Life cycle assessment of construction and demolition waste management in a large area of São Paulo State, Brazil.

The study evaluated the environmental performance of the construction and demolition waste (C&DW) management in the area of PCJ Watershed, located in the São Paulo State, Brazil, by means of an attributional Life Cycle Assessment. The entire C&DW management under the responsibility of the municipal government was considered. The potential environmental impacts were assessed by using two specific life cycle impact assessment methodologies, CML baseline (v3.03) and Impact 2002+ (v2.12). The results obtained by both methodologies highlighted the importance of the avoided impacts from recovered materials, mainly those related to steel, glass and plastics recycling. In particular, the CML baseline indicated "Human Toxicity" as the most important category, mainly due to the avoided impacts from steel recycling and the generated impacts from transportation in all the C&DW management stages. The Impact 2002+ highlighted instead the role of the categories of "Respiratory Inorganics" and "Global Warming", in accordance with the results related again to steel recycling and transportation but also to landfilling of solid residues. The study considered some alternative scenarios of the mineral fraction management, which quantified the expected advantages of increasing C&DW recycling and improving the quality of recycled aggregates.

Avaliação do ciclo de vida do Sistema Municipal de Gerenciamento de Resíduos da Construção Civil da Região Metropolitana de Campinas / Life cycle assessment of Municipal Construction and Demolition Waste Management System of Campinas Metropolitan Region

RESUMO A ausência ou ineficiência de Sistemas Municipais de Gerenciamento de Resíduos da Construção Civil (SMGRCCs) pode ocasionar impactos ambientais, os quais precisam ser avaliados sistematicamente, levando em consideração a realidade local. Existem poucos estudos sobre a quantificação dos impactos ambientais relacionados ao gerenciamento de resíduos da construção civil (RCCs) e, portanto, neste trabalho foi avaliado o desempenho ambiental dos SMGRCCs dos municípios da Região Metropolitana de Campinas (RMC), a partir da metodologia de avaliação do ciclo de vida (ACV). O estudo de ACV foi modelado no software SimaPro 8.2.0; para a avaliação dos impactos ambientais, foi utilizado o método CML baseline 2000, considerando as categorias aquecimento global, toxicidade humana, oxidação fotoquímica, acidificação e eutrofização. Ao comparar o desempenho ambiental atual com o cenário que inclui 70% de reciclagem dos RCCs classe A (meta prevista no Plano de Resíduos Sólidos do Estado de São Paulo), verificou-se redução de 22% dos impactos ambientais. Entretanto, ao analisar os cenários individualmente, por causa das distâncias de transporte, alguns municípios não apresentaram benefícios ambientais resultantes da reciclagem. Esses resultados evidenciam que a reciclagem não deve ser vista como a primeira opção nos SMGRCCs, e que é premente a necessidade de adoção de práticas de redução na fonte e reutilização de resíduos no gerenciamento de RCCs. Esses resultados podem dar suporte ao processo de tomada de decisão, visto que muitos municípios brasileiros estão planejando a implantação de usinas de reciclagem de RCCs.

ABSTRACT The absence or inefficiency of Municipal Construction and Demolition Waste Management Systems (MCDWMS) may cause environmental impacts, which need a systematic evaluation, considering the local reality. There are few studies on the environmental impacts' quantification of construction and demolition waste (CDW) management. Thus, in this work, MCDWMS' environmental performance of the municipalities in the metropolitan region of Campinas was evaluated based on the life cycle assessment (LCA) methodology. The LCA study was modeled using the SimaPro 8.2.0, and the environmental impacts were evaluated by the CML baseline 2000 method, considering the categories of global warming, human toxicity, photochemical oxidation, acidification and eutrophication. When comparing the current environmental performance with the scenario that includes a recycling rate of 70% of CDW Class A (goal established in the Solid Waste Plan of São Paulo State), the environmental impacts were reduced in 22%. However, when analyzing the scenarios individually for each municipality, it was verified that due to the transport distances, some municipalities did not present environmental benefits resulting from recycling. These results demonstrate that recycling should not be the first option in the MCDWMS, and that the adoption of source reduction and reuse of waste within the scope of CDW management is urgent. These results may support the decision-making process in CDW management systems, as currently many Brazilian municipalities are planning the implementation of recycling facilities.

Comparison of scenarios for the integrated management of construction and demolition waste by life cycle assessment: A case study in Brazil.

Brazil, as a result of economic development and strengthening of the construction industry in recent years, is generating an increasing amount of construction and demolition waste (CDW). Hence, environmental assessment of the management systems is vital. A life cycle assessment (LCA) is presented of CDW management in a medium-sized municipality located in the southeast region of Brazil, where the impacts of leaching were not considered due to absence of consistent data. Six different proposed scenarios for the current CDW management situation have been considered. These scenarios comprised the combined use of landfilling, sorting, and recycling, and the use of CDW as paving material for landfill roads, in different percentages. Considering 0.8 ton of waste as the functional unit, the life cycle inventory was performed using primary data obtained from field survey and secondary data from the database Ecoinvent version 3.1, and from the literature. The method CML 2 baseline 2001 was used for environmental impacts evaluation. The results highlight that recycling is beneficial when efficient CDW sorting takes place at construction sites, avoiding the transport of refuse to sorting and recycling facilities, and the distance between the generation source and the recycling unit is within 30 km. Thus, our results are helpful to ensure that the decision-making processes are based on environmental and technical aspects, and not only on economic and political factors, and also provide data and support for other LCA studies on CDW.