The challenges of in-situ monitoring of contaminated landscapes include the rapid assessment of large areas for potential pollutants and their potential health risk due to volatilization. This research tested in a laboratory setting if thermal infrared remote sensing can discriminate between areas with volatilizing chemicals. Five pollutants of metal salts were prepared by mixing antimony with a solvent of hydrochloric acid, and cobalt, lead, nickel, and zinc with a solvent of nitric acid. Four pollutants of hydrocarbons, at two different concentrations, were prepared by mixing diesel, gasoline, motor oil, and olive oil with a solvent of acetone. The pollutants and solvents were in liquid pools and dosed on soils in petri dishes, each pollutant in a separate container, along with controls of a deionized water pool and un-dosed soil. The petri dishes were arranged in arrays, spaced to create intermediate areas without volatilization, and placed adjacent to a fume hood that created an updraft to remove volatilization products. The cooling of the pollutant surface due to volatilization was confirmed using thermocouple-based monitoring of in-situ kinetic temperature, and the thermal infrared radiometric temperature had a strong correlation with kinetic temperature. Based on two-tailed unpaired t tests of temperatures from 256 pixels for each petri dish, with a 0.05 alpha, 97% of the 66 polluted pool pairs had statistically different temperatures, and 85% of the 66 dosed soil pairs had statistically different temperatures. This study validated that thermography can differentiate between pollutant types and concentrations based on volatilization affecting temperature and thereby extend the remote sensing toolbox for environmental forensics. Further work is required to scale up this thermography technique from the relatively simple laboratory setting to more complex field applications.
|Titolo:||Remote sensing for environmental forensics: Thermal infrared images capture different surface temperatures in pollutant pools and dosed soils due to volatilization|
LEGA, MASSIMILIANO [Writing – Original Draft Preparation] (Corresponding)
|Data di pubblicazione:||2017|
|Appare nelle tipologie:||1.1 Articolo in rivista|