Water Pollution

Question 1

What are 7 different types of water pollution?

Answer 1

1) Organic pollutants
2) Pathogens
3) Nutrients and agriculture runoff
4) Suspended solids and sediments
5) Inorganic pollutants (salts and metals)
6) Thermal Pollution
7) Radioactive pollutants

Question 2

What are some examples of Organic Pollutants?

Answer 2

Oxygen-demanding waste (i.e. faeces, sewage, dead organisms)
Oil

Question 3

What causes the decomposition and demands Oxygen with organic wastes?

Answer 3

Bacteria.

Question 4

What DO mg/L level is low enough to be an issue?

Answer 4

Below 4mg/L is an issue

Question 5

How do you calculate BOD in the lab from a sample?

Answer 5

BOD = (DO(t 0 ) – DO(t 5 ))*Dilution Bottle volume /Sample volume

Question 6

How can high nitrate levels in drinking water affect infants?

Answer 6

Diarrhea, dehydration and even blue-baby syndrome (low O2 in the blood).

Question 7

What level of TDS should drinking water not exceed?

Answer 7

500mg/L

Question 8

What hardness should drinking water not exceed?

Answer 8

200mg/L of CaCO3

Question 9

What are some physical water treatment systems?

Answer 9

Sedimentation
Filtration
Gas transfer

Question 10

What are some chemical water treatment systems?

Answer 10

Chemical addition
Chemical coagulation
Ion Exchange

Question 11

What are the 7 Principle processes in potable treatment of water?

Answer 11

1. Aeration
2. Solids separation
3. Coagulation and flocculation
4. Softening (of water hardness CaCO3)
5. Ion exchange
6. Filtration
7. Disinfection (kills pathogens)

Question 12

What is Stokes law?

Answer 12

• An equation for determining the rate of sedimentation.

A particle moving through viscous liquid attains a
constant velocity or sedimentation rate.