Macrophyte Potential to Treat Leachate Contaminated with Wood Preservatives: Plant Tolerance and Bioaccumulation Capacity

• Published in: Plants (Basel) 2020-12, Vol.9 (12), p.1774-15
• Main Authors: Demers, Emmanuelle, Kõiv-Vainik, Margit, Yavari, Sara, Mench, Michel, Marchand, Lilian, Vincent, Julie, Frédette, Chloé, Comeau, Yves, Brisson, Jacques
• Format: Article
• Language: English
• Subjects: Aquatic plants; Arsenates; Arsenic; Bioaccumulation; Biodegradation; Biomass; chlorinated phenols; Chromated copper arsenate; Chromates; constructed treatment wetland; Contaminants; Contamination; Copper arsenate; Copper chrome arsenate; Environmental impact; Environmental Sciences; Flowers & plants; Leachates; Macrophytes; Microorganisms; Pentachlorophenol; Phalaris arundinacea; Phenols; phytoremediation; Phytotoxicity; Plant biomass; Pollutants; Preservatives; Soil contamination; Soil water; Typha angustifolia; Water tanks; Wetlands; Wood preservatives
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants9121774

Pentachlorophenol and chromated copper arsenate (CCA) have been used worldwide as wood preservatives, but these compounds can toxify ecosystems when they leach into the soil and water. This study aimed to evaluate the capacity of four treatment wetland macrophytes, , , and two subspecies of , to tolerate and treat leachates containing wood preservatives. The experiment was conducted using 96 plant pots in 12 tanks filled with three leachate concentrations compared to uncontaminated water. Biomass production and bioaccumulation were measured after 35 and 70 days of exposure. There were no significant effects of leachate contamination concentration on plant biomass for any species. No contaminants were detected in aboveground parts of the macrophytes, precluding their use for phytoextraction within the tested contamination levels. However, all species accumulated As and chlorinated phenols in belowground parts, and this accumulation was more prevalent under a more concentrated leachate. Up to 0.5 mg pentachlorophenol/kg (from 81 µg/L in the leachate) and 50 mg As/kg (from 330 µg/L in the leachate) were accumulated in the belowground biomass. Given their high productivity and tolerance to the contaminants, the tested macrophytes showed phytostabilization potential and could enhance the degradation of phenols from leachates contaminated with wood preservatives in treatment wetlands.