Analysis of hydrodynamic characteristics of a horizontal subsurface flow constructed wetland

Albuquerque, António; Bandeiras, Rodrigo

Publication

Analysis of hydrodynamic characteristics of a horizontal subsurface flow constructed wetland

2007-11-15Book part

dc.contributor.author	Albuquerque, António
dc.contributor.author	Bandeiras, Rodrigo
dc.date.accessioned	2022-07-14T09:25:50Z
dc.date.available	2022-07-14T09:25:50Z
dc.date.issued	2007-11-15
dc.description.abstract	Horizontal subsurface flow (HSSF) constructed wetlands are widely used for wastewater treatment but there’s still a lack of information on flow characteristics changes throughout the porous bed over time. The continuous growth of roots, the adsorption, sedimentation and precipitation of wastewater compounds and the biofilm release over operation time leads to the development of stagnated areas, the appearance of hydraulic short-circuiting and variations in dispersion conditions, which affect substrate distribution throughout the bed and, therefore, may worsen the overall performance of the system. In order to enable a better understanding of the transport mechanisms throughout the bed, two series of tracer tests were performed in a laboratory HSSF system at the hydraulic loading of 4.7x10-3 m3 m-2 h-1. The first series was executed with the bed without vegetation and the second with the bed already colonized with Phragmites australis after an operation period of eight months at an average organic loading of 12 g m-2 d-1 COD. The magnitude of longitudinal dispersion was estimated both by a curve- fitting technique using the non-linear least square optimization method (LSOM) and using the moment method (MOM) over the advection-dispersion-reaction equation. The flow regime and the extension of dead volumes were estimated by the same curve-fitting technique over the multiple tanks in series model (MTS). The results showed that the development of plants and biomass did not contribute for a significant amount of longitudinal dispersion in the overall media length. However, the dispersion was very strong in the inlet section, where the dead volumes increased approximately 65% within the colonized bed. The flow regime may be considered as plug flow throughout the overall length and the tracer retention was associated with dispersion and internal recirculation and, additionally, for Series II it was associated with the occurrence of clusters of biomass and roots. The MTS better explain the tracer results for the overall media length. The MOM seems to be inadequate for estimating Pe leading to underestimated values when compared with the ones calculated by LSOM.	pt_PT
dc.description.version	info:eu-repo/semantics/publishedVersion	pt_PT
dc.identifier.citation	ALBUQUERQUE A. e BANDEIRAS R. (2007). Analysis of hydrodynamic characteristics of a horizontal subsurface flow constructed wetland. In Water Pollution in Natural Porous Media at Different Scales, L. Candela, I. Vadillo, P. Aagaard, E. Bedbur, M. Trevisan, M. Vanclooster, P. Viotti e J. Lopez-Geta (Eds.), Instituto Geologico Y Minero de Espana, Serie nº 22: Hidrogeologia Y Aguas Subterraneas, Madrid, Espanha, 329-338 (ISBN: 978 8 47840 676 0; ISBN 84 7840 676 X)	pt_PT
dc.identifier.isbn	978-84-7840-676-0
dc.identifier.uri	http://hdl.handle.net/10400.6/12287
dc.language.iso	eng	pt_PT
dc.peerreviewed	yes	pt_PT
dc.publisher	Instituto Geologico Y Minero de Espana	pt_PT
dc.rights.uri	http://creativecommons.org/licenses/by-nc/4.0/	pt_PT
dc.subject	Hydrodynamic characteristics	pt_PT
dc.subject	HSSF constructed wetland	pt_PT
dc.subject	Dispersion	pt_PT
dc.subject	Deda volumes	pt_PT
dc.title	Analysis of hydrodynamic characteristics of a horizontal subsurface flow constructed wetland	pt_PT
dc.type	book part
dspace.entity.type	Publication
oaire.citation.conferencePlace	Madrid, Espanha	pt_PT
oaire.citation.endPage	338	pt_PT
oaire.citation.issue	22	pt_PT
oaire.citation.startPage	329	pt_PT
oaire.citation.title	Water Pollution in Natural Porous Media at Different Scales, L. Candela, I. Vadillo, P. Aagaard, E. Bedbur, M. Trevisan, M. Vanclooster, P. Viotti e J. Lopez-Geta (Eds.).	pt_PT
person.familyName	Carvalho de Albuquerque
person.givenName	Antonio João
person.identifier	1284649
person.identifier.ciencia-id	3319-F1FE-0DA8
person.identifier.orcid	0000-0001-7099-0685
person.identifier.rid	C-9293-2009
person.identifier.scopus-author-id	8892509700
rcaap.rights	openAccess	pt_PT
rcaap.type	bookPart	pt_PT
relation.isAuthorOfPublication	9f533b0c-b538-4535-ade3-823df5592b88
relation.isAuthorOfPublication.latestForDiscovery	9f533b0c-b538-4535-ade3-823df5592b88