Efficacy of duckweed (Lemna minor) and water lettuce (Pistia stratoites) in the treatment of herbicide polluted water

Abstract

Agrochemicals including synthetic herbicides are being applied intensively by farmers in Benue State. The aim of this study was to investigate the biosorption potentials of duckweed (Lemma minor) and water lettuce (Pistia stratoites) in the treatment of water contaminated with herbicide. The complete randomized design (CRD) was used. Experimental water samples containing test plants were analyzed for heavy metals (Pb, Cr, Mn), nutrient enrichment (N, P, K) and physicochemical parameters while test plants were evaluated for growth features. Indices of aquatic phytoremediation were computed including HPI (heavy metal pollution indices), PRI (phytoremediation index) and PE (phytoremediation efficiency). Data analysis was done using multivariate analysis tool while mean separation of ANOVA was done using Fisher LSD at p≤005. Plant-herbicide interaction showed that only duckweed had a reducing effect where Cr (0.01 ppm) and Pb (0.009 ppm) concentrations were very low in water. Hence, duckweed treated water had HPI