Presentation on theme: "Enviromental aspects of Brownfield Regeneration Barbara Vojvodíková, Marcela Maturová „This project has been funded with support from the European Commission."— Presentation transcript:
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.“
Awareness What does contaminated site means? What are basic steps in site exploration in relation to environmental burdens? What is elementary classification of decontamination methods? How does selected decontamination methods work?
Goals of the teaching unit Explain contamination issues of brownfield sites Outline approaches to contamination assessment and decontamination methods
Content Contaminated site term definition Enviromental assessment procedure Sampling steps Decontamination methods classification Decontamination methods examples
Contamination Human health Undeground Water Volatile Dust Construction materials
Contaminated sites The term 'contaminated site' refers to a well delimited area where the presence of soil contamination has been confirmed. The severity of the impacts to ecosystems and human health can be such that remediation is needed, specifically in relation to the current or planned 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 verify whether relevant impacts exist.
Environmental Assessment Traditionally brownfield environmental assessment 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 thorough review of conditions at the site. Typically it 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.
Environmental Sampling - 7 steps The scope of environmental sampling can be illustrated by a sample’s life with the following seven consecutive steps: 1.a sample is planned (“conceived”); 2.a sampling point is identified; 3.the sample is collected; 4.the sample is transferred to the laboratory; 5.the sample is analyzed; 6.the sample expires and is discarded; and 7.the sample reincarnates as a chemical data point
Remediation methods The intent of soil 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 by place according remediated media type used strategies
Sorting of decontamination technologies (2) by place – in-situ – ex-situ
Sorting of decontamination technologies (3) by type of media being remediated – soil – sediment, sludge – groundwater – surface water – air emissions – off-gasses
Strategy Pollutants immobilization Extraction and separation from environment Disintegration and transformation of pollutant A few examples
Thermal desorption Thermal desorption removes harmful chemicals from soil and other materials (like sludge and sediment) by using heat to change the chemicals into gases. These gases are collected with special equipment. The dust and harmful chemicals are separated from the gases and disposed of safely. The clean soil is returned to the site. Thermal desorption is not the same as incineration, which uses heat to destroy the chemicals.
Air stripping It’s 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’s commonly used to treat groundwater as part of a pump and treat remedy.
Air stripping Source: http://www.epa.gov/tio/download/citizens/airstripping.pdfhttp://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 most polluted. This reduces the amount of soil needing further cleanup. Soil washing alone may not be enough to clean polluted soil. Therefore, most often it is used with other methods that finish the cleanup.
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.
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.“