Phytoremediation of Chloride Pollution in Surface Waters Using Hydroponics
High salt conditions in surface waters have been shown to alter the composition of macroinvertebrates and can disrupt successful growth of native plant species. This research addresses this issue through phytoremediation: the use of plants to treat and control wastes in the environment. Halophytic plants are naturally able to survive under highly saline conditions and have been successfully used in reducing chloride concentrations of soils. We use these plants in hydroponic growth systems to mimic a soilless aquatic environment. Three halophytic plant species, Salicornia europaea (Glasswort), Spartina pectinata (Cordgrass), and Portulaca oleracea (Purslane), were grown in three nutrient solutions of sodium chloride: 0mM (control), 24mM, and 100mM. Aboveground biomass was harvested, dried, processed, and digested in 0.5% nitric acid for analysis using ion chromatography. Results show that these plants sequester chloride in their biomass with increased efficiency as salt concentration of the nutrient solution increases. Efficiencies vary among individual plant species. The results suggest that the studied plant species may be considered for future applications of remediating salt-contaminated surface waters in hydroponic growth systems.