Copper hydrophytoremediation by wetland macrophytes in semi-hydroponic and hydroponic mesocosms

Abstract

High levels of trace metals such as copper (Cu) can affect water quality and induce toxic effects on living organisms in aquatic ecosystems. This research assesses the potential capacity for Cu phytofiltration by three emergent macrophytes from Cu-contaminated sediments and water containing five concentrations of Cu (0, 50, 100, 150, and 200 µM). We conducted a greenhouse study using semi-hydroponic and hydroponic experimental conditions to simulate a natural wetland system. We selected three plant types that were collected in Quebec (Canada): native Typha latifolia, and native and, exotic Phragmites australis. Under semi-hydroponic, the responses indicated an almost 3-fold higher mean root Cu-accumulation from Cu-0 to Cu-Sediment (80.3–226.1 mg kg⁻¹) and an 8.6-fold increase (122.2–1045.5 mg kg⁻¹) for Cu-0 to Cu-200 µM under hydroponic conditions, resulting in Cu translocation < 1 and BCF >1 under both conditions. We found an inverse correlation between increasing doses of Cu with mean aboveground and belowground biomass together with height, and root length of selected plants under hydroponic conditions. Our results indicate that these wetland macrophytes could be useful in heavy-metal removal from Cu-contaminated sediments and Cu-enriched water.

NOVELTY STATEMENT

Studies in wetland phytoremediation have focus on either contaminated soil or water. This research highlights the comparison of three emergent macrophytes in removing copper from both soil (a simulated riparian wetland) and water (floating treatment wetland). This study compares the phytoextraction and rhizofiltration capacity of Typha latifolia, with native versus exotic Phragmites australis with a translocation factor for Cu < 1 and bioconcentration factor > 1 in the Cu-Sediment and Cu-enriched water.

Keywords:

• Accumulation
• translocation factor
• macrophytes
• phytostabilization

Acknowledgments

The authors are deeply grateful to François Larochelle and Marie-Andrée Paré for their assistance in the greenhouse and with the research. The authors are indebted to research professional Marie-Eve Beaulieu for logistic and technical assistance. Thanks, also due to Degi Harja Asmara, Chantal Giroux for the help with statistical analysis, and Alain Brousseau for chemical analysis of plant tissues.

Disclosure statement

No potential conflicts of interest were reported by the author(s).

Additional information

Funding

This work was funded by IC-IMPACTS, Canada-India Research Centre of Excellence under grants 111809 and 121872. Support was also provided by Spark of Hope Foundation (Toronto), F.K. Morrow Foundation Fellowships - Forest Biology and Economics, and an NSERC Discovery grant to DPK.