Next Article in Journal
Introducing a Calculator for the Environmental and Financial Potential of Drain Water Heat Recovery in Commercial Kitchens
Previous Article in Journal
Flood Forecasting in Large River Basins Using FOSS Tool and HPC
Previous Article in Special Issue
Diffuse Water Pollution from Agriculture: A Review of Nature-Based Solutions for Nitrogen Removal and Recovery
Article

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

1
Laboratory of Environment and Aquatic Biology, Department of Sciences and Environment Management, Nangui Abrogoua University, 02 BP 801 Abidjan 02, Côte d’Ivoire
2
Department of Agronomic, Forestry and Environmental Engineering, University of Man, BP 20 Man, Côte d’Ivoire
3
Graduate National School of Chemistry of Rennes, UMR CNRS 6226, 11 Allée Beaulieu, CEDEX 7, 35708 Rennes, France
4
Laboratory of Environmental Engineering & Management, School of Chemical and Environmental Engineering, Technical University of Crete, 73100 Chania, Greece
*
Author to whom correspondence should be addressed.
Academic Editor: Abasiofiok Mark Ibekwe
Water 2021, 13(24), 3485; https://doi.org/10.3390/w13243485
Received: 3 October 2021 / Revised: 25 November 2021 / Accepted: 1 December 2021 / Published: 7 December 2021
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 × 106 CFU/g in the planted beds, while anaerobic bacteria increased from 0.1 to 2.1 × 106 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. View Full-Text
Keywords: constructed wetlands; vertical flow; domestic wastewater; plant species; bacterial density; aerobic bacteria; anaerobic bacteria; tropical climate; nature-based solutions constructed wetlands; vertical flow; domestic wastewater; plant species; bacterial density; aerobic bacteria; anaerobic bacteria; tropical climate; nature-based solutions
Show Figures

Figure 1

MDPI and ACS Style

Zahui, F.M.; Ouattara, J.-M.P.; Kamagaté, M.; Coulibaly, L.; Stefanakis, A.I. 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, 3485. https://doi.org/10.3390/w13243485

AMA Style

Zahui FM, Ouattara J-MP, Kamagaté M, Coulibaly L, Stefanakis AI. 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):3485. https://doi.org/10.3390/w13243485

Chicago/Turabian Style

Zahui, Franck M., Jean-Marie P. Ouattara, Mahamadou Kamagaté, Lacina Coulibaly, and Alexandros I. Stefanakis. 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" Water 13, no. 24: 3485. https://doi.org/10.3390/w13243485

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop