No abstract

The potential of membrane aeration bioreactors (MABR), biological aerated filters (BAF) and membrane bioreactors (MBR) for grey water recycling has been evaluated. The MBR demonstrated the highest efficacy towards grey water recycling in terms of the three main water quality determinants of CBOD5, turbidity and total coliforms, providing 100% compliance in all cases. The membrane provided a solid free effluent and a biological culture adapted to treat the relatively difficult to degrade fractions of the grey water. The initial flux rate through the system was 28 l m−2h−1, which then gradually decreased to a stable level of 8 l m−2h−1. This demonstrated the process to be operating under sub critical flux conditions where no irreversible fouling occurs. Volumetric loading rates were correspondingly low due to the low flux rates and the weak strength of grey water, but process efficacy remained high throughout the loading rate range of 0.005–0.11 kgBOD m−3d−1 employed. The MBR was seen as particularly suitable as it was very effective at stabilising influent water quality variations and acted as a disinfection barrier to the water, providing a disinfection mechanism.

The potential of advanced biological unit operations for the recycling of grey and black waters has been evaluated. The membrane bioreactor (MBR) demonstrated the greatest efficacy towards water recycling in terms of all the quality determinants. Both the biologically aerated filter (BAF) and the MBR were able to effectively treat the organic and physical pollutants in all the types of wastewater tested. The main difference was observed in terms of the microbiological quality, measured as total coliforms. The open bed structure of the BAF enabled passage of coliforms whereas the complete barrier of the MBR produced a non detectable level in the effluent. The MBR process complied with commonly adopted water recycling quality standards for the all determinants during the grey water trials and failed only in terms of total coliform counts once black water had been introduced into the feed. The MBR was seen as a particularly suitable advanced biological process as it was very effective at stabilising out the considerable load variations encountered during the trial.

No abstract

La drépanocytose affecte 1 à 3 % des nouveau-nés en Afrique subsaharienne. Les situations épidémiologiques et anthropologiques, les politiques de santé inégales d’une région à l’autre depuis plusieurs décennies, font entrevoir l’intérêt d’études situées et historicisées. Dans le contexte de la mise en place d’un centre de recherche et de lutte contre la drépanocytose à Bamako, nous avons étudié en 2007-2008 les interrelations entre les savoirs et le traitement social de cette pathologie, en milieu rural d’une part, urbain d’autre part. Cette recherche, réalisée par entretiens auprès de personnes atteintes, de parents d’enfants atteints, de tradithérapeutes, de personnels biomédicaux et associatifs, révèle l’impact des transformations des savoirs sur le vécu social de la maladie et l’impact de la mondialisation économique et sanitaire sur les trajectoires familiales. Elle plaide pour la prise en compte des contextes sociaux dans les orientations de santé publique et les actions de communication.