On-Site and Full-Scale Applications of Phytoremediation to Repair Aquatic Ecosystems with Metal Excess

Effect of the combined addition of Zn and Pb on partitioning in sediments and their accumulation by the emergent macrophyte Schoenoplectus californicus

“…For zinc, the BCF values obtained in this study increased when the Zn concentration of the sediment also increased, and it was always close to unity. Other emergent macrophytes living in a wide range of Zn sediment concentrations-from 28.5 to 5400 μg Zn/g-also show similar behavior (de Cabo et al 2015).…”

“…Nevertheless, the aging of contaminated sediments leads to the formation of more stable bonds and therefore their association to less mobile geochemical phases, usually decreasing their bioavailability over time (Zhong and Wang 2006;Fan et al 2014). Although high levels of metals are reported in wetland sediments, their low bioavailability and limited transfer to the water column determine that macrophytes of the littoral zone typically exhibit relatively low concentrations of these contaminants (de Cabo et al 2015).…”

“…The BCF derives from the ratio of metal concentration in plant biomass or tissue to metal concentration in the substrate (sediment or water) depending on which is the main structure of accumulation in the plant and the growth substrate (Yoon et al 2006;Zhuang et al 2007;Ladislas et al 2012;Ali et al 2013;Mendoza et al 2015;Oyuela Leguizamo et al 2016;Türker et al 2016;Bonanno et al 2017). Due to emergent macrophytes that mainly accumulate metals in roots (de Cabo et al 2015) and in all cases TF was lower than unity and more than 99% of added metals were associated to sediments, the BCF was calculated in this work as the ratio of metal concentration in roots to the concentration of metal in sediment. For zinc, the BCF values obtained in this study increased when the Zn concentration of the sediment also increased, and it was always close to unity.…”

“…Wetlands usually provide a natural mechanism that diminishes the transport of toxic compounds to other compartments of the ecosystem. This approach usually relies on Bphytostabilization,t he use of plants to immobilize heavy metals and store them in belowground tissues and/or soil which is conducted especially by emergent macrophytes (de Cabo et al 2015). The extent of uptake and the distribution of metals within the plant may have a significant effect on their residence time and potential release.…”

“…Numerous marshes in Argentina are covered by S. californicus. Several studies have demonstrated its ability to maintain ecological functions in marshes, to incorporate important quantities of carbon from the atmosphere into biomass, to protect shorelines, and to tolerate high levels of heavy metals (Arreghini et al 2001;Villar et al 2001;Kandus et al 2010;de Cabo et al 2015). Tolerance is conferred by specific physiological mechanisms which effectively enable it to function normally even in the presence of high concentrations of potentially toxic elements (Baker 1987).…”