Treating+Contaminated+Soil-+Physical+and+Chemical+Remediation

= TREATING CONTAMINATION - PHYSICAL AND CHEMICAL REMEDIATION = = BY: MAUSAMI NAIK =

=What is Contaminated Land? =

=== Everyday, thousands of tonnes of waste is deposited at dump sites without considering the damage it can do to human health and environmental safety. This waste piles on and the amount of toxic materials that gets dumped here increases. There are many sites around Canada that contain toxic materials. These hazardous materials make these sites very harmful to human health. They are also a threat to the ecosystem in that area because they can harm the micro-organisms and other small animals. Since all the living organisms living in that area are part of the ecosystem of that area, a negative effect on one of them affects everyone as a whole. These sites are called contaminated lands. Contaminated land is land that contains hazardous substances that are harmful to humans and the environment. The contaminants can be in the forms of solid, liquid or gas. Most of these contaminated materials come from industrial or commercial activities. These substances mix with the soil or the water and contaminate them, making them dangerous for us. ===

= = =How can we solve this problem? = ===Because these contaminants are harmful to both human health and evironment, the method to treat these contaminants also has to be safe and environmentally friendly. This process of decontaminating land or water is called remediation. Once remediated, the land can be used again safely. We have several technologies today that are used to treat contaminated soil and water. They are physical, chemical and biological remediation. In this wiki, we will be focusing on physical and chemical remediation. ===

__Soil Flushing__
===
 * ===A remediation technology that floods the contaminated soil with a solution and collects the contaminants in one area to be removed. ===
 * ===The fluid used is usually water, acids or bases, solvents or detergents. ===
 * ===The fluid with the contaminated materials is pumped to the surface using standard groundwater extraction wells. ===
 * ===A large amount of fluid is needed to treat the contaminated land. ===

===

__Air Sparging__

 * ===A remediation technique in which air is injected through the contaminated area and the contaminants are removed in the form of air. ===
 * ===As the air bubbles rise, the contaminants are removed by stripping (making physical contact with air). ===
 * ===The contaminats are then lead to an unsaturated area and collected seperately as liquids or vapor using the soil vapor extraction system. ===
 * ===They are then treated seperately as required. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">This process has a duration time of medium to long period, lasting up to a few years. ===

__<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Stabilization and Solidification __

 * ===<span style="color: #100f0f; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">A chemical remediation process in which the contaminanats are required to react with chemical solution that would convert them into a safer form. ===
 * ===<span style="color: #100f0f; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Binding agents like concrete are used to store the safe precipitate. ===
 * ===<span style="color: #100f0f; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">The solidifying agent is either injected into the ground to mix with the contaminants or mixed with the contaminants after they are excavated ===
 * ===<span style="color: #100f0f; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">The solid mixture is then buried in the ground. ===
 * ===<span style="color: #100f0f; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">The process prevents dissolved ions in the groundwater from contaminating other water resources. ===

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__ **<span style="color: #100f0f; font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Chemical Oxidation ** __
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Process includes delievering chemical oxidents into the ground to destroy toxic materials. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">The contaminants can be organic compounds, ionic conpounts or metal ions. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Oxidents like oxygen, ozone, certain liquid chemicals like permanganate and hydrogen peroxide are used. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Oxidents worked into the ground by drills. ===



===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Above are 4 of the many remediation processes that we have today. Some other physical remediation technologies are pump and treat, dual phase vacuum extraction and monitoring-well oil skimming. Chemical remediation technologies include electrolysis, carbon absorption, ion exchange etc. ===

<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Bioremediation By Pirasha Sritharan

 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">It is a process of remediation where specific micro-organisms and plants absorb and break down toxic materials naturally in the environment. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Phytoremediation is a process that uses plants to carry the contaminated materials up to the ground through their roots. Micro-organisms decay these contaminants in the roots of the plant. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Three main types of bioremediation are biostimulation, bioaugmentation and intrinsic bioremediation. ===

<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Rehabilitating Lakes By Ram Rasalingam

 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Sulphur and carbon emissions result in acid precipitation. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Natural reasons for acid precipitation are volcanoes and decaying vegetation. Man-made sources are burning of fossil fuels and emissions from our cars. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Some methods of rehabilitating lakes are adding calcium oxide, and lime. ===

<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Elements and their Oxides By Kevin Yranon

 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Non-metallic oxides are compounds in which oxygen form a covalent bond with a non-metal element. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">A metallic oxide is a compound that consists of a metal reacting with oxygen, forming an ionic bond. ===
 * ===<span style="font-family: 'Palatino Linotype','Book Antiqua',Palatino,serif;">Non-metallic oxides are present in the air and when mixed with precipitation, they raise the pH of rain, which is harmful to the environment. ===

Sources:

Information: textbook- Nelson Chemistry 11- University Preperation [] [] [] []

Pictures: textbook- Nelson Chemistry 11- University Preperation [] [] [] []

Video: []