Magister Scientiae - MSc / It was hypothesized that South African FA and brine could sequester CO2 through mineral carbonation. A statistical approach was undertaken to optimize the % CaCO3 formed from FA/brine/CO2 interaction with input parameters of temperature, pressure, particle size and solid/liquid ratio (S/L) being varied. The ranges adopted for the input parameters were: temperature of 30 ºC or 90 ºC; pressure of 1 Mpa or 4 Mpa; four particle sizes namely bulk ash, > 150 μm, < 20 μm and 20 μm- 150 μm particle size range; S/L ratios of 0.1, 0.5 or 1. The FA/ brine dispersions were carbonated in a high pressure reactor varying the above mentioned input parameters. The fresh Secunda FA of various size fractions was characterized morphologically using scanning electron microscopy, chemically using X-ray fluorescence and mineralogically using qualitative X-ray diffraction. The carbonated solid residues on the other hand were characterized using quantitative X-ray diffraction, scanning electron microscopy, thermal gravimetic analysis and Chittick tests. The raw brine from Tutuka together with the carbonation leachates were characterized using inductively coupled mass spectrometry and ion chromatography. Total acid digestion was carried out to evaluate the differences in the total elemental content in both the fresh ash and the carbonated solid residues. The results suggested that South African FA from Secunda belongs to class F based on the CaO content as well as the total alumina, silica and ferric oxide content, while the RO brine from Tutuka were classified as NaSO4 waters. / South Africa

Magister Artium - MA / A widespread phenomenon on dumpsites in the developing world, subsistence waste picking is also a common practice at the city-owned Coastal Park Landfill (CPL) in Muizenberg. Poor unemployed people from the townships of Capricorn, Vrygrond and Hillview, situated at the foot of the tip ―skarrel for scrap‖ every day. The word skarreling is an Afrikaans term meaning to rummage or scrabble, scuttle or scurry. Thus, if one talks of ―skarreling for scrap‖, it generally refers to poor people trying to eke out a living by looking for recyclables in the waste that can be put to personal use or turned into money. In the two decades since the transition to democracy, South Africa and the City of Cape Town (CCT) have formulated a number of framework and subordinate policies which express their commitment to sustainable development (SD). SD aims to achieve a balance between its three components, economic, environmental and social sustainability. Thus, SD is not only about increased economic efficiency and stability, while at the same time reducing pollution and handling natural resources more thoughtfully; it is also about promoting social equity by reducing poverty and empowering the poor. This study is guided by the assumption that waste pickers in developing countries play an important part in recycling efforts, and that recycling in turn is an integral component of SD, which is the guiding principle of South African policy-making. In an ideal scenario – as implicitly promised by the policies on SD – the management of solid waste should pursue the economic and environmental goals of SD by promoting recycling and should be aligned with the goal of creating sustainable livelihoods. However, the reality in the CCT is a different one. Landfill skarreling in the CCT, and particularly at CPL, is accompanied by conflict and a criminalisation of the skarrelaars. The CCT decided to phase out landfill salvaging in 2008, and subsequently has put a lot of effort into keeping skarrelaars away from its landfills. The implications of this decision – job losses for poor people and a potential increase in crime – have not been thought through. There is thus a dysfunctional triangular relationship around waste recycling in the CCT, leading to tensions between (1) the City‘s commitment to SD; (2) 5 its approach towards recycling (as part of solid waste management) in policy and practice; and (3) the livelihoods of the poor in adjacent townships. In the CCT the goals of SD are undermined by the City‘s recycling strategies, with adverse effects for the livelihoods of the people who live off skarreling. There are several causes for this disjuncture between policy and reality. The first has to do with ignorance on the side of the policymakers. They seem to be badly informed about the extent and nature of skarreling, perhaps assuming that this activity is performed only by a few people who need quick cash for drugs. The second cause can be attributed to the neoliberal macro-policies pursued in South Africa, as well as to the global competition between cities for investment. This neoliberal urbanism leads cities like Cape Town to re-imagine themselves as ―world (-class) cities‖, in which poor waste pickers are perceived as a disturbing factor. In the CCT, this goes hand in hand with an approach reminiscent of the apartheid mindset, which saw the need to control poor, black (and potentially unruly) people. The dissertation therefore focuses on the core themes of sustainable development, (urban) neoliberalism, and informality in combination with a case study of the informal waste pickers at the chosen landfill site. Writing from a political studies angle, this study is framed as a policy critique: it argues that the policies around SWM ignore South African realities, and that the SD policies and their implementation lack coherence. Moreover, the conflict between the skarrelaars and the CCT at the CPL is rooted in inadequate national and local legislation which does not acknowledge the role of informal waste pickers in SWM and aims at excluding rather than including them. If waste pickers were supported in their recycling efforts in both policy and practice, this would be a win-win situation for the state/city (economic benefits and less crime), the skarrelaars (regular employment and incomes) and the environment (less waste buried on landfills). The case study is primarily designed as a qualitative study, but also includes quantitative elements as it attempts a first quantification of the extent and nature of skarreling at the CPL site, one of only three operating dumpsites in Cape Town. The aim on the one hand is to estimate the contribution of the skarrelaars to waste reduction (and therefore to sustainability) in the City, especially since the waste they collect is not buried on the landfill, thereby prolonging the operational life span of the landfill. The other aim is to assess the role of the skarrelaars as an economic factor in the township, in particular the question of how important the incomes generated from skarreling are for their individual livelihoods and for the community as a whole.

The continuing industrial development has led to a corresponding increase in the amount of waste water generation leading to a consequential decline in levels and quality of the natural water in the ecosystem. Textile industries consume over 7 x 10[superscript 5] tons of dyes annually and use up to 1 litre of water per kg of dye processed and are third largest polluters in the world, the problem being aggravated by the inefficiencies of the dye houses. An abundance of physio-chemical methods are in use world wide, however, there is increasing concern as to their impact in effectively treating textile effluents as they introduce secondary pollutants during the ‘remediation’ process which are quite costly to run, maintain and clean up. Research on biological treatment has offered simple and cost effective ways of bioremediating textile effluents. While aerobic treatment of textile dyes and their effluents has been reported, its major draw back is commercial up-scaling and as such anaerobic systems have been investigated and shown to degrade azo dyes, which form the bulk of the dyes used world wide. However, the mechanisms involved in the bioremediation of these dyes are poorly understood. The aims of this study were to identify and investigate the role of enzymes produced by sulphate reducing bacteria (SRB) in bioremediating textile dye and their effluents. Sulphate reducing bacteria were used in this study because they are tolerant to harsh environmental conditions and inhibit the proliferance of pathogenic micro-organisms. The appearance of clear zones in agar plates containing azo dye concentrations ranging from 10 – 100 mgl[superscript -1] showed the ability of SRB to decolourize dyes under anaerobic conditions. Assays of enzymes previously reported to decolourise azo dyes were not successful, but led to the identification of hydrogenase enzyme being produced by SRB. The enzyme was found to be localised in the membrane and cytoplasm. A surface response method was used to optimize the extraction of the enzyme from the bacterial cells resulting in approximately 3 fold increase in hydrogenase activity. Maximum hydrogenase activity was found to occur after six days in the absence of dyes but was found to occur after one day in the presence of azo dyes. A decline in hydrogenase activity thereafter, suggested inhibition of enzymatic activity by the putative aromatic amines produced after azo cleavage. Purification of the hydrogenase by freeze drying, poly ethylene glycol, and Sephacryl – 200 size exclusion- ion exchange chromatography revealed the enzyme to have a molecular weight of 38.5 kDa when analyzed by a 12 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 40 °C while it exhibited a poor thermal stability with a half-life of 32 minutes. The kinetic parameters V[subscript max] and K[subscript m] were 21.18 U ml[superscript -1} and 4.57 mM respectively. Application of the cell free extract on commercial dyes was not successful, and only whole SRB cells resulted in decolourisation of the dyes. Consequently trials on the industrial dyes and effluents were carried out with whole cells. Decolourisation rates of up to 96 % were achieved for the commercial dyes and up to 93 % for the industrial dyes over a period of 10 days.

The handling of wastes is an eternal problem, all societies are confronted to this issue. Their origins are very diverse, they could come from industrial activities, power production, shops, retail or household for instance. While in developed countries the collection is generally efficient and the disposal safe, the situation in developing countries is different. The municipal budget does not allow the construction of advanced and expensive methods of disposal and the collection suffer from the age of vehicles. This generalisation is nevertheless not totally truth as the situation is extremely depend on the country but also of the city considered. Each city will need to adapt its waste management according to its size, climate, wealth, culture, etc... This report will focus on a Namibian medium town, Tsumeb. The aim is to be able to draw a clear picture of the waste management currently achieved. When the situation is well known, new directions to make Tsumeb refuse management more sustainable can be decided. Implementing progressively an integrated waste management (IWM) is a solution to the waste problem as it is considering economic, social and environmental impacts. A waste characterization was done in order to know the exact amount and composition of the waste generated in Tsumeb to implement afterwards the most suitable solution. The refuse of Tsumeb are surprisingly very similar to high income country. Moreover the stakeholders involved in recycling were investigated. A small informal sector is already making a living by recycling a few materials as glass bottle and cans. There is also a possibility to include extra stakeholder in the recycling process in Tsumeb. Recycling companies, recycling organization or investors are also important stakeholder who can be include in Tsumeb recycling plan. Developing recycling in Tsumeb is facing some challenges but it is also full of opportunities. The main issue when it comes to recycling in Namibia is the long transportation distances what makes it expensive. Furthermore, most of the recovered materials have to be sent in South Africa because Namibia does not possess the necessary industries to recycle paper and glass for instance. On another hand the presence in Tsumeb of a small informal sector already working with waste is promising. The workers could be more organized and the municipality can also helping them with logistic and storage to improve the recycling done. The dump site will also be close within the next years and a new sanitary landfill will be open. It will be a great opportunity to implement a recycling facility on site. Informal workers working on the landfill will be more controlled, to avoid for instance children labour. Some stricter health and safety measure can be decided, to give better working condition to the informal manpower. The development of recycling activities in Tsumeb will be highly beneficial to the community. It will create jobs for the poorest part of the population, decrease the cost of the waste management, reduce the pollution and stimulate the local economy.

The generation of solid waste is a natural consequence of human life. Its rate has increase rapidly along the years, mostly due to the population growth, urbanization process coupled to industrialization and economic development. The uncontrolled disposal of solid waste in unsuitable sites, dump sites, has poses a threat to public health and the environment. In this regard Global efforts has been made to rethink municipal solid waste management toward sustainability. Middle- and low-income countries, such as Brazil, should seize the opportunity and centre efforts in the development and strengthen of an inclusive municipal solid waste management, supported by an innovative public policy where all government levels are integrated and focused on resource recovery and recycling through the organization and strengthening of waste pickers, in order to act directly in the income improvement of a marginalized portion of society as a result of the revenue generated by recovered and recycled materials sales, as well as reduce the CO2eq emissions consequent from the disposal of solid waste, among others, hence moving these countries towards the achievement of the SDG goals. In this regard, a well managed inclusive municipal solid waste system requires a reliable data source to support decision makers in the design of public policies with effective actions in the field, otherwise innovative and modern public policies will be filled with fruitless actions, thus, wasting the aptitude of the municipal solid waste management system in help middle- and low-income countries to successfully carry out the SDGs goals. Nevertheless, the estimation methods are a valuable tool for decision makers in middle- and low income countries to outrun the lack of solid waste information and doing so, increase the effectiveness of public polices towards a sustainable and inclusive municipal solid waste system, focused on mitigate negative impacts in the environmental sphere and potentiate the positive outcomes in the public health and human development sphere in these countries. This research proposed an estimate method based on the nominal income which is able to provide a reliable estimate of the residential solid waste generation, as well as its spatial distribution in the municipal level and within the municipal boundaries. The proposed approach has the ability to differentiate spatial distribution of the residential solid waste generation, weighting not just the number of people living in a determined space, but also the purchase power of those people, providing a more accurate view of the issue, which benefits decision makers to design and plan their polices and actions. / Graduate

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Here in, comprehensive management model of municipal solid waste collection and transportation, “MIGRU,” is proposed, based on the Lean Six Sigma, VSM, and Servqual methods. This model considers and includes three important management systems for an efficient collection value chain: quality management, route management, and HR and community management. The proposed model was implemented and validated in the municipality of Lima, Peru, and the results showed that municipal costs were reduced up to 40%, solid waste was reduced in the streets, and routes and processes were updated and improved in addition to an improvement in the participation and environmental education of citizens. Thus, correct management of the proposed model’s three general approaches to a very positive municipal impact at economic and environmental levels, without the investment of excessive amounts of money observed in first-world countries.

Swedish power plants have in general an overcapacity which means that they must import waste from abroad. The imported fuel consists of several types of waste, but the majority originates from municipal and commercial waste. EFO is one of the leading fuel supplying and transport companies in Sweden. The company is owned by eight power plants located all around Sweden. The waste is purchased from other countries and then shipped to Sweden. During the unloading of the ship, when the cargo hatches opens, the malodourous gases will escape and be released in to the air. These malodours can travel quite far and are extremely unpleasant to people who live close by. The aim of this thesis was to suggest ways on how to prevent or reduce the emission of malodours during unloading of bales containing municipal waste. The aim of the project was to determine the causes of malodours, to identify the most common odorants in municipal waste, what properties they have, how they can be affected and how to prevent the formation of them. The problem was tackled by theoretical and practical studies. The theoretical study was a literature study and the practical study was observation at Mälarenergi combined heat and power plant. The results are presented as a number of suggestions for how to prevent or reduce the emission of malodours during unloading of bales containing municipal waste. These suggestions were divide in to the three categories Storage, Unloading and At Port. The suggestions varied from using better sorted waste to researching the possibility to use a portable tent covering the cargo ship during unloading. It was recommended that EFO should use both short- and long-term plans and also conduct further research on other ways to reduce emission of malodours.The suggestions were not tested so it cannot with certainty be determined if the suggestions will reduce or prevent emission of malodour. No laboratory tests were done on the waste. Therefore, the contents and concentrations could not be confirmed. However, it is almost certain that even if there were a slight difference it would not lead to a change of the current treatment process of the MSW. Obviously, there should have been multiple observations carried out at Mälarenergi`s power plant on various occasions and at different weather conditions. Several observations should also have been done on EFO´s other power plants to confirm that the core of the malodour emission problem is the same for all power plants. Basing suggestions on results taken from one instance might not give the correct answer to the problem. Common for malodours found in MSW is that they are formed as a product of degrading MSW. Reducing or stopping the degradation process, will prevent the formation of these compounds. This can be done either by lowering the temperature of the waste bales, altering the pH, decreasing the water content and increasing the level of Oxygen. / De svenska kraft- och värmeverken är så effektiva att det svenska bränslet inte räcker till utan man måste importera från andra länder. Bränslet består till stor del av hushållsavfall och kommersiellt avfall. EFO är ett energianskaffnings- och transportföretag som delägs av åtta svenska el- och värmeleverantörer. De förser sina ägare med bränsle till deras kraft- och värmeverk runt om i landet. Majoriteten av det inköpta bränslet kommer från utlandet och fraktas till Sverige med fartyg. Problemet för boende i närområdet är att avfallet avger dålig lukt när det lastas av från fartyg till hamn. Syftet med den här rapporten var att undersöka hur man kan förhindra eller minska utsläpp av dålig lukt vid avlastning från fartyg till hamn samt att ge förslag på metoder som kan minska luktproblematiken. Övriga mål var att fastställa vilka de mest förekommande luktämnena är, orsaken till att de bildas, vilka egenskaper de har och hur man kan förhindra att de bildas. Arbete består av en litteraturstudie tillsammans med observation gjord på Mälarenergis kraftvärmeverk. Resultaten presenterades i form av ett antal förslag på sätt att minska utsläpp av dålig lukt vid avlastning. Dessa förslag indelades i de tre områdena Lagring, Avlastning och Hamn. Förslagen var breda och sträckte sig från användning av bättre sorterat avfall till att utreda om det finns möjligheter till användning av ett portabelt tält kring fartyget under avlastning. Utöver de presenterade förslagen för minskning av luktutsläpp gavs också rekommendationen att EFO bör använda sig av både kortsiktiga och långsiktiga planer samt forska på ytterligare sätt för att minska utsläpp av dålig lukt. Förslagen har inte prövats och det kan därför inte fastställas om de reducerar och förhindrar utsläpp av dålig lukt. Det gjordes heller inte några laboratoriska analyser på avfallets innehåll därför kan det inte bestämmas om avfallet innehåller samma ämnen och koncentrationer. Sannolikt skiljer sig inte värdena så pass mycket att det skulle kräva andra typer av luktreducerande metoder. Fler observationer borde ha gjorts både på Mälarenergis anläggning och på de andra delägarnas anläggningar. Observationerna skulle då också utförts vid olika tidpunkter samt vid olika väderlek. Det är möjligt att resultatet skulle vara annorlunda om det funnits data från fler observationer. Gemensamt för ämnen som avger dålig lukt är att de uppkommer som en produkt av nedbrutet avfall. Genom att bromsa eller stoppa nedbrytningsprocessen kommer uppkomsten av dessa luktämnen förhindras. Detta kan man göra genom att förändra pH, sänka temperaturen, minska fukthalten och öka syrenivån.

With the complex composition of the radioisotopes and waste materials, the characterization of the volumetric low-level wastes from CANDU plants is challenging. This study presents a technique to localize and quantify the contaminations presented in the CANDU waste containers. MCNP-based models are developed for an N-type coaxial HPGe detector and a LaBr3 detector to simulate the photon peak information. The simulated efficiency and the experimental count rates are combined to estimate the activity of unknown waste samples. During the spectrum collection of a 4L Marinelli beaker source and 1-quart waste samples, the MCNP algorithm showed better accuracy in activity estimation than the Mirion ISOCS/LabSOCS software. With further development, this method has the potential to outperform the popular commercial software in estimating activity for volume sources with complex geometry and uneven distribution. The multi-detector array models with hotspot designs are also studied in this work to provide real-time information about the location and activity of the contamination inside the 2.2 m3 industrial low-level waste containers. The on-site measurements show promising results as the position of the contamination was able to be located within a volume of 61×40×34 cm. Overall, this technique has good potential to be utilized in the nuclear industry for large-volume low-level waste analysis. / Thesis / Master of Science (MSc)

Waste recycling is gaining prominence and acceptance compared to landfilling to reduce greenhouse gas emissions. Municipal solid waste (MSW), the largest source of solid waste, is primarily composed of food waste, plastics packaging and papers. Thermochemical recycling technique, such as pyrolysis, is considered as a promising alternative for producing value-added products. Pyrolysis is a process occurring in inert environments at moderate temperatures controlled by parameters such as the reaction temperature, heating rate and residence time to produce bio-oil and biochar. It is also known for its high tolerance for mixed waste stream. In this thesis, fruit waste (FW) consisted of bananas, apples, oranges and cucumbers peels and commercial high density polyethylene (HDPE) as co-pyrolysis feedstock were investigated. Co-pyrolysis experiments were performed in a tubular furnace reactor to investigate the effect of polymer composition, temperature and CO2 atmosphere. HDPE composition was varied between 33–67% to investigate the effect of feedstock composition at 500 ˚C. A composition was fixed and then effect of temperature was assessed in the range 500–700 ˚C. Finally, in CO2 atmosphere, co-pyrolysis experiments were performed with 50% HDPE at 600 ˚C. The collected bio-oil and biochar were thoroughly characterized via different analytical techniques. The effect of different process parameters on bio-oil was studied by gas chromatography-mass spectrometry (GC/MS), proton nuclear magnetic resonance (1H NMR) and Fourier-transform ion cyclotron resonance mass spectroscopy (FT-ICR MS). Biochar samples are analyzed using scanning electron microscopy (SEM), CHNS elemental analysis and Fourier-transform infrared (FTIR). Detailed product composition revealed that formation of hydrocarbons was promoted with increasing HDPE, while significant deoxygenation was observed with increased temperature. In addition, heavier molecules in the bio-oil were studied via FT-ICR MS. HDPE loading and CO2 atmosphere stabilized the biochar by reducing the oxygen content. The results demonstrated the potential use of HDPE as a co-feed with FW in a pyrolysis system to produce valuable products.

The quick social economic development of Vietnam stimulates great demand of quality as well as quantity on transport service by the increasingly growing needs of customer for transportation. The railway passenger transport is currently still an important branch of a country’s transport system because it is safer, more eco-friendly and much more efficient in comparison to another means. However, the increasing of the number of passengers is the main causes of fast increasing waste amount from the rail service. The aim of this paper is to study how the organic waste from rail service is managed and treated today by the Vietnam railways. The paper ends with some proposal solutions for treating and disposing of organic waste by applying renewable energy technologies for climate change mitigation to protect human health and the environment. / Sự phát triển nhanh chóng của nền kinh tế Việt nam dẫn đến nhu cầu vận chuyển hành khách ngày càng tăng mạnh về số lượng cũng như chất lượng dịch vụ. Vận chuyển hành khách bằng đường sắt hiện tại ở Việt nam vẫn đóng vai trò quan trọng trong hệ thống vận tải quốc gia do lợi thế an toàn cao, thân thiện với môi trường và lợi ích cao của nó so với các phương tiện khác. Tuy nhiên sự biến động lớn của lượng hành khách đi tàu là nguyên nhân làm cho lượng rác thải từ các dịch vụ đường sắt cũng tăng mạnh. Bài báo tập trung vào nghiên cứu và làm rõ hiện trạng quản lý chất thải hữu cơ trên đường sắt Việt nam hiện nay cũng như các chiến lược nhằm xử lý chất thải hữu cơ, sử dụng công nghệ năng lượng tái tạo nhằm bảo vệ môi trường, giảm thiểu biến đổi khí hậu.