Pageof 3ZOOMHomework 2Due: October 7, 2022Question 1 [50 points]Love Canal is one of the most disastrous environmental tragedies in American history. In the 1900’s it was envisioned that by digging a...












Homework 2


Due: October 7, 2022


Question 1

[50 points]



Love Canal is one of the most disastrous environmental tragedies in American history. In the



1900’s it was envisioned that by digging a short canal between the upper and lower Niagara



Rivers power could be generated cheaply to fuel the industry and homes in the area. However



the project was abandoned midway and the canal was turned into a municipal and industrial



chemical dumpsite. Some of the chemicals that were dumped underground included:



polychlorinated dibenzodioxins, trichlorophenol (TCP), chlorobenzenes, and benzyl chlorides
.



Landfills can of course be an environmentally acceptable method of hazardous waste disposal,



assuming they are properly sited, managed, and regulated. However, in 1953, the Hooker



Chemical Company, then the owners and operators of the property, covered the canal with earth



and sold it to the city. The city permitted to build a school, apartments, and private homes. In the



late '50s, about 100 homes and a school were built at the site. In the late 70’s residents started



seeing suspicious black fluids and chemicals in their backyard. The health impacts to the



community included: leukemia, birth defects, and miscarriages.
1




Imagine that (
in late 70’s
) you were tasked to model the concentration of benzene



hexachloride (also called lindane (C
6
H
6
Cl
6
),

one of the potent pollutants, 50 ton of which was



stored underground in the dumpsite
) in the different medium of interest (without direct



measurements using any scientific equipment). As a first order approximation you decide to do



an equilibrium calculation (
which could be a reasonable assumption since more than 20 years



had passed
) to estimate the concentration of benzene hexachloride in: 1) the air the residents



breathe; 2) the surface water from a small lake that the residents use; 3) the soil in which the



vegetation grows; 4) the fish present in the surface water; 5) the suspended solids in the surface



water; and 6) the sediment underneath the surface water. To achieve this you have to first model



(represent) the environment of interest (Love Canal) and then perform a multimedia equilibrium



calculation.


Part A
: Determine the dimensions and property of the environment (See 2D pictorial



representation in the below figure). The environment of interest is the 16-acre Love Canal



Landfill. The atmospheric layer where uniform mixing is achieved can be considered to be of 1



km depth. A surface water coverage of 1/50
th

(a pond) of the land surface to a depth of 20 m can



be assumed and soil covering the remaining land surface to a depth of 5 m (the depth at which



the chemical containers were buried assuming the surface underneath was sealed) can be



assumed. The sediment at the bottom of the surface water can be assumed to be of the depth of 1



cm. The concentration of suspended solids in the surface water can be assumed to be 7.4 mg/l.



Assume an average fish volume of 1 L per fish with one fish for every 100 m
3

of surface water.



















Part B
: Download and use The Canadian Center for Environmental Modeling and Chemistry



Level I model (
https://www.trentu.ca/cemc/resources-and-models/level-i-model) to perform the



level 1 multimedia calculation. Represent the Love Canal environmental compartments



appropriately under the environmental properties tab. Include appropriate chemical emissions



under emissions tab. Determine the concentrations (in g/m
3
) as well as total mass (kg) in all the



six media of interest. Choose Benzene hexachloride (also called lindane) (under chemical



properties tab) and use its default chemical properties. If there are any missing properties in the



chemical properties tab calculate and include them.


Part C
: Using the Canadian Center for Environmental Modeling and Chemistry Level I model



(
https://www.trentu.ca/cemc/resources-and-models/level-i-model) perform the same calculation



for 50-ton release of chlorobenzene.






Compare the distribution (mass) of chlorobenzene and benzene hexachloride between the



different medium (compartments) and provide a detailed analysis. If the distribution



amounts are significantly different in different medium, please explain in detail what



properties of the chemicals would have caused this difference.


Atmosphere


Soil


Surface water



Sediment



16 Acres


Suspended



sediment


Fish




























Question 2

[50 points]



Read Homework 2 Supplement 1 - a recent email from EPA Proposing to Designate



Certain PFAS Chemicals as Hazardous Substances Under Superfund to Protect People’s



Health


Part A
: Perform multimedia equilibrium analysis (hand calculation) to estimate the equilibrium



concentrations (in g/m
3
) as well as mass (kg) of perfluorooctanoic acid (PFOA) &



perfluorooctanesulfonic acid (PFOS) in all six media of interest for a 20-ton release. Use the



same unit environment (dimensions and properties of the media) from Part A of the previous



problem. Assume, the octanol-water partition coefficients for perfluorooctanoic acid (PFOA)



and perfluorooctanesulfonic acid (PFOS) are not readily available and therefore use the fragment



(group) contribution model developed by Meylan and Howard (1995) for the calculations.



Choose the most appropriate correlations from the textbook to relate octanol water partition



coefficient (calculated using your fragment model) to other partition coefficients that are needed.



The Henry’s constant and other properties for perfluorooctanoic acid (PFOA)



and perfluorooctanesulfonic acid (PFOS) can be found in Eichler and Little (2020) [Homework 2



Supplement 2]


Part B
: Using the Canadian Center for Environmental Modeling and Chemistry Level I model



(
https://www.trentu.ca/cemc/resources-and-models/level-i-model) perform the same calculation



for 50-ton release of perfluorooctanoic acid (PFOA) & perfluorooctanesulfonic acid (PFOS).



Provide a detailed analysis of the distribution (mass) of perfluorooctanoic acid (PFOA) and



perfluorooctanesulfonic acid (PFOS) across the different medium (compartments).


[1]

https://www.epa.gov/archive/epa/aboutepa/love-canal-tragedy.html














































Oct 08, 2022
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