Effect of key design parameters on bacteria community and effluent pollutant concentrations in constructed wetlands using mathematical models

• Published in: The Science of the total environment Vol. 584-585; pp. 374 - 380
• Main Authors: Sanchez Ramos, David, Agullo Pujol, Nuria, Samsó Campà, Roger, García Serrano, Joan
• Format: Journal Article Publication
• Language: English
• Published: Netherlands Elsevier B.V 15.04.2017; Elsevier
• Subjects: Aspect ratio; BIO_PORE; Constructed wetlands; CWM1; Depth; Desenvolupament humà i sostenible; Enginyeria ambiental; Environmental Sciences; Modeling; Tractament de l'aigua; Wastewater treatment; Zones humides artificials; Àrees temàtiques de la UPC; BIO_PORE; Aspect ratio; Wastewater treatment; Modeling; Depth; CWM1; MODELING; WASTEWATER TREATMENT; DEPTH; ASPECT RATIO
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2017.01.014

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. [Display omitted] •Effect of design parameters on constructed wetlands' performance is still uncertain.•Water depth and aspect ratio influence on HSSF CWs functioning has been assessed.•Experimental data from a pilot-scale system have been simulated in BIO_PORE model.•Water depth highly influences bacteria community; aspect ratio had minor effects.•Shallow wetlands enhance COD and NH4 removal thanks to their higher redox potential.