How can oxygen-releasing substances be used to stimulate bioremediation?
Oxygen-releasing substances can be used to stimulate bioremediation in the unsaturated zone, but are more commonly introduced into contaminated groundwater or saturated soil. This technique may be used to address source areas, entire plumes, or plume tails (EPA 2004).
What is super-oxygenated water?
Super-oxygenated water (SOW) has significant advantages over other methods that have been used for groundwater remediation at sites contaminated with petroleum hydrocarbons – such as former fuel storage facilities.
How is pure oxygen injected into the subsurface?
Pure oxygen is most commonly introduced into the subsurface via vapor-phase injection. Vapor-phase oxygen (approximately 95% oxygen) is injected into the saturated zone near the base of the contamination using a network of sparge wells.
How do you inject oxygen into a saturated zone?
Vapor-phase oxygen (approximately 95% oxygen) is injected into the saturated zone near the base of the contamination using a network of sparge wells. A series of vertical oxygen injection wells are often alternately sparged in order to increase dissolved oxygen levels more efficiently over larger areas (EPA 2004).
What are the 3 types of remediation that occur?
The main three types of environmental remediation and reclamationSoil remediation. There are many factors that affect the soil condition. ... Groundwater and Surface water remediation. ... Sediment remediation. ... Sources.
What is remediation of contaminated sites?
Site-remediation is the process of removing polluted or contaminated soil, sediment, surface water, or groundwater, to reduce the impact on people or the environment.
What are two forms of remediation for contamination?
Monitored natural recovery (MNR) and enhanced monitored natural recovery (EMNR) These two approaches are used to remedy sediment contamination. They are often used in conjunction with amendments, sediment capping, dredging, or other technologies.
What is in situ and ex situ bioremediation?
Ex situ remediation techniques involve removing the soil from the subsurface to treat it. In situ remediation techniques involve leaving the soil in its original place and bringing the biological mechanisms to the soil.
What is remediation process?
What is Remediation? Remediation refers to the process of reversing or stopping environmental damage. During remediation, polluted or contaminated soil, sediment, surface water, or groundwater is removed to reduce the impact on the environment.
What is remediation system?
Environmental remediation systems reduce a job site's environmental impact tremendously. Using soil and groundwater remediation systems, a company that works with a heavy load of chemical pollutants or other environmental contaminants can reduce the ecological harms those contaminants do.
What are examples of remediation?
Remediation is the act of correcting an error or stopping something bad from happening. When a company that polluted takes steps to clean up the water supply, this is an example of remediation.
What is a remediation order?
A Remediation Order (17198-2018) (PDF 1.5MB) was issued to carry out remediation work required to provide for the repair and rehabilitation of unlawfully cleared native vegetation and regeneration of native vegetation within the remediation area.
What is active remediation?
Active remediation means corrective action that includes active physical, biological, or chemical manipulation of groundwater or of the rock or soil media for the purpose of reducing the amount of contamination or minimizing the spread of contamination.
What is Biopile remediation?
Description. A bio-pile is a bioremediation technology in which excavated soils are mixed with soil amendments, formed into compost piles, and enclosed for treatment. The basic bio-pile system includes a treatment bed, an aeration system, an irrigation/nutrient system and a leachate collection system.
What is insitu and Exsitu conservation?
The process of protecting an endangered plant or animal species in its natural habitat is commonly known as in situ conservation. On the other hand, ex situ conservation is the relocation of endangered or rare species from their natural habitats to protected areas equipped for their protection and preservation.
What is ex situ bioremediation process?
Ex-situ bioremediation is a biological process in which excavated soil is placed in a lined above-ground treatment area and aerated following processing to enhance the degradation of organic contaminants by the indigenous microbial population.
How can sediments at the bottom of a water body become contaminated?
Sediments at the bottom of a water body can become contaminated in a number of ways, including: Urban runoff of surface waters.
How do microorganisms break down contaminants?
The microorganisms break down contaminants by using them as an energy source or cometabolizing them with an energy source. Electrokinetics applies low-intensity direct current through the soil between ceramic electrodes that are divided into a cathode array and an anode array.
What is solidification in a chemical reaction?
Solidification encapsulates waste to form a solid material, coat the waste with low-permeability materials to restrict contaminant migration or both. Solidification can be accomplished by mechanical processes or by a chemical reaction between a waste and binding reagents, such as cement, kiln dust, or lime/fly ash.
What is chemical reduction?
In Situ Chemical Reduction places a reductant or reductant-generating material in the subsurface to degrade toxic organic compounds to potentially nontoxic or less toxic compounds. It immobilizes metals by adsorption or precipitation and degrades non-metallic oxyanions.
What happens if you breathe 1,4 dioxane?
Exposure to high levels of 1,4-dioxane in the air can result in nasal cavity, liver and kidney damage.
Where does arsenic occur?
Contaminants. Exposure to higher than average levels of arsenic occur mostly in the workplace, near hazardous waste sites or in areas with high natural levels. At high levels, inorganic arsenic can cause death.
What is air sparging?
Air Sparging involves the injection of air or oxygen through a contaminated aquifer to remove volatile and semivolatile organic contaminants by volatilization. The injected air helps to flush the contaminants into the unsaturated zone for treatment.
How is ozone injected into the subsurface?
Ozone may be injected into the subsurface in a dissolved or gaseous phase. Injection or sparging of gaseous ozone, typically at a 5% concentration, into a contaminated area in the subsurface is more common. Ozone then dissolves in the subsurface water, reacts with subsurface organics, and decomposes to oxygen.
What substances are used to stimulate bioremediation in the unsaturated zone?
Commonly used substances include hydrogen peroxide, ozone, commercial oxygen-releasing compounds, and pure oxygen. Oxygen-releasing substances can be used to stimulate bioremediation in the unsaturated zone, but are more commonly introduced into contaminated groundwater or saturated soil.
What is biosparging in soil?
Biosparging involves the injection of air or oxygen, and nutrients if needed, into the saturated zone to stimulate microbial activity (although contaminants adsorbed to soils in the unsaturated zone can also be treated by biosparging, bioventing is typically more effective for this situation).
How does bioventing work?
Soil. Bioventing involves supplying air or oxygen, and nutrients if needed, into the unsaturated zone. Oxygen is delivered to the unsaturated zone by forced air movement either through extraction or injection of air to increase oxygen concentrations.
What is aerobic bioremediation?
Aerobic bioremediation is most often used at sites with mid-weight petroleum products ( e.g., diesel fuel and jet fuel), because lighter products such as gasoline tend to volatilize readily and can be removed more rapidly using other technologies (e.g., air sparging or soil vapor extraction).
Why is biosparging important?
Biosparging can be used to reduce the concentrations of petroleum constituents that are dissolved in groundwater, adsorbed to soil below the water table, and within the capillary fringe.
What determines the effectiveness of biosparging?
The effectiveness of biosparging depends on two primary factors — permeability of the soil and the biodegradability of the constituents. In general, the type of soil will determine its permeability. Fine-grained soil such as clay and silt have lower permeabilities than coarse-grained soil like sand and gravel.
Hydrocarbon
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1. Introduction
Oil pollution in the environment is now being taken seriously by the oil industries and as such, these companies are always looking for cost-effective methods of dealing with this pollution. The global environment is under great stress due to urbanization and industrialization as well as population pressure on the limited natural resources.
2. Manuscript
The setting of soil pollution limits assumes an agreed method for measuring the concentration of a pollutant that is relevant to risk assessment across differing soil types.
3. Conclusion
A number of organic pollutants, such as PAHs, PCBs and pesticides, and inorganic pollutants are resistant to degradation and represent an ongoing toxicological threat to both wildlife and human beings.