A Phytoremediation uses plants to remove or degrade contaminants present in soil, water, or air. This technique can occur through 5 mechanisms: phytodegradation, phytoextraction, phytovolatilization, phytostabilization, and phytostimulation. Therefore, for phytoremediation to be effective, the physical environment conditions and the most suitable mechanisms must be known in detail to achieve the objectives.In this case, we will discuss the scientific study conducted in partnership with the NewFields Brazil team, which assessed the phytoremediation potential of native plants at a site contaminated by volatile organic compounds (VOCs), located in a wetland area in southern Brazil.Due to the confidentiality of the case, some project details will not be specified.Scenario AnalysisUpon observing that a remediation target area already had extensive vegetation, the NewFields Brazil team posed the following questions: Can the existing plants at the site contribute to contaminant retention or to a possible natural attenuation of the area? Is it possible that all existing plants at the site possess phytoremediation capabilities?To answer these questions, it is first necessary to understand the types of mechanisms that can act in phytoremediation. These mechanisms are natural processes carried out by plants and can promote the remediation of environmental matrices. They are characteristic of plant genera or species; however, some plant species may provide one, none, or more than one phytoremediation mechanism depending on the target contaminant.Understanding these phytoremediation mechanisms and the physical-chemical, structural, and contamination conditions of the physical environment, the working team synthesized a detailed and innovative methodology to gather information on the phytoremediation capacity of the local flora, so as not to generate ecological disturbances.
Study Methodology
For this project, the working team followed these steps:
- on-site survey of the different plant species existing at the site;
- systematic review of the phytoremediation capacity of the species found, considering the types of contaminants to be treated;
- consolidation of the results obtained and definition of the existing plant species in the area that show the greatest phytoremediation potential.
The field mapping indicated the presence of more than 50 plant genera in the investigated area, including the genera Nephrolepis, Brachiaria Cyperus (L.) and others. From this stage, a literature review was conducted, which aimed to evaluate the application potential of these genera in VOC phytoremediation processes.From the systematic review, it was found that the knowledge of the applicability of flora in the phytoremediation of volatile organic compounds is still limited, especially for the genera sought. However, the data found indicated the vast application of these genera in the phytoremediation of areas contaminated with toxic metals, also known as heavy metals.
Solution Identified
The most abundant plant genera in the area were selected, as the repeated occurrence of these plants may indicate their good adaptability to the contaminated environment. Thus, the team selected 9 plant genera that appeared most frequently in the area and conducted an enhanced and robust literature review. This research indicated that 6 of the 9 genera showed clear scientific evidence of phytoremediation potential, through distinct mechanisms.Following the identification of promising species, additional on-site investigations may be carried out to confirm and quantify the phytoremediation benefits that a possible increase in the number of certain plants in the area could offer in the long term.A good phytoremediation project must consider the local biome and its peculiarities, as the plant species used should integrate with the local flora and fauna even after the period of human intervention. If you are looking for projects with environmental intelligence and innovative initiatives, contact us!
Also discover other application cases
• Application of Phytoremediation in an area contaminated by organic solvents. Click here to learn more about the case.• Application of Phytoremediation as a hydraulic control tool in an area contaminated by agrochemicals. Click here to learn more about the case.
