Dissertação
Desempenho de estações de tratamento de esgoto e impactos de seus efluentes em corpos de água receptores em Minas Gerais
Fecha
2020-12-11Autor
Luís Fernando de Morais Silva
Institución
Resumen
Domestic sewage represents the main pressure on Brazil's water resources due to the absence
or inefficiency of wastewater treatment. The analysis of data from the monitoring of
wastewater treatment plants (WWTPs) allows diagnosis and definition of strategies that aim
the rational use of water resources and propitiate the multiple use of water, with a consequent
increase in water security. Therefore, the objective of this research is to analyze the
performance of WWTPs and the impact of the discharge of its effluents on the water quality
of the receiving bodies located in Minas Gerais. For this, secondary monitoring data,
comprised between 2006 and 2019, of 49 WWTPs in Minas Gerais and their respective
receiving bodies were analyzed statistically. The analysis included: verification of compliance
with the normative standards for the discharge of effluents and water quality; comparison of
the influents and effluents of the WWTPs by treatment modality; comparison of the influents
and effluents of the WWTPs by station size and comparison of the water quality of the
receiving bodies upstream and downstream of the discharges. The results showed an increase
in violations of the legislation after the discharge of effluents from the WWTPs, especially for
the parameters total ammoniacal nitrogen and surfactants, which do not have a discharge
pattern applicable to public sewage systems. High percentages of violations of water quality
standards were found even upstream of the WWTPs, indicating the need for wide-ranging
actions to recover hydrographic basins in order to ensure greater water security. The
comparison of stations by size identified that, in general, treatment in larger WWTPs resulted
in lower concentrations of pollutants in the treated sewage. The comparison of treatment
modalities identified worse performances for anaerobic modalities, especially those using
UASB reactors. Despite being more efficient and presenting lower percentages of violation of
the normative standards, the WWTPs that use aerobic technologies also caused water
pollution, highlighting the need to improve treatments to guarantee water security.