Homework No. 9
HOMEWORK #9 (Due November 21, 2013)
The table above is an illustration of mineral concentration in milligrams per liter in Ellsworth Country.
The chart below is an explanation of concentration of hardness as calcium carbonate in milligram per
liter.
Sean Paquette
Air & Water Pollution Prevention & Control Engineering
MANE-6960H01
Semester Fall 2013
Homework No. 9
Cyanide is extremely toxic to humans. Cyanide is any chemical compound that contains
monovalent combining group CN, also known as a cyano group. This is a carbon atom triplebonded to a nitrogen atom. According to the EPA, “Cyanide is used in a number of industries
and is found at low levels in air from car exhaust. Chronic (long-term) inhalation exposure of
humans to cyanide results primarily in effects on the central nervous system (CNS).”
Furthermore, the EPA states in animal studies it has been suggested that oral exposure to
cassava (a cyanide-containing vegetable) may be associated with malformations in the fetus
and low fetal body weights. A cyanide destruction plant is an example of a water cyanide
detoxification system.
According to Resources Gold Technology located in Florida, this system operates by
introducing a reactant that oxidizes the cyanide ions in solution in gold processing plant
tailings. The reaction that takes place converts the cyanide into a complex or form that is
non-toxic achieving effective cyanide detoxifications. Furthermore, Cyanide Control System
(CCS) is another cyanide detoxification systems designed and manufactured Cyanco. This
system can reduce CN consumption by 7%-25%.
Sean Paquette
Air & Water Pollution Prevention & Control Engineering
MANE-6960H01
Semester Fall 2013
Homework No. 9
A reductive treatment for Cr(VI) is through a chemical reaction, this approach achieves both a reduction
in Cr toxicity and removal of the Cr from aqueous solution. Chemical reduction includes naturally
occurring reduction by soil oxides and natural organic material. Engineered chemical reduction
technologies involve the addition or in-situ injection of an electron donor such as hydrogen sulfide
(H2S). Another possible reductive treatment for Cr(VI) is microbial reduction. Microbial reduction,
“microorganisms can catalyze redox reactions by a combination of several mechanisms, including
enzymatic extra-cellular reduction, non-metabolic reduction by bacterial surfaces and intra-cellular
reduction and precipitation.” A third reductive treatment for CR(VI) is called phytoremediation.
Phytoremediation, “ is a multi-faceted approach towards Cr remediation. Plants contain the Cr by
converting it to the less mobile Cr(III) (phytostabilization) and simultaneously reduce its toxicity. In
addition, phytoremediation can be a removal technology, if Cr is sequestered in plant tissue and the
plants are harvested. The above reductive treatments were researched using
http://www.engr.uconn.edu/~baholmen/docs/ENVE290W/National%20Chromium%20Files%20From%20Luke/Cr(VI)%20Handbook/L1608_C08.
pdf.
Sean Paquette
Air & Water Pollution Prevention & Control Engineering
MANE-6960H01
Semester Fall 2013
Homework No. 9
I have decided to choose my second proposal for my water pollution engineering project, which is
examining the water impacts due oil drilling in the Gulf of Mexico. The Gulf Oil Spill was begun on April
22, 2010 and spilled an estimated 206 million gallons of oil. “The Gulf oil spill is officially the largest
accidental spill in world history. It began when an oil well a mile below the surface of the Gulf blew out;
causing an explosion on BP’s Deepwater Horizon rig that killed 11 people. BP made several unsuccessful
attempts to plug the well, but oil flowed — possibly at a rate as high as 2.5 million gallons a day — until
the well was capped on July 15, 2010. Oil gushed from the broken well for more than 85 days, oiled 572
miles of Gulf shoreline, and killed hundreds of birds and marine life. The long-term effects of the oil and
the 1.82 million gallons of dispersant used on this fragile ecosystem remain unknown, but experts say
they could devastate the Gulf coast for years to come.”
Sean Paquette
Air & Water Pollution Prevention & Control Engineering
MANE-6960H01
Semester Fall 2013