For all of Alan's joking about people as technology, however, he never once diminishes the dignity of the work done by his sorters. Like many of the scrap entrepreneurs I've met over a lifetime around this industry, he identifies with them. After all, they're all in the business of sorting other people's waste. "People think that because these are minimum wage jobs or close to minimum wage jobs, it's a very high-turnover position. I've got 10, 15, 20 years folks."

It may not be the highest paying job, and it may not be glamorous or the sort of thing that your kid will want to tell his friends about. But if you're looking for a consistent job, with benefits, where layoffs are almost unknown, then it doesn't get much more consistent than American recycling. In Houston, a town that knows the heartbreak of boom and bust better than most areas, a stable job like that is worth more than just salary.

YOU WON'T FIND a Chinese version of Alan Bachrach, just as you won't find an Indian, Kenyan, Vietnamese, or Jordanian one, either. The reason is that most of the world remains poor enough to justify employing people to do what Alan does with star screens and air guns.

Consider what happens every night in the courtyard of the Shanghai high-rise where I live. Just past midnight you'll likely hear the clank of a bottle bouncing across concrete. If you follow that bounce back to its source, you'll come to a concrete hut, not much larger than a single-car garage, from which fragrant trash has been spilled several feet into the narrow asphalt road. It doesn't look like American trash: there are few boxes, cans, or bottles. Rather, it's mostly food waste — peels, husks, bones.

Move a little closer, and you might see two or three hunched shadows atop the oozing mess, canvas bags swung over their shoulders, scrounging through it with bare hands, searching for metal cans, plastic bottles, or perhaps something better yet — a stray coin. They're not Shanghainese but often families of poor migrants from farms in the less wealthy provinces, making the best living that they can.

Families that pick through trash in the middle of the night are just the last screen in a profit-driven process that, if you wait outside my building through the night, begins at the gate at first light. There you'll see a squat and brawny migrant woman wearing a fanny pack stuffed with small money, and carrying a small hand scale. If anyone is the Chinese equivalent of Alan Bachrach, presiding over a system that harvests recyclables from the trash, she is it. Her destination is the pile of cardboard tied with twine that's waited beneath the night watchman's gaze, and a waist-high balance scale of the sort that you might find in a doctor's office. As she pulls out the big scale, the early-rising old ladies in my building wander downstairs carrying a few plastic bottles, perhaps a small cardboard box or two, and maybe a small plastic bag filled with cans. The bottles and cans are priced individually; the boxes are attached to a small hook on the hand scale and weighed. Payment is equivalent to a few pennies, which the early risers take to the wet market, in search of the day's vegetables.

Morning brightens, and the recycling lady is joined by her slight husband. While he handles the walk-up transactions, his wife ventures up into my building, responding to dispatches relayed through the guard booth: somebody bought a television and wants the big box in which it was delivered removed. Through the morning, she rides the elevator, up and down, paying a few pennies — the market price — for whatever's available for recycling.

Men on bicycles that pull small trailers begin to arrive. Some are there to buy newspapers, others cans. Whatever it is they want, they pay more for it than what she paid for it in the building, then tie the goods to their trailers and pedal off. Before the end of the day, they'll sell the collections to a small scrap company, one with a warehouse rather than a street corner. But the concept is the same: buy low and sell high. At the scrap company, scrap is combined into bigger loads that can be sold to paper mills, aluminum smelters, and other manufacturers in need of raw materials.

There's no need for single-stream schemes to raise the recycling rate in Chinese cities because, in the end, my Chinese neighbors have something that most Americans don't: a recognition that "the recycling" is worth more than virtue.

It's worth money.

From Junkyard Planet: Travels in the Billion-Dollar Trash Trade by Adam Minter. ©2013 by Adam Minter. Published by Bloomsbury Press. Reprinted with permission.