Phytodesalinization potential of Typha angustifolia, Juncus maritimus, and Eleocharis palustris for removal of de-icing salts from runoff water

Typha angustifolia , Juncus maritimus , and Eleocharis palustris were evaluated for de-icing salt removal from runoff water. Plants were exposed to a range of de-icing salt levels (0.2, 0.7, 4, 8, and 13 dS m −1 ) in laboratory-scale subsurface constructed wetlands (CWs) for 2 months under greenhouse conditions. Effluent characteristics, plant height, biomass, and Cl and Na removal rates and uptake were monitored. More water volume was retained in CWs of T. angustifolia (∼60 %) than of J. maritimus and E. palustris (∼37.5 %), which accounted for the electrical conductivity increase in effluents (1.3–1.9-fold). Based on the NaCl removal rate, T. angustifolia showed the greatest phytodesalinization ability (31–60 %) with the highest removal at the lowest salt levels (0.2–0.7 dS m −1 ), followed by J. maritimus (22–36 %) without differences in removal among levels, and E. palustris (3–26 %) presenting a removal rate highly decreased with increasing salt levels. Plant height and biomass were stimulated at low de-icing salt levels, but, at higher levels, T. angustifolia and E. palustris growth was inhibited (tolerance index ∼67 and 10 %, respectively, in the worst cases). Salt amounts in aboveground biomass in g m −2 differed among levels and ranged as follows: 13.6–29.1 (Cl), 4.2–9.3 (Na; T. angustifolia ); 7.0–12.0 (Cl), 2.7–6.4 (Na; J. maritimus ); and 0.9–7.6 (Cl), 0.3–1.6 (Na; E. palustris ). Chloride and Na translocation decreased with de-icing salt increase in T. angustifolia , while no significant differences were found in J. maritimus , which is interesting for harvesting purposes.