Removal of mercury and heavy metals from contaminated soils

Sasson Yoel (Casali), HUJI, Faculty of Science, The Institute of Chemistry

Physico-chemical soil-washing technique that removes heavy inorganic metals from contaminated soils and industrial waste



Cleantech, environmental catalysis, environmental remediation, green chemistry, sustainable chemistry, soil washing, soil remediation, soil treatment, leaching reagents, industrial waste management, e-waste, inorganic pollutants.

Development Stage

Proof of concept

Patent Status

Provisional patent submitted

Innovation summary

Our innovation utilizes a simple physical-chemical soil-washing technique for the removal of heavy, inorganic toxic metals from contaminated soil, sludge, and industrial waste. This ex-situ technique is applied to excavated soil, either on site or at waste treatment sites, for removing such metals as: mercury, zinc, cadmium, chrome, cobalt, nickel, antimony and vanadium.


Our highly efficient treatment method requires far less water, as compared to existing technologies, and reduces significantly the time and costs involved in remediating excavated toxic soil and waste.



The technology is based on a commercial off-the-shelf chemical agent, which - when added to water - serves as a metal extraction agent in standard soil-washing methods. When mixed with the contaminated soil, the liquid agent prompts an oxidation-reduction (redox) reaction with the inorganic metallic compounds. Consequently, the metal’s solubility level is increased, causing the metallic particles to dissolve in the water, and enabling their easy removal from the soil.


The process includes 3 main steps:


Washing the excavated contaminated soil with the liquid chemical agent.

Physical-chemical separation of the decontaminated soil (returned to the site), from the water (containing dissolved metallic particles and the chemical agent).

The water is mixed in with a new batch of contaminated soil, dissolving the soil’s metallic particles. This step can be repeated several times, each time reusing the water in a new batch of contaminated soil. After accumulating a certain amount of metal, the water is separated from its metallic components, utilizing various methods, resulting in clean, metal-free water. The metal can then be discarded at a waste site.



  • Low-cost, easy, efficient, and fast decontamination solution
  • Replaces existing technologies which are costly, lengthy, and complex
  • A single method for treating several types of metals simultaneously, otherwise requiring multiple remediation techniques
  • Far more cost effective than any other commercial method.


Development milestones

Proof of concept has been achieved. The next phase required is optimization research and scaling up.



  • Decontamination of soil, sludge, and industrial wastes for agriculture
  • Petro-chemical waste
  • Textile waste
  • Paint waste
  • Dentistry waste
  • Oil and gas drilling waste
  • E-waste
  • Chemical and industrial waste landfills

Researcher information           http://chemistry.huji.ac.il/casali/sasson.htm


Contact for more information:

Eitan Dekel
VP Business Development - Computer Science
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