Greenhouse gas emissions and wastewater treatment performance by three plant species in subsurface flow constructed wetland mesocosms

Chen, Xin, Zhu, Hui, Yan, Baixing, Shutes, R. Brian E., Xing, Defeng, Banuelos, Gary, Cheng, Rui and Wang, Xinyi (2020) Greenhouse gas emissions and wastewater treatment performance by three plant species in subsurface flow constructed wetland mesocosms. Chemosphere, 239 , 124795. ISSN 0045-6535 (doi:10.1016/j.chemosphere.2019.124795)

Abstract

Greenhouse gas (GHG) emissions from constructed wetlands (CWs) have raised environmental concern and thus offset their environmental and ecological benefits. This study evaluated the influence of plant species, i.e., Canna indica (C. indica), Cyperus alternifolius (C. alternifolius), Phragmites australis (P. australis) and unplanted control, on GHG emissions, pollutant removal and associated microbial abundance in subsurface flow constructed wetland (SSFCW) mesocosms. C. indica outperformed the other tested plant species in pollutant removal, and the presence of plants irrespective of species enhanced the removal efficiencies of nitrogen, phosphorus and organics in SSFCW mesocosms compared to unplanted control. The greatest carbon dioxide (CO ) flux (582.01 ± 89.25 mg/m /h), methane (CH ) flux (21.88 ± 2.51 μg/m /h) and nitrous oxide (N O) flux (37.27 ± 15.82 μg/m /h) were observed in mesocosms planted with C. indica, P. australis and C.alternifolius, respectively. Unexpectedly, the mcrA and pmoA genes were not detected in any mesocosms. For denitrifiers, the N O fluxes showed a significantly (p < 0.05) positive correlation with nirS and nirK genes abundance. The abundance of nosZ gene (ranged from 0.18 × 10 to 0.75 × 10 copies/mg gravel) and nosZ/(nirS + nirK) (ranged from 1.29 × 10 to 2.12 × 10 copies/mg gravel) in this study was lower than that in most reported studies. Regarding the global warming potential (GWP), the lowest value was observed in mesocosms planted with C. indica. In conclusion, C. indica is selected as the optimal plant species in this study due to its lower GWP and excellent pollutant removal performance. [Abstract copyright: Copyright © 2019 Elsevier Ltd. All rights reserved.]

Item Type: Article
Keywords (uncontrolled): Functional genes abundance, Greenhouse gas emissions, Plant optimization, Subsurface flow constructed wetlands, Water purification
Research Areas: A. > School of Science and Technology > Natural Sciences
Item ID: 27677
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Depositing User: Jisc Publications Router
Date Deposited: 02 Oct 2019 19:43
Last Modified: 11 Nov 2019 08:38
URI: https://eprints.mdx.ac.uk/id/eprint/27677

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