6.4, 7.2, &7.4 Water

Water Canada has ____of the world’s fresh water supply. The water supply is available as: ______water (e.g. Great Lakes, rivers) ______sources (e.g. underground aquifers) Water is an excellent ______which makes it not only very useful in chemistry, but important for life. Being a good solvent, however does mean that it also is great at __________________________________.

Water Contaminants _________– inert suspended particles (e.g. silt) _________– viruses, bacteria, algae _________– any dissolved substance (metals, minerals, and other chemicals) Source of Contamination Untreated _____water (e.g. Ottawa River) _________/agricultural waste (e.g. Walkerton) Landfill _________ (e.g Chelsea landfill) _____fire emissions Impact Dead Zones _____________- is the increase in __________of a substance as you progress up the food chain.

Drinking Water Treatment Municipal Water Treatment Process 1. _________– screens filter out large debris. 2. _________, _________, sedimentation – particles settle out of solution. Al2(SO4)3 can be used as a coagulant [along with Ca(HCO 3 ) 2 ] 2Al 3+ (aq) + 3SO 4 2- (aq) + 3Ca 2+ (aq) + 6HCO 3 - (aq) 2Al(OH) 3(s) + 3Ca(SO 4 ) (s) + 6CO 2(g)

Drinking Water Treatment 3. _________– water flows through layers of sand and active carbon. This removes _________, _________, and _________impurities 4. _________– Chlorine or other reagent is added to the kill any microorganisms and react organic solvents. 5. _________– Air, O 2 or O 3 added to reduce unwanted taste/colour.

Drinking Water Treatment 6. _________– addition of sodium carbonate and calcium hydroxide precipitates Ca 2+ and Mg 2+ out of water. Ca 2+ (aq) + 2CO 3 - (aq) CaCO 3(s) Mg 2+ (aq) + 2OH - (aq) Mg(OH) 2(s) 7. _________– small amounts of _______is added to help prevent tooth decay. 8. ______-_________ – another treatment of chlorine to remove any microorganisms. _________is added to stabilize the _________so that it remains in solution during transportation to your tap.

Drinking Water Treatment Point of Use Water Treatment Less than ____ of municipally treated water is used for drinking. Other treatment methods could include one or more of: Boiling _________ Chlorination Reverse Osmosis _______________

Waste Water Treatment "Every time you drink a glass of water, the odds are good that you imbibe at least one molecule that passed through the bladder of Oliver Cromwell. It's just elementary probability theory?" Richard Dawkins

Waste Water Treatment _________waste Disease _________– e.g. Cholera Chemical release – e.g. nitrates, phosphates contraceptives Oxygen depletion – ____________of waste by bacteria has high BOD (biological oxygen demand). This can _______the relatively little O 2 that is dissolved in water

Waste Water Treatment Dead zone gulf of Mexico Chemical _______& oxygen ________

Waste Water Treatment Process ___________Treatment: Screening, _______, settling, filtering ___________ Treatment Aeration ___________