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.

A simple method combining slurry sampling after cryogenic grinding and the use of a permanent modification of the integrated platform inside the transversely heated graphite atomizer (THGA) was proposed for the determination of Cd and Pb in foods. Potentialities of the cryogenic grinding were evaluated for grinding different materials of difficult homogenization such as high fat and high fiber tissues. Animal and vegetal samples were cut into small pieces and ground in liquid nitrogen for 2 min. Slurries were prepared directly in the autosampler cup after cryogenic grinding by transferring an exact amount of homogeneous powdered material (5-20 mg) to the cup, followed by 1.00 mL of 0.2% (v/v) HNO3 containing 0.04% (v/v) Triton X-100 and sonication for 30 s, before transferring into the platform previously coated with 250 microg W and 200 microg Rh. Use of a tungsten carbide-rhodium permanent modifier combined with NH4H2PO4 conventional modifier improves tube lifetime and increases the pyrolysis temperature for Cd. Homogeneity tests, carried out by comparing the between- and within-batch precision for each kind of sample, showed no significant differences at the 95% confidence level, indicating good homogeneity for 5-20 mg masses. Detection limits were 3.3 ng g(-1) Cd and 75 ng g(-1) Pb for 1% m/v slurries. Results for determination of Cd and Pb in foods slurries were in agreement with those obtained with digested samples, since no statistical differences were found by the paired t-test at the 95% level.

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