A influência da cortina retentora de resíduos na qualidade da água da Lagoa da Pampulha – Belo Horizonte/MG

Abstract

The Pampulha Lagoon, is a small urban reservoir located in the municipality of Belo Horizonte, Minas Gerais, that receives a high load of nutrients and waste from domestic and industrial sewage, as well as, diffuse pollution which causes water eutrophication. As a way to reduce the impacts caused by pollution in the Lagoon a waste retaining curtain was installed by the municipal government in its narrowest part. The objective of this study was to verify the effect of the waste retaining curtain on the water quality dynamics of the Pampulha Lagoon from a limnological parameter analysis. Surface water samples were collected in a 29 points sampling grid in April 2018 and the following parameters were measured: chlorophyll a, turbidity, colored dissolved organic matter (CDOM), depth (Secchi disk), pH and water temperature. The monitoring points were separated into two groups located before and after the waste retaining curtain, groups 1 and 2, respectively. Chlorophyll-a and Turbidity presented the highest variability for both groups and Group 2 presented lowers values for all analyzed limnological parameters, especially for Chlorophyll-a, Turbidity and CDOM, when compared to group 1. Based on a statistical analysis, it can be shown that the waste retaining curtain is effective in retaining part of the polluting load that arrives at the Pampulha Laggon, decreasing the concentration of limnological parameters which can be directly associated to better overall water quality.