ANÁLISE DA EFICIÊNCIA DO TRATAMENTO DO EFLUENTE DE TANQUE SÉPTICO POR SISTEMA ALAGADO CONSTRUÍDO EM ESCALA PILOTO

Abstract

Based on the concern with the destination of wastewater, and the lack of coverage of efficient treatment systems in Brazil, it was found in the pilot sewage treatment station composed of a biodigester septic tank followed by a flooded system formed by a water hyacinth pond and built flooded system planted with swamp cane, a viable alternative, both technically and economically, reducing the amount of organic matter and soil pollution with a biological agent, especially in rural areas, or in communities where there is no network collector. The research proposal was to analyze the general efficiency of removing some parameters and check if the final effluents reach the effluent discharge standards of the current federal, state and municipal laws. For this purpose, the association of two septic tank after-treatments was evaluated, the first being a constructed flooded system formed by water hyacinth pond - Eichhornia crassipe (SAC 1) followed by a constructed flooded system planted with Cana do Brejo - Costus spicatus jacq. (SAC 2). Collections and laboratory analyzes of the powders treated by the septic tank and effluent treated in both SACs were carried out. The percentage efficiency of pollutant removal from each SAC was evaluated. In addition, the principal components analysis (PCA) was performed to observe the relationship between the physical-chemical parameters in the first and second main components and the correlation of the physical chemical parameters in each treatment. There was a strong correlation between nitrate and nitrite in all treatments. For other situations, the correlations were moderate, indicating little association between the studied variables. There was no efficiency in removing the parameters nitrite and nitrate, in any of the treatments. SAC 2 showed better results in the percentage efficiency of removing pollutants such as chemical oxygen demand (COD) with an average efficiency of 50.86% between SAC 1 and SAC 2, and Ammonia which had an average efficiency of 28.81% between SAC 1 and SAC 2.