Sidney de Souza Martinez’s scientific contributions

The main objective of this research was to evaluate the water quality of the Baquirivu-Guaçu river located in the cities of Arujá and Guarulhos, State of São Paulo, during the period from 1983 to 2010, based on the urban population increase as well as the land use diversification and occupation in those urban areas. For this purpose two-monthly records from CETESB were used that include the following parameters: thermotolerant coliforms, biochemical oxygen demand (BOD 5.20), total phosphorous, total nitrogen, Water Quality Index (WQI) and Trophic State Index (TSI). The results obtained show that urban and industrial expansions and the deficiencies in sewage domestic treatment were responsible by the pollution of Baquirivu-Guaçu river surface water. The sewage treatment plant (STP), located in Arujá city, that has operated since 2004, prevented reaching the worst levels that occurred at the beginning of the 2000s and temporarily attenuated the pressure on the quality indices. However, especially at the end of the study period, there was a need to adapt the sewer system to changing use and land cover, both with regard to its design and as to the introduction of new steps in treatment.