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Enviromental aspects of Brownfield Regeneration. Barbara Vojvodíková, Marcela Maturová.
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Enviromental aspects of Brownfield Regeneration Barbara Vojvodíková, Marcela Maturová „This project has been funded with support from the European Commission. This publication [communication] reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.“
Contents • Contaminated site term definition • Enviromental brownfield assessment procedure • Sampling steps • Decontamination methods classification • Decontamination methods examples
Contamination Construction materials Volatile Dust Undeground Water Human health
Contaminated sites • The term 'contaminated site' refers to awelldelimited area where the presence ofsoilcontamination has been confirmed.The severity of the impacts toecosystems andhuman health can besuch that remediation isneeded,specifically in relation to the current orplanned use of the site.
Potentially contaminated site • The term "potentially contaminated site" includes any site where soil contamination is suspected but not verified and detailed investigations need to be carried out to verifywhether relevant impacts exist.
Environmental Brownfield Assessment • Traditionally brownfield environmentalassessment covers three phases: • site assessment, • site investigation, and • development of remedial actions.
Site Assessment • A preliminary examination of a site to determine the potential contamination. It includes a review of present and historical landuses and preliminary tests of places that are suspected
Site Investigation • This phase includes a more thoroughreview of conditions at the site. • Typicallyit includes: • Performing soil borings and collecting soil samples; • Installing water monitoring wells and collecting groundwater samples from each well; and • Analyzing all samples for the presence of contaminants.
Remediation methods • The intent of remediation is two-fold: • to eliminate the exposure of humans and living organisms to the contaminants, and • to eliminate the sources of contamination to groundwater.
Sorting of decontamination technologies • in-situ • ex-situ by place • soil • sediment, sludge • groundwater • surface water • air emissions • off-gasses according remediated media type Pollutants immobilization Extraction and separation from environment Disintegration and transformation of pollutant used strategies
Exampleof contaminated soil isolating Ruhr District, Germany, 2011 Photo by B. Vojvodíková
Thermal desorption • Thermal desorption removes harmful chemicals from soil and other materials (like sludge andsediment) by using heat to change the chemicals into gases. • These gases are collected withspecial equipment. The dust and harmful chemicals are separated from the gases and disposedof safely. The clean soil is returned to the site. • Thermal desorption is not the same asincineration, which uses heat to destroy the chemicals.
Thermal desorption Source: http://www.epa.gov/superfund/community/pdfs/suppmaterials/treatmenttech/thermal_desorp.pdf
Air stripping • It is the process of forcing air through polluted water to remove harmful chemicals. • The air causes the chemicals to change from a liquid to a gas (evaporate). • The gas is then collected and cleaned. • It is commonly used to treat groundwater as part of a pump and treat remedy.
Air stripping Source: http://www.epa.gov/tio/download/citizens/airstripping.pdf
Soil washing • Soil washing “scrubs” soil to remove and separate the portion of the soil that is mostpolluted. • This reduces the amount of soil needing further cleanup. • Soil washing alone maynot be enough to clean polluted soil. • Therefore, most often it is used with other methods that finish the cleanup.
Soil washing Source:http://www.epa.gov/superfund/community/pdfs/suppmaterials/treatmenttech/soil_washing.pdf
Bioventing • Technology that stimulates the natural in situ biodegradation of any aerobically degradable compounds in soil by providing oxygen to existing soil microorganisms. • Uses low air flow rates to provide only enough oxygen to sustain microbial activity. • Oxygen is most commonly supplied through direct air injection into residual contamination in soil.
Bioventing Source: http://www.frtr.gov/matrix2/section4/4_1.html
Conclusions • For determination of site’s environmental burdens it is necessary to perform site investigation • Based on the findings a proper decontamination method or combination of methods must be chosen • There are many decontamination methods and their suitability depends on media type and contaminants detected
Thank you for your attention http://browntrans.vsb.cz „This project has been funded with support from the European Commission. This publication [communication] reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.“