File water qualityx

heehawultraMécanique

22 févr. 2014 (il y a 3 années et 6 mois)

76 vue(s)

Water Quality



Clean water is essential in life!

However, fresh clean water is in limited supply on Earth


There are three different types of contamination:


Physical (floating debris, suspended dirt)


Biological (bacteria, viruses, micro
-
organisms)


Chemical (water soluble compounds)






The water purification process at treatment facilities
aims to improve the quality of this water.


To make water “potable”, various techniques are used
to treat the water like: coagulation, flocculation,
sedimentation, filtration, aeration and disinfection.




Ultimately, chemicals are added to the water in order
to form precipitates that can be filtered out.

A sample of water can be purified by using the “right”
anion to form a precipitate with a certain
cation
,
according to the solubility chart for double
displacement reactions. (page 424)


Ex: What anion could be used to form a precipitate
with:

a) Fe
+3


b) OH
-
1


c) SO
4
-
2


a)
carbonate, or phosphate, or sulphide


Ex: Construct a flow chart to show how a water sample
containing Sr
+2

and Mn
+2

can be separated out
one

at
a
time.