Mercury removal by Aquarius palifolius (Nees & Mart.) Christenh. & Byng: Isotherms model, superoxide dismutase activity, and chlorophyll content

Mercury is one of the heavy metals that became a global threat in this industrialization era. Artisanal and Small-Scale Gold Mining activities are the leading cause of this mercury pollution. Sustainable and environmentally friendly methods can be a solution to overcome this problem. Bioremediation methods use plants with defense mechanisms against mercury, namely Mexican sword plants or Aquarius palifolius, which is a promising solution. This research aimed to analyze the isotherm model of mercury content in A. palifolius in the Free Water Surface-Constructed Wetland (FWS-CW) reactor using the Langmuir and Freundlich isotherm equations; analyzed the activity of antioxidant enzymes in A. palifolius such as Superoxide dismutase (SOD); and also analyzed the effect of mercury stress on chlorophyll levels in A. palifolius. This research shows that the mercury phytoremediation process by A. palifolius is more suitable with the Langmuir isotherm model. There are no significant differences in SOD activity and chlorophyll levels between A. palifolius with and without mercury concentration. This indicates that A. palifolius is a hyperaccumulator plant that can survive in mercury stress conditions and even remove mercury from contaminated water.