Nov 2 Lecture: Water Pollution

Question 1

give 2 broad types of pollutants

Answer 1

1. organic matter

2. domestic pollution

Question 2

organic matter as a pollutant

Answer 2

• can spread diseases

- decomposed by bacteria with a variety of ill effects

Question 3

decomposition of organic matter is first performed by ___ microorganisms, and then by ___ bacteria that can only dominate the microbial community in the absence of ___

Answer 3

aerobically

anaerobically
oxygen

Question 4

domestic pollution:

Answer 4

some of the bacteria that oxidize organic matter are pathogenic

• difficult to measure
• bacteria such as cholera, hepatitis can be pollutants in water

Question 5

5 examples of organic matter than can pollute water

Answer 5

1. algae in a pond
2. human/ animal waste
3. runoff from animal feedlot
4. discharge from food processing plants
5. runoff from streets/ highways

Question 6

biochemical oxygen demand=

Answer 6

(BOD)
= the measure of organic matter load in a body of water

ie how much oxygen is required to breakdown the organic matter aerobically

Question 7

oxygen sag curve:

Answer 7

a graph of dissolved oxygen content as a function of distance from a waste source

represents BOD

Question 8

in eutrophication, algal growth proceeds in the ___ zones and chokes out other plants.

Answer 8

photic zone

Question 9

explain eutrophication

Answer 9

algae grows in photic zone, chokes out other plants

• these plants die, drop to bottom of lake (they become part of the organic matter load and increase the BOD)
• re-releases abundant nutrients into the water, cycle is repeated
• layers of water become oxygen depleted= kills oxygen dependent animals

Question 10

identify the 3 main pollutants that come from agriculture

Answer 10

1. fertilizers/ organic waste
2. herbicides/ pesticides
3. sediment pollution

Question 11

__ are concentrated along the food chain!

Answer 11

toxins

eg DDT

Question 12

how does sediment pollute water?

Answer 12

sediments choke waterways and reduce sunlight penetration

- plant/ animal success is reduced by murky water

Question 13

what is a solution to sediment pollution?

Answer 13

settling ponds

Question 14

industrial pollution mainly contributes ___

Answer 14

metal pollutants

Question 15

___ ____ can accumulate in the bodies of simple organisms

- concentrates up the food chain

Answer 15

heavy metals

- cadmium, lead, mercury, etc