Phytoremediation as an environmentally acceptable method for soil protection

by Apr 2, 2024blog

Phytoremediation technologies use living plants to clean up soil, air and water contaminated with hazardous contaminants. It is defined as “the use of green plants and the associated microorganisms, along with proper soil amendments and agronomic techniques to either contain, remove or render toxic environmental contaminants harmless”. The term is an amalgam of the Greek phyto (plant) and Latin remedium (restoring balance). The advantage of phytoremediation is a lower price compared to conventional techniques or some specialized ones (ex. chemical precipitation, membrane filtration, ion exchange, adsorption with activated carbon, etc.). Various organic and inorganic compounds are subject to phytoremediation. The techniques can be applied in situ and ex situ. These techniques do not require expensive equipment and are easy to implement, they do not require the transmission of pollution, which reduces the risk of its further spread. The advantage is also that applying these techniques reduces the possibility of additional pollution that may be a consequence of water or wind activity (spills, erosion).

      Phytoremediation is proposed as a cost-effective plant-based approach to environmental remediation that takes advantage of the ability of plants to concentrate elements and compounds from the environment and to detoxify various compounds without causing additional pollution. The concentrating effect results from the ability of certain plants called hyperaccumulators to bioaccumulate chemicals. The remediation effect is quite different. Toxic heavy metals cannot be degraded, but organic pollutants can be, and are generally the major targets for phytoremediation. Several field trials confirmed the feasibility of using plants for environmental cleanup.

     Since 1973, one of the biggest polluters in the zinc and lead smelting plant “Topilnica” in Veles has been destroying the environment, polluting the soil with lead (Pb), cadmium (Cd), zinc (Zn), mercury (Hg), arsenic (As), indium (In) and water and air with sulfur dioxide (SO2) and carbon dioxide (CO2). In 2003, the smelter was closed, but high concentrations of heavy metals remained in the soil, contaminating green food produced in the regions around Veles. In 2005, the Ecological Society Villa Zora of Veles, together with experts from the Faculty of Agriculture and Food at the University of St. Kiril and Metodij in Skopje, took samples from the most polluted areas in Veles, through pilot plants, which according to various scientific researches (including the one done by EPTISA) are hyper-absorbers of heavy metals from the soil (oilseed beet, kale, alfalfa). After decontamination of the soil, the oilseed will be used to produce oil, which can further be used to produce biodiesel fuel. At the same time, the production of biodiesel contributed to the sustainability of the project due to the use of a natural resource and the reuse of the same resource (oilseed), to produce a fuel that is more environmentally friendly compared to fossil diesel fuel. The biodiesel fuel produced can be used by farmers to plow new hectares the following year, to prepare the soil for decontamination. 

    After one year, in a follow-up study, sample results showed a reduction in heavy metal contaminated soil, a 15% reduction for Cd, 45% for Pb and up to 70% for Zn in Veles soil. In 2019, the Ecological Associations “Vila Zora” from Veles and “Eco Guerilla” from Tetovo jointly presented the results and analyzes of soil pollution in the Polog and Vardar regions, as well as from other parts of the country. This was part of the project “Let’s protect the soil from pollution” in the framework of which analysis was made of the soil, vegetables, and fruits for pollution with heavy metals in Veles, Skopje, Tetovo and Kavadarci. Within the framework of the project was also the development of the Strategy for decontamination of the contaminated soil in Veles, which can be used as a model for other municipalities in the country.In addition, 1000 farmers from the target municipalities were educated on phytoremediation and how to decontaminate their soil using this method. This project helped educate farmers to learn how to decontaminate their soil and institutionalize this environmental problem through strategic documents for municipalities.

From the students of SSOU “Dimitrija Chupovski” Veles , North Macedonia