ISSN 2375-1266
African Journal of Environmental and Waste Management ISSN 2375-1266 Vol. 11 (8), pp. 001-009, August, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals
Full Length Research Paper
Efficacy of Horizontal Surface Flow Wetlands Vegetated with Echinochloa pyramidalis for the Elimination of Fecal Bacteria and Nutrients in Domestic Wastewater
Lekeufack Martin1, Fonkou Théophile1*, Pamo Tedonkeng Etienne2 and Amougou Akoa3
1Laboratory of Applied Botany, University of Dschang, Cameroon.
2Department of Animal Production, Faculty of Agronomy, University of Dschang, Cameroon.
3Department of Plant Biology, Faculty of Science, University of Yaoundé I, Cameroon.
Accepted 24 July, 2020
Abstract
The aim of this study was to evaluate the removal of faecal bacteria and nutrients from domestic wastewater, in surface flow wetlands vegetated with Echinochloa pyramidalis. Horizontal surface flow (HSF) wetlands were fed with primarily treated domestic wastewater at organic loading rates varying from 20.74 to 27.15 g BOD/m2/day for two consecutive years. Water samples were collected at two weeks interval from the inflow and the outflow of the treatment wetlands for physicochemical and faecal bacteria analyses. Physicochemical parameters with highest removal rates were total suspended solids (TSS, 62-80%), Nitrates (57-73 %) and PO4-3 (57-84 %). Faecal indicators reductions of 1.4 and 0.3 log units (1st year) and 1.15 and 0.65 log units (2nd year) were respectively recorded in the vegetated and the control wetlands. Reductions of total coliforms, faecal coliforms and faecal streptococci were significantly higher in the vegetated wetland than in the non-vegetated control in both seasons of the first year. In the contrary, there was no significant difference in the removal rates of faecal indicators between vegetated wetland and the non-vegetated control during the dry season of the second year. Wetlands vegetated with E. pyramidalis was proven to be continuously efficient in the removal of faecal indicators for the two years of study, with no significant differences between the seasons of the year and between the years.
Key words: Wastewater, wetlands, Echinochloa pyramidalis, faecal bacteria removal, nutrients removal.