Effect of Plant Species on the Performance and Bacteria Density Profile in Vertical Flow Constructed Wetlands for Domestic Wastewater Treatment in a Tropical Climate - Université de Rennes Accéder directement au contenu
Article Dans Une Revue Water Année : 2021

Effect of Plant Species on the Performance and Bacteria Density Profile in Vertical Flow Constructed Wetlands for Domestic Wastewater Treatment in a Tropical Climate

Résumé

Bacteria are frequently studied due to their involvement in pollutants transformation processes during wastewater treatment. In this study, the treatment efficiency, bacteria densities and their vertical profile were investigated in pilot-scale vertical flow constructed wetlands (VFCW) planted with different plant species under a tropical climate in west Africa. Five beds were planted with local plant species, i.e., Andropogon gayanus, Chrysopogon zizanioides, Echinochloa pyramidalis, Pennisetum purpureum and Tripsacum laxum, while one bed remained unplanted. These species have been rarely used in CWs while some (e.g., T. laxum) are tested for the first time. After a 7-month trial, bacteria densities were measured in substrate samples separated into six layers along the bed depth. Plants presence enhanced the bacterial density and VFCW efficiency; the removal rates of organic matter (90.9-95.9%; COD and 95.2-98.5%; BOD5), nitrogen (74.3-84%; TN and 76-84%; NH4-N) and phosphorus (77.4-96.9%; PO4-P) were higher by 5.9-24.1% compared to the control bed, providing an overall excellent treatment performance for a single-stage VFCW system. Small numbers of anaerobic bacteria were obtained in the VFCWs, explaining the low-to-zero NO3-N removal, except for the VFCWs with T. laxum and P. purpureum. Aerobic bacteria decreased from the upper to bottom layers from 17.4 to 0.1 x 10(6) CFU/g in the planted beds, while anaerobic bacteria increased from 0.1 to 2.1 x 10(6) CFU/g. Anaerobic bacteria were more abundant in the unplanted than in the planted beds. The total bacteria count was dominated by aerobic bacteria, and decreased from the surface towards the bottom. Overall, the VFCW with P. purpureum demonstrated the highest efficiency, indicating that this design is an effective and sustainable nature-based solution for wastewater treatment in a tropical climate.
Fichier principal
Vignette du fichier
water-13-03485-v3.pdf (2.52 Mo) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-03553225 , version 1 (02-02-2022)

Licence

Paternité

Identifiants

Citer

Franck Michael Zahui, Jean-Marie Petemanagnan Ouattara, Mahamadou Kamagate, Lacina Coulibaly, Alexandros I. Stefanakis. Effect of Plant Species on the Performance and Bacteria Density Profile in Vertical Flow Constructed Wetlands for Domestic Wastewater Treatment in a Tropical Climate. Water, 2021, 13 (24), pp.3485. ⟨10.3390/w13243485⟩. ⟨hal-03553225⟩
20 Consultations
55 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More