Monitoring of urban and rural basins: water quality of Mourão basin.

F H Passig,P C Souza,K Q Carvalho,L K Gusmão,S B Lima,M C R Halmeman

doi:10.1590/1519-6984.01213suppl

Abstract

The Mourão River basin is located on the central western region of the Paraná State - Brazil, between coordinates 23º 44' - 24º 25 South latitude and 52º 12' - 52º 30' West longitude, between 270 and 820 m above sea level, and 1,648.21 km2 drainage area. Water quality was evaluated by monitoring physical, chemical and microbiological parameters. Monthly samplings were performed for a year at five sites in the basin for analysis of: pH, temperature, dissolved oxygen, biochemical oxygen demand, total nitrogen, ammoniacal nitrogen, nitrite, nitrate, total phosphorus, turbidity, total solids, volatile solids and fecal coliforms. The results of the evaluated parameters showed higher values than the limits set by CONAMA Resolution 357 from 2005 for Class 2 in some samples. The Water Quality Index (WQI) indicated that 72% of samples had average quality and 28% had good quality for the Mourão River basin. Higher values of WQI were observed after rainfall period with median of 75 compared to the dry period with median of 62. The source of the Mourão River is contaminated with fecal coliforms, evidencing the real need to treat sewage in rural areas.

Highlights

Hydrological studies in watersheds are important to demonstrate the anthropogenic influences on environmental characteristics of water resources
Taking into account that the rivers of Mourão River basin are classified as Class 2, according to the Ordinance 19 of SUREHMA of 1992, the results of the water quality parameters monitored in the sites P1, P2, P3, P4 and P5 were compared to limits set forth in Conama Resolution 357/2005 (Brasil, 2005) for such rating
The Mourão River basin was examined for different forms of nitrogen: total Kjeldahl nitrogen, ammoniacal nitrogen, nitrite and nitrate, as shown in Figure 8, with minimum and maximum, lower and upper quartiles and the median

Summary

Introduction

Hydrological studies in watersheds are important to demonstrate the anthropogenic influences on environmental characteristics of water resources. According to studies of the Brazilian National Water Agency (ANA), over 80% of the rivers in Brazil are in a good condition, but almost half of them, concentrated in urban areas, have poor or very poor quality. In this scenario, the Paraná River basin, which covers almost all the rivers of the Paraná State, has the worst indicators of pollution (ANA, 2012). The use of the WQI as a tool for classifying surface water resources considers converting a set of limnological data (water quality parameters) into a numerical value This index has been widely used to know the quality of waters (Cude, 2001). The present study sought to present a diagnosis of water quality on the basis of current legislation and on the determination of the Water Quality Index (WQI) for the Mourão River basin

Material and Methods

Results and Discussions

Conclusion