Experience of phytoremediation use of cannabis in South Africa
Industrial hemp is renowned for its phytoremediation properties, which allow it to purify the earth - and possibly also water - and that in this it is promoted by a high growth rate surpassed only by bamboo, excellent stress tolerance and a 2.5 meter deep root system that penetrates deep into the ground. And this is in addition to the fact that, as an agricultural crop, the plant is able to "isolate" 22 tons of carbon dioxide per hectare, surpassing any forest or other commercial agricultural crop.
An example of the excellent phytoremediation properties of the hemp plant, namely its ability to absorb heavy metals from the soil and accumulate them inside the plant's root system, is a project in South Africa led by Thiago Campbell (Master of Environmental Sciences from the University of the Witwatersrand), in which hemp is investigated as a tool for cleaning up the poisoned industrial center of South Africa (South Africa).
Gauteng, a province in South Africa, has at least 380 mining waste sites that contain high levels of toxic and radioactive metals, including high concentrations of arsenic, cadmium, cobalt, copper, zinc and uranium. For example, the levels of uranium in Lake Robinson, located in the above-mentioned province, are 40,000 times higher than normal natural levels. It is a legacy of 130 years of lucrative yet irresponsible mining practices in the region.
According to Thiago Campbell, “Industrial hemp is renowned for its phytoremediation properties, which allow it to purify the soil - and possibly water as well - and that it does so by a high growth rate surpassed only by bamboo, excellent stress tolerance and a 2-deep root system. , 5 meters, which penetrates deep into the ground. And this is in addition to the fact that, as an agricultural crop, the plant is able to "isolate" 22 tons of carbon dioxide per hectare, surpassing any forest or other commercial agricultural crop. Supercharging heavy metals, the hemp plant differs significantly from its phytoremediation counterparts, including Indian mustard, water hyacinth, alfalfa and sunflower, in its potential to create secondary markets. ”
Health concerns about the potential to use raw hemp grown on “contaminated” land automatically exclude it from medical or recreational use, but Mr. Campbell's research demonstrates that the heavy metal is “recovered in quantities that are not toxic or are dangerous to humans and give us the opportunity to block them in the final non-food products. " For example, this kind of raw material could be effectively used in green building or in the production of biocomposite materials.
Research into the phytoremediation properties of the hemp plant is actively pursued in Italy, where several programs are being implemented at once (GREEN - “Generare Risorse Ed Economie Nuove” and BIO SP.HE.RE - “Bio Integrated Spirulina and HEmp REmediation”) aimed at studying the properties of hemp in soil cleaning contaminated in the course of technogenic activities.
In addition to Italian research experience, there are several examples of the application of the phytoremediation potential of cannabis in land clearing. The first example of using hemp as a super battery was the experience of cultivating a hemp plant in the exclusion zone of the Chernobyl nuclear power plant in the 90s of the last century. In particular, a high ability to “pull” heavy metals such as lead, nickel, cadmium, zinc and chromium from contaminated soil has been documented. A similar experience was used to neutralize heavy metal pollution from textile factories in the city of Rawalpindi (Pakistan), as well as the experience of using a hemp plant for cleaning soil as a result of radiation contamination was studied by Japanese specialists after the accident at the nuclear power plant in Fukushima.