What is phytoremediation? Phytoremediation is a term for technology that uses plants to absorb toxins from the air, soil, and water of polluted areas. While phytotechnology is limited by its gradual pace, rooting depth of plants used, and potential ingestion of toxins by other fauna onsite, it can bring great benefits if properly used. Additionally, this method is advantageous due to its low energy and labor requirements, compared to topsoil removal and other ex situ AKA offsite methods, which can destroy soil structure and expose laborers to toxins. Phytoremediation can also be implemented pre-emptively by being integrated into landscaping plans or land repurposing (ex. Converting contaminated sites into parks).
There are several mechanisms that use plants to purge contaminants. They are as follows:
This mechanism is probably closest to what you imagine phytoremediation as. Willow, Indian mustard, hybrid poplars, and cattails can rapidly accumulate heavy metals (like lead or chromium), pesticides, solvents, and crude oil from soil and water in their plant tissue. That tissue can then be safely harvested and disposed of.
This mechanism can be utilized to absorb soil or water pollutants – organic and metal – and release them as vapors into the atmosphere. Most research on phytovolatilization focuses on two groundwater contaminants, tetrachloroethylene (PCE) and trichloroethylene (TCE), using willow and hybrid poplar. However, Indian mustard and canola plants can also be used to safely phytovolatilize selenium.
St. Augustine grass, annual ryegrass, sunflower, and cowpea are often used for this mechanism. Plants used for rhizodegradation facilitate the growth of microbes in their rhizosphere AKA the root zone area. They do this by releasing nutrient-rich fluids for smaller organisms.
This mechanism prevents the spread of organic or metal pollutants to surrounding areas, groundwater, or air. For heavy metals, red fescue and other species of grass are recommended. Phytostabilization is best for areas that have low levels and a shallow depth of contamination.
Certain plants, like hybrid poplar trees and parrot feather, can directly degrade organic pollutants like TCE and trinitrotoluene (TNT), respectively.
One prominent phytoremediation effort in Alabama was done by the PIP in collaboration with Sloss Industries, supported by the Cawaco Resource Conservation and Development Council, which opened in 2003. The organization, chaired by Dr. Davinderjit K. Bagga, created a Demonstration Site that can be toured at Sloss Industries.
Birmingham Business Journal. 2020. Sloss To Help Open ‘Plant Solution To Pollution’. [online] Available at: [Accessed 24 December 2020].
Limmer, M. and Burkin, J., 2016. Phytovolatilization Of Organic Contaminants. [online] ACS Publications. Available at: [Accessed 24 December 2020].
Gadsden Times. 2003. Chemical-Cleansing Plants Touted For Cleanup. [online] Available at: [Accessed 24 December 2020].
Greipsson, S., 2020. Phytoremediation | Learn Science At Scitable. [online] Nature.com. Available at: [Accessed 24 December 2020].
Radziemska, Maja et al. “Phytostabilization-Management Strategy for Stabilizing Trace Elements in Contaminated Soils.” Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/ PMC5615495/ International journal of environmental research and public health vol. 14,9 958. 25 Aug. 2017, doi:10.3390/ijerph14090958