a b s t r a c tThroughout the year of 2004, 54 samples (1 L each) were collected from commercial sources in the Vale do Paraíba region (eastern portion of São Paulo State, Brazil). The concentrations of (Ca, Cr, Cu, Fe, Mg, Mn, Ni, Se, Zn, Cd and Pb) in these samples were analyzed by two atomic-absorption spectroscopy (AAS) methods. Ca, Cu, Fe, Mg and Zn were determined by flame atomic-absorption spectroscopy (FAAS) and (Cd, Cr, Mn, Ni, Pb and Se) were determined by electrothermal atomic-absorption spectroscopy (ETAAS). Tests to determine and quantify essential, nonessential and toxic elements present in bovine milk are rare in Brazil, especially so for Vale do Paraiba region. Tests were performed on standard NIST-certified milkpowder to validate the reliability of subsequently collected analytical data. Ca presented a lower recovery value (85.3%). The finding for Ca macro-nutrient was found to be below recommended international standards (1300 mg/L) for all samples possibly due to milk heterogeneity and losses in the pasteurization process. Significant results for Pb were found in all milk samples with average values at 0.230 mg/L from a minimum of 0.062 mg/L and maximum of 0.476 mg/L.

Este trabalho mostra o efeito da temperatura de digestão do agente precipitante nas características físicas e químicas do Nb2O5.nH2O e do ZrO2.nH2O. Os compostos foram obtidos pelo método da precipitação em solução homogênea com a decomposição térmica do (NH4)2CO3 realizada a 45 ºC e a 90 ºC. A difração de raios X mostrou que o Nb2O5.nH2O preparado em qualquer uma das duas temperaturas é material cristalino apresentando espaçamento interlamelar, enquanto que o ZrO2.nH2O é amorfo. Pela análise térmica observou-se grau de hidratação semelhante para todos os materiais. As isotermas de Langmuir revelaram que os melhores resultados de adsorção foram alcançados para ambos os materiais preparados a 90 ºC.

-Catalytic ozonation has been recognized in the scientific community as an efficient technique, reaching elevated rates of recalcitrant organic material mineralization, even at the presence of scavenger species of hydroxyl free radicals. This study presents the most significant factors involving the leachate treatment stabilized by the municipal landfill of the city of Guaratinguetá, State of São Paulo, Brazil, by using a catalytic ozonation activated by metallic ions Fe 3+ , Zn 2+ , Mn 2+ , Ni 2+ and Cr 3+ . The Taguchi L 16 orthogonal array and its associated statistical methods were also used in this study. Among the researched ions, the most notable catalysis was obtained with ferric ion, statistically significant in the reduction of COD with a confidence level of 99.5%.

-This study presents the results of a mature landfill leachate treated by a homogeneous catalytic ozonation process with ions Fe 2+ and Fe 3+ at acidic pH. Quality assessments were performed using Taguchi's method (L 8 design). Strong synergism was observed statistically between molecular ozone and ferric ions, pointing to their catalytic effect on OH

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