Vertical-flow constructed wetlands as an emerging solution for faecal sludge dewatering in developing countries

I. M. Kengne, E. Soh Kengne, Amougou Akoa, N. Bemmo, P.-H. Dodane, D. Koné
2011 Journal of Water, Sanitation and Hygiene for Development  
Yard-scale experiments aiming at assessing the suitability of vertical-flow constructed wetlands to dewater faecal sludge (FS) were conducted in Yaoundé (Cameroon). During 6 months, beds vegetated either with Cyperus papyrus L. or Echinochloa pyramidalis (Lam.) Hitchc. & Chase were fed under constant solids loading rates (SLR) of 100, 200 and 300 kg TS (total solids) m À2 /year. Physicochemical parameters of raw FS and percolate as well as the dewatering efficiency of each bed unit were
more » ... d unit were monitored weekly. Results showed that, despite the high loading rates, the beds' pollutant removal efficiencies were more than 78% for the parameters considered and were not affected by the SLR or the macrophyte types. Beds loaded at 100 kg TS m À2 /year rarely clogged with an average dry matter content ≥ 30%. However at SLR ≥ 200 kg TS m À2 /year, the occurrence of clogging was higher in the papyrus beds than those of E. pyramidalis. Approximately 30-40 cm/year of sludge will be accumulated in beds loaded at the lowest SLR against 50-70 cm/year at 200 kg TS m À2 /year and more than 80 cm/year at 300 kg TS m À2 /year. These promising findings suggest the system as adequate for further investigation at real scale for FS dewatering in the context of developing countries. I. M. Kengne
doi:10.2166/washdev.2011.001 fatcat:i7ky3yrv3vhkhfub2bqia7byf4