Quality of the water from the Pindare river Basin, In the facts corresponding to the municipalities of Pindare Mirim, Tufilandia and Alto Alegre In the State of Maranhao

Abstract

This study aimed to characterize chemical-physical water area of the middle reaches of the river Pindaré under the jurisdiction of the municipalities of Pindaré- Mirim, Tufilândia and Alto Alegre / MA. In order to obtain a representative sample, water was collected in ten different points distributed in Rio Pindaré over 24 months in different seasonal periods in 2010 and 2011. The physical-chemical parameters analyzed were: temperature, pH, turbidity , electrical conductivity, dissolved oxygen and ammonium ion (NH4 +), nitrite (NO2), nitrate (NO3) and total phosphorus (PO43-). During the study period, there was wide variation in most of the variables analyzed, with emphasis on the total phosphorus (PO43-) and electrical conductivity presented results higher than those established by Resolution CONAMA 357/05. As to pH, the water of the river Pindaré were mostly acidic time. The average nitrate concentrations ranged from 0.249 mg L-1 (dry season) and 0.267 mg L-1 (rainy season). The points collected in different periods, in the municipality of Alto Alegre was no significant statistical difference when the tested parameter is pH. When the parameters tested were the electrical conductivity and ion ammonium, nitrite and nitrate, a statistically significant difference was observed in all points tested in three municipalities with p = 0.05. The results showed that the river Pindaré has a good environmental quality, despite its deforestation along its banks thereby undermining the sustainability of the basin. The physical and chemical characteristics were extremely important in the dynamics of the aquatic ecosystem and the values found are considered suitable for maintenance of aquatic life, according to Resolution CONAMA 357/2005.

Keywords

• Sustentabilidade. Rio. Características limnológicas. Qualidade ambiental.