Reactive transport simulation in a tropical horizontal subsurface flow constructed wetland treating domestic wastewater

A promising approach to the simulation of flow and conversions in the complex environment of horizontal subsurface flow constructed wetlands (HSSF-CWs) is the use of reactive transport models, in which the transport equation is solved together with microbial growth and mass-balance equations for sub...

Full description

Saved in:

Bibliographic Details
Published in:	The Science of the total environment Vol. 449; pp. 309 - 319
Main Authors:	Mburu, N., Rousseau, D.P.L., van Bruggen, J.J.A., Thumbi, G., Llorens, E., García, J., Lens, P.N.L.
Format:	Journal Article
Language:	English
Published:	Kidlington Elsevier B.V 01-04-2013 Elsevier
Subjects:	Applied sciences Biological and medical sciences Biological treatment of waters Biotechnology Computer simulation Construction CWM1-RETRASO Degradation Environment and pollution Exact sciences and technology Fundamental and applied biological sciences. Psychology Horizontal Horizontal subsurface flow constructed wetland Industrial applications and implications. Economical aspects Mathematical models Mechanistic models Microorganisms Other wastewaters Pollution Reactive transport Transformations Wastewaters Water treatment and pollution Wetlands Mechanistic models CWM1-RETRASO Horizontal subsurface flow constructed wetland Reactive transport Theoretical study Modeling Horizontal subsurface flow constructed Pilot plant scale Biological purification Transport process Domestic waste water Artificial medium Waste water purification Mathematical model Wetland
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	A promising approach to the simulation of flow and conversions in the complex environment of horizontal subsurface flow constructed wetlands (HSSF-CWs) is the use of reactive transport models, in which the transport equation is solved together with microbial growth and mass-balance equations for substrate transformation and degradation. In this study, a tropical pilot scale HSSF-CW is simulated in the recently developed CWM1-RETRASO mechanistic model. The model predicts organic matter, nitrogen and sulfur effluent concentrations and their reaction rates within the HSSF-CW. Simulations demonstrated that these reactions took place simultaneously in the same (fermentation, methanogenesis and sulfate reduction) or at different (aerobic, anoxic and anaerobic) locations. Anaerobic reactions occurred over large areas of the simulated HSSF-CW and contributed (on average) to the majority (68%) of the COD removal, compared to aerobic (38%) and anoxic (1%) reactions. To understand the effort and compare computing resources needed for the application of a mechanistic model, the CWM1-RETRASO simulation is compared to a process-based, semi-mechanistic model, run with the same data. CWM1-RETRASO demonstrated the interaction of components within the wetland in a better way, i.e. concentrations of microbial functional groups, their competition for substrates and the formation of intermediary products within the wetland. The CWM1-RETRASO model is thus suitable for simulations aimed at a better understanding of the CW system transformation and degradation processes. However, the model does not support biofilm-based modeling, and it is expensive in computing and time resources required to perform the simulations. ► A tropical HSSF-CW is simulated in the recently developed CWM1-RETRASO model. ► CWM1-RETRASO efficiency was inferred by comparison with a semi-mechanistic model. ► CWM1-RETRASO elucidates transformation and degradation processes in HSSF-CW. ► COD degradation pathways happen simultaneously at different or same locations. ► Anaerobic reactions are the dominant COD degradation processes within the HSSF-CW.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0048-9697 1879-1026
DOI:	10.1016/j.scitotenv.2013.01.069