Gestion des déchets | EPFL Graph Search

La gestion des déchets, une des branches de la rudologie appliquée, regroupe la collecte, le négoce et courtage, le transport, le (le traitement des rebuts), la réutilisation ou l'élimination des déchets, habituellement ceux issus des activités humaines. Cette gestion vise à réduire leurs effets sur la santé humaine et environnementale et le cadre de vie. Un accent est mis depuis quelques décennies sur la réduction de l'effet des déchets sur la nature et l'environnement et sur leur valorisation dans une perspective d'économie circulaire. Tous les déchets sont concernés (solides, liquides ou gazeux, toxiques, dangereux), chacun possédant sa filière spécifique. Les modes de gestion diffèrent selon que l'on se trouve dans un pays développé ou en développement, dans une ville ou dans une zone rurale, que l'on ait affaire à un particulier, un industriel ou un commerçant. Les déchets non dangereux sont habituellement gérés sous la responsabilité des autorités locales, alors que les déche

Waste Reduction Strategies: A Different Perspective on Waste Flow Modeling and its Application to Concrete and Phosphorus

Anna Minata Cissé

Changing consumption patterns and global population growth lead to ever-increasing waste generation. Human activity and waste generation are irrevocably linked, and the current situation thus calls for a more circular approach to waste management, where wastes become new resources. Industrial ecology offers a variety of waste reduction-favoring concepts. As a first step this project identifies waste-preventing, waste-reducing, end of pipe (EOP) waste management approaches and legislation as classification categories for waste management strategies. Although, according to the waste hierarchy, waste prevention is the most preferable waste management approach, it is the least implemented. To facilitate the identification of waste prevention and reduction potentials, a special waste flow diagram from the waste management perspective is elaborated. The model tends to visualize all waste flows, including by-product valorization along a product's life cycle through the choice of a thematic-geographic system boundary. In a further step the applicability of the waste flow model is tested for concrete-related wastes and phosphorus (P) flows in wastes. The quantification of concrete waste flows for the city of Zurich shows that recycling is well implemented, whereas preferable waste management strategies, prevention and reduction of waste, are hardly put into practice. Scenario modeling is used to show the benefits of these techniques and the comparative LCA for different construction methods and materials identifies waste prevention as most beneficial option. For P, the waste flow model is applied to test its ability to detect P recovery potentials, however no new findings in terms of P-recovery potential are identified. The most compelling result regarding phosphorus is found in the extension to the initial investigation, the mass flow analysis for a wet-chemical and a thermochemical P-recovery procedure from sewage sludge ashes. The analysis shows that for EOP waste technologies, the material output can be bigger than the input due to the extended use of additives. Although all generated by-products can, in this case, be valorized by other industrial activities, this finding highlights the need for more waste prevention-oriented waste management strategies, thus avoiding the necessity to generate high by-product flows in the first place.

2018

Contribution du SIG à l'analyse des liens déchets-santé en milieu urbain dans les pays en développement

Sonwouignandé Kientga

Among the factors of health risks in urban areas, the solid and liquid wastes worsen particularly the problems of public health in developing countries. Uncontrolled solid waste disposal sites and waste water sites constitute major sources of danger for public health. Often, there is no mapped and documented inventory. The perception of danger related to infectious sources by the exposed populations is generally not well-known and even often ignored by the public institutions in their management policy of health and wastes. The same can be considered for the link between diagnosed diseases in health care services and the presence of waste disposal sites near patients' residences. The goal of this study is to determine the main factors of waste management and their consequences on health. This goal shall be reached using a GIS approach and through a case study concerning two districts in the town of Ouagadougou in Burkina Faso. In detail, the objectives are: i) to build a spatial database for waste disposal sites and public health care management and to propose a methodological approach for the elaboration of a GIS, associating social science, health and the geographical information science; ii) to identify and to analyze indicators of public health related to domestic and industrial waste; ii) to compare these indicators with the different actors' perception, according to the distance and dangers represented by the seriousness of potential danger sources; iv) to analyze if there is a relation between the actors' perception and the diseases diagnosed in health care services; v) to promote GIS in institutional structures in order to facilitate decision-making in waste management. Geographical information science has contributed to the creation of a database containing general geographical data, the disposal waste sites, the data of the actors' perception and health data. This database was used for spatial-thematic, temporal and statistical analyses. At first we have established an inventory of disposal waste sites. Hereafter we have analyzed their spatial influence. We then compared the situation to the perception of dangers and to the people's health risks, related to the distance to sources of potential danger. An analysis of the relation between the disease cases listed (counted) in health centers and the presence of waste (infectious) sources was carried out. This allowed some degree of comparison between the subjectivity of danger perception and the reality. The inventory of potential danger sources and the analysis of their influence spheres shows that 86 % (456 ha) of the study area is threatened by a danger, among which 45 % (235 ha) are considered exposed to a higher danger. The results also show that only 14 % of the population in both sectors (2'574 inhabitants of 18'978 total inhabitants) is not exposed to potential health risks. The analysis of the perceived danger according to the distance revealed that the perceived danger generally decreases proportionally to the distance. Surprisingly certain persons living near a polluted site don't consider the site as dangerous. However others, living far away from the same site, perceive it as dangerous. In these cases the subjective dimension of the perception is thus revealed. The temporal analyses of listed diseases show a correlation between the cases of malaria and the precipitation. The time gap between precipitation-related peaks and malaria cases related peaks varies from two to three months, leaving enough time to take preventive measures. We were not able to establish a link between the patient's residence and pollution sources; because the patient's geographical location is not mentioned in the health care services' registers. A modification of the registration forms has been suggested. The developed methodology and the results gathered led to the establishment of suggestions and recommendations based on the integration of GIS in waste and health management. This study has already contributed to the setup of a geo-information network composed of various actors in waste and health management.

EPFL2008

Environmental policies: designing acceptable road pricing and voluntary waste sorting schemes

Linda Melina Tesauro

Growing urban population implies many challenges for the municipalities in terms of mobility, housing, waste management or infrastructures. Public policies are thus needed to ensure a sustainable development. The main objective of this thesis is to analyze different environmental policies in the domain of mobility and waste management in order to help municipalities in designing more efficient measures.Firstly, Chapter 2 focuses on traffic congestion and in particular the acceptability of a congestion charge. We design a large survey with different plausible schemes for the Canton of Geneva, Switzerland and assess their acceptability with a discrete choice experiment (DCE). Results show that public support depends crucially on the policy design and the information provided. We find an important demand for exemptions and a preference for constant pricing. This implies a clear trade-off between efficiency and acceptability. However, the gap can be partly closed by information provision. Analyzing heterogeneity, we observe that preferences vary according to personal characteristics, especially where people live and how they commute.Chapter 3 analyzes the determinants of households' municipal waste sorting. We design a survey to investigate households' sorting motivation and use a DCE to assess households' waste sorting scheme preferences in the Canton of Geneva. We observe that households' waste sorting depends on personal characteristics such as sensitivity to the environment, guilty conscience or information level. However, it is the satisfaction with the existing sorting scheme that increases most the probability to sort waste. Our results show clear preferences for better infrastructures, but with thresholds. Interestingly, the best infrastructures and services are not always needed. By looking at heterogeneity and linking personal beliefs and characteristics with preferences, we find different groups sorting a similar number of categories, but with different underlying mechanisms like a lack of knowledge or a need for more convenient infrastructures and services.To complement our analysis on voluntary policies and in particular on the effectiveness of convenient infrastructures, Chapter 4 assesses a new voluntary environmental policy implemented in the Canton of Geneva and compares the results with a bag tax, a monetary incentive policy introduced in the neighboring canton, Vaud. The voluntary policy consists of the distribution to households of specific bins for organic waste to increase the sorting rate and decrease the amount of unsorted waste. We use a difference-in-differences methodology to assess the causal impact of the policy on organic waste as well as on overall waste generation. We find that the introduction of the voluntary policy increases significantly the proportion of households sorting organic waste. Interestingly, we observe some positive spillover effects on other waste sorted. By comparing the voluntary policy in the Canton of Geneva and the bag tax in the Canton of Vaud, we find similar effects on organic waste sorting. However, the impact of the voluntary policy is smaller on unsorted waste than the short-term effect of the bag tax.In conclusion, we show that price is not the only factor to consider in environmental policies. More stringent policies can be acceptable if well designed. Furthermore, the power of non-monetary incentives should not be underestimated.

EPFL2022