Potential use of floating treatment wetlands established with Canna flaccida for removing organic contaminants from surface water

Abstract

Surface water bodies worldwide may be contaminated with various organic contaminants. In many cases, the actual toxicity thresholds to nontarget organisms are unknown, thus presenting unknown risks. This study evaluated the potential use of floating treatment wetlands (FTWs) planted with Canna flaccida (common name: Canna) for removing two pharmaceuticals (acetaminophen and carbamazepine) and one herbicide (atrazine) from contaminated water. Triplicate FTWs with varying plant densities were established in 378 L mesocosms. After dosing the mesocosms with the contaminants, water samples were collected over a 12-week period for analysis. The planted FTWs showed differing abilities for removing acetaminophen, atrazine, and carbamazepine. Plant densities on the FTWs did not affect dissipation of acetaminophen or atrazine, but did carbamazepine. All acetaminophen residues were removed from the water within 2 weeks, while all atrazine residues were removed within 12 weeks. Approximately, 79À92% of these residues removed were associated with the FTWs. In contrast, all of the carbamazepine was not removed after 12 weeks, at which time only 29-36.7% of the total removed was associated with the FTWs. Overall results suggest that FTWs established with C. flaccida are promising for removing trace concentrations of acetaminophen, atrazine, and carbamazepine from surface water.

Artificial wetlands and floating islands: Use of macrophytes

“…Surface water bodies around the world can be contaminated with various pollutants. In many cases, the actual toxicity thresholds for non-target organisms are unknown, presenting unknown risks (REINOSO et al, 2017;DE OLIVEIRA et al, 2019;HWANG et al, 2020). Many of the chemicals used in daily life are eventually found in environmental compartments and many of those products expand the list of unregulated chemical compounds, known as emerging pollutants or organic micro pollutants, some pollutants are listed in Table 3.…”

“…The Surface flow systems planted with Eichornia crassipes and Vertical Flow systems planted with Heliconia rostrata removed 97 and 89% of caffeine and ibuprofen, respectively. The performance between the macrophyte systems in the mesocosm units showed potential to eliminate emerging compounds (HWANG et al, 2020). and four biocides (DEET, TCS, CBD, and MP) in the influent (mixture composed of domestic sew-age and livestock wastewater from a small village) in concentrations ranging from 30.5 ± 1.25 ng/L to 105 ± 5.14 ng/L and from 63.4 ± 2.85 ng/L to 515 ± 19.7 ng/L, respectively.…”

Phytoremediation by ornamental plants: a beautiful and ecological alternative

“…Plant height, stem diameter, and leaf area index are also positively related to the tolerance and accumulation of contaminants, since the impact on photosynthesis and biomass production influences the volatilization and excretion of contaminants during detoxification (Liu et al 2018a). For example, in constructed wetlands, the ideal species are those with broad leaves and a dense root system; these characteristics increase the plant transpiration surface and efficient distribution of the roots in the water column, assuring great uptake and removal of contaminants from water (Hwang et al 2020). Similarly, these characteristics are also observed during screening of plants for soil decontamination.…”

“…Similarly, Canna flaccida Salisb. removed all acetaminophen (5905.5 mg L −1 ) residues from water in two weeks, and all atrazine residues (226.5 µg ml −1 ) -a herbicide used on a large scale -in 12 weeks of treatment (Hwang et al 2020). In the same way, the sunflower (H. annus) completely removed ibuprofen (15 mg L −1 ) in 48 h and 50% of acetaminophen (15 mg L −1 ) after 96 h of water treatment, while the uptake of the anticonvulsant carbamazepine (15 mg L −1 ) was 30% in 96 h (Ryšlavá et al 2015).…”

“…As biotechnology, phytoremediation uses the potential of plants to remove pollutants and contaminants from the environment, which occurs through different processes such as phytoextraction, phytostabilization, phytodegradation, and phytovolatilization (Hwang et al 2020) In phytoextraction, the most well-known technique (Asgari Lajayer et al 2019), plants uptake and concentrate contaminants in their harvestable biomass, while phytodegradation occurs with mineralization of the contaminant inside plants or at the soilroot interface (with the help of microorganisms), normally decreasing its toxicity (Liu et al 2018b). Through the phytostabilization process, plants immobilize contaminants in the rhizosphere by its lignification or humidification (Lee et al 2020).…”