Monitoring of toxic chemical in the basin of Maringá stream=Monitoramento de compostos químicos tóxicos na bacia do ribeirão Maringá

This study aimed to track the spatial and temporal variations of toxic chemical compounds, such as the metals Al, Cd, Pb, Cu, Cr, Mn, Zn and the pesticide glyphosate, in Maringá stream and in a stretch of Pirapó river. The results pointed out that, in the case of metals, one of the possible sources of these elements is associated to agricultural activities. For glyphosate, were not found concentrations above those established by the Brazilian Water Quality Legislation (CONAMA 357/2005). Concerning this, we emphasized that the impact caused by the agrochemical on water quality should be evaluated considering the adverse effects to the environment caused by its degradation, that produces recalcitrant and surfactant compounds that may be even more toxic for humans and aquatic environment. <br><br>Esse estudo teve por objetivo monitorar a variação espaço-temporal de compostos químicos tóxicos, como os metais Al, Cd, Pb, Cu, Cr, Mn, Zn e o defensivo agrícola glifosato, nas águas do ribeirão Maringá e de um trecho do rio Pirapó. Os resultados obtidos mostraram que no caso dos metais uma das possíveis fontes destes elementos na bacia está vinculada às atividades agrícolas. Para o defensivo glifosato, neste trabalho não foram encontradas concentrações acima do permitido pela legislação (CONAMA 357/2005). Sobre esse aspecto, ressalta-se que o impacto dos produtos agrícolas sobre a qualidade da água deve ser avaliado do ponto de vista dos efeitos adversos ao ambiente causados por sua degradação, gerando, por sua vez, compostos recalcitrantes e surfactantes e que podem ser muito mais tóxicos à vida aquática e ao homem

Nitrogen forms and total phosphorus in water courses: a study at Maringá stream, Paraná State - doi: 10.4025/actascitechnol.v35i4.14018

This paper aimed to monitor the nitrogen compounds and total phosphorous in the Maringá Stream watershed in order to investigate the spatial and temporal variations in the water quality. For this, samplings were collected from seven sites during the period from October 2008 to September 2009. The results indicated the most critical stretches of water pollution with the inflow of the discharges from a sewage treatment plant of the city. Also it is important to highlight the influence of diffuse pollution coming from agricultural runoff and wastewater from fishing lakes, on the water quality.