Characterization of surface water quality of Crumaú river, main drainage area to Bertioga channel in the Santo Amaro Island, central coast of Sao Paulo state. Bruno Otero Sutti, Bárbara Chiarati Maria, João Marcos Miragaia Schmiegelow, Luciana Lopes Guimarães, Roberto Pereira Borges

Abstract

Estuarine mangrove formations are environments with naturally intense organic matter transformation, and therefore, play an important role in the global biogeochemical cycle of nutrients. Historically these environments in Brazil suffered irregular occupation that provide several sewage discharges places (point and nonpoint). The aim of this study is to analyze the surface water quality from the Crumaú River through microbiological and physicochemical parameters. The waters were collected in two different places in the course of the Crumaú River for a distance of about 4 km, one close to the pollution sources (P1), and other near the outfall (P2). Salinity and pH determination was made in parallel to ammonia and microbiological determinations. High levels of ammonia were observed for P1, which could be explained by the presence of sewage pollution sources in nearby areas. Also, this site (P1), rates of E. coli are higher than the proposed in the regulations with remarkable difference about location analyzed in the outfall (P2). The differences measured in the parameters in the two sampling sites (P1 and P2), shows that the Crumaú river plays an important role in the water self-purification for the pollutants analyzed. However, it is necessary to alert to about the worsening of water quality by the absence of effluents treatment.