Minimização da emissão de carbono pela coleta seletiva em Salinas-MG em diferentes cenários

Abstract

The City of Salinas-MG is in the Jequitinhonha Valley, a region with major deficiencies in basic sanitation. The city has a selective collection system and an association of collectors. However, selective collection covers approximately 29.6% of the conventional collection routes, and the percentage of recycling/reuse is low, only 1.95% of the total urban solid waste (USW). The objective of this work was to evaluate the environmental impact of the emission of Greenhouse Gases from USW in scenarios of expansion of selective collection, considering levels of 5%, 10% and 20% of use of USW from Conventional Collection by Selective Collection in a period of 20 years. These percentages were chosen because they are achievable in the total amount of recyclable materials, which are in the Conventional Collection.The methodology consisted of forecasts of population growth and of generation of USW per capita. The masses of recyclable materials were calculated according to the National Sanitation Information System. The period studied was from the year 2023 to 2042. The methodology was in accordance with the FUNASA and IBGE USW management manual, and resulted in the forecast of a per capita generation in 2042 of 0.9 kg.inhab-¹.day-¹.for a population of 48,205 inhabitants. The mass of USW accumulated was 263,528.73 tons, equivalent to 1,14,0817 m³. the percentage of the mass of USW that could be recycled from that amount is 40.1% of the Conventional Collection of USW, which corresponds to 105,675 tons of USW. After calculating the masses of recyclable materials in the specified period of time, the quantitative of mass of Recyclable materials stratified were analyzed according to the gravimetric study of the use of Selective Collection of plastics, paper, glass, and ferrous metals. GABI software version 9.1 using the CML 2001 method was used to carry out a partial Life Cycle Analysis (LCA) of Recyclable Waste in order to evaluate the equivalent CO2 that would no longer be emitted by the landfill in the scenarios of expanding selective collection at levels of 5%, 10% and 20% of recyclable materials, according to the methodology adapted from LEME (2010) In these evaluated scenarios of selective collection at the levels of 5%, 10% and 20%, a potential increase was observed in relation to the current scenario (1.95% of selective collection) of 8,037.63; 21,214.06, and 47,566.94 tons of USW, respectively, which could be reused and/or recycled from the Conventional Collection by Selective Collection. The potential reduction in Global Warming Potential was of 9,076.09; 23,954.92, and 53,712.58 tons of CO2 equivalent, respectively. In conclusion, it is assumed that the addition of selective collection will enable environmental gains by decreasing GWP emissions, economic gains by increasing population income generated by the increase in commercialization of materials, and social gains by valuing recyclable material collectors in the city of Salinas-MG.