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Estudo da separação e aproveitamento da parte metálica e de óxidos presentes no resíduo gerado no corte de rochas ornamentais. / Study of separation and reuse of metallic part and present oxides in residue generated in ornamental rocks cutting.Eduardo Junca 30 November 2009 (has links)
Este trabalho tem como objetivo o estudo do reaproveitamento da parte metálica e a caracterização dos óxidos presente no resíduo de granito gerado na etapa de desdobramento. Inicialmente, foi feita a caracterização química e física do resíduo através de análise química, difração de raios-X, microscopia eletrônica de varredura e análise granulométrica. Após a caracterização do resíduo, foi dado inicio aos processos para a recuperação do Fe metálico que envolveram: separação magnética, mesa concentradora e ciclonagem. A separação magnética foi realizada em três etapas: a primeira onde se utilizou um separador magnético a úmido de alta intensidade, onde foi utilizado apenas o campo magnético remanescente do equipamento. Na segunda etapa, onde o material magnético obtido na primeira etapa foi submetido a uma nova separação magnética manual utilizando um imã de terras raras. Na terceira etapa, o material magnético obtido com o imã de terras raras foi submetido a uma separação magnética manual com um imã ferrítico. Nos ensaios de mesa concentradora, foram realizadas variações na inclinação da mesa, freqüência de oscilação e vazão de água de lavagem. Já nos ensaios de ciclone, o parâmetro variado foi à pressão de alimentação. Foram realizadas variações nos parâmetros dos equipamentos com o intuito de se aperfeiçoar e definir os melhores parâmetros para a recuperação do Fe metálico. Após cada ensaio, foi realizada a análise química volumétrica para a determinação do teor de Fe metálico obtido em cada produto. Pelos resultados obtidos, o método de separação magnética foi a que apresentou os melhores resultados, sendo possível a obtenção de um concentrado ferroso com 93% de Fe metálico e um concentrado granítico com 0,6% de Fe metálico. Já nos ensaios de mesa concentradora, o melhor resultado obtido foi um concentrado ferroso com apenas 13,7% de Fe metálico, e nos ensaios de ciclone foi possível à obtenção de um produto com apenas 7,2% de Fe metálico. A partir do concentrado ferroso e granítico obtido na separação magnética foi realizada a caracterização através de microscopia eletrônica de varredura, difração de raios-X e análise granulométrica. A partir do concentrado ferroso obtido, foram produzidos briquetes com uso de 2% de cal hidratada como aglomerante. Foram realizados testes de resistência mecânica a verde e a seco nos briquetes produzidos. Foi obtido uma resistência mecânica a verde de no máximo 1,02 kN e a seco de no máximo 3,59 kN. / The aim of this work is to study the reuse of the metallic part and the characterization of oxides present in the waste from granite sawing. First, the chemical and physical characteristics of the waste were analyzed by chemical analysis, X-ray diffraction, scanning electron microscopy and size analysis. Procedures for the metallic iron recovery (magnetic separation, concentrator table, and cyclonic separation) were performed after the waste characterization. Magnetic separation was performed in three phases. First, using a high intensity wet magnetic separator, which only the remaining magnetic field of equipment was utilized. In the second phase, the magnetic material obtained in first phase was subjected to a new manual magnetic separation using rare earth magnets. In a third phase, magnetic material obtained with rare earth magnets was subjected to manual magnetic separation using ferrite magnets. In the experiments of concentrator table, were carried out changes in table inclination, oscillation frequency and wash water flow. For cyclone tests, the varied parameter was the water supply pressure. Variations in equipment parameters were performed in order to improve and decide the best parameters for recovery of metallic iron. After each experiment, volumetric chemical analysis was performed to determine the metallic iron content of each product. The results show that the magnetic separation method had the best results since it is possible to obtain a ferrous concentrated with 93.0 wt. % metallic iron and granite concentrated with 0.6 wt. % metallic iron. While for concentrator table tests, the best result presented a ferrous concentrated with only 13.6 wt. % metallic iron; and for cyclone tests, a product with only 7.2 wt. % of metallic iron was obtained. Ferrous and granite concentrated from magnetic separation were characterized by scanning electron microscopy, X-ray diffraction and size analysis. Using the obtained ferrous concentrated, briquettes were produced with 2 wt. % hydrated lime as binder. Produced briquettes were tested using dry and wet mechanical strength test. Wet mechanical strengths of up to 1.02kN were obtained, and a maximum of 3.59kN was registered to dry mechanical strength.
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High-Solids Anaerobic Digestion of the Organic Fraction of Municipal Solid Waste State of the Art, Outlook in Florida, and Enhancing Methane Yields from Lignocellulosic WastesHinds, Gregory Richard 28 October 2015 (has links)
Anaerobic digestion (AD) is a biotechnology that employs natural microbial metabolism under oxygen-free conditions to stabilize organic waste. AD has been shown to be the most environmentally sustainable technology for treating the organic fraction of municipal solid waste (OFMSW), as it allows for the recovery of energy and nutrients from the waste. AD of OFMSW also saves landfill space and reduces leachate generation and fugitive methane emissions from landfills. High-solids AD (HS-AD) technologies (those designed to process feedstocks with >15% total solids content) have been shown to yield additional benefits when compared with liquid AD (L-AD) for treating OFMSW, including reduced parasitic energy demands, reactor volume requirements, water usage, and excess leachate generation. These factors paired with increasingly stringent environmentally-driven legislation have resulted in the steady development of HS-AD technologies in Europe since the 1990’s and the recent advancement of HS-AD in the United States. However, HS-AD implementation in the US is hindered by the low cost of landfilling and a general lack of regulatory drivers encouraging organics separation and recycling. The goal of this research was to contribute to accelerating the implementation and improving the efficiency of HS-AD technologies. The specific objectives were to: (i) assess the state of the art of HS-AD in Europe and the US and investigate trends in development; (ii) conduct a case study assessment of the outlook for implementation of HS-AD in the state of Florida; and (iii) investigate the potential to enhance methane (CH4) yields in HS-AD of lignocellulosic wastes through bioaugmentation with pulp and paper mill anaerobic sludge.
Information sources for the assessment of the state of HS-AD in Europe and the US included “grey” and published literature and discussions with consultants and technology vendors. In Europe as of 2014 there were 244 full-scale AD facilities for processing OFMSW with a total capacity of almost 8 million tons per year (TPY), approximately 89% of capacity was “stand-alone” (systems treating only OFMSW), 62% was HS-AD, and 70% installed since 2009 was HS-AD. In the US, as many as 181 AD facilities are now processing OFMSW with an approximate total capacity of 780,000 TPY. Only 24% of the total capacity is currently stand-alone HS-AD with the remaining capacity being stand-alone L-AD (28%) or L-AD codigestion (48%) at wastewater treatment plants or on-farm systems. Development trends in the US are mirroring those in the EU, however, with stand-alone capacity steadily increasing and HS-AD capacity increasing particularly rapidly relative to L-AD for OFMSW processing. The number of full-scale HS-AD facilities in the US has increased from one in 2011 to eight in 2015 and another 19 systems are expected to be operational by 2017. There are at least nine vendors of HS-AD technologies in the US, including four with facilities currently in operation and another four with projects in the planning, permitting, or construction phases. Landfill bans and taxation, mandated source-separation of OFMSW, and policies incentivizing recycling and renewable energy generation are critical factors driving the development and implementation of HS-AD.
The case study of HS-AD implementation in Florida incorporated information from industry and data from the Florida Department of Environmental Protection. There is high demand for organics recycling in Florida, with numerous counties generating several hundred thousand TPY of OFMSW and lacking organics recycling infrastructure. HS-AD implementation could increase the statewide recycling rate by as much as 13% and contribute significantly to the reaching the state’s recycling goal of 75% by 2020. Furthermore, up to 7,000 and 3,500 TPY of bioavailable nitrogen and phosphorus, respectively, and up to 500 MW of energy could be recovered through HS-AD of OFMSW in the state. Based on current energy conversion efficiencies, 500 MW of energy translates to either 175 MW of electricity (approximately 660,000 metric tons of CO2 equivalents offsets per year) and 200 MW of heat or nearly 80 million diesel gallon equivalents of vehicle fuel. However, because of the low cost of both landfilling and energy in the state and the lack of markets for compost and renewable energy certificates, legislative action is needed to improve the economic feasibility of HS-AD. Accordingly, a number of policy recommendations were formulated, including banning disposal of OFMSW to landfills and mandating source-separation of OFMSW by all generation sources.
Two phases of side-by-side bench-scale batch HS-AD experiments were carried out to investigate the potential to enhance CH4 yield from lignocellulosic waste in HS-AD through bioaugmentation with pulp and paper mill anaerobic sludge. In the first phase, the average CH4 yield from yard waste inoculated with pulp and paper sludge reached 100.2 ± 2.4 L CH4/kg VS, a 73% enhancement compared with the average CH4 yield achieved through inoculation with domestic wastewater anaerobic sludge (58.1 ± 1.2 L CH4/kg VS). In the second phase, CH4 yield from yard waste inoculated with digestate from digesters originally inoculated with pulp and paper sludge was 68% greater than the CH4 yield achieved through inoculation of yard waste with digestate from digesters originally inoculated with domestic wastewater sludge (36.5 ± 0.2 L CH4/kg VS versus 21.7 ± 0.4 L CH4/kg VS). The enhancement in CH4 yield achieved in this study is comparable to enhancements achieved through lignocellulosic pretreatment methods. However, this strategy incurs significantly less additional environmental and economic costs when compared with pretreatment, suggesting that it could serve as an alternative to pretreatment and improve the overall sustainability of HS-AD processes.
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Re-defining the concepts of waste and waste management:evolving the Theory of Waste ManagementPongrácz, E. (Eva) 25 September 2002 (has links)
Abstract
In an attempt to construct a new agenda for waste management, this
thesis explores the importance of the definition of waste and its impact
on waste management, and the role of ownership in waste management. It is
recognised that present legal waste definitions are ambiguous and do not
really give an insight into the concept of waste. Moreover, despite its
explicit wish of waste prevention, when according to present legislation a
thing is assigned the label of a waste, it is going to be treated like
waste, implicitly legislation thus amasses waste. The philosophical
ramifications inherent in such definitions mean that they are not capable
of constructing a system that, by its very nature, results in a
sustainable waste management system. It is also a fact that, while there
are numerous practices as to how to deal with a particular type of waste,
there is no theory of waste management. In this thesis, waste as a concept
is analysed from the point of view of why and when waste is created. Using
the PSSP language, waste is classified based on the Purpose and
Performance attributes. New, dynamic definitions for waste and waste
management are offered, which explain why waste is created and
intrinsically offer a solution to how the problem could be solved.
Additional waste-related concepts are introduced, which are thought to
have great potential for improvement on waste regulation. The concept of
ownership is explained as rights and responsibilities of waste
creators/owners: it is thus crucial to raising awareness about waste.
Ownership in itself often dictates which waste management options are
preferentially adopted by a given community. The role of legislation in
producing monitoring systems for the transfer of ownership as well as
abandonment of ownership is analysed. To avoid obstacles to resource
conservation due to materials being considered waste, a definition for
non-waste is introduced. The new agenda for waste management thus focuses
upon the development of more appropriate, sustainable definitions so that
what is now commonly perceived as being waste will in fact be increasingly
seen as resource-rich, 'non-waste'. The role of waste management is
explained as control of all waste-related activities, with the aim of
preventing, minimising or utilising waste. The need for a theory of waste
management is explained, and the first building blocks of the theory are
proposed. This thesis is offered as the first step toward scientification
of waste management.
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Vyhodnocení množství zpětně odebraných baterií a akumulátorů v rámci České republiky s využitím GIS / Quantity assessment of backward collected batteries and accumulators in the framework of the Czech Republic using GISKukal, Tomáš Augustin January 2017 (has links)
The number of batteries and especially accumulators, which we use, is growing every time and collection with take-away is growing too. Now it is absolutelly important look for a way to optimalization, which can be for example builing new processing equipment. Graduation thesis deal with data analysis from battery collection, data processing and building a data model in four variants. Graduation thesis work with number of battery and accumulators in czech households and bring answer to question "How many batteries we have got approximately in our households?" Output is processing questionary about Research of battery in households,which is used in next work. The main output is data model.Model work with distance of take-way route on principe Service area and Transportation theory. Data are obtained by ArcGIS and processed in Excel. The output are map schematics which are based from four studies. First study shows present state, next shows battery factory in another capital town in regions of the Czech Republic. Third shows variant battery factories in three biggest cities and fourth battery factory in all czech cities, that have 100 000 residents. The best combinations is probably study with three biggest cities, because in this study is saving 50 % of costs and withal it is not necessary build many...
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Posuzování životního cyklu skládkování odpadu / Life cycle assessment of landfillingKosová, Kristýna January 2017 (has links)
This thesis is focused on the method of Life Cycle Assessment (LCA) in Waste Management in the Czech Republic. The aim of this work is creation of landfill model and evaluate the main material, energy and elementary streams with influence on the environment. The output is an overview of each impact indicator, assessment most affected environmental categories by landfilling. and where is appropriate the optimization. The thesis consists of two parts, theoretical and experimental. The theoretical part deals generally about LCA, landfilling and municipal waste, their production and the possibilities of further handling them. In the experimental part is evaluated and compare the impact of 1 tonne lanfilling waste per 1 calendar year on several Czech landfills. The next was created average landfill model and its comparison with database models. Key words Landfill, Life Cycle Assessment, Waste Management, Municipal solid waste
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Právní úprava odpadového hospodářství v České republice / Legal regulation of waste management in the Czech RepublicHuml, Miroslav January 2011 (has links)
English recapitulation of this thesis -Legal regulations of the Waste management in the Czech Republic The main purpose of the thesis is to demonstrate the most important waste management principles in the Czech Republic and in the other European countries. The thesis is divided into 8 chapters. The first chapter deals with a general introduction concerning the topic. It indicates global situation and undesirable influences of deficiencies in the waste management on condition of world seas and oceans. The second chapter considers the waste management as a branch of science activity. This branch was established in 1980s in west European countries, however, 10 years later also in the Czech Republic. The first Parliament Act on the waste management in Czechoslovakia was created in 1991. There were some mistakes and dubiousness in the Act and it was necessary to put them aside before joining the European Union in 2004. Before 2004, this Act had been changed completely two times. The Act of Czech Parliament 185/2001 Sb. went into force on 1st January 2002. Since then, it has been novelized many times according to the European law and is currently responding to the European directives. The third chapter mentions some other acts which are connected with the waste management in the Czech Republic. On the top of...
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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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NON-INVASIVE CHARACTERIZATION OF UNSATURATED ZONE TRANSPORT IN DRY COAL ASH DUMPS: A CASE STUDY OF TUTUKA, SOUTH AFRICAMuchingami, Innocent I. January 2013 (has links)
Doctor Scientiae / The management of the large volumes of solid wastes produced as coal combustion
residue is of particular concern due to the presence of leachable metals and salts which
may constitute a long term environmental risk and potential contamination of both
surface and groundwater systems of the surrounding environment. In order to
implement an efficient monitoring scheme and to assess the impact of the ash dump on
the hydrologic system, a thorough knowledge on the migration of solutes fluxes in dry
ash dumps as well as the controls on the transport of these solutes to the underlying
groundwater system is required.
The conventional methods which have been widely used for such applications are
centred on extracting and analysing several samples from observation wells are drilled
on the dump. This has however created a potentially hazardous situation as the
installation of monitoring wells may result in the creation of new fluid pathways and
results in further migration of leachates. Nevertheless, non–invasive characterization
has often been useful in the determination of subsurface hydraulic properties and is a
key step towards the solution of real-life problems in hydrology, hydrogeology and soil
science. In contaminant transport non-invasive methods have often proved to be an
efficient tool as compared to traditional drilling and sampling techniques which in most
cases results in the creation of preferential flow paths and do not allow for the space
and time resolution needed for the monitoring of hydrological and environmental
processes.
In this context, this study seeks to develop a generic conceptual model for the ash
dump through the use of non-invasive geophysical techniques and numerical modelling techniques at the Tutuka Ash dump, Mpumalanga South Africa. Changes in electrical
resistivity were used correlate changes in moisture contents during moisture and salt
leachate ingression in ash dumps with a sufficient accuracy. A determination of the
suitability of Archie‘s law to describe the relationship between electrical resistivity and
solute transport ash medium was achieved through empirical laboratory experiments.
Electrical resistivity tomography was then used as an appropriate tool for the elucidation
of potential flow paths and brine dispersion in the ash dump. The flow rates through the
ash dump were estimated by considering the rate of brine injection and the distance
travelled by the brine plume over the time spanned in time lapse infiltration experiments.
Additional geophysical profiles managed to show the lithostratigraphy of underlying
hydro-geology, thereby ensuring that the knowledge of the geology can be established
without the application of any intrusive methods.
To ensure that development of the conceptual model of the unsaturated zone transport
of the ash dump was developed with sufficient accuracy, numerical models were also
used to describe solute transport in the vadose zone. The HYDRUS2D numerical
package was used simulate the flux dynamics within the unsaturated zone of the coal
ash medium, so as to develop a conceptual understanding of water flow and salt
transport through the unsaturated zone of the coal ash medium. The results from the
study suggested a conceptual solute transport model that consists of a two layers. The
upper layer represented the unsaturated zone of the ash dump which was the source of
any potential contaminant transport that could be of concern. The lower layer describe
the underlying the subsurface environment to the ash dump which include the soil zone,
the shallow aquifer and the deep fractured rock aquifer. To enable this conceptualisation, results from the numerical simulations and
geophysical interpretations of the electrical resistivity profiles were the critical
components for optimising the site-specific subsurface water flow and solute transport
processes, as well as producing the most acceptable conceptualisation of the ash dump
system that could be used in hazard assessment and mitigation against potential
groundwater pollution. The conceptual models developed in this study proposed an
explanation on impact of the ash dump to the hydro-geologic and the eco-hydrologic
environment by proposing a scenario of contamination of the underling ash dump and
the existing. In this regard, the study managed to provide important scenarios that may
be necessary during mitigation procedures for both the ash dump and the wetland.
Key words: non-invasive, coal ash, time lapse, electrical resistivity tomography,
numerical models, HYDRUS2D, conceptual model.
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Solid waste management in urban fringe settlements : the case of Winterveld, PretoriaMoiloa, Lebohang Regina 19 September 2007 (has links)
Governments and municipalities in the developing world face the challenge of rapid environmental deterioration in the growing informal settlements along the urban fringes. Waste management, its efficiency, or lack thereof, is becoming an increasingly urgent issue. In this thesis, Winterveld, located approx. 50 km north of Pretoria, is studied as a typical example of the problems and bottlenecks related to solid domestic waste management in a mixed urban fringe settlement. While the formal parts of Winterveld receive waste removal services, the – much larger - informal parts are not being provided with such services. A wide range of methodologies was employed to assess the current status of waste management and related environmental problems. Policies and actual service delivery by the City of Tshwane, responsible for providing waste removal service to the area, were investigated; surveys were conducted among waste removal contractors in and around Winterveld, and the residents from both formal and informal settlements. Field surveys were conducted to identify environmental problems on site, dumping sites and their change over time were mapped and digitized on orthophotos. Vegetation surveys complemented the fieldwork, as illegal dumping sites often are masked by vegetation. The following aspects were investigated: 1) the efficiency of governmental and municipal efforts regarding waste removal in informal Winterveld; 2) environmental and health problems caused by improper handling of waste; 3) the residents' attitudes towards waste management; 4) possible solutions to the problems. The findings revealed that Winterveld is not an exception from other informal settlements with regards to waste management. People are of the opinion that waste management is the sole responsibility of the government thus the residents are doing little to improve their own area. Government initiatives which include provision of facilities for waste management are misused and vandalised by the residents. Dumping along the roads, according to some residents is used as a call to the government to attract attention that the residents need removal services. The initiatives by the municipality should ensure that solid waste management facilities are socially acceptable and environmentally and economically sound. It is therefore very important to involve the community when investigate technologies that will benefit the economy and the environment maximally. Informing people may encourage them to change their negative attitudes by making them feel as an important part of waste management, this will eventually compel them to cooperate and play a positive role in waste management. Until such time that they change their attitudes, there is little hope that they will appreciate and protect the facilities provided. / Dissertation (MSc)--University of Pretoria, 2007. / Geography, Geoinformatics and Meteorology / MSc / Unrestricted
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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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