Degradation of TCE Enhanced Using Phytoremediation

By: Leslie Romero

Trichloroethylene (TCE) is a common organic environmental pollutant found in groundwater, also known to be a human carcinogen. This contamination is associated with its improper disposal and spills. Due to its contamination prevalence, it has been a priority for the United States Environmental Protection Agency to find effective methods to decrease the contamination. To approach the situation, phytoremediation may be used as a cheaper alternative by using the ability of plants to take up chemicals from water and soils through its root system to degrade pollutants. For the most part, plants use their symbiotic relationships with internal microorganisms (endophytes) to adapt to environmental changes and degrade pollutants. Some plant species can recruit more beneficial microorganisms than others, suggesting the effect to be plant genotype-specific. To further study this remediation by using endophytes, a natural bacterial endophyte, Enterobacter sp. strain PDN3, was isolated and characterized from poplar trees. After a three-year field trial, inoculated poplar trees demonstrated a growth increase and reduced TCE phytotoxic effects. These trees expelled 50% more chloride ion, indicating towards an increase of TCE metabolism in plants. These findings suggest phytoremediation can be used as a cost-effective approach for degradation TCE, or even other pollutants. 

                 
                      

                                Figure 1. Phytoremediation process. Photo credit: http://pubs.sciepub.com/ijebb/2/4/5/

Original Article: Enhanced Degradation of TCE on a Superfund Site Using Endophyte-Assisted Poplar Tree Phytoremediation. Sharon L. Doty, John L. Freeman, Christopher M. Cohu, Joel G. Burken, Andrea Firrincieli, Andrew Simon, Zareen Khan, J. G. Isebrands, Joseph Lukas, and Michael J. Blaylock. Environmental Science & Technology. 2017. 51 (17)