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The main objective of this study was to evaluate the contribution of activated carbon, based on coconut shell, in the treatment of mangrove and well contaminated water from the BONAPRISO district. More precisely, it consisted of preparing the activated carbon, then characterizing the mangrove water and the well water through a manual of sampling procedure; and finally verifying that the activated carbon produced had a good capacity for absorption of bacteria contained in the different sampled waters. Therefore, it emerged from this study that the activated carbon produced from coconut pods carbonized at 561°C, ground and activated at 443°C, had a specific surface of 658 m2/g and pore sizes of 20 µm. Thereafter the various waters characterized showed a yellowish coloration for well water and whitish for mangrove water, a pH ranging from 6.5 and 6.8, respectively; and the total flora had a total load of 2.18×105 CFU/ml for well water and a total load of 3.24×105 CFU/ml for mangrove water. Finally, the effectiveness of activated carbon in fixing bacteria, such as total flora, streptococci, and faecal coliforms showed that it was adsorbed in well water: 86.45% total flora; 91.67% streptococci; 100% faecal coliforms, and therefore, acted at 92.7%. Similarly, in mangrove water, there is 51.22% of total flora, 100% streptococci, and 92.4% faecal coliforms were fixed and, therefore, acted at 81.20%. The remaining bacteria, in well water (13.55% total flora; 8.33% streptococci) and in mangrove water (48.78% total flora; 7.6% faecal coliforms), respectively, could not be fixed. Key words: Coconut shell, faecal coliforms, streptococci, mangrove, activated charcoal.

EPI sciences The main objective of this study in the district of Douala V is to set up participatory pre-collection of household solid waste which, by protecting the environment, promotes the recovery of this waste. More specifically, the aim was to make an inventory of solid waste management, to raise awareness of households on participatory pre-collection, to describe the technical organization of the service and to evaluate the parameters of financial analysis for a pre-collection activity. To do this, available documents, direct observations, interviews and survey form were used. The main results of this study showed that the daily production or ratio of one inhabitant of Douala V is 1.05kg/hab/jour; the annual production is estimated at 363,870 tons. The low collection rate of about 23% was observed. With regard to household sensitization, 43% of the households surveyed are willing to pay for the pre-collection service and 52% are against and 5% are uninformed. The provisional financial analysis is based on one year; the investment cost is estimated at 3 327 400 CFA (5079 €). Overall, it appears that the solid waste collection rate in Douala V is below average, so it appears that pre-collection and recovery of household solid waste have a major role to play in the solid waste management system. Cette étude déroulée dans l’arrondissement de Douala V a pour objectif principal de mettre sur pied la pré-collecte participative des déchets solides ménagers qui en protégeant l’environnement, favorise une valorisation de ces déchets. Il s’agissait plus spécifiquement de faire un état de lieux de la gestion des déchets solides, de sensibiliser les ménages sur la pré-collecte participative, décrire l’organisation technique du service et d’évaluer les paramètres d’analyse financière pour une activité de pré-collecte. Pour ce faire, des documents disponibles, observations directes, entretiens et fiche d’enquête ont été utilisés. Les principaux résultats de cette étude ont montré que la production journalière ou ratio d’un habitant de Douala V est de 1,05kg, la production annuelle est estimée à 363 870,45 tonnes. Le taux de collecte faible d’environ 23%. Pour ce qui est de la sensibilisation des ménages, 42,66% des ménages enquêtés sont prêts à payer pour le service de pré-collecte et 52,33% sont contre et 5% sont sans avis. L’analyse financière prévisionnelle est basée sur une année, le coût d’investissement s’estime à deux mille huit cent quatre-vingt-onze Euro (2 891 Euro). Il ressort globalement que le taux de collecte des déchets solides à Douala V est en dessous de la moyenne, il apparait donc que la pré-collecte et la valorisation des déchets solides ménagers ont un rôle majeur à jouer dans le système de gestion des déchets solides.