Inventário e gerenciamento das emissões de gases de efeito estufa: estudo de caso em companhia de saneamento

Abstract

Greenhouse Gas (GHG) emission inventories are strategic tools for environmental management that estimate emissions by specific sources in a geographic area and a specific time interval. The development of an inventory is the first step in the creation of programs aimed at improving air quality. This research aimed to prepare an inventory of GHG emissions resulting from the activities of Companhia de Saneamento de Alagoas (CASAL) at the Capital Unit in 2018 and propose a management of its emissions. The methodology employed involved bibliographic research, the elaboration of the inventory of greenhouse gás and the proposal to manage their emissions through mitigation and compensation measures. The method used to estimate GHG emissions was that indicated by the Brazilian GHG Protocol Program, complemented with the guidelines of the Intergovernmental Panel on Climate Change (IPCC) for the case of wastewater treatment. The results of the GHG emissions inventory indicate that in 2018, CASAL, the Capital unit emitted 31,099.33 tCO2e, of which 86.77% (26,980.70 tCO2e) came from direct emissions (scope 1), while indirect ones represented 13.23% (4,118.63 tCO2e). Among indirect emissions, it appears that scope 2 was responsible for 11.56% of the total value (3,596.91 tCO2e) while scope 3 comprises 1.67% (521.72 tCO2e). The company's main sources of emissions were the sewage treatment and energy consumption categories, respectively. In the management of emissions, mitigating and compensatory measures were suggested. As mitigating measures to reduce the company's emissions, we highlight the use of fuels produced from renewable sources and the use of biogas from sewage treatment plants. As a compensatory measure, it was suggested through reforestation with native trees. The application of management within the company Will provide a reduction of at least 10.13% from the base year in 2018.