Hydrophytic plants Canna indica, Epipremnum aureum, Cyperus alternifolius and Cyperus rotundus for phytoremediation of fluoride from water

Hydrophytes namely Canna indica, Epipremnum aureum, Cyperus alternifolius and Cyperus rotundus were found to eliminate fluoride from water. The fluoride concentrations were checked using Sodium fluoride, Trisodium2-parasulfophenylazo-1,8-dihydroxy-3,6-napthalene disulfonate method. The chlorophyll pigments were quantified by Arnon's method. Sugar and protein contents of candidate plant tissues before and after fluoride exposure were quantified using Anthrone and Bradford's routine methods, respectively. Superoxide dismutase, catalase and glutathione peroxidase activities were measured using the manufacture's protocols. C. indica, E. aureum, C. alternifolius and C. rotundus could remove up to 95, 52, 65 and 56% fluoride respectively from solution at the strength of 10 ppm within 10 d. Increasing fluoride concentration (10-50 ppm) was found to inhibit the removal by C. indica when by 31%; while the biomass (1-5 plants) enhanced the removal by 39%. Bioaccumulation and translocation factors calculated considering the measured fluoride contents in roots and leaves of C. indica, E. aureum, C. alternifolius and C. rotundus were found to be 14.28, 1.82, 1.20 and 1.07; and 0.26, 1.87, 1.75, 0.52, respectively. Reduction in the total chlorophyll, carbohydrates and proteins contents in the leaves of C. indica, E. aureum, C. alternifolius and C. rotundus was observed by 21, 38,46 and 18%; 49, 49, 60 and 76%; and 48, 60, 76 and 75%, respectively. Superoxide dismutase, catalase and glutathione peroxidase in the roots of C. indica, E. aureum, C. alternifolius and C. rotundus were observed to be induced 200, 133, 207 and 383%; 282, 159, 64 and 39%; and 314, 161, 175 and 171%, respectively. While, the leaf tissues showed induction by 227, 162, 181, 167%; 195, 250, 116 and 117%; and 104, 202, 271 and 84%, respectively. C. indica was found to hyperaccumulate fluoride mainly in the root tissues which is advantageous as it arrests its further translocation to shoot and food chain subsequently. (C) 2020 Published by Elsevier B.V.