Enviromantal engneering project - Essay Example

Technology Brief definition of the technology Contaminants of concern Duration of the project Cost  In situ chemical oxidation (ISCO) Uses chemicals called “oxidants” to help change harmful contaminants into less toxic ones. is conducted in place, without having to excavate soilFuels, solvents, and pesticides.May take a few months or years to clean up a sitesave time and moneyIn situ chemical reduction(ISCR)Uses chemicals called “reducing agents” to help change contaminants into less toxic or less mobile forms.

It is described as “in situ” because it is conducted in placeseveral types of contaminants dissolved in groundwater and dense non-aqueous phase liquids (DNAPL’s) e.g. metal chromium and TCE ISCR may take as little as a few months and PRBs may take several years to clean up a site.Save time and money.In situ thermal treatmentIn situ thermal treatment methods move or mobilize harmful chemicals in soil and groundwater using heat.non-aqueous phase liquids (NAPLs) including: solvents, petroleum, and creosoteMight take a few months to a few years to clean up a site.

Relatively expensive to ISCO and ISCRIncinerationIt is the process of burning hazardous materials at high temperatures to destroy contaminants. Harmful solvents, PCBs (polychlorinated biphenyls), and pesticides,Might take a few weeks to several years to clean up a site.Relatively expensive to ISCO and ISCRMonitored natural attenuationRelies on natural processes to decrease concentrations of contaminants in soil and groundwater.Scientists monitor concentrations of contaminants to ensure natural attenuation is working.

May take several years to decades to clean up a site.Cost depends on the clean up duration.PhytoremediationUses plants to clean up contaminated environments.Metals, pesticides, explosives, and oil.May take several years to clean up a site.Saves energy and money.Pump and treatGroundwater is pumped from wells to an above-ground treatment system that removes the contaminants.Dissolved chemicals, including: industrial solvents, metals, plume and fuel oil.May last from a few years to several decades.

Relatively expensive in comparison to the other technologies.(Source: United States Environmental Protection Agency. 2012. A Citizens Guide.)B.Contaminated soil excavation- The application of contaminated soil excavation by Atma environmental consultants at a site in Donvale, Victoria, Australia is well justified because, the soil at site was contaminated with Arsenic which is a toxic chemical; so as to allow a residential development. Phytoremediation-The use of willow and poplar trees to clean up subsurface hydrocarbon contamination in Manitoba and Seskatchwan petroleum sites by Federated cooperatives, is well justified as the site was remediated successfully through Phytoremediation.

Furthermore, instead of excavating and transferring the contaminated soil to another site, this process proved successful as it was done on site- saving time and energy. Bioremediation- According to Prof. Shaily Mohindra of UCLA, conventional technologies for cleaning ground water are not always effective. Moreover, these methods usually move pollutants from one point to another. For that reason, Mohindra endorses Bioremediation using Pseudonocardia dioxanivorans bacteria for the mitigation of next generation pollutants e.g. Perfluorinated compounds, nano materials, and dioxane.

The progress of remediation will be monitored usin stable isotopes. Pump and treat- The application of pump and treat technology in Hanford has been successful in soil and ground water remediation. By 2011, 24.7 billion gallons of ground water had been treated, although the whole process of remediation will be completed in the next 25 years. At the end of the remediation process Contaminants such as plutonium and its derivatives e.g. Carbon tetrachloride will be successfully removed from the soil and ground water.

In situ thermal remediation- pump and treat technology had been used for more than 17years to clean up chlorinated solvents from the subsoil in Stuttgart with minimal success rates. However, in January 2013 an in-situ thermal remediation pilot test offered a suitable alternative for remediation even under prevailing difficult geological conditions in Stuttgart. Monitored natural attenuation- The Company was justified as it relied on natural processes to clean up the site. C.An environmental disaster similar to the silent spring has also been observed in Oregon (Lower Columbia).

Since 1985, conservation centered on removing the nearly extinct bald eagle from the federal extinction list resulted in significant overall increase in bald eagle numbers. Yet, in lower Columbia most of the eagle nests in the lower Columbia failed to hatch eaglets; and have been producing half the number of eaglets they should produce. What is more, a scientific inquiry into this dilemma, scientists discovered astonishing pattern that: the shells obtained from the eagles nests were abnormally too thin and contained elevated levels of a toxic chemical DDT(a chlorinated hydrocarbon insecticide) as well as its derivative DDE.

Additionally, every egg that had been scientifically tested since 1985 had high concentrations of DDT residue. In addition, DDT levels are higher in the Columbia River system in comparison to any other river system in Oregon, despite DDT being banned 40 years ago. The scientists concluded that the pesticide had accumulated in the river sediment over the years and it takes a long time to for DDT and its derivatives to break under normal environmental conditions (American Land ep.210). The U.S.

Environmental Protection Agency (EPA) decided to ban agricultural use DDT in 1972, following an extensive review of its environmental and health hazards. This resolution was founded on a number of well documented properties such as: (a) it is widely dispersed by erosion, runoff and volatilization, (b) DDT and its derivatives are toxicants with long-term persistence in water and soil, (c) the high lipophilicity as well as low-water solubility of DDT result in bioaccumulation of DDT in the fat of humans and wildlife which is hazardous (EPA A-1).

Because of this properties, DDT and its derivatives are concentrated by aquatic organisms e.g. fish in water, enter the food web e.g. bald eagles feed on fish, and are bioaccumulated by organisms e.g. bald eagles at higher trophic levels (EPA B-1). Since the ban, the use of DDT in the U.S. has been effectively discontinued (EPA A-1). Long-lasting pesticides like DDT were used to manage target organisms over extended periods of time and reduce the need for reapplication, but may also affect non-target flora and fauna e.g. bald eagles for long periods of time (EPA B-1).

Works CitedUnited States Environmental Protection Agency. 2012. A Citizens Guide. www.epa.gov/superfund/sitesThe American Land: Episode 210. https://www.youtube.com/watch?v=fp4CQhC_uPsUnited States Environmental Protection Agency. 2001. Water. http://water.epa.gov/scitech/swguidance/standards/criteria/current/upload/2001_10_12_criteria_ambientwqc_ddt80.pdf