One scientist has figured out a way to turn car exhaust into printer ink. Jarhe Photography/

To reduce air pollution, some innovators are making good use out of it.

We know the basics of what can be recycled and reused: paper, plastic, metal, glass. But there is an increasing host of waste that can now get repurposed thanks to technological advances.

Scientists have figured out, for example, how to use human poop—and that of horses, rhinos, and elephants—to power buses, rickshaws, and even homes. There’s technology now to turn restaurant grease into biofuel, ocean waste into shoes, and sewage into natural gas. Bill Gates has even proven that sewage can power the very system that turns sewage into—gulp—drinking water.

But how do you recycle something you can’t touch?

I’m talking about the smog that blankets cities including Beijing, Delhi, and Los Angeles. Or the toxic gas that escapes from the hundreds of millions tons of garbage that end up in landfills. As it turns out, scientists and entrepreneurs have gotten creative about using those waste products as well.

Back in December, a Chinese artist grabbed international headlines when he paraded around Beijing with a vacuum and a brick made from the city’s notorious smog. The city was experiencing severe haze for three days straight at the time. “Nut Brother,” as he is known, vacuumed up more than 100 grams of fine particles from the air, mixed it up with clay, and turned it into a single brick. Although it was a simply a stunt to raise awareness about China’s air pollution problem, it illustrated that air pollution could perhaps be made into something tangible.

A month earlier, a Dutch artist used the same idea to turn air pollution into something more delicate: jewelry. Daan Roosegaarde created a 23-foot tower in Rotterdam that essentially works like an air purifier, sucking up smog and spitting out clean air. The fine-dust particles that are collected via ion technology get turned into gemstones, which are set into fashionable rings. Each ring represents 1,000 cubic meters of air cleaned. As Fast Co. Exist notes, however, this one project of course won’t cure air pollution.

But one MIT graduate and innovator in India hopes his idea might be a good start. Anirudh Sharma has come up with a way to harvest black smoke—the kind you see billowing out of chimneys and from car mufflers—and repurpose it into printer ink. “The pigmentation of that blackened smoke is actually unburned carbon released from incomplete combustion,” or soot, he says. “If you capture that carbon and take it through a very simple chemical process, you can make really high-quality raw material that is important to printing and ink industries.”

The black, powdery substance left behind by the after the carcinogens and impurities are removed is what Sharma calls “black gold.” Mixed with a bit of alcohol and oil, it can turn into a cheaper alternative to traditional ink. You can see the process in this demo video:

Called Kaalink, the project started as a research experiment at MIT, where Sharma studied. Now, he and his team at Sbalabs, a spinoff of MIT Media Lab, are hoping to partner with companies to take their product worldwide. Here’s the process: Handheld devices will be attached to cars to capture the carbon. For every six miles the car travels, enough carbon is produced to generate two cartridges of ink.

“We are cleaning the environment by not releasing the carbon that would otherwise enter into the lungs of people,” he says. “Then that [carbon] becomes financially viable, because whatever [is captured] can be repurposed and sold to [use in] newspapers, print magazines, T-shirts.”

While Sharma is getting innovative to reduce the impact of carbon emissions, a team of scientists in San Francisco is working to turn methane gas into fish food. Their weapon of choice: Methylococcus capsulatus, a type of microbe that feeds on methane from decomposing vegetables.

At the biotechnology company Calysta, engineers are pumping methane into tanks filled with these bacteria before heating them and killing them. What’s left is a pink powder that they then pack together into high-protein fish food, reports CBC News.

This can solve two problems. For one, the company argues, the gas used can come from the plethora of garbage dumps around the world, thereby helping reduce methane emissions everywhere. Secondly, it can make aquaculture more sustainable: Instead of “tapping the planet dry,” the fish can feed on this processed waste. Plus, the process is not restrained to fish food. Speaking to CBC, the industrial microbiologist David Bressler of the University of Alberta says that the microbe can become food for livestock, pets—even humans. (It will admittedly take time to combat the yuck factor.)

As Sharma tells me during our interview, there’s no better time to get creative about tackling air pollution. Research shows that a staggering 3.5 billion people still breathe polluted air every day, as CityLab reported earlier this year. In places like China, Indonesia, and India, air pollution is responsible for killing millions each year.

And while these projects won’t solve the problem on their own—the solution will have to come from policy and behavioral changes worldwide—the creativity in the scientific and innovation world regarding reuse is a welcome sign.

Top image: Jarhe Photography /

About the Author

Most Popular

  1. A photo of a new subdivision of high-end suburban homes in Highland, Maryland.

    Unpacking the Power of Privileged Neighborhoods

    A new study shows that growing up in an affluent community brings “compounding privileges” and higher educational attainment—especially for white residents.

  2. Life

    Think You’re Faster Than the D.C. Streetcar? Think Again.

    Streetcars without dedicated lanes tend to be on the slow side. But beating this much-maligned public transportation mode on foot wasn’t as easy as it looks.

  3. Equity

    In Need of Housing, Barcelona Fines Landlords For Long-Vacant Buildings

    The massive fines levied against the investment funds have been interpreted as a “declaration of war” from Mayor Ada Colau, who wants more affordable housing.

  4. A cyclist rides through a desert park and nature preserve in Phoenix.

    The Inequality of America’s Parks and Green Space

    New research finds that income, education, and race are correlated with access to green space across and within U.S. metro areas.

  5. Map of United States with Numbers on Each State

    The Affordable Home Crisis Continues, But Bold New Plans May Help

    Wyoming fares best; Nevada the worst. No state has an adequate supply of homes for its poorest renters a new National Low Income Housing Coalition report finds.