Removal of perfluoroalkyl acids (PFAAs) in constructed wetlands: Considerable contributions of submerged macrophytes and the microbial community

Li, Xiaoqing; Hua, Zulin; Wu, Jian-yi; Gu, Li

doi:10.1016/j.watres.2021.117080

Cited by 86 publications

(24 citation statements)

References 62 publications

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“…Our data are in line with the results of previous greenhouse exposure experiments that have shown that plants and crops can take up considerable amounts of PFAS. − ,,− For instance, Stahl et al showed that perennial ryegrass accumulated PFOS and PFOA to different extents at four successive cuttings, which ranged from 408 to 7520 ng g dw –1 . In addition, Krippner et al demonstrated maize having a high accumulation capacity for 10 perfluoroalkyl acids (PFAA) mixture, as maize straw had a total PFAS content of around 52 000 ng g dw –1 .…”

Section: Resultssupporting

confidence: 89%

“…Recent studies have demonstrated that plants are capable of PFAS uptake via the vascular system. After uptake, PFAS can be translocated to stems, shoots, leaves, and fruits. − Studies also found that the extent of PFAS accumulation and translocation inside the plant (manifested by bioaccumulation factors, BCFs, and translocation factors, TFs, respectively) tends to decrease with increasing carbon-chain length. − Hydrophobicity or the PFAS chain length seems to have a greater impact on the root uptake and translocation than differences resulting from the functional head group. − However, target pollutants in past studies were mainly PFOS and PFOA, and their uptake and translocation patterns were only investigated among agricultural crops, − wetland plants, , and trees . Since the behaviors of accumulation vary greatly among plant species, clarifying accumulation patterns across different plant taxa is crucial to better understand plant uptake and translocation of PFAS, particularly in terms of identifying suitable candidates for phytoremediation in future work.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bioaccumulation and Translocation of 6:2 Fluorotelomer Sulfonate, GenX, and Perfluoroalkyl Acids by Urban Spontaneous Plants

Zhi

Grieger

et al. 2022

ACS EST Eng.

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There is limited information available regarding the bioaccumulation potential of polyfluoroalkyl substances (PFAS) in urban vegetation. Using a controlled greenhouse exposure setting, we investigated the bioaccumulation and translocation of select PFAS in four common urban spontaneous plants. Target compounds included legacy PFAS (perfluoroalkyl carboxylic and sulfonic acids, PFCA/PFSA), a fluorotelomer sulfonate (6:2 FTS), and an emerging fluorinated ether (i.e., hexafluoropropylene oxide dimer acid (HFPO-DA), or GenX). Results from this study showed that bioaccumulation factors in root and shoot (BCFroot and BCFshoot) ranged from 0.7 to 83.6 and 0.95 to 26.9, respectively. Phyllanthus urinaria harbored the highest PFAS bioaccumulation capacity among the four urban weed species. The log BCFroot of PFCA homologues showed a concave shape as a function of chain length, while log BCFroot of PFSA increased with chain length. The BCFroot of GenX was lower than that of PFOA; likewise, 6:2 FTS bioaccumulated to a less extent than PFOS. Root uptake seemed to be the dominant accumulation mechanism for the shorter-chain compounds, whereas adsorption was the dominant mechanism for longer-chain compounds such as PFOA. BCFroot and BCFshoot showed consistent trends in response to foliar and root characteristics. Leaf area and average root diameter were the most correlated traits with PFAS bioaccumulation factors, with higher BCF values for plants with smaller leaves and finer roots. This study also provides an important basis for the role and selection of urban weeds in future PFAS bioaccumulation and translocation studies within urban settings.

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Section: Resultssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Bioaccumulation and Translocation of 6:2 Fluorotelomer Sulfonate, GenX, and Perfluoroalkyl Acids by Urban Spontaneous Plants

Zhi

Grieger

et al. 2022

ACS EST Eng.

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“…The relative abundance of Thiobacillus also increased with iron oxide (0.23%), which was 2 times higher than that of the control group (0.11%). This bacterium was able to eliminate PFOA from wastewater via a biosorbent process .…”

Section: Resultsmentioning

confidence: 99%

“…Previous research studies confirmed that CWs were contaminated by PFAS, mainly derived from the point sources of municipal wastewater treatment plants . To date, research studies on PFAS performance in CWs have mainly focused on the toxicity and distribution of PFAS and the roles of different components, especially plants and biofilm microbes . Among the components in CWs, the substrate also plays multiple roles in the function of CWs, such as contaminant adsorption, media for plant growth, and associated microbial development.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Removal of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) in Constructed Wetlands: Iron Cycling and Microbial Mechanisms

Kang

Guo

et al. 2023

ACS EST Water

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Perfluoroalkyl substances (PFAS) are persistent and ecotoxic chemicals in aquatic environments. To date, little is known about measures for strengthening PFAS removal in constructed wetlands (CWs). In this study, the role of iron oxide and ironreducing bacteria (FeRB) in perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) removal was investigated in CWs. The removal efficiencies of PFOA and PFOS in the effluent were improved by 33.0 and 40.8%, respectively, in CWs with iron oxide and FeRB. The acetate as an intermediate product was also detected. The PFOS content was 86.7% lower at a substrate depth with poor oxygen. Almost 5.07% of PFOA and 24.6% of PFOS were absorbed by the substrate. Iron oxide increased the proportion of Proteobacteria, especially β-Proteobacteria. Increased proportions of genes that were related to iron reduction or oxidation, e.g., c-type cytochrome, reductase, and PilA, MtrC, MtrD, MshA, and FccA genes, were detected, which contributed to the iron cycle results. Meanwhile, the enhanced function of carbohydrate metabolism and greater proportions of genes involved in acetate decarboxylation (M00357; Methanosarcina and Methanothrix) played an important role in PFOA and PFOS removal. Given the increasing concerns related to PFAS, this study provides an effective and ecological in situ bioremediation method for PFAS removal.

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“…Second, this study focused on the hydrodynamics and contaminant transport in laboratory flumes, there are also some other techniques such as numerical simulation (Han et al, 2016) and field investigation (Errico et al, 2019; Lacy & Wyllie‐Echeverria, 2011) to supplement this study. In addition, the simulated plant (plastic material) was used to test the physical characteristics of flow (e.g., velocity and secondary flow), the actual vegetation (e.g., Potamogeton wrightii ) could be planted in the flume to not only investigate the flow characteristics but also some biological (e.g., microbial community influenced by the vegetation [Li et al, 2021]) and physio‐chemical properties (e.g., uptake, sorption behaviour of the vegetation‐contaminants [de la Paz et al, 2019]) of the simulated ecosystem. Given the natural confluences in river networks is more complex than the simulated experimental confluences, to conduct a systematic analysis for hydrodynamic and water quality in vegetated Y‐shaped confluence, it is encouraged to conduct a continuous series of studies including the control experiments in the lab, the field studies and numerical modelling.…”

Section: Limitations and Perspectivesmentioning

confidence: 99%

An experimental study of the hydrodynamics and contaminant transport in a Y‐shaped confluence with flexible submerged vegetation

Tong

Liu

Yang

et al. 2022

Hydrological Processes

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Vegetation greatly affects the flow characteristics and contaminant transport in river confluences. In this study, the flow characteristics and contaminant transport in the non‐vegetated/vegetated Y‐shaped confluence were explored systematically through a series of experiments. A total of 10 scenarios were designed to answer the three main research questions: what is the difference between the flow characteristics and contaminant transport in (1) asymmetrical and Y‐shaped confluences; (2) non‐vegetated/vegetated Y‐shaped confluences; (3) vegetated Y‐shaped confluences with different confluence ratios? The experimental results revealed that vegetation remarkably changes the internal flow structure in Y‐shaped confluences. Briefly, the velocity profile can be divided into three vertical layers within the vegetated system, but it remains nearly constant in the non‐vegetated channel. Vegetation changes the circulation location and reduces the intensity of the secondary current, weakening the strength of contaminant mixing. However, the turbulent kinetic energy within the vegetated system is larger than that in the non‐vegetated case, and it peaks at the top of the vegetation canopy. Under different confluence ratio cases, the overall fluctuation of the longitudinal dispersion coefficients along the cross‐sections in the mainstream was similar but increasing the confluence ratio causes the circulation to appear to advance and enhances its intensity. In addition, the vegetation density (200 item/m2) in this study render the manning roughness coefficient at 0.068, which is larger than that under lower vegetation density cases. The outcomes from this study are helpful for both environmental and river management applications.

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Removal of perfluoroalkyl acids (PFAAs) in constructed wetlands: Considerable contributions of submerged macrophytes and the microbial community

Cited by 86 publications

References 62 publications

Bioaccumulation and Translocation of 6:2 Fluorotelomer Sulfonate, GenX, and Perfluoroalkyl Acids by Urban Spontaneous Plants

Bioaccumulation and Translocation of 6:2 Fluorotelomer Sulfonate, GenX, and Perfluoroalkyl Acids by Urban Spontaneous Plants

Enhanced Removal of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) in Constructed Wetlands: Iron Cycling and Microbial Mechanisms

An experimental study of the hydrodynamics and contaminant transport in a Y‐shaped confluence with flexible submerged vegetation

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