Lec 6

Question 1

What are the concepts that equilibrium concentrations of contaminants are based on?

Answer 1

Partitioning, sorption and exhange

Question 2

Partitioning

Answer 2

Tendency of a contaminant to exist at equilibrium between two phases

Question 3

Sorption

Answer 3

A partitioning and exchange phenomenon that describes a contaminant to accumulate at the solid surface from the surrounding solution/air

Question 4

Exchange

Answer 4

Displacement of the charged species by another species that has higher affinity for the same site on the solid surface

Question 5

Fugacity

Answer 5

Molecule’s tendency or driving force to escape the system it is in

Question 6

Sorption types

Answer 6

Electrostatic
Physical
Chemical

Question 7

Sorbent characteristics for sorption of organic compounds

Answer 7

Hydrophobicity
Specific surface

Question 8

Sorbate (contaminant) characteristics to influence sorption

Answer 8

Hydrophobicity
Ionic charge
Kow
Water solubility (?)

Question 9

Which do sorb charged species

Answer 9

Clays, smaller particles

Question 10

Measures of hydrophobicity of a compound

Answer 10

Low water solubility ~ sorption tendency
Kow (octanol water partition coefficient)

Question 11

Partition coefficients

Answer 11

Kow: octanol water partition coefficient
Kd: soil distribution coefficient
Koc: soil adsorption coefficient

Question 12

Is Kow related with water solubility of the compound?

Answer 12

NOOOOO

Question 13

high logKow means?

Answer 13

-more hydrophobic
-partitioning more into octanol than water
-potential to bioconcentrate in living organisms

Question 14

-logKow ?

Answer 14

Kow < 1
İt is partitioning more into water than octanol

Question 15

Soil components (extremely variable, heterogeneous)

Answer 15

inorganic fraction (45-49.9%)
organic matter (0.1-5%)
water
air

Question 16

Most important soil properties of HWM & most critical factors im sorption of chemicals

Answer 16

CEC (cation exchange capacity)
SOM (soil organic matter)

Question 17

CEC

Answer 17

quantity of cations sorbed per mass of soil (meq/100g soil)

Question 18

Higher CEC

Answer 18

Higher removal potential
Higher sorption of ionic compounds into soil

Question 19

SOM

Answer 19

Determines how much a soil can adsorb org contaminants
Humic (org) + Non-humic (inorg)
MMMOST COMMON SORBENT IN SOILSSS

Question 20

Higher SOM

Answer 20

Higher sorption of org compounds into soil

Question 21

Humic fraction (org)

Answer 21

Humin
Humic acids
Fulvic acids

Question 22

Isotherm

Answer 22

Langmuir: monolayer adsorption of sorbate
Freundlich: multilayer adsorptionof sorbate

Question 23

Langmuir

Answer 23

Ce/qe (y) vs Ce (x)

slope: 1/a
y-intercept: 1/ab

Question 24

Freundlich

Answer 24

lnqe (y) vs lnCe (x)
slope: 1/n
y-intercept: lnKf

Question 25

Kd (mL/g)

Answer 25

Soil distribution coefficient
(mg/g) / (mg/mL)

Question 26

Koc (mL/g)

Answer 26

Soil adsorption coefficient
(mg/g) / (mg/L)

Question 27

Retardation factor (R)

Answer 27

If R > 1, contaminant is moving slower than groundwater: advantageous for waste management context

Question 28

What is R directly related with

Answer 28

HYDROPHOBICITY OF CONTAMINANT

Question 29

Non-polar sorbents

Answer 29

GAC
SOM (Soil organic matter)