Quali-quantitative characterization of organic matter in urbanized drainage basins as a basis for the application of Water Resources Management Instruments

Caracterização quali-quantitativa da Matéria Orgânica em bacias hidrográficas urbanizadas como base para a aplicação dos Instrumentos de Gestão de Recursos Hídricos

ABSTRACT

The challenge imposed by law no. 9433/97 to establish mechanisms for the recovery of bodies of water led to a dynamic of research that could guarantee not only an adequate understanding of the management instruments but also the technical basis for their application. In this research, emphasis was placed on understanding the dynamics of organic matter (OM) in a drainage basin heavily influenced by anthropogenic activities, through the analysis and interpretation of qualitative and quantitative information. The case study was the Iguaçu River basin, from its headwaters in the Metropolitan Region of Curitiba (MRC) to the municipality of União da Vitória_. The results obtained showed a large deposition of labile OM in the MRC coming probably from domestic effluents, with consequent DO depletion and water quality degradation. However, after the more urbanized region, there is a reduction in the concentration of OM and the indication of the predominance of pedogenic material, suggesting that in addition to the dilution effect, there is less input of anthropogenic effluents in this region, which results in an improvement in water quality, represented mainly by the recovery of the DO concentration. The combined use of quantitative data and UV-visible spectroscopy was fundamental to comprehend the variation in the characteristics of OM and its sources along the studied section.

Keywords:
Water quality; UV-Visible; Urban basins; Iguaçu River