Geochemistry of intertidal sediment pore waters from the industrialized Santos-Cubatão Estuarine System, SE Brazil

The geochemical composition of sediment pore water was investigated in comparison with the composition of sediment particles and surface water in an estuary within one of the most industrialized areas in Latin America (Santos-Cubatão estuarine system, SE Brazil). Pore and surface waters presented anomalously high levels of F(-), NH4(+), Fe, Mn and P due to two industrial point sources. In the summer, when SO(4)(2-)/Cl(-) ratios suggested an enhanced sulfate reduction, the higher dissolved levels observed in pore waters for some metals (e.g., Cu and Ni) were attributed to reductive dissolution of oxidized phases. Results evidenced that the risks of surface water concentration increase due to diffusion or advection from pore water are probably dependent on coupled influences of tidal pumping and groundwater inputs.The geochemical composition of sediment pore water was investigated in comparison with the composition of sediment particles and surface water in an estuary within one of the most industrialized areas in Latin America (Santos-Cubatão estuarine system, SE Brazil). Pore and surface waters presented anomalously high levels of F-, NH4+, Fe, Mn and P due to two industrial point sources. In the summer, when SO42-/Cl- ratios suggested an enhanced sulfate reduction, the higher dissolved levels observed in pore waters for some metals (e.g., Cu and Ni) were attributed to reductive dissolution of oxidized phases. Results evidenced that the risks of surface water concentration increase due to diffusion or advection from pore water are probably dependent on coupled influences of tidal pumping and groundwater inputs842427441A composição geoquímica das águas intersticiais de sedimentos foi estudada em comparação com a composição das partículas sedimentares e de águas superficiais em um estuário de uma das áreas mais industrializadas da América Latina (sistema estuarino de Santos-Cubatão, sudeste do Brasil). Águas intersticiais e superficiais apresentaram altos níveis de F-, NH4+, Fe, Mn e P, devido a duas fontes industriais pontuais. No verão, quando as razões SO42-/Cl- sugeriram aumento na redução do sulfato, os níveis mais elevados de alguns metais dissolvidos nas águas intersticiais (como Cu e Ni) foram atribuídos à dissolução redutiva de fases oxidadas. Os resultados sugerem que os riscos de aumento nas concentrações das águas superficiais por difusão ou advecção das águas intersticiais provavelmente dependem de influências conjuntas do aporte de águas de maré e águas subterrânea