Midterm 2

Question 1

what are the 3 types of aquatic toxicity tests

Answer 1

Static
static renewal
flow through

Question 2

What is a static toxicity test

Answer 2

a static toxicity test has the exposure solutions prepared at the beginning of the study and these are the exposures which remains for the duration of the test

Question 3

what is a static renewal toxicity test

Answer 3

one in which exposure solutions are replaced at regular intervals over the course of the test

Question 4

what is a flow through exposure

Answer 4

the effluent is continuously supplied to the test vessel during the course of the study

Question 5

static vs flow through

Answer 5

flow through is much more complex and challanging to maintain and requires regular monitoring, used for chemicals which are volatile or for chemicals which degrade quickly

Question 6

LOEC

Answer 6

lowest observed effect conc

Question 7

NOEC

Answer 7

no observed effect conc, the highest tested concentration which does not cause any observed or statictcally adverse effects

Question 8

TEC

Answer 8

threshold effect conc, mean of loec and noec

Question 9

what is the relatioship between LOEC and NOEC and the exposure conc

Answer 9

they are dependent on the exposure contrations meaning that they can change based on the interval at which you observed effect

Question 10

What is hormesis

Answer 10

hormesis is an observed positive response compared to the control organism at low conc in a tox test

Question 11

what can reduce the toxicity of metals in fresh water

Answer 11

DOC as it forms complexs with the metal ions which once bound are no longer toxic

Question 12

in what from is metal the most toxic when dissolved

Answer 12

ion

Question 13

what are 2 factors which can reduce toxivity of metals in water

Answer 13

DOC and Water hardness

Question 14

how do metal ions induce there toxicity on fish

Answer 14

via the gills since they regulation the internal ionic balance and move ions in and out of the body via active transport if however metal ions are present then they take up this space and reduce the amm of esstinal ions which can enter the cell

Question 15

what are the 2 deferent sources from which DOM can originate

Answer 15

Allochtonous- arises from sorounding catchment
Autochtonous- arises from the aquatic system

Question 16

what are the three Cs associated with the biotic ligand model

Answer 16

Concertation
Complexation
competition

Question 17

what are some envoirmental impacts of mining

Answer 17

Dust, noise
erosion
metal contamination
relase of chemivals
acid and acid rock drainage

Question 18

what are tailings

Answer 18

group rock and process effulents which are generated in a mine processing plant(waste from ore extraction)

Question 19

where to tailings go

Answer 19

TMF tailing managment facility
TSF- tailings storage facility

Question 20

what is a orphanded or abandoned mine

Answer 20

-Owner cannot be found or owner is unable to unwilling to carry out clean up

Question 21

what are some abandoned mines in canada

Answer 21

giant mine
kam kotia
britannina

Question 22

who is Robert Fireland

Answer 22

he was neamed devleoper of the yeat in 1996 while leaving mines abandoned and the envoirment heaviliy polluted

Question 23

what is the fastest growing soild waste stream

Answer 23

E-waste

Question 24

what is bioaccumulation

Answer 24

the progressive increase in the amount of a substance in a organsim or party of an organism that occurs bc the rate of intake exceeds the organisums ability to remove the substance from the body

Question 25

what is Bioconcentration

Answer 25

Process leading to a higher conce of a synctace in a organsim than in environmental media to which it is ecposed

Question 26

biomagnification

Answer 26

sequence of processes in a ecosystem by which higher conc are attained in organisms at higher trophic levels (predator has higher con then prey)

Question 27

what is BCF

Answer 27

Bioconcentration factor- a meaure of the tendency for a substance in water to accumulate in orgsnisms

high BCF means it accumlates at a greater degree

Question 28

what does bioaccumulation of organic molecules usually correlate with

Answer 28

lipophilicity

Question 29

what does bioaccumulation of metal ions correlate with

Answer 29

Binding of metal ions to biomoecules

Question 30

what properties are in organic substances which tend to bioaccumulation at higher rates

Answer 30

Fat-soluble
hydrophobic

Question 31

why is understanding bioaccumulation so important

Answer 31

Low conc in environment can result in high conc in biota

Question 32

BAF

Answer 32

bioaccumulation factor- a field basised measurement (inculdes diatiry exposure)

Question 33

BCF

Answer 33

lab based test- does not inculde dietary exposure

Question 34

what type of repones is impossible to have hormesis as a result

Answer 34

Mortaility

Question 35

when is hormesis only possible

Answer 35

When the reponse being meausred is inhibition

Question 36

what does pH do to toxicity of metal ions

Answer 36

lowers it

Question 37

when is a complexation interaction

Answer 37

one which reduces the free ion count in the water

Question 38

how to cations effect toxicity of free metal ions

Answer 38

reduce it

Question 39

what is Kisladag

Answer 39

Open put gold mine in turkey which uses a heap leach process

Question 40

what is a common chemical used to recover gold ore

Answer 40

Cyanide is often used which is highly toxic to the environment

Question 41

Kam Kotia Mine

Answer 41

biggest enviromental disaster in ontrario
acid drainage
sulphine ore