ch.2b

Question 1

What categories are contaminants generally divided into

Answer 1

Organic and inorganic

Question 2

What are some general characteristics of metals

Answer 2

-shiny
-malleable
-Ductile
Conductive

Question 3

What are some general characteristics of metalloids

Answer 3

• semiconductors

- some metallic properties

Question 4

What are some general characteristics of heavy metals

Answer 4

• metals that are denser then iron

- term now applies to metallic elements of concern regardless of density

Question 5

What are trace elements

Answer 5

Those present in low concentrations (less than ppm)

Question 6

True or false: 3. Many important contaminants have both natural and anthropogenic sources.

Answer 6

True

Question 7

Where do metal gradients develop

Answer 7

• Near cities/other developed areas
• mining operations
• near human activity

Question 8

Can metals and metalloids be artificially produced

Answer 8

No

Question 9

What should you consider before classifying something as a contaminant

Answer 9

The background levels in that area as in some places the normal levels can be much high then recommended levels

Question 10

When is a higher then recommended metal concentration considered a pollutant

Answer 10

If all 3 are met

• Concentrations higher then background levels
• least partially caused by humans
• Has a deleterious effect

Question 11

Why is it difficult to prove polltuion

Answer 11

• it mixes with things in the env (one contam can look like many)
• Env interactions ( is Al toxic or the low pH)

Question 12

What is the transport of contaminants influenced by

Answer 12

How they partition between phases (Gas/Aq or Aq/Sed or Dissolved liquid/Solid)

Question 13

Can you assume Thermodynamic Equilibrium on a board scale

Answer 13

NO

Question 14

Can you assume that the local distribution of a compound is approximately at steady state

Answer 14

Yes

Question 15

Do you assume partitioning is fast or slow

Answer 15

Fast

Question 16

Can you assume that X (in pase A) is in equilibrium with X (in phase B)

Answer 16

Yes

Question 17

What is Kow

Answer 17

Octanol/water coefficient

Question 18

What is Kp

Answer 18

Partition Coefficient

Question 19

What is Kd

Answer 19

Distribution Coefficient

Question 20

What is the equation for Kd

Answer 20

(Conc of X in phase solid)/(conc of X in phase liquid)

Question 21

What is adsorption

Answer 21

implies association with surface only – difficult to distinguish surface and subsurface

Question 22

How adsorption for a compound usually determined

Answer 22

Empirically estimated with laboratory experiments

Question 23

What can Henry’s law help you predict

Answer 23

Portioning between aqueous and gas phase

Question 24

What is the Equation for henry’s LAw

Answer 24

H=P/C

H: Henry’s law coefficient
P: Vapour pressure
C Water solubility

Question 25

What does a low Henry's Law coef mean

Answer 25

Compound tends to stay in the aqueous phase

Question 26

What does a high Henry's law Coef mean

Answer 26

Likely will travel atmospherically if discharged aqueously

Question 27

How are contaminants usually degraded? What are some other ways

Answer 27

- oxidative - Hydrolysis Other ways: - Enzymes - abiotic (UV, heat) - photolysis

Question 28

True or false: Biological degredation can proceed to mineralization

Answer 28

True

Question 29

True or False: Mineralization often occurs abiotically

Answer 29

False

Question 30

What is photolysis

Answer 30

chemical bonds broken when they destabilize due to absorbed light (usually UV-vis)

Question 31

True or false: Rings and double bonds are the most vulnerable to photolysis

Answer 31

True

Question 32

What is direct photolysis

Answer 32

The compound absorbs light and breaks on its own

Question 33

What is indirect photolysis

Answer 33

Other compound absorbed light and becomes reactive with compound of interest

Question 34

What is the results of hydrolysis

Answer 34

Hydroxy and molecular splitting

Question 35

Does hydrolysis occur abiotically at a significant rate

Answer 35

No

Question 36

What are the major classes of contaminants

Answer 36

1. Organic compounds 2. Inorganic Gases 3. Metals and Metalloids 4. Nutrients 5. Organometals

Question 37

What class of contaminants compounds used as poisons and by-products/ products of industrial processes

Answer 37

-Organic compounds

Question 38

Give 5 examples of Organic compounds

Answer 38

1. CFC's 2. Dioxins 3. PAH 4. PCB 5. Herbicides

Question 39

Give 3 examples of inorganic gases

Answer 39

1. CO2 2. NOx 3. SO2

Question 40

Give 5 examples of metals and metalloids

Answer 40

1. Al (mine drainage) 2. As (mining) 3. Cd (electroplating) 4. Cr (Catalysts) 5. Pb (Gasoline) 6. Hg (Amalgams)

Question 41

Give 2 examples of things that would fall into the nutrient class of contaminants

Answer 41

1. Nitrogen species | 2. Phosphate species

Question 42

Give 4 examples of things that would fall into the organometal class of contaminants

Answer 42

1. Tin (TBT (causes shell abnormalities), TMT (neurotoxin), TET(neurotoxin)) - Used as antifouling paints 2. Tetra alkyl lead (anti knock) 3. Methyl mercury 4. Radionuclides (weapons products)