Assessment for Less than 20-ppm Oil Leakage in Soil Using Terahertz Wave

Area of Science:

• Environmental Science
• Analytical Chemistry
• Spectroscopy

Background:

• Accurate detection of trace oil leaks is vital for soil protection.
• Current methods struggle to detect oil concentrations below 20 parts per million (ppm).

Purpose of the Study:

• To evaluate Terahertz (THz) time-domain spectroscopy for characterizing crude oil content in soils.
• To establish THz spectroscopy as a viable method for rapid, sensitive detection of soil oil contamination.

Main Methods:

• Utilized THz time-domain spectroscopy to analyze crude oil in soil samples.
• Developed a linear model correlating THz attenuation coefficient with crude oil concentration.
• Applied effective-medium theory to understand THz dielectric constant variations with oil content.

Main Results:

• A linear model predicted a detection limit for crude oil between 4.11 and 16.2 ppm.
• Organic compounds (aromatic, aliphatic) showed higher THz absorption than minerals.
• THz dielectric constants were effectively modeled to reflect crude oil content.

Conclusions:

• Terahertz (THz) technology demonstrates high sensitivity for detecting trace oil in soil.
• This method surpasses the limitations of conventional techniques for low-concentration oil detection.
• THz spectroscopy presents a promising tool for environmental monitoring of soil oil contamination.