Effects of Urban Sewage on Dissolved Oxygen, Dissolved Inorganic and Organic Carbon, and Electrical Conductivity of Small Streams along a Gradient of Urbanization in the Piracicaba River Basin

摘要: In Brazil most of the urban sewage is dumped without treatment into rivers. Because this, it extremely important to evaluate consequences organic matter rich on structure and functioning river ecosystems. this study we investigated effects dissolved oxygen (O2), inorganic (DIC) carbon (DOC), electrical conductivity (EC) in 10 small streams Piracicaba River basin, southeast region Brazil. which one developed regions country, only 16% total load generated treated. These were classified two groups, with heavy influence another less influence. Both concentrations seasonal variability distinct between groups. The that received effluent had a combination low O2 high DIC, DOC, EC. polluted streams, forms EC higher concentration lower during water period. variations small. We also efficiency plant installed years ago catchment these streams. It was observed an increase after beginning treatment, decrease DIC DOC especially However, no significant change EC, suggesting major ions still unaltered, secondary necessary order reduce ion stream.