Application of a life cycle assessment for assessing municipal solid waste management systems in Bolivia in an international cooperative framework

Can tourism support resource circularity in small islands? On-field analysis and intervention proposals in Madagascar

Open dumping and burning of solid waste are common practices in low-income countries. On small and touristic islands, the problem is exacerbated due to the additional volume of waste amount generated by tourists. This article presents how, using Nosy Be island in Madagascar as a case study, waste recovery and recycling can be fostered by tourism to tackle the waste challenge. About 95% of the waste of Nosy Be is openly dumped, discarded to sea or openly burned. Field analysis, interviews with local stakeholders and waste flow analysis served as methodological tools to assess the current solid waste management (SWM) system of Nosy Be. Stakeholder mapping and involvement as well as first exchange among local and international actors provided the basis to identify key practice and opportunities. Research findings highlight the importance of active participation and involvement of local partners supported by international experts, to suggest how touristic centres can serve as core of circular approaches. The article presents potential circular models to be implemented in Nosy Be, taking tourism as the entry point including the aspects of financial support, separated waste flows and the interest in 'green tourism marketing'. This case study underlines how international cooperation, touristic activities and common efforts can potentially help low-income communities improve their SWM practices.

Global perspective of municipal solid waste and landfill leachate: generation, composition, eco-toxicity, and sustainable management strategies

Globally, more than 2 billion tonnes of municipal solid waste (MSW) are generated each year, with that amount anticipated to reach around 3.5 billion tonnes by 2050. On a worldwide scale, food and green waste contribute the major proportion of MSW, which accounts for 44% of global waste, followed by recycling waste (38%), which includes plastic, glass, cardboard, and paper, and 18% of other materials. Population growth, urbanization, and industrial expansion are the principal drivers of the ever-increasing production of MSW across the world. Among the different practices employed for the management of waste, landfill disposal has been the most popular and easiest method across the world. Waste management practices differ significantly depending on the income level. In high-income nations, only 2% of waste is dumped, whereas in low-income nations, approximately 93% of waste is burned or dumped. However, the unscientific disposal of waste in landfills causes the generation of gases, heat, and leachate and results in a variety of ecotoxicological problems, including global warming, water pollution, fire hazards, and health effects that are hazardous to both the environment and public health. Therefore, sustainable management of MSW and landfill leachate is critical, necessitating the use of more advanced techniques to lessen waste production and maximize recycling to assure environmental sustainability. The present review provides an updated overview of the global perspective of municipal waste generation, composition, landfill heat and leachate formation, and ecotoxicological effects, and also discusses integrated-waste management approaches for the sustainable management of municipal waste and landfill leachate.

Environmental impact scenarios of organic fraction municipal solid waste treatment with Black Soldier Fly larvae based on a life cycle assessment

Biowaste treatment with Black Soldier Fly (BSF) larvae is an alternative option for organic waste valorization. Its environmental impacts should be assessed and compared with conventional treatment options. The research aims to evaluate the treatment of organic fraction of municipal solid waste (OFMSW) with BSF larvae through a life cycle assessment (LCA). This study employed data inventories from literature and aimed to provide a wide range of production parameter values to identify the potentialities of BSF treatment in the best-case and worst-case scenarios. The SimaPro9, the database Ecoinvent3.5, and the impact assessment method IMPACT 2002+ have been employed for the analysis. A sensitivity analysis of relevant parameters was conducted, considering the avoided impacts that can be obtained thanks to the exploitation of larvae proteins for bioplastics or fishmeal production. Research findings highlight six main environmental impact indicators: respiratory inorganics (kg PM2.5-eq), ozone layer depletion (kg CFC-11-eq), terrestrial ecotoxicity (kg TEG soil), land occupation (m2 organic arable), global warming (kg CO2-eq), and non-renewable energy (MJ primary). The most relevant process generating impacts is BSF breeding, followed by boiling, storage, and OFMSW treatment. The environmental performance is better when the conventional fishmeal substituted, thanks to BSF larvae production, is made from areas 10,000 km far, implementing a 100% renewable energy scenario, reducing the energy consumption by 50%, increasing the lifespan of the equipment to 15 years, and products are employed locally. The current study represents the first attempt to evaluate the global higher or lower environmental impact scenario related to OFMSW treatment through BSF larvae.

Social, economic and environmental benefits of organic waste home composting in Iran

Organic waste management is challenging in low-middle income countries. Environmental impacts and high management costs affect the sustainable development of cities, an issue that is exacerbated by the lack of social involvement. The research conducted in Iran aims to assess the benefits of organic waste home composting in Shiraz to improve solid waste management (SWM) sustainability. The introduction of a pilot project to assess home composting systems was described, together with an economic, social and environmental analysis. The current SWM system (S0) has been compared with the new strategy proposed (S1), where home composting is considered to be introduced to collect about 10% of the municipal solid waste generated in a 10-year horizon. An economic balance related to the capital costs and operational costs of both systems was introduced, in parallel with a life cycle assessment (LCA) of the SWM system, and a questionnaire survey of the local population. Results showed that S1 leads to around 5% economic savings for the municipality due to the avoidance of organic waste transportation and disposal. Environmental benefits include a lowering of CO2-Eq emissions of about 19,076 tonnes year-1. In addition, about 28% of the interviewed (n = 319) agreed to employ the home composting system at home (CI 5.5%, 95% of confidence level) supporting the theory that about 10% of the organic waste can be segregated and home-composted. The research underlines that home composting can contribute to improve the sustainability of SWM systems in developing countries.

Life cycle assessment of municipal solid waste generated from hilly cities in India - A case study

Improper disposal of waste poses a grave environmental threat, contributing to pollution of air, water, and soil. It is necessary to address this issue in order to mitigate the adverse effects of solid waste on both the environment and public health. In many developing nations, municipal authorities of bigger cities are enduring significant challenges in proper management of waste. The present study evaluates the impacts of various waste management alternative scenarios for environmental impacts for the selected study locations using Life Cycle Assessment (LCA) methodology. The methodology comprised of five different scenarios of waste management including an existing baseline scenario. In this context, the environmental impact categories analyzed were Global Warming potential (GWP), Acidification potential (AP), Eutrophication potential (EP) and Human Toxicity potential (HTP). The results indicated that amongst all the proposed scenarios, Scenario 1 and 4 exhibited the maximum and minimum environmental impacts respectively. The study revealed that least greenhouse gas emissions, acidification potential, eutrophication potential and human toxicity potential were comparatively lesser for scenario 4 varying from 5.65 to 11.36 kg CO2eq t-1; 1.24-3.345 kg SO2eq t-1, EP 0.19-0.68 kg PO4eq t-1, and 0.35-4.22 kg 1,4-DBeq t-1 respectively. Further, a sensitivity analysis was also performed to evaluate the influence of recycling rate of valuable resources in all the considered scenarios. The sensitivity analysis indicated an inversely proportional relation between change in recycling rate and total environmental burdens.

Reducing waste management scenario space for developing countries: A hierarchical clustering on principal components approach

The complexity of waste management (WM) problems resulted in the explosion of scenarios that challenge focused discussion among stakeholders and hinder the integrity of policy responses in developing countries. Hence, drawing similarities is essential to reduce the number of scenarios to simplify the WM efforts. To extract similarities, measuring WM performance is not enough, but the background factors related to this performance should be incorporated. These factors form a unique system characteristic that facilitates or hinders WM functions. Thus, this study applied multivariate statistical analysis to clarify underlying characteristics that facilitate efficient WM scenario developments for developing countries. The study first analysed drivers associated with improved WM system performance using bivariate correlation analysis. As a result, twelve significant drivers associated with controlled solid waste were identified. Then, it mapped the countries based on their WM system characteristics using the combined principal component analysis and hierarchical clustering approach. Thirteen variables were examined to extract similarities between the countries. The results identified three homogenous clusters. The clusters were found considerably parallel to the global classifications based on income and human development index. Hence, the presented approach is efficient in explaining similarities that reduce WM scenarios and favours cooperation among countries.

Integration of LCSA and GIS-based MCDM for sustainable landfill site selection: a case study

The paper aims at developing a framework for decision-support to select a sustainable landfill site in Bardaskan City (Iran) by combining life cycle sustainability assessment (LCSA) concepts and geographic information system (GIS)-based multi-criteria decision-making (MCDM). Overall, 13 criteria were chosen (three constraints and 10 factors) and classified into three main aspects of sustainability (i.e., environmental, social, and economic) to achieve the research goals. Boolean and fuzzy logic were employed to standardize the classified constraints and factors, respectively. Analytic hierarchy process (AHP) was used to calculate the factors' weights and then suitability maps were produced using the GIS analysis. The layers were combined using simple additive weighting (SAW). Next, the most sustainable sites were obtained. The results indicated that distance from city backline, groundwater depth, and distance from rural areas were the most significant factors with the weight of 0.338, 0.141, and 0.129, respectively. The final map of suitable sites was created by classifying the SAW layer according to 75, 80, and 85% of suitability to show the high, medium, and low priority areas for landfill site selection, respectively. Therefore, integration of LCSA and GIS-based MCDM to select the sustainable landfill site for municipal solid waste (MSW) is highly important, which can be effectively employed in regional and urban planning to select the location of appropriate and sustainable landfills.

Comparison of environmental impacts related to municipal solid waste and construction and demolition waste management and recycling in a Latin American developing city

Construction and demolition waste (CDW) and municipal solid waste (MSW) are the waste flows mostly generated at a global level. In developing countries, most of these waste streams are disposed of in open dumps. Policy-makers should be informed in which priorities should be established in order to improve the quality of the environment. The current research compares the environmental impacts generated by the MSW and CDW management system of La Paz (Bolivia). The aim is to evaluate (1) which environmental impact indicators are more important per waste flow and (2) if recycling can be considered a good option for mitigating such environmental footprint. A life cycle assessment (LCA) of the formal MSW management and the CDW mismanagement (i.e., open dumping) were conducted. The analysis of the management system (2019) is compared with future developments in recycling that counts with the support of an international cooperative project financed by the Italian cooperation. Results reported that, at a municipal level, CDW mismanagement contributes more than 60% to the freshwater aquatic ecotoxicity, which represents the most relevant impact generated by this waste stream. Recycling allows achieving avoided impacts higher than the ones produced for three of six environmental impacts, suggesting MSW and CDW recovery as an important option for preventing environmental degradation. The research is the first attempt to highlight the importance of organizing appropriate CDW management systems into an integrated waste management scheme for mitigating environmental impacts in developing cities.

A systematic review of life cycle assessment of solid waste management: Methodological trends and prospects

Solid waste disposal has led to increasing concerns over resource, health, and environmental problems. These issues have been investigated using the Life Cycle Assessment (LCA) technique which helps identify the roots of varying hazards and allows decision-makers to improve the environmental performance of waste management practices. However, there is a lack of review studies that conducted meta-analysis related to developments in critical methodological steps of LCA on solid waste management. To fill this gap, this review paper examines 15 elements comprising the preference of journals, 13 LCA method-related characteristics, and economic assessment. Insights on the limitations and current practices of LCA applications, along with trends for future research, are provided. 240 studies on the LCA of SWM from 2009 until 2020 were systematically reviewed and classified into two major year-groups (i.e., 2009-2014 and 2015-2020) to investigate the trend changes. Among the studied elements, it is found that energy-related applications are on the increase in LCA studies on solid waste management. Anaerobic digestion facilities nearly double in appearance in the second year-group (2015-2020). There is also a more frequent occurrence of certain characterization methods like ReCiPe and CML. Functional units become more diverse, but are overall mostly defined on a mass basis. A frequently identified issue of many LCAs on solid waste management is the ambiguity of data sources such as out-of-date literature or inconsistent geographical references. By addressing issues of methodological standardization, this review study provides a basis to further increase the reliability of results of future LCA studies on solid waste management.

Environmental assessment of construction and demolition waste recycling in Bolivia: Focus on transportation distances and selective collection rates

Construction and demolition waste (CDW) management in developing countries is a global concern. The analysis of scenarios and the implementation of life cycle assessment (LCA) support decision-makers in introducing integrated CDW management systems. This paper introduces the application of an LCA in La Paz (Bolivia), where CDW is mainly dumped in open areas. The aim of the research is to evaluate the benefits of inert CDW recycling in function of the selective collection rate, defined as the amount of waste (%_wt.) sorted at the source in relation to the total waste amount produced, and the distances from the CDW generation to the material recycling facility. The outcomes of the research suggest that increasing the selective collection rates (5% to 99%) spread the importance of transportation distances planning since it affects the magnitude of the environmental impacts (1.05 tCO₂-eq to 20.7 tCO₂-eq per km traveled). Transportation limits have been found to be lower than about 40 km in order to make recycling beneficial for all environmental impacts and for all selective collection rate, with the eutrophication potential as the limiting indicator. The theoretical analysis suggests implementing LCA with primary data and involving statistics related to the transportation of virgin materials avoided thanks to recycling. The outcomes of the research support the implementation of CDW recycling in developing countries since it has been found that material recovery is always beneficial.

Circular Economy, International Cooperation, and Solid Waste Management: A Development Project in La Paz (Bolivia)

This paper introduces the preliminary results of a development project focused on waste recycling and recovery in La Paz (Bolivia). The aim is to share best practices and to present real-world challenges when implementing appropriate waste management systems in developing countries. Environmental pollution, social inequality, lack of resources, and economic discrepancies are challenges still present in the 21st century, and a global call-for-action is needed to support sustainable development. The project “LaPazRecicla”, financed by the Italian Agency for Development Cooperation, provides perspectives that are potentially useful for policy-makers, waste management practitioners, and circular economy visionaries. The article aims to present the effective contribution of the practical actions to the local municipality, and to introduce the reason for why theoretical methods were employed to support the project. The outcomes provided two main indications: on one hand, cooperation among interdisciplinary actors and financial support can give the chance of improvement, suggesting international donors should continue in this direction; on the other, political instability, lack of local technical knowledge, and the absence of planning for a long-term period makes these actions unsuitable for tangible change. Global reflections are required in order to measure the potential benefits of small-scale projects, evaluating the time needed to move towards a sustainable future in low-income countries.

Environmental impact assessment of the current, emerging, and alternative waste management systems using life cycle assessment tools: a case study of Johannesburg, South Africa

Proper information regarding the performance of waste management systems from an environmental perspective is significant to sustainable waste management decisions and planning toward the selection of the least impactful treatment options. However, little is known about the environmental impacts of the different waste management options in South Africa. This study is therefore aimed at using the life cycle assessment tool to assess the environmental impact of the current, emerging, and alternative waste management systems in South Africa, using the city of Johannesburg as a case study. This assessment involves a comparative analysis of the unit processes of waste management and the different waste management scenarios comprising two or more unit processes from an environmental view. The lifecycle boundary consists of unit processes: waste collection and transportation (WC&T), material recycling facilities (MRF), composting, incineration, and landfilling. Four scenarios developed for the assessment are S1 (WC&T, MRF, and landfilling without energy recovery), S2 (WC&T, MRF, composting, and landfilling with energy recovery), S3 (WC&T and incineration), and S4 (WC&T, MRF, composting, and incineration). Based on the result of this study, MRF is the most environmentally beneficial unit operation while landfill without energy recovery is the most impactful unit operation. The result further revealed that no scenario had the best performance across all the impact categories. However, S3 can be considered as the most environmentally friendly option owing to its lowest impact in most of the impact categories. S3 has the lowest global warming potential (GWP) of 33.19 × 10⁶ kgCO₂eq, ozone depletion potential (ODP) of 0.563 kgCFC-11e, and photochemical ozone depletion potential (PODP) of 679.46 kgC₂H₂eq. Also, S4 can be regarded as the most impactful option owing to its highest contributions to PODP of 1044 kgC₂H₂eq, acidification potential (AP) of 892073.8 kgSO₂eq, and eutrophication potential (EP) of 51292.98 MaxPO4^-3eq. The result of this study will be found helpful in creating a complete impression of the environmental performance of waste management systems in Johannesburg, South Africa which will aid sustainable planning and decisions by the concerned sector.

Achieving waste recovery goals in the medium/long term: Eco-efficiency analysis in a Brazilian city by using the LCA approach

The aim of this study was to analyse how to ensure that medium- and long-term waste recovery goals can be achieved in Brazilian cities, based on the incorporation of viable and accessible technology. The identification of the strengths of the Brazilian cities with better (dry and wet) waste recovery rates allowed different strategies to be proposed for João Pessoa (the city selected as a case study). Those strategies were based on the improvement of (1) the selective collection of the recyclable dry waste fraction, (2) the material recovery facility to increase the recovery of recyclable dry waste fraction to be recycled and/or wet waste fraction to be composted, and finally (3) the working conditions of waste workers. A combination of these improvement strategies at two different levels of implementation (partial and total) allowed the definition of 14 alternative scenarios, which were analysed from an eco-efficiency perspective (environmental vs. economic). After analysing the evolution over time of the alternative scenarios proposed, the proposal that was finally selected was based on the initial implementation of a mechanical biological and composting facility capable of handling up to 50% of the mixed municipal solid waste collected by 2023 with a material recovery efficiency of 30%. From there, the efficiency of the mechanical biological and composting facility should increase up to 60% to achieve the waste recovery goals by 2034 (management of 60% of the mixed waste collected). This rate has not yet been reached in any of the Brazilian mechanical biological and composting facilities analysed, so the reduction in the amount of waste generated and the increase in the selective separation of waste at source are identified as key elements to be able to fulfil the long-term goals. The approach used in the case study provides guidelines for application in other geographical contexts.

Life cycle assessment applied to waste management in Italy: A mini-review of characteristics and methodological perspectives for local assessment

Life cycle assessment (LCA) and related tools are commonly used to evaluate the potential environmental impacts of waste treatment scenarios. This manuscript presents a mini-review of studies published over the last 10 years in Italy and aims to investigate how life cycle thinking tools are applied to assess the environmental sustainability of local-level waste policies. Results reveal that different waste flows, technologies and policies have been investigated independently and in varying detail. Review suggests that boundary selection significantly affects LCA results; integration of different waste systems is therefore crucial to avoid spatial or temporal shifts of environmental impacts. Moreover, the description of methodological characteristics, limitations and transversal aspects of Italian waste management studies allows various stakeholders to assess the reliability of past and future research for waste policy planning and rebound effects prevention. This review also highlights the need to define minimum requirements of transparency and ease of reporting of the studies to private and public stakeholders. Finally, the paper investigates whether using both the organisational LCA and the life cycle sustainability approach for the overall waste management process may be useful to develop a standard method to address multi-functionalities and multiple sites.

Sensitivity analysis and improvements of the recycling rate in municipal solid waste life cycle assessment: Focus on a Latin American developing context

The life cycle assessment (LCA) of municipal solid waste (MSW) systems in developing countries is a matter of research. Obtain reliable results is challenging since field data and local databases are not always available. The research presented in this paper explores this issue in La Paz (Bolivia), where six environmental impact categories were assessed. The LCA, related to the formal MSW management system of the city, involves a sensitivity analysis of ten parameters and the scenario assessment in relation to the increase of the recycling rate. Results report that the environmental impacts are mostly sensitive in relation to landfill gas collection efficiency, use of plastic bags, the transportation distances of collected waste, and the replacement rate of virgin materials. Global warming potential is the impact category most variable (341.38-551.95 kg CO₂-eq t_MSW^-1), although it is not considerably reduced by recycling, which contributed mostly to the human toxicity and freshwater aquatic ecotoxicity. Doubling the amount of MSW recycled, from 235 t to about 473 t per year, human toxicity potential reduces of about 18% while freshwater aquatic ecotoxicity of about 12%. This research contributes for evaluating the most sensitive parameters in an MSW-LCA and to support policymakers towards waste recycling and sustainable development in Latin America developing cities.

Sustainable municipal waste management strategies through life cycle assessment method: A review

Increasing amounts of municipal solid waste (MSW) has gained widely concern on reduction, utilization and minimizing environmental impacts associated with waste management. Life cycle assessment (LCA) has been used to evaluate total environmental impact of municipal waste management (MSWM) options in strategy-planning and decision-making process. The exiting LCA studies have covered a large range of detailed focus from waste treatment technology to applied modelling methods in LCA of MSWM, yet an important concern for stakeholders, the relationship between practical management strategies and their LCA results, has not been comprehensively summarized. This paper reviews recent LCA studies focusing on MSWM system in 45 cases from both developing and developed regions to promote evolution of the MSWM system through modification of waste management strategies. Selected literatures conducted LCA with system boundary covering the whole MSWM system rather than single treatment process or specific type of waste. This review has explored distribution and evolution of LCA studies in waste management field and summarized critical parameters (system boundary, functional unit, assessment approach and data uncertainty) for conducting LCA of MSWM system. Comparison results from 45 worldwide cases indicated 33%-154% environmental benefit in Global warming potential (GWP) impact with implement of integrated solid waste management system to replace single landfill, incineration, or open dumping treatment. Key issues with upgrading of MSWM system have been highlighted to raise concern, i.e., the importance of targeted management strategy on organic and recyclable waste, the growing contribution of waste collection and transportation to the total environmental impact, as well as promoting multi-impacts assessment for MSWM system to achieve environmentally effective, economically affordable, and socially acceptable. Rather than focus on technical factors, results from this study indicated the key influences from understanding local limitation, environmental concern, management chain and comprehensive impact, providing useful strategies on improving MSWM with generalization results of LCA studies.

Formal and informal waste selective collection in developing megacities: Analysis of residents' involvement in Bolivia

The implementation of waste selective collection (SC) schemes in low-income countries is a challenge although it is one important way for improving environmental sustainability. The inclusion of the population is necessary for gaining effective results, and social surveys are support methods for understanding citizens' involvement and behaviour. The aim of the research is to assess the support of the citizens concerning the formal and informal recycling in a low-middle income country. The study presents a questionnaire survey conducted in 2018 in La Paz, Bolivia, where 774 citizens were interviewed for evaluating their support to the formal and informal SC systems. Two questionnaires were submitted to two different users' categories: users of the formal recyclable waste gathering points; and citizens of the neighbourhoods. Evidence of the survey shows that about 8% of the population supports the formal SC while about 48% are used to selecting their waste at home. About 79.2% of them bring the waste to the informal recycling shops or provide it to waste pickers, throwing the waste into or nearby the mixed containers in order to facilitate their collection. This research demonstrates how social inclusion is important for planning recycling systems within a developing big city, starting from the SC. Results suggest that the informal sector can be an effective means for improving the recycling behaviour of the citizens. The study can be of interest to stakeholders involved in introducing recycling policies in developing cities where the SC rate is still low, and informal waste collection exists.

Life Cycle Impact Assessment of Garbage-Classification Based Municipal Solid Waste Management Systems: A Comparative Case Study in China

Confronted with a series of problems caused by surging generation of municipal solid waste (MSW), the Chinese central and local governments have promulgated and implemented policies to deal with them, including promotions of the classification of MSW. However, to date, practical knowledge and understanding about benefits for garbage classification from its environmental performance perspective is still limited. The present study is purposed to comprehensively investigate the environmental effects of garbage classification on municipal solid waste management (MSWM) systems based on three proposed garbage classification scenarios in China, via a comparative life cycle impact assessment (LCIA). Taking advantage of Impact Assessment of Chemical Toxics (IMPACT) 2002+ method, this comparative LCIA study can quantitatively evaluate midpoint, endpoint, and single scored life cycle impacts for the studied MSWM systems. A Monte Carlo uncertainty analysis is carried out to test the effectiveness and reliabilities of the LCIA results. The LCIA and uncertainty analysis results show that MSWM systems based on various garbage classification scenarios have significant variations in the studied midpoint, endpoint, and single scored environmental impacts. Different garbage classification scenarios have their individual environmental-friendly superiority for specific impact categories. Overall, results of this study demonstrate that MSW treatment systems integrated with garbage classification are more environmentally friendly by comparison with non-classification; and that the more elaborate the level of MSW classification, the smaller its impacts on the environment.

Assessment of Used Baby Diapers Composting in Bolivia

Solid waste open dumping in developing countries is a global concern. To move towards sustainable development, mixed waste should be reduced, and recyclable waste recovered. The aim of the current research was to find appropriate solutions to disposable used baby-diapers recycling in Bolivia since it is a waste fraction widely produced and commonly disposed of in open dumps. Composting of the organic diaper hydrogel was assessed in five trials, adding components available locally: cow dung, activated bacteria, and Californian red earthworms (Eisenia fetida). It was observed that about 60 days were globally required for biomass decomposition with cow dung, activated bacteria, and earthworms, and more than 70 days for the treatment of the substrate mixed only with manure, while the diaper hydrogel did not degrade without cow dung. This research is the first that attempted to treat disposable used baby diapers with the vermicomposting process. In general, the outcomes of the research are promising: vermicomposting with cow manure can be a recycling option for disposable used baby diapers, introducing appropriate practices toward a circular economy in developing regions.