Global Health EngineeringOpen OpportunitiesThe Queen Elizabeth Central Hospital in Blantyre, Malawi, manages the solid waste produced at its premises by itself. The waste incinerator, built in its direct proximity, aims to improve solid waste management practices and is supposed to treat waste from this and other government hospitals in the city. However, more expertise and resources are needed to maximize the incinerator's use time. Most of the waste is continuously burned outside the incinerator's building, leaving the system unused and producing fumes toxic to the environment and human beings in this densely populated area. The incinerator is equipped with a petrol tank, facilitating the start-up procedure, and a forced convection fume cooling and treatment system. The fume cleaning system is electrically powered and functional. However, the cleaning efficiency remains unknown. - Environmental Technologies, Mechanical Engineering
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| Poor sanitation is a significant problem in sub-Saharan Africa. The pit latrines, which are the most commonly used toilet, can be difficult to empty and often overflow, and there are few safe disposal options for the contents. Concurrently, while domestic food production could increase food security, households struggle to obtain expensive inputs like fertilisers. Urine diverting toilets (UDT) may help mitigate both problems.
Urine diverting toilets separate urine from faeces. Many prototype UDTs have been developed, among them the EOOS UDT (EOOS Social Design, n.d.; Gruendl et al., 2018) - through extensive testing and funding provided by the Bill and Melinda Gates Foundation. A detailed design for producing the mould has been made open source, allowing for adaptation and experimentation. The EOOS UDT can therefore be locally manufactured and has been designed in a simple way to allow households to make the toilets themselves. - Mechanical Engineering, Water and Sanitary Engineering
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| Article 6 of the Paris Agreement encourages international cooperation and allows high-income, high-polluting countries to meet their carbon reduction commitments affordably by funding carbon reducing activities in lower-income countries, claiming the carbon reductions for themselves (Asian Development Bank, 2020). Specifically, Switzerland, under its CO₂ Act and through the Swiss Foundation for Climate Protection and Carbon Offset (KliK Foundation) aims to offset about 40 million tonnes of CO₂ by 2030—10% of its national emissions–with over half of these offsets occurring abroad.
One upcoming collaboration is with Malawi, which involves distributing 10,000 household biogas digesters to dairy farmers (Foundation for Climate Protection and Carbon Offset (KliK), 2023). This project is expected to mitigate approximately 436,000 tons of carbon dioxide equivalent (CO2e) annually. Typically, animal dung is stored in piles, decomposing anaerobically and releasing methane into the atmosphere. By feeding it into a digester, this methane release is prevented, converting it into biogas that can be used as cooking fuel. Biogas can replace wood fuel for cooking, which is often sourced from local forests, thus reducing carbon emissions from deforestation as well as from the burning of biomass. The CO2e savings depend on a household's successful adoption of biogas technology, the replacement or reduction of non-renewable fuels such as wood, and the cessation of dung piling for storage. The CO2e offset for a large biogas project consisting of thousands of households is determined by the approved methodology applied. These methodologies provide guidelines on estimating CO2e emissions and on how a project should monitor and verify the CO2e savings annually across thousands of households. Currently, there are five popular methods used to estimate CO2e savings from biogas projects, each with slight differences in their calculations and estimations.
All methodologies make reductive estimations on biogas adoption and usage that could result in CO2e savings being grossly overestimated. For instance, yearly surveys are conducted to monitor the functionality of biogas digesters. The percentage of biogas digesters found to be functional are then assumed to be operating optimally and replacing the ideal amount of wood fuel. However, these surveys typically sample only a very small number of households and assume that biogas usage is homogeneous across all households. Literature indicates that biogas usage is lower than the ideal scenario and varies considerably between household and throughout a year.
To date, no comprehensive study has compared the methodologies used to estimate carbon savings from biogas projects using accurate numerical data from literature. A recent publication by Gill-Wiehl, Kammen, and Haya (2024) suggests that carbon offset projects installing improved cookstoves may have over-credited carbon savings by a factor of 9.2, indicating the necessity of a similar investigation for small-scale biogas projects. Given the number of biogas projects proposed under the forthcoming Article 6 trading agreements, it is crucial to assess these methodologies. This assessment will help ensure accuracy and reliability in carbon savings estimates and provide recommendations for methodological improvements at this critical time. - Environmental Engineering, Mechanical and Industrial Engineering
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| Absorbent hygiene products (AHP) is a broad category of products that includes baby diapers, sanitary protection pads, tampons, adult incontinence products and personal care wipes. Nowadays, it is one of the most challenging types of post-consumer waste that is not recycled and usually disposed of via either landfill or incineration. AHP waste currently represents about 2-3% of the total municipal solid waste, and represents up to 15-25% of the residual waste stream in some treatment facilities, where selective collection rates above 70% are in place (European Commission, 2024). Literature review is necessary to gain a detailed understanding of existing technologies that allow for the recycling of AHP products, and assess to what degree they are/can be separated in different settings. - Mechanical Engineering
- Semester Project
| Cape Maclear, a township with approximately 20,000 inhabitants, located on the southern shore of Lake Malawi, has transformed over the past two decades from a quiet fishing village to one of Malawi’s most popular tourism destinations. Presently, farmers use the only available source of water by redirecting water flows through open channels dug in the soil. With water being a scarce and precious resource, the largest problem of the existing solution is that only a part of initial water flow nourishes the plants. Farmers in Cape Maclear do all the earth work and crop collection manually. They also rely on a single source of water for their crops all year round. A feasibility study, aiming to install a drip irrigation system in Cape Maclear is the first step to help the farmers and preserve water. - Environmental Engineering Design, Farm Management, Rural Management and Agribusiness, Sustainable Development, Water and Sanitary Engineering
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| Cape Maclear, a township with approximately 20,000 inhabitants, located on the southern shore of Lake Malawi, has transformed over the past two decades from a quiet fishing village to one of Malawi’s most popular tourism destinations. Five master's theses, completed in the spring semester 2024, performed a feasibility study of a waste management system in Cape Maclear and worked on its implementation. The following topic were explored:
- Waste Separation and Valorization Pathways.
- Construction of the Glass Crusher and Evaluation of Waste Valorization Pathways.
- Development of a Low-Cost Incinerator.
- Willingness to Pay and Economic Feasibility for Waste Collection.
- Waste Logistics and Transport Modelling.
This work is a follow up of the second master’s thesis (Construction of the Glass Crusher), within which two glass crushers were built. Further work is necessary to establish a process that allows for safe glass disposal. Glass tumbling is a well known technique for blunting sharp edges of glass pieces. Its implementation in a low-income context requires research, implementation, and results analysis in the field.
- Mechanical Engineering
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| At Openversum, our mission is to democratize access to safe water technologies in low- and middle-income regions like Ecuador and Colombia. Through our innovative microfranchising model, we empower local entrepreneurs with the necessary tools and expertise to assemble, distribute, and maintain advanced multi-layer membrane filters. These filters are adept at removing pathogens, heavy metals, and micropollutants, showcasing proven efficacy in laboratory and field settings. However, the dynamic nature of water purification challenges necessitates ongoing enhancements and contextual adaptations to optimize our technology's impact and reach. - Environmental Engineering Design, Environmental Technologies, Mechanical Engineering
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| In Blantyre, Malawi, different ways of recycling PET and HDPE are investigated. Plastic bottles can be remelted into sheets for desk or table-top construction; manufacturing of insulating wool is also investigated for applications in housing construction. Presently, around 20 tonnes of dirty mixed-type plastic chips are stored on a pile and can be accessed by Malawian NGOs, WASTE Advisers and Art Malawi. However, this large quantity of plastic requires washing and separation before being further used. This master's thesis focuses on the problem of plastic separation by type - a low-cost solution to separate the most abundant compounds: HDPE from PET. The metric which will validate the project and the setup is separated plastic purity. Even though, the problem is not new, nor are the solutions, most of the proposed techniques are not suitable for the low-income context, where deliveries of chemicals from abroad are often limited and require long waiting time. Potential mechanisms to separate the two types of plastics are electrostatic forces, flotation, centrifugal forces; all can be combined with applying widely-available chemicals to change the material's physical and chemical properties, e.g., hydrophobicity. - Mechanical and Industrial Engineering, Plastics
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| Anaerobic digestion (AD) is considered one of the oldest and most sustainable biological treatment technologies for stabilizing and reducing organic waste, including food waste, sewage sludge, industrial waste, and farm waste. AD transforms organic matter into biogas (60–70 vol-% of methane), thereby reducing the volume of the waste whilst destroying some of the pathogens present in the waste feedstocks and limiting odor problems associated with waste materials (Appels et al., 2008; Gerardi, 2003). AD is a promising energy, waste management, and sanitation solution in low-resource, low-income settings (Forbis-Stokes et al., 2016; Owamah et al., 2014). However, it does not fully eliminate pathogens for safe environmental discharge. Three ETH master students (Hardeman, 2022; Jäggi, 2023; Luz, 2022) iteratively developed and optimized the biogas reactor and the solution for sludge pasteurization to homogeneously heat the effluent and render the liquid safe for discharge. However, continuous operation was not efficient enough. The most recent work by Jent Imelman on process cycle optimization is still ongoing and not yet published. The conclusions of the four student projects allow to build a prototype to test the critical parts of the system - the heat exchangers and the burner. - Mechanical Engineering
- ETH for Development (ETH4D) (ETHZ), Master Thesis
| Bio-waste (also called organic waste or green waste) can be used as a sustainable feedstock to produce biogas: an alternative energy source. However, in order to be efficient, a biogas plant must process large amounts of organic material. Currently, Entsorgung + Recycling Zürich (ERZ) processes bio-waste from households that is stored in special green containers and collected weekly with compactor trucks. This material then gets converted into biogas (or compost) at the fermentation plant.
As each green bin serves numerous households and is quite deep (approximately 1.5m), liquids seep down and pool at the bottom, while other particles may stick to the container walls. When ERZ arrives on site, the containers are emptied into the trucks and later placed back to their original location, but without cleaning them. Cleaning is either left to the landlord or done with a specialized vehicle, but is rare, and the containers may become less appealing to use over time. - Mechanical Engineering
- Master Thesis
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