Physiological Responses of Pistia stratiotes and Its Fluoride Removal Efficiency

Phytoremediation technology using aquatic plants is being used increasingly in constructed wetlands to purify wastewater. The physiological responses of water lettuce (Pistia stratiotes) and its effectiveness in removing fluoride (F ^-) from water are described in this article. The results indicate that Pistia stratiotes has the ability to accumulate F ^-. The removal efficiency ranged from 27.79% to 56.32% for the various initial F ^-concentrations tested, and was highest (56.32%) in the highest initial concentration group 60mg/L. The F ^- concentrations in control groups (without Pistia stratiotes) changed very little, from -1.135% to -0.007% of the initial concentrations. At the highest removal rate, the bioconcentration factor was 7.84. The rate of purification conformed to the Michaelis-Menten equation, and the correlation coefficients (R ²) were all greater than 0.97. The Specific Growth Rates (SGR) of the treatment groups were -8.03% to -1.22%, and the SGR of plants under F ^-stress decreased during the experimental period. The partial correlation analysis showed that concentrations of F ^- in water were strongly linearly correlated with peroxidase.