| Environnement, ingénierie & développement |  |
N°76 - avril 2018
1. L’influence de la précollecte des ordures ménagères sur la qualité de la salubrité dans le District d’Abidjan (Côte-d’Ivoire)
In Abidjan, as in the rest of Côte-d'Ivoire, garbage collection is more needed in neighborhoods as an activity to ensure its survival or a supplementary income. Two effects combine to explain the rise of these informal jobs by young people or Small and Medium Enterprises (SMEs). On the one hand, the constant increase in the working population affected by mass unemployment. On the other hand, the impotence of companies committed by local authorities to ensure the pre-collectiveness of garbage. How does this new social practice determine the areas of cleanliness and model household waste collection practices?The reflection proposed here is based on a survey of 300 households in the communes of Cocody and Yopougon. It aims to analyze the effectiveness of the informal precollect in the district of Abidjan. The results of our survey reveal that the pecuniary logic of the precollectors leads to the amplification of the inequalities of access to the service of collection of waste and exposure to its nuisances. Finally, the study also shows that some precollectors contribute to the movement of waste, one of the consequences of which is the proliferation of wild dumps in the district.
2. Éditorial n°76 Déchets Sciences et Techniques
Ce numéro 76 de "Déchets Sciences et Techniques" est particulier. Il s’agit en effet du premier numéro, à l’exception du numéro spécial sur le congrès E3D 2016 tenu à Lomé au Togo, dont les articles sont issus d’auteurs appartenant exclusivement à des équipes de recherche du Sud, en l’occurrence africaines. Cette situation n’est pas habituelle pour la revue qui a, bien au contraire, la volonté de cultiver la mixité d’origine des articles publiés. Mais force est de constater que la tendance n’est pas nouvelle, et que les contributions des équipes de recherche du « Nord » sont minoritaires dans les récents numéros de la revue.
3. Elaboration d’une approche multicritère pour la recherche de sites de décharges contrôlées de classe 1 au Maroc
In this paper, we propose a multicriteria approach allowing the selection of Class 1 landfill sites, which receive household and similar waste, taking into account the environmental constraints and the orientations of urban planning documents while remaining in line with the Moroccan laws texts, essentially the law 28.00. For its application, we opted for the province of Tetouan located in the North of Morocco. The approach adopted is based on a succession of three major steps : (1) Systematic inventory of the environment and associated activities, (2) Identification of free surfaces and (3) Site selection. At the end of this work, our initial goal was achieved, the potential regulated landfill site for the province of Tetouan was selected. The standardization of this approach in order to apply it to various other areas constitutes a valuable gain of time. Its application on other zones in order to validate the relevance of the parameters retained and the robustness of the applied rating system constitutes our main perspective.
4. Essai de production et de valorisation de compost d’Acacia cyanophylla pour la production de plants de chêne liège (Quercus suber L.) : résultats en pépinière et après transplantation
This article aims to improve cork oak seedlings quality by use of compost to make growing media in substitution of the forest humus. A. cyanophylla composts were made with or without activator. Nine composts based growing media and a control made of forest humus were made, physically and chemically characterized and used for seedlings production in nursery according to a three block design. Seedlings growth and root growth potential measured in nursery as well as field recovery were monitored to highlight the compost effects on seedlings quality. A. cyanophylla compost improves cork oak seedlings quality as compared to forest humus. Seedlings supplied by compost based growing media showed significant growth gains ranging from 28% to 48% in height, 17% to 30% in diameter and 15% in dry matter, belter root potential growth and better recovery in field as compared to those of control. A. cyanophylla has good composting ability; its compost can be easily produced even without activator. Cork oak seedlings quality can be improved with growing media based on A. cyanophylla compost.
5. Proposition d’un outil d’évaluation du service publique de gestion des déchets solides municipaux en Afrique
In many African cities, like other cities around the world, municipal solid waste management (MSWM) is contracted to private sector entities by delegation under a Public Private Partnership (3P) framework. At the heart of the 3P, is a contract whose renewal will be done after a multi-criteria assessment. The aim of this paper is to propose an assessment tool to evaluate a public MSWM service based on a set of criteria (objectives to be achieved) and indicators (action variables) that seem essential for an efficient and sustainable MSWM service in the African context.
6. Axes stratégiques pour la pérennisation d’unités de compostage en Afrique : cas de Bouaké en Côte-d’Ivoire
Composting is preferentially cited as the appropriate course for valorising the fermentable fractions of household solid waste in Africa ; however, the initiatives through this way presents mitigable results. Indeed, composting of household solid waste in Africa faces a major challenge, which is that of large-scale development and the perpetuation of pilot actions initiated in this direction after the end of external financing. While a pilot composting activity, jointly carried out by ANASUR (Agence nationale de la salubrité urbaine) through its Project for the Professionalization of the Waste Sector (PPWS) and by a french consortium composed of the GoodPlanet foundation, ETC…Terra and Gevalor associations through their Africompost Program, finds a development at Bouaké, we think that it is necessary to glimpse its winnings factors.In Bouaké, the potential for composting is large and varied, atmospheric conditions are also amenable to activity, and the first phase of market research has identified potential markets for compost in a market where its main competitor is chicken’s shit sold at CFAF 30,000 (54 USD) at the ton. A prospective analysis of the development of the activity to 10,000 tons of solid waste to be treated yearly to produce 1,600 tons of compost announces a cost of CFAF 101,939 (192 USD) per ton of compost produced (CFAF 16,310/t of waste treated ; 30.66 USD/t of waste treated). The financial mix plan to balance the budget consists of sales of compost […]