Performances of vegetated beds with Echinochloa pyramidalls in the purification of wastewater from distillery in sub-Saharan Africa.Original Title Performances des filtres plantes de Echinochloa pyramidalis dans l'epuration des eaux usees de distillerie en Afrique subsaharienne.

摘要

Trials were made in a yard scale subsurface flow wetland system for the treatment of wastewater from a distillery in Cameroon producing 432 m3.d-1 of effluent. The system comprises a neutralizing element, a pre-decantation basin, a digester and two horizontal subsurface flow wetlands. The system was submitted to experimental HLR of 4.10-2 m.day-1, 3.10-2 m.day-1 and 2.10-2 m.day-1. The performance of the system submitted to the HLR of 2.10-2 m.day-1 was then evaluated through monthly measurements of several physicochemical parameters. Results showed that a horizontal subsurface flow bed system can be used to reduce the pollution load of the effluent to be compatible with the self-purification capacities of the nearby river where it is discharged. The plant E. pyramidalis effectively contributed to the nutrient removal, since percentage reductions of 80%, 90% 79%, 60%, 90%, 79% and 50% were obtained respectively for the water conductivity, colour, Suspended solids, BOD₅, total nitrogen and total phosphorus. These percentages are higher than those recorded in the control bed.