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Impact of clogging on accumulation and stability of phosphorus in the subsurface flow constructed wetland.
- Source :
-
Chemosphere . Feb2023, Vol. 313, pN.PAG-N.PAG. 1p. - Publication Year :
- 2023
-
Abstract
- Substrate clogging is one of the major operation challenges of subsurface flow constructed wetlands (SSF-CWs). And the phosphorus (P) removal performance and stability of P accumulation of SSF-CWs would be varied with the development of substrate clogging. In this study, three horizontal SSF-CWs microcosms with different clogging degrees were conducted to explore the mechanism of P accumulation behavior influenced by substrate clogging. Increase in clogging degree resulted in hydraulic retention time (HRT) diminution and adsorption sites increase, which jointly led to reduced P removal efficiency at low clogging degree (L-CW), however, higher P removal efficiency was obtained as adsorption sites increase offset HRT diminution at high clogging degree (H-CW). Substrate adsorption was the primary removal pathway in all SSF-CW systems. It accounted for 77.86 ± 2.63% of the P input in the H-CW, significantly higher than the control (60.08 ± 4.79%). This was attributed to a higher proportion of Fe/Al–P accumulated on the substrate of H-CW, since clogging aggravated the anaerobic condition and promoted the generation of Fe ions. The increase in clogging degree also elevated the release risk of the accrued P in SSF-CWs, since Fe/Al–P was considered bioavailable and readily released under environmental disturbance. The obtained results provide new insights into the P transport and transformation in SSF-CWs and would be helpful to optimize substrate clogging management. [Display omitted] • Clogging aggravated anaerobic condition in SSF-CWs and promoted Fe remobilization. • Newly generated Fe ions precipitation with dissolved P affected P fraction. • Clogging improved P removal as adsorption sites increase offset HRT diminution. • Fe/Al–P accumulation caused by clogging elevated P release risk of SSF-CWs. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00456535
- Volume :
- 313
- Database :
- Academic Search Index
- Journal :
- Chemosphere
- Publication Type :
- Academic Journal
- Accession number :
- 161141985
- Full Text :
- https://doi.org/10.1016/j.chemosphere.2022.137429