title: Effect of key design parameters on bacteria community and effluent pollutant concentrations in constructed wetlands using mathematical models.
abstract: Constructed wetlands are currently recognized as an effective environmental biotechnology for wastewater treatment, but the influence of their design parameters on internal functioning and contaminant removal efficiency is still under discussion. In this work, the effect of aspect ratio and water depth on bacteria communities as well as treatment efficiency of horizontal subsurface flow constructed wetlands (HSSF) under the Mediterranean climate was evaluated, using a mathematical model. For this purpose, experimental results from four pilot-scale wetlands of equal surface area but different aspect ratios and water depth were used. The HSSF system was fed with municipal wastewater. The experimental data were simulated using the BIO_PORE model, developed in the COMSOL Multiphysics™ platform. Simulations with the BIO_PORE model fitted well to the experimental results, showing a higher removal efficiency for the shallower HSSF for COD (93.7% removal efficiency) and ammonia nitrogen (73.8%). The aspect ratio had a weak relationship with the bacteria distribution and the removal efficiency. In contrast, the water depth was a factor. The results of the present study confirm a previous hypothesis in which depth has an important impact on the biochemical reactions causing contaminants transformation and degradation.
authors.affiliation: Research Group on Hydroecology, School of Civil Engineering, Universidad de Castilla-La Mancha, Av. Camilo José Cela s/n, E-13170 Ciudad Real, Spain. Electronic address: david.sanchezramos@uclm.es.
authors.forename: David
authors.initials: D
authors.lastname: Sanchez-Ramos
authors.affiliation: GEMMA - Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona, 1-3, Building D1, E-08034 Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Agulló
authors.affiliation: IRSTEA, Freshwater Systems, Ecology and Pollution Research Unit, 5 rue de la Doua, CS70077, F-69626 Villeurbanne cedex, France. Electronic address: roger.samso@irstea.fr.
authors.forename: Roger
authors.initials: R
authors.lastname: Samsó
authors.affiliation: GEMMA - Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona, 1-3, Building D1, E-08034 Barcelona, Spain. Electronic address: joan.garcia@upc.edu.
authors.forename: Joan
authors.initials: J
authors.lastname: García
mesh_terms: D001419:Bacteria; D008962:Models, Theoretical; D009584:Nitrogen / Q000032:analysis; D014865:Waste Disposal, Fluid; D062065:Wastewater; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D009584:Nitrogen; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Aspect ratio; BIO_PORE; CWM1; Depth; Modeling; Wastewater treatment