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

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.

Construction and demolition waste recycling in developing cities: management and cost analysis

In Bolivia, construction and demolition waste (CDW) is unmanaged. The current research implemented a CDW flow analysis and a cost assessment in the city of La Paz, aiming to compare future recycling scenarios. Lack of data is challenging; therefore, a review of 31 international studies has been conducted. Results report that the waste generation rate (WGR) of concrete residential buildings can be of about 91.9-113.3 kg m^-2 for construction and about 867.2-1064.8 kg m^-2 for demolition. In addition, positive correlation was found in national WGR with number of inhabitants and the GDP. By these results, it was estimated that about 271,051-349,418 tonnes of CDW are potentially generated yearly in La Paz, about two times more than the CDW projected by local authorities. By the scenarios analysis, it was estimated that 56.1-71.1% of the inert aggregates can be recycled. The cost of the system is estimated between 7.8 and 31.1 USD t_CDW^-1, for a total annual cost (20 years horizon) of about 2.3-9 million USD y^-1 depending on the management scenario. In the best scenario, an average fee of less than 1% of the current costs of a flat in La Paz can be required, potentially affordable for the local economy. The most attractive scenario involves the source separation of recyclable materials and the hybrid organization of stationary and mobile recycling facilities. Results show that a CDW management can be implemented in La Paz to foster a circular economy in developing cities.

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.

Construction and Demolition Waste Management Research: A Science Mapping Analysis

Construction and demolition waste treatment has become an increasingly pressing economic, social, and environmental concern across the world. This study employs a science mapping approach to provide a thorough and systematic examination of the literature on waste management research. This study identifies the most significant journals, authors, publications, keywords, and active countries using bibliometric and scientometric analysis. The search retrieved 895 publications from the Scopus database between 2001 and 2021. The findings reveal that the annual number of publications has risen from less than 15 in 2006 to more than 100 in 2020 and 2021. The results declare that the papers originated in 80 countries and were published in 213 journals. Review, urbanization, resource recovery, waste recycling, and environmental assessment are the top five keywords. Estimation and quantification, comprehensive analysis and assessment, environmental impacts, performance and behavior tests, management plan, diversion practices, and emerging technologies are the key emerging research topics. To identify research gaps and propose a framework for future research studies, an in-depth qualitative analysis is performed. This study serves as a multi-disciplinary reference for researchers and practitioners to relate current study areas to future trends by presenting a broad picture of the latest research in this field.

Method of Construction Projects’ Classification for Habitat Assessment in Poland and the Problem of Choosing Materials Solutions

The planning stage plays a key role in the success of each construction project. It also pertains to projects implementedin the Natura 2000 areas that cover ca. 18% of the total land area in the EU. Permission for the realization of such a project is issued after an analysis of its environmental impact on the Natura 2000 area. An important part of the analysis undertaken as part of a habitat assessment should be the evaluation of proposed material solutions. The research has revealed that habitat assessments in Poland do not fulfill this postulation. The decision-making process is based on the legal qualification criteria, and the fundamental importance in it has a precautionary principle. Practical realization of this principle demonstrates, however, shortcomings in its methodology. The article presents the results of two research stages. In the first stage, the documentation of 292 construction projects was examined in order to prepare the principal components of a checklist. They are correlated to the legal qualification criteria. However, they are more precise and systematic. In the second stage of the research, a survey of 47 experts was performed, and the result of the research is an innovative module of the checklist for qualification of construction projects to the habitat assessment, including questions on materials solutions. The research has proved that introduction of this proposal to the checklist may improve the quality of habitat assessments, increase their trustworthiness and ensure full exploitation of the possibilities which are given by the use of uniform research methods.

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.

Potential Energy Savings from Circular Economy Scenarios Based on Construction and Agri-Food Waste in Italy

In this study, our aim was to explore the potential energy savings obtainable from the recycling of 1 tonne of Construction and Demolition Waste (C&DW) generated in the Metropolitan City of Naples. The main fraction composing the functional unit are mixed C&DW, soil and stones, concrete, iron, steel and aluminium. The results evidence that the recycling option for the C&DW is better than landfilling as well as that the production of recycled aggregates is environmentally sustainable since the induced energy and environmental impacts are lower than the avoided energy and environmental impacts in the life cycle of recycled aggregates. This LCA study shows that the transition to the Circular Economy offers many opportunities for improving the energy and environmental performances of the construction sector in the life cycle of construction materials by means of internal recycling strategies (recycling C&DW into recycled aggregates, recycled steel, iron and aluminum) as well as external recycling by using input of other sectors (agri-food by-products) for the manufacturing of construction materials. In this way, the C&D sector also contributes to realizing the energy and bioeconomy transition by disentangling itself from fossil fuel dependence.