Evaluation of Pilot-Scale Constructed Wetlands with Phragmites karka for Phytoremediation of Municipal Wastewater and Biomass Production in Ethiopia
- 15 Downloads
A pilot horizontal subsurface flow constructed wetland (HSSFCW) was constructed, covered with geomembrane, and packed with gravel as substrate. Phragmites karka was planted in one cell and the other cell was left unplanted. The experiment was carried out over a 3-year period at two hydraulic loading rates (HLRs): 0.025 m/d and 0.05 m/d. The aim of the study was to evaluate the phytoremediation and biomass production potential of Phragmites karka for municipal wastewater treatment to remove chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP). The highest average COD, TN, and TP removal performances attained were 94.1%, 97.3%, and 89.9%, respectively, at HLR of 0.025 m/d, and 90.4%, 86.8%, and 88.5%, respectively, at HLR of 0.05 m/d. COD, TN, and TP removal performances were considerably higher in the planted HSSFCW than in the unplanted (p < 0.05). The study found: a progressive increase in plant density, from 3 ± 1 to 113 ± 43 shoots per m2; an increase in plant height (erect), from 8 to 365 cm; and growth of the running stem of P. karka (stolon) to 16 m after 16 months. The maximum nutrient content and nutrient accumulation of the above-ground biomass of P. karka recorded were 78.7 gN/kg DW and 21.6 gP/kg DW, and 2014.7 gN/m2 and 550.4 gP/m2 throughout the experimental period. The findings from the experiments showed the successful performance of the HSSFCW cell planted with P. karka for the treatment of municipal wastewater. P. karka demonstrated high biomass production and high nutrient removal performance. We conclude that scaling up this pilot HSSFCW has great potential for treating municipal wastewater in Ethiopia and other low-income countries with similar climatic conditions.
KeywordsConstructed wetland Phragmites karka Nutrients Plant biomass Phytoremediation
The authors thank Ethiopian Institute of Water Resources, Addis Ababa University (AAU), which supervised the financial support provided by the United States Agency for International Development (USAID) and the Research Fund for International Young Scientists (Grant Agreement No: W/5799-1). The authors are also thankful to the Addis Ababa Water and Sewerage Authority for allowing the pilot-scale constructed wetland system on the premises of its wastewater treatment plant and the laboratory facilities. The authors also acknowledge the University of Connecticut for access to its electronic library and Ann Byers for editing the English language manuscript at short notice.
The first author conducted experiments in the field and wrote the manuscript. The other authors supervised the experimental site and structured, read, edited, and approved the final manuscript. All authors have read and approved the final manuscript.
This work was supported by the United States Agency for International Development (USAID) and the Research Fund for International Young Scientists (Grant Agreement No: W/5799–1).
Compliance with Ethical Standards
Ethical Approval and Consent to Participate
Consent for Publication
Availability of Supporting Data
Supporting data available.
Conflict of Interest
The authors declare that they have no conflict of interest.
- Angassa K (2011) Evaluation of the performance of constructed wetland system for the treatment of brewery wastewater. Addis Ababa University Institute of TechnologyGoogle Scholar
- APHA (1999) Standard methods for the examination of water and wastewater, 20 Edn. American Public Health AssociationGoogle Scholar
- Astuti JT, Sriwuryandari L, Sembiring T (2018) Application of vetiver (vetiveria zizanioides) on phytoremediation of carwash wastewater. Pertanika J Trop Agric Sci 41:1463–1477Google Scholar
- Choudhary AK, Kumar S, Sharma C (2011) Constructed wetlands: an approach for wastewater treatment. Elixir Pollut 37:3666–3672Google Scholar
- Ewemoje OE, Sangodoyin AY, Adegoke A (2015) On the effect of hydraulic retention time and loading rates on pollutant removal in a pilot scale wetland. J Sustain Dev Stud 8:342–355Google Scholar
- Fu X, Wu X, Zhou S, Chen Y, Chen M, Chen R (2018) A constructed wetland system for rural household sewage treatment in subtropical regions. Water (Switzerland) 10. https://doi.org/10.3390/w10060716
- Grinberga L, Lagzdins A (2017) Nutrient removal by subsurface flow constructed wetland in the farm Mezaciruli. Rural Environ Eng, Landscape Architecture 1:161–165. https://doi.org/10.22616/rrd.23.2017.024
- Henze M, Comeau Y (2008) Wastewater characterization. In: Henze M, Van Loosdrecht MCM, GAE, DB (eds) Biological wastewater treatment: principles, modelling and design. IWA Publishing, London, UK, pp 33–52Google Scholar
- Hua Y, Peng L, Zhang S, Heal KV, Zhao J, Zhu D (2017) Effects of plants and temperature on nitrogen removal and microbiology in pilot-scale horizontal subsurface flow constructed wetlands treating domestic wastewater. Ecol Eng 108:70–77. https://doi.org/10.1016/j.ecoleng.2017.08.007 CrossRefGoogle Scholar
- Jampeetong A, Brix H, Kantawanichkul S (2012) Effects of inorganic nitrogen forms on growth, morphology, nitrogen uptake capacity and nutrient allocation of four tropical aquatic macrophytes ( Salvinia cucullata, Ipomoea aquatica, Cyperus involucratus and Vetiveria zizanioides ). Aquat Bot 97:10–16. https://doi.org/10.1016/j.aquabot.2011.10.004 CrossRefGoogle Scholar
- Kadlec R, Wallace S (2009) Treatment wetlands, 2nd edn. Taylor & Francis Group, LLC, Boca RatonGoogle Scholar
- Kassa Y, Mengistou S, Ababa A (2014) Nutrient uptake efficiency and growth of two aquatic macrophyte species under constructed wetland, Ethiopia. SINET Ethiop J SciJ Sci 37:95–104Google Scholar
- Kyambadde J (2005) Optimizing processes for biological nitrogen removal in Nakivubo wetland, Uganda. Royal Institute of Technology, StockholmGoogle Scholar
- Panwar RS, Makvana KS (2017) Reed-Phragmitis karka based constructed wetland for the treatment of domestic wastewater in Ujjain city of Central India. Int J Sci Res Biol Sci 4:1–5Google Scholar
- Phillips (1995) Flora of Ethiopia and Eritrea. Poaceae (Gramineae). The national herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, SwedenGoogle Scholar
- Shuib N, Baskaran K (2011) Effects of different substrates and hydraulic retention time (HRT) on the removal of total nitrogen and organic matter in a sub-surface horizontal flow constructed wetland. Int J Environ, Cultural, Economic Soc Sustain 7:227–241. doi: https://doi.org/10.18848/1832-2077/CGP/v07i05/55000
- USEPA (2000) Constructed wetlands treatment of municipal wastewaters. EPA’s Office of Research and Development, Cincinnati, Ohio 45268Google Scholar
- von Sperling M (2007) Wastewater characteristics, treatment and disposal. IWA, London New York, New Delhi, IndiaGoogle Scholar
- Wang W, Ding Y, Ullman JL, Ambrose RF, Wang Y, Song X, Zhao Z (2016) Nitrogen removal performance in planted and unplanted horizontal subsurface flow constructed wetlands treating different influent COD/N ratios. Environ Sci Pollut Res 23:9012–9018. https://doi.org/10.1007/s11356-016-6115-5 CrossRefGoogle Scholar
- Zhao F, Liu C, Rafiq MT et al (2014) Screening wetland plants for nutrient uptake and bioenergy feedstock production. Int J Agric Biol 16:213–216Google Scholar
- Zhou Q, Zhu H, Bañuelos G, Yan B, Liang Y, Yu X, Cheng X, Chen L (2017) Effects of vegetation and temperature on nutrient removal and microbiology in horizontal subsurface flow constructed wetlands for domestic sewage. Water Air Soil Pollut 228:1–13. https://doi.org/10.1007/s11270-017-3280-1 CrossRefGoogle Scholar