Phytofiltration of As³⁺, As⁵⁺, and Hg by the aquatic macrophyte Potamogeton pusillus L, and its potential use in the treatment of wastewater

ABSTRACT

The aim of this paper was to investigate the capacity of the aquatic macrophyte Potamogeton pusillus to remove As³⁺, As⁵⁺, and Hg from aqueous solutions. The plants were exposed to 0 mg.L⁻¹, 0.1 mg.L⁻¹, 0.5 mg.L⁻¹, 1 mg.L⁻¹, or 2 mg.L⁻¹ of As³⁺, As⁵⁺, and Hg for 20 days. The results obtained for the individual removal of As³⁺, As⁵⁺, and Hg from water solutions, together with their accumulation in P. pusillus, indicate that this plant can be effectively used for the removal of Hg and of moderate concentrations of As³⁺ or As⁵⁺ (0.1 mg.L⁻¹) from aquatic systems. Roots and leaves accumulated the highest amount of As when the plant was exposed to As⁵⁺, but when it was exposed to As³⁺, the root accumulated the highest amount of As, and the leaves, the highest amount of Hg. When compared to other aquatic plants species, the results showed that P. pusillus demonstrated a higher Hg accumulation (2465 ± 293 µg.g⁻¹) when the transfer coefficient was 40,580 ± 3762 L.kg ⁻¹, showing the great potential of this macrophyte for phytoremediation of water contaminated with Hg. To the extent of our knowledge, this is the first report on bioaccumulation of As³⁺, As⁵⁺, and Hg by P. pusillus.

KEYWORDS:

• aquatic plant
• bioaccumulation
• metal
• metalloid
• photosynthesis

Acknowledgments

Authors would like to acknowledge grants and fellows from the Agencia Nacional de Promoción Científica y Técnica (FONCyT/PICT-1597 and FONCyT/PICT-1411), CONICET (National Research Council), and Secretaría de Ciencia y Tecnología from the National University of Córdoba (Argentina). The present work is part of the PhD thesis of J. Griboff, who gratefully acknowledges fellowship from CONICET. We acknowledge the assistance of Mg. Joaquín Gastaminza during sample measurement in ICP-MS.

Supporting information is shown in Figure S1: Time-dependent removal of As³⁺, As⁵⁺ and Hg from aqueous solutions by P. pusillus; Figure S2: Contents of total proteins in P. pusillus exposed to different concentrations of As³⁺, As⁵⁺and Hg; and Table S1:Bioconcentration factor (BCF) for As³⁺, As⁵⁺ and Hg in P. pusillus.

Additional information

Funding

CONICET (National Research Council), Secretar de Ciencia y Tecnología, and Agencia Nacional de Promoción Científica y Técnica, FONCyT/PICT-1597 and FONCyT/PICT-1411.