Tropicultura (Jan 2010)
Performances des filtres plantes de Echinochloa pyramidalis dans l'épuration des eaux usées de distillerie en Afrique subsaharienne
Abstract
Performances of Vegetated Beds with Echinochloa pyramidalis in the Purification of Wastewater from Distillery in Sub-Saharan Africa. 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.
