Avaliação da Qualidade da Água e do Comportamento de Cu, Cr e Pb em Rio Urbano da Cidade de Ponta Grossa, Paraná, Brasil

Resumo

Water quality assessment in urban rivers is paramount for understanding environmental dynamics and
potential risks to human health. This study aimed to investigate the water quality and behavior of trace
metals in the Cará-Cará River, Ponta Grossa, Paraná, Brazil, over a ten-month period. Physicochemical
parameters including pH, total alkalinity, dissolved chloride ions, total suspended solids, ammoniacal
nitrogen, and total phosphorus were monitored alongside the determination of copper, chromium, and
lead concentrations using atomic absorption spectroscopy. Four sampling sites (P1, P2, P3, P4) along the
river were selected to assess the influences of urbanization, agricultural, and industrial activities on water
quality. The mean concentrations of total Cu at P1, P2, P3, and P4 were 3.2 ± 2 µg L-1, 2.6 ± 1.3 µg L-1,
4.0 ± 3.2 µg L-1, and 3.1 ± 1.7 µg L-1, respectively. Similarly, mean concentrations of total Cr were
0.9 ± 0.48 µg L-1, 1.2 ± 0.64 µg L-1, 2.3 ± 3.4 µg L-1, and 0.9 ± 0.58 µg L-1 for P1, P2, P3, and P4, respectively.
Additionally, mean concentrations of total Pb were 4.5 ± 2.4 µg L-1, 3.63 ± 2.6 µg L-1, 3.37 ± 1.96 µg L-1,
and 3.19 ± 1.83 µg L-1 for P1, P2, P3, and P4, respectively. Regarding metals, a decreasing trend was
found as Pb ≥ Cu > Cr. The metals are mainly associated with particulate matter in suspension or colloids,
which indicates a tendency for shorter residence time in the water column and less bioavailable forms of
metals. Overall, while the physicochemical parameters suggested good water quality, variations in metal
concentrations indicated localized impacts from anthropogenic activities. These findings provide valuable
insights into the dynamics of trace metals in urban river systems, informing targeted environmental
management strategies for sustainable water resource protection.