Levantamento das cargas orgânicas lançadas nos rios do estado de São Paulo

Abstract

Based on population data provided by the 2000 IBGE census, the volume of domestic sewage, the volume of treated sewage, the potential and remnant domestic sewage loads and the equivalent carbon and nitrogen loads were estimated for each one of the 645 counties of the São Paulo State and for the catchments of the rivers Piracicaba, MogiGuaçu, Turvo, Peixe, Aguapeí, São José dos Dourados, Itapetininga, Apiaí, Taquari, and Paranapanema. In order to estimate these parameters the existence of sewage collecting system, and the existence of any kind of sewage treatment in each county of the State were taken into account. The database generated in this study may be found at . Despite of the historical attempts of the São Paulo State government in treating sewage, only 17% of the sewage volume produced in the State has some type of treatment before it is launched to rivers. Consequently, the load of untreated sewage is indeed very large. This input of extra organic matter causes severe alterations in water bodies. Among the catchments we have analyzed the Piracicaba River basin is the most affected by domestic sewage, followed by Mogi-Guaçu and Turvo basins. On the other hand, the basins of the rivers Itapeteninga, Apiaí, Taquari and Paranapanema are the least affected.www.cena.usp.br/biota ResumoOs parâmetros: volume de esgoto gerado, volume de esgoto tratado, cargas poluidoras domiciliar potencial e remanescente, cargas equivalentes de carbono e nitrogênio foram estimados neste estudo a partir dos dados populacionais do censo 2000 do IBGE para todos os municípios do Estado de São Paulo bem como as bacias hidrográficas dos rios Piracicaba, Mogi-Guaçu, Turvo, Peixe, Aguapeí, São José dos Dourados, Itapetininga, Apiaí, Taquari e Paranapanema,. Para essas estimativas foram levados em consideração o nível de atendimento das populações pela existência de redes coletoras de esgoto e a existência ou não de algum tipo de tratamento de esgoto em cada município do Estado. Todas essas estimativas encontram-se disponíveis em . Apesar da preocupação histórica do Governo Paulista com saneamento básico, somente 17% do esgoto gerado no Estado sofre algum tipo de tratamento prévio. Portanto, a carga domiciliar remanescente é extremamente elevada. Esse aporte extra de matéria orgânica causa mudanças profundas nos corpos hídricos receptores. Dentre as bacias hidrográficas acima citadas, a bacia do rio Piracicaba é a mais severamente afetada por despejos de esgoto doméstico, seguida pelas bacias dos rios Mogi e Turvo. Por outro lado, as bacias do Alto Paranapanema (Itapeteninga, Apiaí, Taquari e Paranapanema) são as menos afetadas.

Anthropogenic sources and distribution of phosphorus in sediments from the Jaguaribe River estuary, NE, Brazil

“…The most necessary variables can be estimated from surveys and inventories of these activities, such as population parameters, urban and rural area extensions per basin, and agriculture production and fertilizer use. Emission factors have been successfully used to estimate nutrient and pollutant loads at local, regional and global levels (Lacerda et al, 2006;Martinelli et al, 2002;NRC, 2003), and have been adopted as a standard methodology by various environmental agencies (EEA, 1999;EPA, 2002).…”

Phytoplankton biodiversity changes in a shallow tropical reservoir during the hypertrophication process

“…This fact was already pointed out in studies conducted in Brazilian inland waters (Martinelli et al, 2002;Barbosa et al, 1993;Tundisi, 2003;Tundisi and Matsumura-Tundisi, 2003;Agostinho et al, 2005). However, long-term studies on biodiversity changes due to eutrophication are still unavailable for tropical inland waters.…”

Dissolved nitrogen in rivers: comparing pristine and impacted regions of Brazil

“…The only exception to this procedure was the Óbidos sampling site on the Amazon River, where we assumed that the percentage deforested area was the same as for the Brazilian Amazon estimated by Instituto Nacional de Pesquisas Espaciais (INPE). The population densities of the watersheds of the State of São Paulo and Ji-Paraná in the Amazon were estimated by determining the size of the watershed and the population living in these areas obtained by demographic census of the counties for each watershed (IBGE, 2008), as described in Martinelli et al (2002). For the entire Amazon watershed and its major tributaries, the population densities were obtained from Revenga et al (1998).…”

“…The most pristine is the Paranapanema and the most impacted the Piracicaba, which has a population density ten times greater than in sub-catchments of the Paranapanema basin (Table 1), and receives large sewage discharges. As most of the sewage is not treated in the State of São Paulo (Martinelli et al, 2002) and in Brazil in general (IBGE 2000(IBGE , 2002 rivers draining highly populated areas receive a high load of labile organic matter, proportional to the population density.…”