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Hazardous Waste Management.pptx

This ppt deals with Hazardous waste management, it's law and hazardous site remediation

This ppt deals with Hazardous waste management, it's law and hazardous site remediation

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Hazardous Waste Management.pptx

  1. 1. Mumbai University B.E. SEM VII (Civil Engineering) DLOC: Municipal Solid and Hazardous Waste Management (SHWM) Module 5 Hazardous Waste Management By Mrs. Puja Kadam M.E. ( Civil and Environmental ) Assistant Professor Department of Civil Engineering, VCET, Vasai
  2. 2. Hazardous Site Remediation The overall objective in remediating hazardous waste sites is the protection of human health and the environment by reducing risk. There are three primary approaches which can be used in site remediation to achieve acceptable levels of risk: •the hazardous waste at a site can be contained to preclude additional migration and exposure •the hazardous constituents can be removed from the site to make them more amenable to subsequent ex situ treatment, whether in the form of detoxification or destruction •the hazardous waste can be treated in situ (in place) to destroy or otherwise detoxify the hazardous constituents
  3. 3. Hazardous Site Remediation • Each of these approaches has positive and negative ramifications. Combinations of the three principal approaches may be used to address the various problems at a site. • There is a growing menu of technologies available to implement each of these remedial approaches. • Given the complexity of many of the sites, it is not uncommon to have treatment trains with a sequential implementation of various in situ and/or ex situ technologies to remediate a site. • Hazardous waste site remediation usually addresses soils and groundwater .
  4. 4. Hazardous Site Remediation • However, it can also include wastes, surface water, sediment , sludges, bedrock, buildings, and other man-made items. • The hazardous constituents may be organic, inorganic and, occasionally, radioactive. • They may be elemental ionic, dissolved, sorbed, liquid, gaseous, vaporous, solid, or any combination of these.
  5. 5. Hazardous Site Remediation- In situ Techniques • Containment is one of the available treatment options. There are several reasons for using containment techniques. • A primary reason is difficulty in excavating the waste or treating the hazardous constituents in place. • This may be caused by construction and other man-made objects located over and in the site. • Excavation could also result in uncontrollable releases at concentrations potentially detrimental to the surrounding area. • At many sites, the low levels of risks posed, in conjunction with the relative costs of treatment technologies, may result in the selection of a containment remedy.
  6. 6. Hazardous Site Remediation- In situ Techniques • One means of site containment is the use of an impermeable cap to reduce rainfall infiltration and to prevent exposure of the waste through erosion . • Another means of containment is the use of cut-off walls to restrict or direct the movement of groundwater. • In situ solidification can also be used to limit the mobility of contaminants. Selection among alternatives is very site specific and reflects such things as the site hydrogeology , the chemical and physical nature of the contamination, proposed land use , and so on. Of course, the resultant risk must be acceptable.
  7. 7. Hazardous Site Remediation- In situ Techniques • As with any in situ approach, there is less control and knowledge of the performance and behavior of the technology than is possible with off-site treatment. • Since the use of containment techniques leaves the waste in place, it usually results in long-term monitoring programs to determine if the remediation remains effective. • If a containment remedy were to fail, the site could require implementation of another type of technology.
  8. 8. Hazardous Site Remediation- Ex Situ Techniques • The ex situ treatment of hazardous waste provides the most control over the process and permits the most detailed assessments of its efficacy. • Ex situ treatment technologies offer the biggest selection of options, but include an additional risk factor during transport. • Examples of treatment options include incineration ; innovative thermal destruction, such as infrared incineration; bioremediation ; stabilization/solidification; soil washing; chemical extraction; chemical destruction; and thermal desorption.
  9. 9. Hazardous Site Remediation • Another approach to categorizing the technologies available for hazardous waste site remediation is based upon their respective levels of demonstration. • There are existing technologies, which are fully demonstrated and in routine commercial use. • Performance and cost information is available. • Examples of existing technologies include slurry walls, caps, incineration, and conventional solidification/stabilization.
  10. 10. Hazardous Site Remediation • The next level of technology is innovative and has grown rapidly as the number of sites requiring remediation grew. • Innovative technologies are characterized by limited availability of cost and performance data. • More site-specific testing is required before an innovative technology can be considered ready for use at a site. • Examples of innovative technologies are vacuum extraction, bioremediation, soil washing/flushing, chemical extraction, chemical destruction, and thermal desorption. • Vapor extraction and in situ bioremediation are expected to be the next innovative technologies to reach "existing" status as a result of the growing base of cost and performance information generated by their use at many hazardous waste sites.

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