Hydraulic behaviour of horizontal subsurface flow constructed wetlands with different aspect ratio and granular medium size

García, Joan; Chiva, Jordi; Aguirre, Paula; Álvarez, Eduardo; Sierra, Joan Pau; Mujeriego, Rafael

doi:10.1016/j.ecoleng.2004.09.002

Cited by 94 publications

(52 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the past, much of the design of CWS has been done with little knowledge of (or consideration for) the roles played by each component and how their effects could be enhanced and optimized. However, over the most recent years some accumulated knowledge has been increasingly applied in the construction and operation of new systems, which results in a much greater variety of plant species, support matrix materials and constructed wetland designs being seen, studied and introduced in newly set up CWS [35,42,43,58,60,[73][74][75][76][77][78][79][80][81][82][83][84][85]. The goals of the target contaminants to remove in those CWS have also become increasingly more ambitious.…”

Section: Removal Of Organic Xenobiotics In Cwsmentioning

confidence: 99%

Organic xenobiotics removal in constructed wetlands, with emphasis on the importance of the support matrix

Dordio

Carvalho

2013

Journal of Hazardous Materials

196

View full text Add to dashboard Cite

Section: Removal Of Organic Xenobiotics In Cwsmentioning

confidence: 99%

Organic xenobiotics removal in constructed wetlands, with emphasis on the importance of the support matrix

Dordio

Carvalho

2013

Journal of Hazardous Materials

196

View full text Add to dashboard Cite

“…Preferential flow paths in the subsurface, for instance, can lead to considerable variability in the HRT. The heterogeneity of the filtering media is due to multiple factors, including (i) changes in porosity and (ii) grain size distribution, (iii) presence of plant roots and rhizomes, (iv) biological, physical and chemical clogging and (v) variations induced by different packing and compaction of the bed (Persson et al, 1999;Rash and Liehr, 1999; 5 García et al, 2004;Małoszewski et al, 2006;Kjellin et al, 2007;Brovelli et al, 2009;Leverenz et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Design methodology accounting for the effects of porous medium heterogeneity on hydraulic residence time and biodegradation in horizontal subsurface flow constructed wetlands

Brovelli

Carranza-Díaz

Rossi

et al. 2011

Ecological Engineering

View full text Add to dashboard Cite

Horizontal flow constructed wetlands are engineered systems capable of eliminating a wide range of pollutants from the aquatic environment. Nevertheless, poor hydrodynamic behavior is commonly found resulting in preferential pathways and variations in both (i) the hydraulic residence time distribution (HRTD) and, consequently, (ii) the wetland's treatment efficiency. The aim of this work was to outline a methodology for wetland design that accounts for the effect of heterogeneous hydraulic properties of the porous substrate on the HRTD and treatment efficiency. Biodegradation of benzene was used to illustrate the influence of hydraulic conductivity heterogeneity on wetland efficiency. Random, spatially correlated hydraulic conductivity fields following a log-normal distribution were generated

show abstract

“…Na implantação dos SACs em estudo, optou-se por dividir, com muretas de concreto, uma área vegetada total de 24 m por 4 m nas quatro unidades da estação. Os números de dispersão obtidos, na ordem de 0,040, sugerem que o movimento dos traçadores no sistema foi governado por processos advectivos e dispersivos, de maneira semelhante às observadas em outros SACs de escoamento subsuperficial, tal como observado por GARCÍA et al (2004). Outra observação importante é que, no caso estudado, o número obtido pela equação de SPERLING (2002), que iguala d à razão B/L, é equivalente a 0,041, o que indica haver grande correlação com os dados obtidos via perfis de DTR.…”

Section: Resultsunclassified

Uso de traçadores para avaliação da hidrodinâmica de sistemas alagados construídos operando sob condições climáticas tropicais

Borges¹,

Matos²,

Calijuri

et al. 2009

Eng. Agríc.

View full text Add to dashboard Cite

RESUMO:Sistemas alagados construídos (SACs) são, atualmente, importante opção para o tratamento de resíduos e controle da poluição pontual e difusa. O uso de SACs tem aumentado ano a ano, entretanto o nível de entendimento da hidrodinâmica do processo não tem crescido na mesma proporção. Traçadores fluorescentes apresentam-se como opção na determinação de curvas de distribuição de tempos de residência (DTR) e de parâmetros hidrodinâmicos, como número de dispersão e eficiência hidráulica. A pesquisa foi realizada com o objetivo de avaliar dois corantes (rodamina WT e fluoresceína sódica) na determinação das características hidrodinâmicas de SACs com escoamento subsuperficial, operando em região de clima tropical. Os tempos de residência experimentais (τ R ) para os SACs variaram entre 4,5 e 5,0 dias, e os parâmetros de modelos teóricos foram obtidos para cada sistema, indicando dispersões muito pequenas. Os SACs, que apresentavam relação comprimento/largura (L/B) de 24/1, comportaram-se como sistemas de escoamento próximo ao pistonado. Embora a massa total adicionada não tenha sido recuperada (a adsorção é um dos mecanismos de perda), a pesquisa indicou que a rodamina WT pode ser utilizada com resultados satisfatórios na avaliação do comportamento hidrodinâmico de SACs. PALAVRAS-CHAVE:comportamento hidrodinâmico, distribuição de tempos de residência, fluoresceína sódica, número de dispersão, rodamina WT, wetlands construídas. FLUORESCENT DYES FOR HYDRODYNAMIC EVALUATION OF CONSTRUCTED WETLANDS UNDER TROPICAL CONDITIONSABSTRACT: Nowadays, constructed wetlands (CW) systems are an important wastewater treatment option. Subsurface flow (SSF) constructed wetlands are one of the main types which are being used, and in researches, these systems dyes tracer experiments are an appropriate tool to determine residence time distribution (RDT) curves and parameters of hydrodynamic models, as a wetland dispersion numbers and hydraulic efficiency. The objectives of this paper are to evaluate and compare the performance of two fluorescent tracers (rhodamine WT and sodium fluorescein) on subsurface-flow CWs hydrodynamic characteristics determination. The cells were operated at actual hydraulic residence time (τ R ) of a 4.5 d ~ 5.0 d range and the parameters of theoretical models were obtained for each system, indicating very low dispersion. The CWs with length/widths ratio equals to 24 presented as plug flow near systems. Although the recovery of total amount was small (high absorption is one of the loss mechanisms during these types of studies), rhodamine WT is a suitable tracer in mesocosms SSF constructed wetland systems of study.

show abstract

Hydraulic behaviour of horizontal subsurface flow constructed wetlands with different aspect ratio and granular medium size

Cited by 94 publications

References 10 publications

Organic xenobiotics removal in constructed wetlands, with emphasis on the importance of the support matrix

Organic xenobiotics removal in constructed wetlands, with emphasis on the importance of the support matrix

Design methodology accounting for the effects of porous medium heterogeneity on hydraulic residence time and biodegradation in horizontal subsurface flow constructed wetlands

Uso de traçadores para avaliação da hidrodinâmica de sistemas alagados construídos operando sob condições climáticas tropicais

Contact Info

Product

Resources

About