Soil vapor extraction in sandy soils: influence of airflow rate.
Airflow rate is one of the most important parameters for the soil vapor extraction of contaminated sites, due to its direct influence on the mass transfer occurring during the remediation process. This work reports the study of airflow rate influence on soil vapor extractions, performed in sandy soils contaminated with benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene. The objectives were: (i) to analyze the influence of airflow rate on the process; (ii) to develop a methodology to predict the remediation time and the remediation efficiency; and (iii) to select the most efficient airflow rate. For dry sandy soils with negligible contents of clay and natural organic matter, containing the contaminants previously cited, it was concluded that: (i) if equilibrium between the pollutants and the different phases present in the soil matrix was reached and if slow diffusion effects did not occur, higher airflow rates exhibited the fastest remediations, (ii) it was possible to predict the remediation time and the efficiency of remediation with errors below 14%; and (iii) the most efficient remediation were reached with airflow rates below 1.2 cm(3)s(-1) standard temperature and pressure conditions.
Albergaria
José Tomás
JT
REQUIMTE, Instituto Superior de Engenharia do Porto, R S Tomé, 4200-072 Porto, Portugal. jta@isep.ipp.pt
Alvim-Ferraz
Maria da Conceição M
Mda C
Delerue-Matos
Cristina
C
D001554:Benzene / Q000032:analysis / Q000737:chemistry; D001555:Benzene Derivatives / Q000032:analysis / Q000737:chemistry; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005740:Gases / Q000032:analysis / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013750:Tetrachloroethylene / Q000032:analysis / Q000737:chemistry; D014050:Toluene / Q000032:analysis / Q000737:chemistry; D014241:Trichloroethylene / Q000032:analysis / Q000737:chemistry; D014835:Volatilization; D014992:Xylenes / Q000032:analysis / Q000737:chemistry
D001555:Benzene Derivatives; D005740:Gases; D012987:Soil; D012989:Soil Pollutants; D014992:Xylenes; D014241:Trichloroethylene; D014050:Toluene; D012822:Silicon Dioxide; D001554:Benzene; C004912:ethylbenzene; D013750:Tetrachloroethylene