19 research outputs found

    Tabular cusum control charts of chemical variables applied to the control of surface water quality

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    The aim of this study was to evaluate the application possibility of tabular CUSUM control charts in the quality control of chemical variables in surface water. It was performed bibliographic and field research to collect water samples from 2003 to 2009, totaling 30 samples, some monthly and others semi-annual in order to observe the variables that regulate water quality. It was found that these charts may be applied to control the quality of river water; showing to be effective in the perception of changes during the process, especially for small samples (n=1) which there is no repetition as in this research. It was also concluded that the Mandurim River does not presents significant levels of pollution

    Reúso de águas residuárias da piscicultura e da suinocultura na irrigação da cultura da alface Reuse of wastewater from swine and fish activities in the lettuce culture

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    Este trabalho teve o objetivo de avaliar o desenvolvimento, a produção e a qualidade sanitária da cultura da alface irrigada com águas residuárias originadas da suinocultura e da piscicultura. Os tratamentos avaliados foram: T1 - alface irrigada com água de origem subterrânea e adubação suplementar; T2 - alface irrigada com água residuária de viveiro de peixes alimentados com ração; T3 - alface irrigada com água residuária originária de lagoa de estabilização de dejetos de suínos, e T4 - água de lagoa de cultivo de algas, alimentada com resíduo de biodigestor de dejeto de suíno. Os tratamentos não apresentaram diferenças significativas para altura da alface, diâmetro da cabeça, comprimento da raiz, massa da raiz, massa total da planta, massa fresca e massa seca; os tratamentos T4 e T2 apresentaram os maiores valores para comprimento da maior folha e número de folhas, respectivamente; em geral, as análises foliares e a extração de macro e micronutrientes pela cultura não apresentaram diferenças significativas; ocorreu contaminação de coliformes fecais e totais em todos os tratamentos; não ocorreu contaminação de Escherichia coli em todos os tratamentos; todos os Coeficientes de Uniformidade de Christiansen (CUC) encontrados foram acima de 85%, exceto para o tratamento T3 que foi de 74,05%; ocorreram alterações químicas no solo proporcionais às características das águas utilizadas nos respectivos tratamentos.<br>The objective of this work was to evaluate development, production and sanitary quality of the irrigated lettuce with wastewater from fish and swine activities. The evaluated treatments was: T1 - lettuce irrigated with water from underground origin and supplemental fertilization; T2 - lettuce irrigated with wastewater from fish activities and fish fed with ration; T3 - lettuce irrigated with wastewater from swine treated in stabilization lagoon; and T4 - lettuce irrigated with effluent from seaweed lagoon, fed with wastewater from swine activities treated with anaerobic reactor. The treatments did not present significant differences for next culture characteristics: height, diameter head, length root, mass root, total mass plant, green mass and dry mass; the treatments T4 and T2 presented the biggest values for length and number leaf, respectively; in general, leaf analyses and extraction of macro and micronutrients by culture did not present significant differences; contamination by fecal coliforms in all treatments occurred; no contamination by Escherichia coli was observed in all treatments; all the Coefficients of Uniformity of Christiansen (CUC) observed were above 85%, except for treatment T3 where was 74%; chemical alterations in the soil occurred proportional to characteristics of waters used in the treatments

    Kinetic behavior of nitrification in the post-treatment of poultry wastewater in a sequential batch reactor

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    A sequential batch reactor with suspended biomass and useful volume of 5 L was used in the removal of nutrients and organic matter in workbench scale under optimal conditions obtained by central composite rotational design (CCRD), with cycle time (CT) of 16 h (10.15 h, aerobic phase, and 4.35 h, anoxic phase) and carbon: nitrogen ratio (COD/NO2--N+NO3--N) equal to 6. Complete cycles (20), nitrification followed by denitrification, were evaluated to investigate the kinetic behavior of degradation of organic (COD) and nitrogenated (NH4+-N, NO2--N and NO3--N) matter present in the effluent from a bird slaughterhouse and industrial processing facility, as well as to evaluate the stability of the reactor using Shewhart control charts of individual measures. The results indicate means total inorganic nitrogen (NH4+-N+NO2- -N+NO3--N) removal of 84.32±1.59% and organic matter (COD) of 53.65±8.48% in the complete process (nitrification-denitrification) with the process under statistical control. The nitrifying activity during the aerobic phase estimated from the determination of the kinetic parameters had mean K1 and K2 values of 0.00381±0.00043 min-1 and 0.00381±0.00043 min-1, respectively. The evaluation of the kinetic behavior of the conversion of nitrogen indicated a possible reduction of CT in the anoxic phase, since removals of NO2--N and NO3--N higher than 90% were obtained with only 1 h of denitrification
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