Hydrochemistry of two small estuaries: Cururupe and Acuípe River, Ilhéus, Bahia
ALVES1, C.P. & SOUZA2, M.F.L.
1 Universidade Estadual de Santa Cruz, Programa de Pós-Graduação em Desenvolvimento e Meio Ambiente / Departamento de Ciências Exatas e Tecnológicas, Rod. Ilhéus/Itabuna, Km 16, CEP: 45.650-000; Ilhéus – Bahia - Brazil.
2 Universidade Estadual de Santa Cruz, Departamento de Ciências Exatas e Tecnológicas, Rod. Ilhéus/ Itabuna, Km 16, CEP 45.650-000; Ilhéus – Bahia – Brazil.
ABSTRACT: In this work the effect of leachate waste from the Ilhéus garbage dump on the water quality of Cururupe River estuary was focused. Sampling was carried at the estuaries of Cururupe River and Acuípe River (assumed as natural background). pH, temperature, dissolved oxygen, electrical conductivity and salinity were measured in situ. Dissolved inorganic nutrients, total alkalinity, biochemical oxygen demand and Fe2+ were also analyzed. The presence of dump does not affect significantly these variables. Both estuaries are dystrophic and Cururupe River and Acuípe River can be classified in class 7 and 8, respectively (CONAMA no. 20). According the new CONAMA resolution nº 357 the classification is conflicting, but Cururupe River exhibited a better water quality. This fact can be explained by depuration of leachate wastes in mangrove of Cururupe River, and the greater area covered by wetlands in Acuípe River. The BOD results also stressed the limitation of this test as an indicator of organic pollution, and suggest that correlation analysis can be used as an indirect method to evaluate environmental disturbance.
Key-words: Leachate waste, biochemical oxygen demand, dissolved inorganic nutrients, water quality, environmental regulation.