Water Treatment and Quality Flashcards Preview

Chemistry Unit 3/4- Stoichiometry and Solutions > Water Treatment and Quality > Flashcards

Flashcards in Water Treatment and Quality Deck (17):
1

fresh water

water that is not salty. Most of this fresh water is in the form of polar ice

2

ground water

water that seeps through the ground below the surface. Not accessible because it is in remote locations or too far below Earth’s surface.

3

surface water

( lakes, rivers, reservoirs etc) is a tiny fraction of Earth’s water

4

- what is meant by water quality

- Water quality describes the condition of the water, including chemical, physical, and biological characteristics, usually with respect to its suitability for a particular purpose such as drinking or swimming
- is affected by substances that have dissolved in it. Many ions that are in water are found from more than one category of sources

5

harmful substances found in water (natural and from 
human activities)

- rain and snow contain dissolved gases from the atmosphere
- CO2 gas dissolves in water resulting in dilute solution of carbonic acid (dissolves compounds in soil and rocks)
- arsenic (found naturally but long term exposure can cause cancer), calcium and magnesium (cause hard water)

6

- Beneficial substances found in water (natural and from 
human activities)

- Fluoride?

7

- Beneficial substances found in water (natural and from 
human activities)

- Fluoride, calcium, iron,

8

- How do good and bad substances get into the water supply

run-off, point sources and non-point sources.

9

point source

pollution has a single source with specific location (leaking oil or pulp mill)

10

Non-point source

does not come from a single, easily defined location such as pesticides and fertilizers. Can be combinations of thousands of different sources

11

soft water

water that contains small concentrations of ions that form insoluble compounds with soap

12

permanent hardness

can’t be removed by boiling, only by chemical methods but water can be turned basic by this. Use ion-exchange water softeners to stop basic water from forming

13

- Ion exchange water softeners

CHECK IF YOU NEED TO KNOW

14

desalination

CHECK IF YOU NEED TO KNOW- the process of obtaining fresh water from salt water
- potable water: water that is safe to drink

15

reverse osmosis

CHECK IF YOU NEED TO KNOW- process of using high pressure to force water from a concentrated solution through a semi-permeable membrane to get a less concentrated solution
- there are aso reverse osmosis desalination plants

16

hard water

it is hard to form a lather with soap. - another sign of hard water is calcium carbonate (called lime scale) that build up inside water pipes, kettles and humidifiers. Vinegar helps to remove this.

17

temporary hardness

can be removed by boiling the water