Parametrização e pré-dimensionamento de emissários subfluviais em Macapá e Santana/AP viabilidade técnica, econômica e ambiental

Abstract

Coastal cities in the Amazon are extremely lacking in basic infrastructure for the treatment and final disposal of urban domestic sewage. A sustainable alternative solution to address the problem would be to implement sub-river outfalls and effluent treatment pre-conditioning that significantly reduced the impacts of pollution. The objective of the research was to analyze the technical, economic and environmental feasibility of alternative projects for the adequate disposal of domestic effluents in the coastal zone of the state of Amapá (ZCEA)/Brazil. For this, the basic sizing of the infrastructure and the current level of treatment of domestic effluents discharged in natura into the Amazon River were taken into account. The research methodology presented the following steps: a) pre-dimensioning of the main infrastructural elements of subfluvial outfalls (EM); b) assessment of the reduction of impacts on water quality on the metropolitan shore of the cities of Macapá and Santana; c) economic evaluation with alternatives for implementing pre-conditioned outfalls for the final disposal of domestic sewage, compared with other alternative studies in the Amazon region. The results indicated technical, environmental and economic viability for underwater outfalls in the North and Central Zone of Macapá, where there is a high self-cleaning capacity of the Amazon River and regular bathymetry. However, technical feasibility, especially in Fazendinha and Santana, was not satisfactory due to topobathymetric irregularities and traffic on the waterway in the Santana Channel. We conclude that the self-purification and sanitary conditions in the studied stretches of the Amazon River are a sustainable, efficient and competitive alternative technology that is extremely favorable for implementing underwater outfalls, due to its simplicity and mainly suitability to the regional socioeconomic reality.