Influência dos emissários submarinos de Ipanema (ESEI) e Barra da Tijuca (ESBT) na qualidade da água costeira do município do Rio de Janeiro

Abstract

The world's coastal regions are home to the majority of the population, and their activities involve the production, mainly, of domestic sewage. As a result, many coastal cities have opted to use submarine outfalls, because they have an important role in diverting sewage from beaches, have a high dispersion and purification capacity of organic matter in the marine environmental, besides being a good economic alternative. Thus, the study aimed to evaluate the water quality around the outlets of the diffusers of the submarine emissaries of Ipanema (ESEI) and Barra da Tijuca (ESBT), located in the city of Rio de Janeiro, based on data made available by INEA. Water quality parameters data (thermotolerant coliforms, dissolved oxygen, temperature, total phosphorus, nitrite, nitrate, ammoniacal nitrogen and pH) from monthly monitoring of the surroundings of these outfalls, from April 2021 to March 2023, were used to verify compliance with water quality standards and to calculate the water quality index, using the Canadian Council of Ministers of the Environment Index (CCME-WQI). Resolution CONAMA No. 357/2005, class 1 saline water, was used as a quality standard for comparison and for calculating the CCME-WQI. The data showed that the CCME-WQI calculated around the outfalls varied between average and excellent, and that most of the results were in accordance with the values presented for the water class in CONAMA nº 357/2005 during the evaluated period. Furthermore, despite some results being above legislation, the quality of the water found around the outfalls indicated the effectiveness of their disposal of sanitary effluents