Separating Mixtures in Industry: Impacts on People and the Environment

From your kitchen to the factory

You separated beans, rice and salt at home. Industries separate mixtures too, but in amounts measured in millions of litres and thousands of tonnes. At that scale, the methods have big effects on people and the environment, both good and bad.

In this lesson, you'll look at four industries and learn to assess their impacts: weigh the benefits against the costs.

Assessing impacts

To assess an industrial process, ask:

• Environmental benefits and costs: Does it protect or harm air, water, land and living things? How much energy does it use?
• Social benefits and costs: Does it make people healthier or put them at risk? Does it create jobs? Who benefits, and who lives with the effects?
• Can the costs be reduced? Better technology, rules, cleanup, or doing things differently.

There is rarely a simple yes-or-no answer. A good assessment shows both sides and gives evidence.

Examples from Ontario

• Clean water for all? Water treatment plants protect millions of people from disease. But some First Nations communities in Ontario and across Canada have lived under drinking water advisories, where tap water isn't safe to drink without boiling, or at all. In Neskantaga First Nation in northern Ontario, a boil-water advisory began in 1995 and has lasted for decades; it was still in place in 2025. Communities and governments have been working to build and repair treatment plants and train local operators.
• Oil refining in Sarnia. Sarnia has several oil refineries and chemical plants that provide many jobs and products. Aamjiwnaang First Nation is right beside them, and community members have raised concerns about air pollution and its effects on their health.
• Mining in Sudbury. Sudbury has mined nickel and copper for over a century. In the past, smelter pollution and logging left the land around the city bare. Since the late 1970s, a large community regreening effort has planted millions of trees and helped the land recover, and pollution controls at the smelters have cut emissions a lot.
• Recycling. Separating recyclables means fewer raw materials need to be mined or cut, and less goes to landfill. But if people put the wrong items in the blue bin, whole loads can be harder to recycle.

Jobs, trades and new technology

Separation processes need skilled people:

• Water and wastewater treatment operators run and test treatment plants. In Ontario they must be certified.
• Millwrights (industrial mechanics) install and repair the pumps, crushers, conveyors and separators in mills and plants. It's a skilled trade learned through an apprenticeship.
• Process operators in refineries and mills control the machines and check the products.
• Environmental technicians test water, air and soil around industries.

Emerging technologies are changing these jobs. Some recycling facilities now use optical sorters with cameras, and some use artificial intelligence (AI) that has been trained with thousands of pictures to recognize items like plastic bottles and cartons on a fast-moving belt. A puff of air then pushes each item into the right bin. This can sort faster and more accurately, which keeps recycled materials cleaner. It also changes the work people do: fewer people sort by hand, and more people are needed to program, maintain and repair the machines.