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The effect of sewage effluent on trace metal speciation : implications for the biotic ligand model approachConstantino, Carlos January 2013 (has links)
This research examined the suitability of the biotic ligand model (BLM) approach for assessing environmental risk in surface waters consisting substantially of treated sewage effluent, and the implications of its use within a compliance-based regulatory framework aimed at controlling discharges of metals into the aquatic environment. The results from a series of Daphnia magna acute copper toxicity assays conducted in an undiluted sewage effluent medium demonstrated that BLMs could predict an acute copper toxicity endpoint with suitable accuracy. This finding contributes further support for the use of BLMs for assessing risk and compliance, even in effluent impacted waters. Additional studies, however, also demonstrated that effluent derived organic matter contained a greater concentration of metal complexing ligands per milligram of dissolved organic carbon than organic matter derived from natural sources. This indicates that effluent derived organic matter offers greater protection against the potentially adverse effects from metals than the protection offered by organic matter derived from natural sources. These studies also demonstrated that improvements in the accuracy of BLM forecasts were achievable by taking these differences into account which, from a regulatory perspective, is also desirable since this enhances the environmental relevance of compliance criteria. These findings therefore justify that consideration for the influence of site-specific metal complexation characteristics should included as part of the regulatory framework within which BLMs will be applied. The implication of the BLM approach for Severn Trent Water Limited is that, as currently proposed, the approach will require a reduction in the concentration of copper in the effluent discharges for a small number of wastewater treatment works (9), whereas for zinc, concentration reductions may be required for numerous treatment works (126).
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Uranium associations and migration behaviour at the Needle's Eye natural analogue site in SW ScotlandXu, Xiaolu January 2015 (has links)
This thesis investigated uranium (U) migration behaviour at the Needle‟s Eye natural analogue site, located close to Southwick Water, South West Scotland. The results of this study are important for the prediction of U behaviour in the far-field environments of nuclear waste repositories over long time-scales. The Needle‟s Eye natural analogue site was selected because the processes involved in U mobilisation, the direction of water flow and the extent of retention of uranium in peaty soils had already been identified. To this end, previous results demonstrated that groundwater passing through the mineralisation oxidized U and transported it to the peaty area, where 80-90% of the released U has been retained. Sequential extraction of the peaty soils indicated that more than 90% of the solid phase U was bound to the organic fraction. However, in-depth characterisation of U associations within the soil porewaters and the peaty soils at this site was lacking. Therefore, the processes controlling the migration of uranium within this organic-rich system were the main focus of this study. There were five sampling trips carried out from 2007-2011, in which cave drip waters, bog waters and surface soil and soil core samples were selectively collected for analysis by a range of methods described below. The cave drip waters emerging from the mineralisation were oxidizing and slightly alkaline (7.6-7.8), U was mainly in truly dissolved (<3 kDa) forms (Ca2UO2(CO3)30, CaUO2(CO3)32- and UO2(CO3)22-). It is known that the formation of the ternary Ca-UVI-CO3 complexes inhibits the reduction of U and so it is likely that it is UVI that is present within the peaty soils and their associated porewaters. Sampling trip 1 quantified the U concentrations in cave waters and soil core porewaters. By 30 m from the cave, U concentrations in the soil porewaters had decreased by a factor of ~10. Ultrafiltration fractionated the colloidal fraction (3 kDa-0.2 μm) into large (100 kDa-0.2 μm), medium (30-100 kDa) and small (3-30 kDa) colloidal fractions. It was found that U was mainly associated with the large colloid (100 kDa-0.2 μm) but, with increasing distance from the mineralisation, the U distribution became bimodal with both large and small fractions being equally important. Iron (Fe) was exclusively associated with the large colloid fraction in the peaty soil porewaters. Gel electrophoresis and gel filtration, applied to study the interactions of U (and other elements) with humic substances (HS), showed that the associations were quite uniform with increasing depth of the cores and increasing distance from the U mineralisation. Uranium (and other elements including Fe) was associated with the largest humic molecules. Sampling trip 2 involved collection of three more soil cores and ultrafiltration again fractionated the total dissolved porewater into large, medium and small colloids. This time, the truly dissolved (<3 kDa) fraction was also analysed. Again, U was mainly associated with the large colloidal (100 kda-0.2 μm) fraction. With increasing distance and increasing depth, U was still predominantly associated with the large colloidal fraction, but the importance of the truly dissolved (<3 kDa) phase could not be neglected. At the same time, Fe was also mainly associated with the large colloidal fraction. The remainder of the experimental work on samples from trip 2 focused on determining the importance of U associations with both Fe and humic components of the solid phase. Sequential extraction of the whole soil mainly targeted different iron phases and found that U was mainly released in the sodium acetate and sodium dithionite solutions, which indicated U was associated with (i) Fe carbonates; and (ii) crystalline Fe oxides (e.g. goethite, hematite, and akaganetite). However, very little Fe was extracted in the “carbonate-bound” fraction and separate experiments showed that U was not associated with Fe carbonates but instead had been released from the surfaces of HS and humic-bound Fe surfaces. XRD spectroscopy showed that mineral compositions were in reasonable agreement with the sequential extraction results and SEM-EDX analysis indicated that U in the soil was generally not present in crystalline form, as only two particles with high U content were found after 4-hour searching. Exhaustive extraction of HS showed that >90% U was associated with organic substances, in agreement with previous work and novel experiments involving gel electrophoresis in conjunction with sequential extraction was used to study the relationships between U, Fe and the HS. It was demonstrated that ~20-25% U was weakly held by the HS or at humic-bound Fe surfaces, ~45% was incorporated into crystalline Fe oxides which were intimately associated with HS and the remainder was in the form of strong U-CO3-humic complexes. In sampling trip 3, U migration behaviour in the soil porewaters was the focus. A 30-m transect line, comprising seven0-5 cm soil samples, starting at the cave and passing through the peaty area towards the Southwick Water, was established. Soil porewaters from these surface soils were fractionated into colloidal (3 kDa-0.2 μm) fraction and truly dissolved (<3 kDa) phase. There was a major change in U speciation, from Ca2UO2(CO3)3 0,CaUO2(CO3)32- and UO2(CO3)22- in the truly dissolved fractions of waters close to the cave to a predominant association with the highly coloured colloidal fractions as soon as the boggy area was reached. With distance through the boggy area, it was clear that the colloidal U was being incorporated into the solid phase since porewater concentrations had decreased ~100-fold by 30 m from the cave. Ultrafiltration in conjunction with acetate extraction was then used to extract U from the porewater colloids isolated from a soil core (20 m from cave). In the organic-rich portion of the core (0-30 cm), ~60-70% U was colloidally associated and ~85-95% of this U was extracted from the colloidal fraction. This indicated that the interactions between U and the porewater colloids were weak. In sampling trip 4, U associations in the porewater colloids were still the main focus. Gel filtration of porewater colloids confirmed that U, Fe and humic colloids were intimately associated. It was concluded that although U in the cave drip water was mainly in truly dissolved forms, weak U----humic/Fe colloids were formed immediately when U entered the peaty area. In sampling trip 5, results for soil core porewaters showed that Fe in the whole core was mainly in the form of FeII. Thus strongly reducing conditions prevailed through the core which was situated within the peaty area. Combining the results from the five sampling trips, three zones within the peaty area were distinguished. Zone I was characterised by extremely high concentrations of dissolved HS and this was where the change in U speciation from dissolved to colloidal forms took place. Zone II contained most of the soil cores collected during this study and was characterised by strongly reducing conditions and moderate concentrations of HS. Colloidal U was removed to the solid phase as waters flow through this area. Zone III marks the transition to the saltmarsh. Focusing on Zone II, a conceptual model of U behaviour was developed: upon entering the peaty area, U is weakly held by very large humic-Fe colloids. These colloids are removed to the solid phase and over time the associations of U are transformed; some becomes incorporated into stable humic-bound crystalline oxides as a result of redox cycling of Fe, some becomes strongly complexed to HS and the remainder is weakly held by the HS and/or humic-bound Fe surfaces. The crystalline Fe oxides were transformed to Fe sulfides below 30 cm depth but the associated U was not transferred to these sulfides. Instead the weak associations became more important. In the wider context, since only UVI forms soluble complexes with acetate, UVI does not appear to be reduced even under the strongly reducing conditions encountered within waterlogged organic-rich soils. Initial interactions between UVI and porewater colloids appear to be weak but stronger interactions such as incorporation into Fe phases and complexation by HS occur once the colloids and associated U are removed to the solid phase. Waterlogged organic-rich soils appear to be a long-term sink for U but changing climatic conditions leading to the drying out of such soils may ultimately release U in association with smaller, more mobile organic-rich colloids.
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Developing sustainable household waste management : a Local Authority approach to zero wasteCole, Christine January 2014 (has links)
This project was a case study with a Local Authority (Charnwood Borough Council, Leicestershire) to research the options in response to the challenges of managing household waste. This research focused on establishing and analysing methods of improving the sustainability of household waste management operation within a Waste Collection Authority, where the interaction with a variety of external and internal stakeholders meant a holistic approach was needed. Waste management practices and performances in Charnwood were evaluated and benchmarked against national standards and the demography of a semi-rural Borough. Waste management practices nationally were also reviewed. The performance of the LA was quantitatively compared with other UK LAs where higher recycling performances are achieved. Differences were separate food waste collection and treatment; a larger proportion of urban housing and the university with a transient population. Other differences included strategy and operational practices for garden waste, the storage, collection, transportation and treatment of waste. A time series statistical model was modified and applied to investigate long term waste generation trends from the Boroughs official waste data returns to Defra. These were used to assess the success of interventions undertaken. This statistical model was able to differentiate interventions that were able to achieve lasting improvements in either waste minimisation or recycling. The declaration of a Zero Waste Strategy was to capture the public imagination. A series of focus groups and public consultations were held to judge public reaction and develop and refine the strategy. These were used to adapt the Zero Waste idea to suit the local conditions. A major conclusion was that householder involvement would be crucial for successful implementation of the further separation of waste that would be required.
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Invisible spaces : variegated geographies of waste in ChinaInverardi-Ferri, Carlo January 2016 (has links)
With millions of people involved in collecting and treating recyclable products, waste recycling provides a critical entry point to an investigation of the spaces and dynamics of the Chinese economy. Based on sixteen months of in-depth ethnographic research, this thesis, 'Invisible spaces: variegated geographies of waste in China', describes and analyses waste and its boundaries, as well as the actors that deal with it at different scales within the country. The work examines how waste circulates, how it is regulated, and how it is represented in China. It presents stories of the people and places that configure the waste industry, and situates its analysis at the intersection of three different strands of literature: i) variegated capitalism; ii) informal economy; and iii) geographies of waste. The research contends that the 'afterlives' of goods are a productive prism which can be used to understand the variegated mode of capitalism in contemporary China and thus investigates the following question: to what extent do the different cultural, social, political, economic, and material dimensions of waste reveal the heterogeneous characteristics of Chinese capitalism? Central to my analysis is the concept of invisibility. I conceive invisibility as a socio- political process that brings about an uneven access to resources and labour for subaltern groups, as well as a relational concept encompassing the three complementary and dialectical dimensions of absolute, relative, and relational space. Invisibility is not only a metaphor to define the agency of informal workers, but also an allegory to describe the marginalisation of their activities and spaces. It is an asset and a curse, a condition and a strategy. These multiple dimensions make invisibility a productive device bringing to light the geographies of different accumulation regimes and everyday practices, as well as a potent tool to analyse the alternative representations of waste, value, labour, and development at play in contemporary China. With this in mind, the thesis engages with a number of important debates in geography. In particular, the five empirical chapters engage with literature on global production networks, labour geography, primitive accumulation, geographies of waste, and urban political ecology. While drawing these literatures into conversation with the variegated capitalism framework, the work suggests that the invisibility of waste activities is a powerful tool to analyse the nature and the mechanisms of the variegated modes of production in contemporary China.
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Adsorption and time dependent fixation of uranium (VI) in synthetic and natural matricesAshry Abdelaal, Ahmed January 2017 (has links)
Disposal of low level radioactive liquid waste to soil is commonly practiced. Therefore, sorption of uranium from aqueous solution and fixation of uranium into soil are processes which are crucial to the attenuation of uranium and protection of groundwater. Exposure of human populations is either by direct water consumption or through crop irrigation and transfer into the food chain. In this study a range of materials, including natural materials (e.g. biochar and the natural zeolites ‘Chabazite and Mordenite’) and the synthetic zeolite ‘Faujasite-X’, were investigated as potential adsorbents for UVI from aqueous solution. A range of experiments were carried out to investigate the efficacy of using these adsorbents to successfully adsorb and fix UVI from aqueous solutions. These included sorption and desorption experiments, quantifying time-dependent fixation of UVI and applying kinetic models of this process and measuring isotopically exchangeable UVI within adsorbent materials when possible. The factors affecting adsorption processes, such as solution pH, initially added UVI concentrations and adsorption contact time, were also investigated. Speciation of U in the solution phase was investigated using the Windermere Humic Aqueous Model (WHAM-VII). Saturation indices of potential solid phases were also configured using known solubility products and the free ion activities predicted from the speciation model, WHAM-VII. Mordenite zeolite showed a poor adsorption affinity for UVI as the solution pH was continuously buffered towards high pH values > 6.5 which favours UVI ion solubilisation as a result of uranyl carbonate complex formation. Uranium (VI) ion adsorption on chabazite at pH 4.7 at 20 oC was found to fit the Freundlich adsorption isotherm but the optimised equation parameters were unique for each contact time of 1, 5, 10, 20 and 30 days. The time-dependent fixation of UVI on chabazite was found to follow an irreversible first-order kinetic equation and an intraparticle diffusion model suggesting slow penetration of chabazite porous structure following initial surface adsorption. Isotopically exchangeable 238UVI (the E-value, UE) adsorbed on chabazite showed that > 65% of initially added UVI remained isotopically exchangeable. Faujasite-X also showed time-dependent fixation of UVI over 35 days of adsorption contact time at pH values 4, 5 and 6. The adsorption kinetics were best described by an irreversible first-order equation and a spherical diffusion model. Desorption trends showed that UVI adsorption into faujasite- X was almost wholly irreversible. Saturation indices calculated from the solubility products and free ion activities of constituent ions showed that the fixation of UVI was not controlled by the precipitation of any solid phase investigated at the studied range of pH values. Bone biochar, a by-product from the production of biofuel and syngas by gasification, was tested as a material for adsorption and fixation of UVI from aqueous solutions. A batch experiment was conducted to study the factors that influence the adsorption and time-dependent fixation on biochar at 20◦C, including pH, initial concentration of UVI and contact time. Uranium (UVI) adsorption was highly dependent on pH. However, it was found that UVI adsorption on biochar was high over a wide range of pH values, from 4.5 to 9.0, and adsorption strength was time-dependent over several days. The experimental data for pH> 7 were most effectively modelled using a Freundlich adsorption isotherm coupled to a reversible first order kinetic equation to describe the time-dependent fixation of UVI within the biochar structure. Desorption experiments showed that UVI was only sparingly desorbable from the biochar with time and isotopic dilution with 233UVI confirmed the low, and time-dependent, lability of adsorbed 238UVI. Below pH 7 the adsorption isotherm trend suggested that precipitation, rather than true adsorption, may occur. Across all pH values (4.5–9) measured saturation indices suggested precipitation was possible: autunite below pH 6.5 and swartzite, liebigite or bayleyite above pH 6.5 Another source of bone biochar with a fraction size of (20x 60 mesh) was investigated as candidate materials for soil remediation. Its ability both to adsorb uranium and to render it non-labile (i.e. chemically inactive) was tested by addition to a wide range of soils recently spiked with 238UVI and incubated under moist conditions. The overall aim was to recommend improved strategies for immobilisation of uranium in soils subject to application of low level radioactive waste solutions. Several measurements were made to assess possible reductions in U availability from biochar addition, including U solubility in 0.01 M Ca(NO3)2, exchangeability in 1 M Mg(NO3)2 solution and isotopic dilution with 233U and 236U. Results showed that 41.3 %, 27.6%, 28.9% and 31.7% were isotopically exchangeable on average for soil amended with 0%, 3%, 5% and 10% loading of biochar, but overall there appeared to be only marginal advantages in adding even large concentrations of biochar to soil. The major factor controlling U solubility, exchangeability and lability was soil pH and the pH value resulting from biochar, rather than the biochar itself. Therefore, while the use of biochar to effectively remove U from water is clear, its role in adsorbing U in the highly buffered soil environment is probably minimal.
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Development of a multi-criteria, GIS-based, backcasting framework model (G-BFM) for progression towards zero waste futures, for holistic resource management policy and practice in Northamptonshire by 2050Head, Nicholas January 2015 (has links)
The complex nature of waste management and planning requires a long-term strategic policy formation approach incorporating sustainable development principles. Consequently, the transition from a waste paradigm to valuing materials as resources is central for transitioning towards a 'zero waste' future. A need is identified, via infrastructure planning, to move beyond short-term forecasting and predictive methods previously used in waste research in order to overcome target-driven decision-making. The application of a participatory backcasting methodology: visioning, baseline assessment, scenario development and feasibility testing; produced transformative scenarios which are visualised using GIS reflecting the choices, ideas and beliefs of participants. The structural governance (e.g. waste infrastructure planning and strategic waste policy) of an English county is used to evaluate the efficacy of waste management scenarios. A quantitative model was developed to test scenarios for three metrics (tonnages, economics and carbon). The final model utilises the synergy between backcasting and GIS to spatially and temporally analyse empirically quantified outputs. This structured approach produced three transformative scenarios and one reference scenario. Waste prevention and changes to systemic waste generation produced long-term tonnage reductions across the transformative scenarios. Costs of future waste management witnessed the reference scenario outperforming one of the transformative scenarios; while the highest emissions savings were attributable to the scenario most closely reflecting the notion of 'deep sustainability'. In terms of waste infrastructure planning, a centralised pattern of large integrated facilities emphasising catchments rather than administrative boundary were most effective. All three transformative scenarios surpassed the 90% recycling and recovery level used as the zero waste benchmark. The research concludes that backcasting can offer a range of potential futures capable of achieving an arbitrary definition of zero waste. Further, these futures can be visualised and analysed via GIS; enhancing stakeholder engagement. Overall, the GIS-based Backcasting Framework Model (G-BFM) produced has the potential to benefit a range of stakeholders and practitioners and is strategically scalable.
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Understanding waste management behaviour in care settings in South West England : a mixed methods studyManzi, Sean January 2015 (has links)
Introduction - Health and social care sector activities in the United Kingdom have a considerable carbon footprint which impacts on the natural environment. Waste management is one area of focus for the reduction of this environmental impact. Previous research has studied the quantities and compositions of healthcare waste highlighting the potential for recycling. Limited research to date has investigated both health and social care waste management in a holistic study incorporating the behaviour, composition and systems. The current study aimed to investigate waste management behaviour, systems and compositions at four health and social care sites in the South West of England, then derive a framework of health and social care waste management behaviour incorporating points of intervention for the improvement of waste management practices. Methods - A mixed methods multi-strategy concurrent triangulation design was used to investigate the waste management at four health and social care sites in the South West of England. This consisted of a management interview sub-study investigating waste management policy, guidance and training. An observational sub-study was used to investigate health and social care employee waste management behaviour. An audit of the clinical and domestic waste streams provided an overview of the waste composition at each site. Finally a self-report questionnaire sub-study of decision making was conducted to investigate the conscious and habitual aspects of waste management decision making. The findings from these four sub-studies were then synthesised through a data triangulation process. Findings - The domestic waste bins were most commonly used to dispose of waste during the observational sub-study. The waste audit sub-study found the domestic waste stream contained the largest percentage of potentially recyclable waste. The observational sub-study also uncovered twenty unique primary themes influencing the employee waste management behaviour. These themes included aspects internal to the health and social employee such as confusion, and external themes such as equipment. The management interviews highlighted a lack of waste management training and a reliance on the local site waste management policies to guide and monitor employee waste management behaviour. Discussion - The health and social care waste management behaviour improvement framework (HWMBIF) is presented. The HWMBIF is a novel framework, derived from the triangulated data of the current study, for understanding and improving waste management behaviour at the participating sites. Several interventions based in the HWMBIF and on the study findings are presented. Future research will focus on testing and refining the HWMBIF, the suggested interventions and developing further interventions.
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Cellulose degradation under alkali conditions, representative of cementitious radioactive waste disposal sitesBassil, Naji Milad January 2015 (has links)
Deep geological disposal in a multibarrier cementitious facility is being developed by a number of countries for the safe, long-term disposal of intermediate-level radioactive wastes. Intermediate-level radioactive waste, which dominates the radioactive waste inventory in the United Kingdom on a volumetric basis, is a heterogeneous wasteform that contains organic materials including cellulosic materials, encased in concrete. Under the alkaline conditions expected in the cementitious geological disposal facility (GDF), these materials will undergo abiotic, chemical hydrolysis, and will produce degradation products including isosaccharinic acid (ISA) or gluconic acid (GA) that can form soluble complexes with radionuclides. Alkaliphilic microorganisms sampled from a hyperalkaline site contaminated with lime-kiln waste, were able to degrade cellulosic material (tissue paper) in Ca(OH)2 saturated microcosms at a starting pH of 12. Enzymatic processes in these microcosms caused the production of acetate, acidification of the microcosms and a cessation of ISA production. Enrichment cultures prepared at pH 10 and inoculated with a sediment from the same hyperalkaline site were able to degrade ISA, and couple this degradation process to the reduction of electron acceptors that will dominate as the GDF progresses from an aerobic ‘open phase’ through nitrate- and Fe(III)-reducing conditions post closure. A strictly alkaliphilic bacterium belonging to the Bacillus genus was isolated from the nitrate-reducing enrichment culture, and was found to degrade a variety of organic molecules that are expected to be found in a cementitious GDF. Detailed investigation into the growth of this bacterium suggested that different mechanisms are involved in the biodegradation of ISA and GA, and that bacterial growth is coupled to a decrease in soluble U(VI) concentrations. This implies that microorganisms could have a role in attenuating the mobility of radionuclides in and around a GDF via (i) the biodegradation of cellulose and cessation of ISA production, (ii) the biodegradation of the ligands (ISA and GA) and (iii) the immobilisation of radionuclides. This should facilitate the reduction of undue pessimism in the long-term performance assessment of suchfacilities.
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Solid waste management livelihood on Lagos dumpsite : analysis of gender and social differenceObadina, Adeola January 2016 (has links)
Increasing urbanisation has increased waste generation. This has led to an increase in waste being left uncollected in certain areas of low-income countries. With the inability of municipal authorities to provide the required collection services, there has been the emergence of private sector initiatives in waste management. Nonetheless, this does not offer a complete solution as waste still adorns many of these streets. This however, provides sources of livelihood for the urban poor, both men and women. They can be found in virtually all cities in low-income countries occupied in collecting, recovering, sorting, and recycling waste materials. Their activity not only creates a means of livelihood for them but also ensures sustainability in solid waste management. In most low-income countries, women still enjoy fewer rights and access to assets and resources than men. Accordingly in Nigeria, women are highly represented in low paid employment. The emphasis in development on issues of equity and inclusion, and women s autonomy and empowerment shows that women still count among the most vulnerable and excluded social groups. This doctoral study examines the issue of women in solid waste livelihoods in Lagos, Nigeria. The focus of the study is to identify gender and other socially-related constraints to participation by men and women in solid waste livelihoods in five Lagos dumpsites. It also analyses how these constraints affect their income levels. The research draws on a feminist approach using mixed methods of participant observation, questionnaire survey and interviews. The fieldwork commenced with identification of waste workers activities on the five dumpsites through participant observation. This was followed by the questionnaire survey which was piloted, refined and administered face to face to 305 dumpsite workers. Findings from the questionnaire survey revealed gender differences amongst waste scavengers, waste buyers and waste merchants according to the following criteria: age, marital status, other income-earning household members, hours worked daily, years spent working, education level, and number of dependent children. These factors also further reinforce gender differences in income generation. Further enquiry through qualitative interviews highlighted gender differences in tool usage and the types of waste resources handled. Inequality was also evident in terms of social equality, political power and decision making. The results also highlight childcare as one of the most important challenges that women alone face. Other findings include the impact of current modernisation policies on women s financial security, autonomy, and well-being. The waste livelihood activities observed offer positive economic benefits, and incomes higher than the minimum wage. However, it is important for those engaged in modernisation policy to understand the potential impact of these measures on the livelihood of waste workers, and to ensure their commitment to change will not reinforce inequality.
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L'implication des ménages dans un service public local d'environnement : le cas de la gestion des déchets ménagers par les collectivités territoriales françaises / The involvement of households in a local public service of environment : The case of solid waste management by French local authoritiesVicard, Fanny 27 January 2012 (has links)
Cette thèse aborde la question de l’implication des ménages dans un service public local d’environnement. Elle propose une analyse économique des mécanismes par lesquels les collectivités territoriales impliquent les usagers du service dans la réduction des déchets et le recyclage, compte tenu de la diversité des situations locales.La thèse est construite en deux parties. La première partie présente les leviers d’action dont disposent les collectivités territoriales pour encourager les usagers du service à des pratiques de gestion des déchets plus respectueuses de l’environnement. La thèse mobilise principalement ici les approches de l’économie de l’environnement pour proposer une grille d’analyse de la politique des déchets à l’échelle des collectivités territoriales. Cette grille d’analyse permet de construire une typologie des mesures mises en place par les collectivités territoriales françaises pour impliquer les usagers du service dans la réduction de la production de déchets et le recyclage. Quatre stratégies d’implication ont été identifiées empiriquement, résumant des combinaisons particulières de mesures développées par les collectivités territoriales.La deuxième partie porte sur les déterminants des choix des collectivités territoriales et sur la capacité des stratégies d’implication à encourager l’effort de recyclage des ménages.Elle propose un modèle microéconomique pour analyser simultanément les décisions des collectivités territoriales et des ménages face au problème de la gestion des déchets ménagers. La thèse s’appuie principalement sur les modèles développés dans le champ de l’économie publique et de l’économie des déchets. Les propositions théoriques formulées dans ce modèle sont ensuite testées empiriquement. La thèse met en évidence l’importance dans les choix publics de la prise en compte des caractéristiques des usagers du service,une politique étant d’autant plus efficace que les usagers sont prêts à la mettre en oeuvre.Elle souligne également que l’effort de recyclage des usagers du service est plus important si les collectivités territoriales ont une volonté affichée de responsabiliser l’ensemble des usagers par des mesures qui contraignent directement la production de déchets. / This thesis deals with the issue of households’ participation to a local public service provision, offering an economic analysis of the strategies developed by local governments in France to involve households in waste reduction practices and recycling.In a first part, we present the policy instruments available to local governments in the French context to foster the adoption by households of waste management practices more respectful of the environment. Environmental economics are used here to build aconceptual framework to understand local governments’ waste management policy. On this basis, a typology of the measures undertaken by local governments to involve households in waste reduction practices and recycling is developed. We identify four distinct strategies,as specific combinations of the measures implemented by local governments.In the second part, we assess the determinants of local governments’ choices with regard to their waste management strategy and the ability of each strategy to promote recycling effort by households. Drawing on insights from public economics and economicsof household waste management, a microeconomic model is developed to simultaneously analyze local governments and households waste management decisions. Theoretical propositions derived from the model are then empirically tested. The results highlight their mportance for local governments of taking into account households’ characteristics in the definition of their waste management strategy. We also show that households’ recycling effort rises when local governments implement measures directly constraining household waste production.
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