Appropriate solid waste management (SWM) strategies are necessary to avoid severe environmental and sanitary impacts, especially in low-income countries. Such strategies are most likely to succeed whether implementing actors are supported by scientific research. In this paper, the results of a collaboration between local authorities and researchers are presented and discussed that are the assessment of waste generation in the city of Quelimane (Mozambique), integrating existing and field-collected data and the design of a small-scale center for plastic sorting to complement the SWM system of the city. The center is expected to receive about 0.3–0.4 t/day of plastic waste (5%–7% of the overall amount of plastic waste daily produced in Quelimane). As long-term sustainability represents a typical issue, simplicity of operation was a leading principle in the design of the center; moreover, the design included a treatment plant (WWTP) for generated wastewater, whose management is usually neglected in such interventions. Among others, natural wastewater treatment (constructed wetlands) has been chosen for its affordability. Noteworthy, the so-conceived WWTP appears as a novelty in the scientific literature associated with small-scale plastic sorting plants. The system is designed to treat an average flow of 6 m³/day and consisted of a septic tank followed by a subsurface flow constructed wetland. Overall, the COD (chemical oxygen demand) and TSS (total suspended solids) removal higher than 80% and 90% were estimated, respectively. Based on this work, both the center and the WWTP were successfully realized, which are waiting to become operational. In the authors’ opinion, the implemented procedure could become a reference for broader investigations and surveys.

Solid waste management (SWM) is recognized worldwide as an important issue to deal with in pursuing livability. The favela (slum) of Rocinha represents a good synthesis of all challenges which can be encountered in this field: high population density , lack of space and narrow streets, residents struggling with low incomes. In Rocinha, services coverage is lacking and unsatisfying in many sectors, including SWM. In this study, we investigate the reason for this inadequacy. Waste streams have been analyzed as a first step. The second step was the description of the SWM system and of its criticalities. All accessible information has been used and Geographical Information Systems (GIS) played an important role in the data processing. In the final discussion, we suggest a small-scale and decentralized waste management network, collaborating with the centralized collection system. This study is a piece of the project Polimipararocinha of Politecnico di Milano (Italy) which pursues the overall urban re-qualification of Rocinha.

Dumpsites are a common way for waste disposal around the world. Since their impact is not controlled, they represent a threat to the public health and to the environment, being a source of pollutants and greenhouse gases. The dumpsite of Ngong (Kajiado County, Kenya) has been addressed since years as a serious issue affecting the surrounding community. A project for its closure and the establishment of a new facility for waste treatment was elaborated in 2017, and recently the conversion of the dumpsite in a park has been proposed by the local authorities. Nonetheless, the framework appears still complex from the environmental, economic and social points of view: any intervention is expected to raise challenges for the municipal solid waste management (MSWM) system in place, which involves many stakeholders, including informal workers of the dumpsite. After presenting a general overview on the MSWM system in place at the time, this paper presents the results of the social assessment (SA) carried out in 2018, where some of the criticalities encountered by the local authorities at a later time were already predicted. In the opinion of the authors, the importance of qualitative and sociological research within a technological project is highlighted by the results of the SA, and the shared methodology can be helpful for practitioners on the field, whose support will enhance the capacity of stakeholders to deal successfully with challenges related to waste management.