Environmental Engineering Reference
In-Depth Information
high enough concentration, fouls up the air. The way to deal with it is to use technology to transform risks
and by-products into smaller risks and smaller by-products.
To see how this works, let's take the fossil fuel that has historically and today been associated with the
most environmental hazards: coal.
MANAGING BY-PRODUCTS AND RISKS—A UNIVERSAL CHALLENGE
Much of present-day energy discussion proceeds as if certain types of energy (fossil fuel, nuclear) are
inherently dirty and dangerous and others (wind, solar) are clean and safe. But there is no limit to how
much cleaner and safer fossil fuel use can be. For example, someday it might be possible to completely
purify coal so that it generates no air pollutants and the materials that would have become air pollut-
ants—nitrogen, sulfur, heavy metals—become valuable commodities. To a great extent, this is what we do
with oil. What was once oil pollution dumped into a lake is now the basis for the plastic keyboard I am
typing on.
At the same time, there is also no getting around the fact that
every
form of energy has risks—and every
industry is responsible for managing them.
Consider the following story about the health and safety hazards of producing wind power. We think
of wind as “clean” because there is no smoke coming out of the windmill. But in looking at any energy
technology, we must remember that it's a process, starting with mining the materials necessary for the ma-
chines all the way to disposing of them. And wind turbines require far more toxic materials than fossil
fuels do—materials called rare-earth elements. These elements are “rare,” not in the sense that there are
few of them, but in the sense that they exist in low concentrations in the Earth: it takes a lot of mining and
a lot of separating of the desired metals from other elements using hazardous substances like hydrofluoric
acid in order to get usable rare earth elements.
Here's what this process looks like in a major facility in China—where most rare earths for wind
power are mined. This dispatch is from reporter Simon Parry, who visited to experience a rare earth mine
firsthand. As you read his account, ask yourself: Does this mean that wind power is dirty and immoral?
On the outskirts of one of China's most polluted cities, an old farmer stares despairingly out across an
immense lake of bubbling toxic waste covered in black dust. He remembers it as fields of wheat and
corn.
Hidden out of sight behind smoke-shrouded factory complexes in the city of Baotou, and patrolled by
platoons of security guards, lies a five-mile-wide “tailing” lake. It has killed farmland for miles around,
made thousands of people ill and put one of China's key waterways in jeopardy.
This vast, hissing cauldron of chemicals is the dumping ground for seven million tons a year of
mined rare earth after it has been doused in acid and chemicals and processed through red-hot furnaces
to extract its components.
