Potential of macrophytes for removing atrazine from aqueous solution

Abstract

-The potential of three macrophytes, Azolla caroliniana, Salvinia minima, and Lemna gibba was assessed in this study to select plants for use in environmental remediation contaminated with atrazine. Experiments were carried out in a greenhouse over six days in pots containing Hoagland 0.25 strength nutritive solution at the following atrazine concentrations: 0; 0.01; 0.1; 1.0; 10.0 mg L -1 . Decrease in biomass accumulation was observed in the three macrophytes, as well as toxic effects evidenced by the symptomatology developed by the plants which caused their deaths. The chlorosis and necrosis allowed to observe in the plants the high sensitivity of the three species to the herbicide. Plants presented low potential for removal of atrazine in solution when exposed to low concentrations of the herbicide. However, at the 10.0 mg L -1 atrazine concentration, L. gibba and A. caroliniana showed potential to remove the herbicide from the solution (0.016 and 0.018 mg atrazine per fresh mass gram, respectively). This fact likely resulted from the processes of atrazine adsorption by the dead material. The percentage of atrazine removed from the solution by the plants decreased when the plants were exposed to high concentrations of the pollutant. Azolla caroliniana, S. minima, and L. gibba were not effective in removing the herbicide from solution. The use of these species to remedy aquatic environments was shown to be limited.Keywords: Azolla caroliniana, Salvinia minima, Lemna gibba, herbicide, bioremediation.RESUMO -Avaliou-se, neste estudo, o potencial de três macrófitas -Azolla caroliniana, Salvinia minima e Lemna gibba -com vistas à seleção de plantas para remediação de ambientes contaminados por atrazine. Foram realizados experimentos em casa de vegetação durante seis dias, em vasos contendo solução nutritiva Hoagland (0,25 de força iônica), nas seguintes concentrações de atrazine: 0; 0,01; 0,1; 1,0; e 10,0 mg L -1 . A redução da biomassa acumulada pelas macrófitas foi observada, bem como os efeitos de toxidez evidenciados pela sintomatologia desenvolvida nas plantas, os quais causaram sua morte. Clorose e necrose observadas nas plantas mostraram a alta sensibilidade das três espécies ao herbicida. As plantas demonstraram baixo potencial para remoção de atrazine, quando expostas ao herbicida em baixas doses. Entretanto, na concentração de 10,0 mg L -1 de atrazine, L. gibba e A. caroliniana mostraram potencial para remover o herbicida da solução (0,016 e 0,018 mg de atrazine por grama de massa fresca, respectivamente). Esse fato provavelmente resultou do processo de adsorção de atrazine pela matéria morta. A porcentagem de atrazine removida da solução pelas plantas diminuiu quando estas foram expostas a altas concentrações do poluente. Azolla caroliniana, S. minima e L. gibba não foram eficazes na remoção do herbicida na solução. A utilização dessas espécies para sanar ambientes aquáticos mostrou-se limitada.

Fabrication and Characterization of a Novel Herbicide Delivery System with Magnetic Collectability and Its Phytotoxic Effect on Photosystem II of Aquatic Macrophyte

“…caroliniana plants have the capacity to remove atrazine from the environment with an accumulation of ca. 0.018 mg per fresh mass gram when the plants are exposed at 10.0 mg·L –1 ATZ concentration . These authors also report that A.…”

“…0.018 mg per fresh mass gram when the plants are exposed at 10.0 mg•L −1 ATZ concentration. 52 These authors also report that A. caroliniana biomass was not reduced by ATZ at <1.0 mg•L −1 levels, indicating a good tolerance of the plant to the herbicide. On the other hand, for the higher dose of MP-ATZ (0.04 μmol•L −1 ), our results showed that values were statistically similar to ATZ, suggesting an early trend to improve the herbicidal effect on PSII that may be related to a time-/dose-dependent response of A. caroliniana plants and differences of the mechanism of action between the ATZ and MPs:ATZ.…”

Ecosystem services provided by freshwater macrophytes

“…The maintenance of a clear-water state by submerged macrophytes helps improve water quality in relation to eutrophication, but macrophytes benefits for water quality goes beyond this aspect. The concentrations of several inorganic and organic pollutants, including trace metals, atrazine, pharmaceuticals, pesticides and nanoparticles (Srivastava et al, 2008;Dhote & Dixit, 2009;Guimara ˜es et al, 2011;Kochi et al, 2020;Dias et al, 2021), only to cite some examples, reduce in the presence of macrophytes. The mechanisms explaining this ESs are beyond the scope of this review, but they are related to direct (e.g., absorption) and indirect (e.g., changes in the environment features, providing habitat for bacteria etc.)…”

Potential of Salvinia biloba Raddi for removing atrazine and carbendazim from aquatic environments

“…Phytoremediation has been extensively implemented for treating pesticides in wetlands systems using different helophyte species (i.e., emergent plants) (Matamoros et al 2012;Vymazal and Březinová 2015;Vryzas 2016). Yet, an alternative approach based on aquatic free-floating plants can be utilized for agrochemical remediation or biomonitoring in water bodies (Guimarães et al 2011;Della Vechia et al 2016;Escolá Casas and Matamoros 2022). In this context, two subsets of phytoremediation are particularly promising for alleviating the water contamination by crop protection products: rhizodegradation and phytodegradation.…”