A method of mercury removal from topsoil using low-thermal application

Area of Science:

• Environmental Science
• Environmental Chemistry
• Soil Remediation

Background:

• Mercury contamination poses significant environmental and health risks due to its toxicity and variable bioavailability.
• Industrial activities create mercury "hot spots" in soils, necessitating effective remediation strategies.
• Existing ex situ soil remediation methods are often costly, environmentally disruptive, and involve soil transportation.

Purpose of the Study:

• To evaluate a low-cost, simple approach for removing mercury from contaminated soil using low-temperature thermal desorption.
• To assess the efficacy of thermal desorption in reducing total mercury concentration in soil.
• To determine the impact of thermal treatment on soil biological activity and growth properties.

Main Methods:

• Laboratory-scale experiments were conducted to theoretically calculate mercury removal rates based on time and temperature.
• Plot-scale experiments applied laboratory findings to a practical, in situ remediation scenario.
• Mercury-polluted soil samples were sourced from a chemical production facility in southern Poland for testing.

Main Results:

• Laboratory experiments at 373 K reduced total mercury concentration in soil by approximately 32%.
• Plot-scale experiments at 440 K achieved a mercury removal of 60-70% from the soil.
• Post-treatment soil biological activity tests revealed no negative impact from the applied high temperatures.

Conclusions:

• Low-temperature thermal desorption is a viable and cost-effective method for mercury removal from contaminated soils.
• The thermal desorption process effectively reduces mercury concentrations without compromising soil health or biological functions.
• This approach offers a promising alternative to traditional, more expensive, and environmentally impactful remediation techniques.