by In a major breakthrough for environmental technology, scientists have developed a new method for purifying polluted soil without the need for excavation or transportation. The high-temperature electrothermal (HET) process, developed by researchers at Rice University and the United States Army Engineer Research and Development Center (ERDC), offers an eco-friendly solution by treating the soil on-site.
The HET process begins by adding a carbon-rich electrically conductive material, such as biochar, to the polluted soil. Biochar, a non-toxic charcoal-like substance produced through pyrolysis, is mixed directly into the soil. This process involves decomposing organic material through heat in the absence of oxygen.
Once the biochar is added, the soil mixture undergoes flash Joule heating, a procedure developed by Rice University. This involves quickly passing an electrical current through the mixture, rapidly heating it to temperatures ranging from 1,000 to 3,000 ºC (1,832 to 5,432 ºF). The intense heat converts organic contaminants, such as pesticides and crude oil, into nontoxic minerals like graphite. Additionally, a variety of heavy metals, including lead, arsenic, and mercury, are converted into vapor and can be collected through extraction pipes. This unique ability to target multiple pollutants sets the HET process apart from existing remediation technologies.
While the high temperatures employed in the HET process may initially harm some beneficial microorganisms in the soil, tests have shown that the treatment actually improves plant germination rates by 20 to 30%. This unexpected benefit is attributed to the generation of growth-boosting minerals during the remediation process, as well as increased water infiltration due to the presence of biochar.
Once further developed and scaled up for field use, the HET process could revolutionize soil remediation by enabling the use of tractors to tow HET units across large areas of polluted soil. This rapid, water-free method of soil purification offers a versatile solution for handling a wide range of pollutants.
ERDC research chemist Mine Ucak-Astarlioglu emphasized the significance of the technology, stating, “This method is very rapid, water-free, and handles multiple pollutants in soil.” Flash Joule heating holds great promise not only for critical metals recovery from waste but also for heavy metals removal in soil remediation.
The HET process represents a remarkable advancement in environmental technology, showcasing the potential for on-site soil remediation without the need for exorbitant excavation and transportation costs. By addressing multiple pollutants simultaneously and enhancing plant growth, this eco-friendly method offers a sustainable solution to combat soil pollution and improve the health of our ecosystems.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
