Avaliação dos resíduos de pavimentação e escavação gerados em obras de manutenção de redes coletoras de esgoto: subsídios para gestão ambiental

Abstract

Brazil still has low rates of sewage collection and treatment. In order for the universalization of sewage services to be achieved, it will be necessary to carry out works, which in turn generate waste, commonly disposed of in landfills. The work of evaluation of the paving and excavation residues generated in maintenance works of sewage collection networks in order to obtain subsidies for environmental management was developed in the Metropolitan Region of Recife, in Pernambuco, from January to August, 2018. This work carried out the analysis and calculation of the waste generation of 4797 works and had as objective to diagnose the aspects of the generation of construction waste and demolition of the maintenance works in the networks and extensions of sewage collectors; create indicators of generation of waste to subsidize the estimate of generation of waste by managers; to identify, in a preliminary way, the technological routes for reuse, recycling and final disposal of the waste studied, in order to stimulate a more in-depth analysis of its feasibility aspects. The study was carried out through field surveys; analysis of reports; worksheet control analysis; cost management with waste management and acquisition of new materials; survey of environmental aspects and impacts; diagnosis of existing technological routes. At the diagnostic stage, it was possible to verify that only 15% of the sewage collection constructions done reused material from the excavation, while 85% of this material went to landfills. Waste generation indicators were created, taking into account aspects such as sewerage network mileage, number of wells, number of sewage connections, population, quantity of works, waste management costs and acquisition of new inputs. It was possible to estimate the quantity of works, as well as the costs with destination and acquisition of new inputs for the implantation and post universalization phases, reaching the value of approximately US$ 7,68 million. From the technological route propositions for each identified waste, it was seen that, with the exception of those contaminated with sewage, all had alternatives for reuse or recycling processes. Allocation of waste on the existing technological route indicated that 100% of the waste not reused on site was destined for landfills, where from the propositions of the new technological routes, the possibility of reuse of the waste could reach up to 87% of all material that is demolished or excavated.