6. Mixtures and water resources- water pollution & importance of wetlands

Water Pollution

Harmful substances or objects that make water dirty.

Pollutants

Substances or objects that are harmful to water and the environment.

Insoluble pollutants

Dirty things that do not dissolve in water, like oil or garbage.

Soluble pollutants

Chemicals or poisons that dissolve in water.

Living germs

Tiny living things like bacteria that can make people or animals sick.

Sewage

Waste matter carried away in pipes or drains.

Wetland

An area where the soil is full of water, with plants that love water, and the water level is high.

Water table

The level underground where the soil is completely filled with water.

Waterlogged

When soil is completely filled with water.

Purify

To clean water.

Still

A device used to clean water by heating it to steam and then collecting the clean water.

Sifting

The first step in cleaning water where large trash like fish and plants are removed using a big screen.

Sedimentation

A cleaning step where dirty water stands still so that medium-sized dirt particles sink to the bottom.

Sludge

The medium-sized dirt particles that sink to the bottom of water during cleaning.

Aeration

Pumping air bubbles through water to help good bacteria break down small bits of dirt.

Filtering

Passing water through layers of sand and gravel to remove tiny particles and most bacteria.

Disinfection

Adding chemicals to water to kill any remaining germs.

Temporary wetland

A wetland that is wet for 1 to 4 months a year.

Seasonal wetland

A wetland that is wet for 5 to 11 months a year, usually during the rainy season.

Permanent wetland

A wetland that is wet all year round.