Use of Eichhornia crassipes and Pistia stratiotes for environmental services: Decontamination of aquatic environments with atrazine residues

Abstract

There is a need for efficient technologies to remove atrazine residues that are detected in water bodies. These residues are harmful as they intoxicate plankton and may decrease oxygen in the water. This study evaluated the growth, physiology, and leaf anatomy of Eichhornia crassipes and Pistia stratiotes that were exposed to atrazine for phytoremediation purposes. To carry out this evaluation, atrazine concentrations ranging from 0 to 1000 μg L-1 were added into 5 L pots with macrophytes, which were maintained for 28 d in these solutions. Following this period, atrazine toxicity, chlorophyll content, and dry mass were measured. High-performance liquid chromatography was used to quantify residual atrazine concentrations in the solution and plant material samples. It was found that E. crassipes was sensitive to an atrazine concentration of 1000 μg L-1. Atrazine reduced macrophyte growth, promoted a decrease in chlorophyll, and altered anatomical parameters; however, plant growth was uninterrupted, and macrophytes remained physiologically active until the evaluation period. The residual atrazine concentrations in solution were 35.56% and 79.19% for E. crassipes and 76.13% and 78.83% for P. stratiotes, respectively; this was lower than plants that were unpotted for atrazine concentrations of 10 and 100 μg L-1. The results indicate that E. crassipes and P. stratiotes may be suitable phytoremediators in aquatic ecosystems for atrazine concentrations up to 10 and 100 μg L-1, respectively.