Perfluoroalkyl and polyfluoroalkyl substances removal in a full-scale tropical constructed wetland system treating landfill leachate
| Autor: | Karina Yew-Hoong Gin, Yiliang He, Martin Reinhard, Huiting Chen, Tingru Yin, Xinzhu Yi |
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| Rok vydání: | 2017 |
| Předmět: |
Geologic Sediments
Environmental Engineering 0211 other engineering and technologies Carboxylic Acids 02 engineering and technology 010501 environmental sciences Reed bed 01 natural sciences Soil Water Pollution Chemical Leachate Fluorotelomer Waste Management and Disposal Groundwater 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering 021110 strategic defence & security studies Fluorocarbons Singapore Sulfonamides Chemistry Ecological Modeling Water Biodegradation Sedimentation Plants Pollution Biodegradation Environmental Environmental chemistry Wetlands Constructed wetland Aeration Surface water Water Pollutants Chemical Environmental Monitoring |
| Zdroj: | Water research. 125 |
| ISSN: | 1879-2448 |
| Popis: | Landfill leachate is often an important source of emerging organic contaminants including perfluoroalkyl and polyfluoroalkyl substances (PFASs) requiring proper treatment to protect surface water and groundwater resources. This study investigated the occurrence of PFASs in the leachate of a capped landfill site in Singapore and the efficacy of PFASs removal during flow through a constructed wetland (CW) treatment system. The CW treatment system consists of equalization tank, aeration lagoons, sedimentation tank, reed beds and polishing ponds. Target compounds included 11 perfluoroalkyl acids (PFAAs) (7 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkane sulfonates (PFSAs)) and 7 PFAA precursors. Although total PFASs concentrations in the leachate varied widely (1269 to 7661 ng/L) over the one-year sampling period, the PFASs composition remained relatively stable with PFCAs consistently being predominant (64.0 ± 3.8%). Perfluorobutane sulfonate (PFBS) concentrations were highly correlated with total PFASs concentrations and could be an indicator for the release of PFASs from this landfill. The release of short-chain PFAAs strongly depended on precipitation whereas concentrations of the other PFASs appeared to be controlled by partitioning. Overall, the CW treatment system removed 61% of total PFASs and 50–96% of individual PFASs. PFAAs were removed most efficiently in the reed bed (42–49%), likely due to the combination of sorption to soils and sediments and plant uptake, whereas most of the PFAA precursors (i.e. 5:3 fluorotelomer carboxylate (5:3 acid), N-substituted perfluorooctane sulfonamides (N-MeFOSAA and N-EtFOSAA)) were removed in the aeration lagoon (>55%) by biodegradation. The sedimentation tank and polishing ponds were relatively inefficient, with only 7% PFASs removal. |
| Databáze: | OpenAIRE |
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