Formatted Title
Scaling up of Mercury-Contaminated Soil Thermal Desorption Treatment: Laboratory, Pilot and Full-Scale in Israel
Background/Objectives
Many nations have recognized the environmental and health hazards associated with mercury and have taken steps to minimize or eliminate its use in various industrial applications. The Minamata Convention on Mercury, established in 2013, is a global treaty with the goal of safeguarding human health and the environment from the detrimental effects of mercury. It advocates for the phase-out of specific mercury-based processes, including mercury electrolysis, in favor of safer and more environmentally friendly alternatives. Mercury, in its various forms - elemental, inorganic, and organic compounds - can pose risks to human health, affecting the nervous system, respiratory system, gastrointestinal tract, and skin. This results in symptoms such as tremors, muscle weakness, memory impairment, and developmental issues, particularly in foetuses and young children.
Approach/Activities
In a collaborative effort, Haemers Technologies, LDD Advanced Technologies, and Tidhar joined forces to remediate the former plant of the Electrical Industries Company, situated on a 60-acre site in Acre Bay, Israel. This facility operated from 1956 to 2003, primarily involved in chlorine and polyvinyl chloride (PVC) production. The chosen approach for land remediation involves the application of thermal treatment, among other techniques.
In early 2022, the initial laboratory phase was conducted to evaluate the kinetics of thermal treatment specific to mercury contamination. The results demonstrated a substantial reduction in overall mercury content, with a degradation/elimination rate of 92% observed after 24 hours at 200°C, increasing to 96% after 168 hours at 260°C.
Results/Lessons Learned
Following the kinetic study phase, Haemers Technologies conducted an on-site pilot of ex situ thermal desorption (ESTD), targeting approximately 275 m3 of extensively contaminated soil. The soil was heated to a target temperature of 350°C over 35 days, effectively remediating significant contamination with volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), and mercury. The consolidation of these soils into a treatment pile validated the treatment's efficacy and ensured compliance with air emission standards.
After the successful pilot phase, the project transitioned to its full-scale phase, with the first thermopile containing 4000 tons of contaminated soil scheduled for treatment by the end of 2023. A vapor treatment unit has been installed to manage extracted vapors, undergoing collection and condensation. The non-condensable fraction is subjected to further treatment before release into the atmosphere.
This project represents a significant collective achievement, showcasing the potential for broad application in addressing mercury contamination at similar brownfield sites in need of an effective technical solution.