4. Conclusions
The removal of mercury by T. domingensis in constructed wetlands
and its relative metal absorption were studied. Metal biomagnification
on plant tissue increased with the exposure time according to a first order kinetic with constant rate parameter of about 7 times higher than the control experiment, demonstrating an excellent performance of the species, reducing in 99.6 ± 0.4%
the mercury concentration in contaminated water. When compared to other species, the results showed that the T. domingensis has higher mercury accumulation capacity (273.3515 ± 0.7234 mg kg1), attaining water to plant transfer coefficient of
7750.9864 ± 569.5468 L kg1. These results show a high potential of the studied aquatic macrophyte T. domingensis in constructed wetlands with subsurface flow, for the phytoremediation of mercury contaminated waters.