Soils and sediments may become contaminated by diesel, petroleum, BTEX, polycyclic aromatic hydrocarbons (PAHs) and other volatile and semi volatile organic compounds. Sediment remediation is the process of neutralizing contaminants and restoring environments to their pre-contamination condition. There is a variety of treatment options available and the choice of which one to use depends on the nature of the contaminant and on the time and money that are available for the procedure.
Sedimentary contamination refers specifically to underwater soils. When the sediment underlying rivers and harbors becomes compromised, their navigational and recreational use is impaired. As of 2004, the Environmental Protection Agency estimated there were roughly 144 sites that required cleaning up. Sixty of these were considered major enough to require tracking at the national level, while others could be tackled by state or local authorities, by voluntary action or by other federal agencies.
The three basic approaches to the control of contaminated sediments and soils are: in situ capping, dredging and monitored natural recovery. The main sources of sedimentary contamination are industrial accidents and mining incidents. Additional contaminants to those specified above include phthalate esters, metals and organometals (mercury, lead, etc.), cyanide, chlorinated hydrocarbons (PCBs) and mononuclear aromatic hydrocarbons (MAHs).
These chemicals are either only partially soluble or completely insoluble in water and become part of the aquatic sedimentary environments. This means that large volumes of contaminants are present that are not detectable using conventional water technologies. Over time, the ecology of benthic organisms, their organic content and the sizes and shapes of the particles conspire to accumulate sedimentary contamination.
Once a government agency identifies a site to be remediated, prompt action is essential in order to protect human health as well as the environment. All remediation projects require regulatory oversight. In the USA, this is provided by the Region 9 of the EPA.
The process of remediation goes down right to the level of nanotechnology. Specifically, nanoremediation refers to the use of nanoparticles. These are defined as particles between one and one hundred nanometers in size. One nanometer is equal to one billionth of a meter. Nanoparticles have a high surface area per unit mass, which makes them highly reactive. Their small size also allows them to infiltrate tiny pores in sediments, making target contaminants more accessible.
During the nanoremediation process, a decontaminant on the nanoparticle scale comes into contact with a target contaminant in a detoxification reaction. To date, the global nanoremediation project has identified up to 70 sites around the world that require this type of treatment. Currently, nanorem treatment has been used to clean up groundwater projects, although research is being conducted into using it for wastewater treatment.
What makes nanoremediation is the minute scale of the contaminants being removed. Any idiot can filter out junk the size of coffee grounds. Nanoparticles are too small to filter using available technology, and so that is why neutralizing chemical reactions are necessary. Once those are under control, maybe we can start tackling pico particles, which are one thousandth of a billionth of a meter.
Sedimentary contamination refers specifically to underwater soils. When the sediment underlying rivers and harbors becomes compromised, their navigational and recreational use is impaired. As of 2004, the Environmental Protection Agency estimated there were roughly 144 sites that required cleaning up. Sixty of these were considered major enough to require tracking at the national level, while others could be tackled by state or local authorities, by voluntary action or by other federal agencies.
The three basic approaches to the control of contaminated sediments and soils are: in situ capping, dredging and monitored natural recovery. The main sources of sedimentary contamination are industrial accidents and mining incidents. Additional contaminants to those specified above include phthalate esters, metals and organometals (mercury, lead, etc.), cyanide, chlorinated hydrocarbons (PCBs) and mononuclear aromatic hydrocarbons (MAHs).
These chemicals are either only partially soluble or completely insoluble in water and become part of the aquatic sedimentary environments. This means that large volumes of contaminants are present that are not detectable using conventional water technologies. Over time, the ecology of benthic organisms, their organic content and the sizes and shapes of the particles conspire to accumulate sedimentary contamination.
Once a government agency identifies a site to be remediated, prompt action is essential in order to protect human health as well as the environment. All remediation projects require regulatory oversight. In the USA, this is provided by the Region 9 of the EPA.
The process of remediation goes down right to the level of nanotechnology. Specifically, nanoremediation refers to the use of nanoparticles. These are defined as particles between one and one hundred nanometers in size. One nanometer is equal to one billionth of a meter. Nanoparticles have a high surface area per unit mass, which makes them highly reactive. Their small size also allows them to infiltrate tiny pores in sediments, making target contaminants more accessible.
During the nanoremediation process, a decontaminant on the nanoparticle scale comes into contact with a target contaminant in a detoxification reaction. To date, the global nanoremediation project has identified up to 70 sites around the world that require this type of treatment. Currently, nanorem treatment has been used to clean up groundwater projects, although research is being conducted into using it for wastewater treatment.
What makes nanoremediation is the minute scale of the contaminants being removed. Any idiot can filter out junk the size of coffee grounds. Nanoparticles are too small to filter using available technology, and so that is why neutralizing chemical reactions are necessary. Once those are under control, maybe we can start tackling pico particles, which are one thousandth of a billionth of a meter.
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