Examinando por Materia "DEMANDA QUÍMICA DE OXÍGENO (DQO)"

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  • Miniatura
    PublicaciónAcceso abierto
    Estudio comparativo de la remoción de materia orgánica en humedales construidos de flujo horizontal subsuperficial usando tres especies de macrófitas
    (2013-11-21) Montoya, J. I. (Jorge Ignacio); Ceballos, L. (Leonardo); Casas, J. C. (Juan Carlos); Morató, J. (Jordi)
    Constructed wetlands appear at the present time like a promising technology in reducing the pollution by waste waters; this study investigated the organic matter removal with synthetic waste water, in terms of chemical oxygen demand (COD), biological oxygen demand (BOD5) and in situ measurements of pH, oxygen and temperatura every 15 days, during three months, in six horizontal subsurface-flow constructed wetland systems, in pilot scale, seeded with three different macrophytes: Canna limbata, Heliconia psittacorum and Phragmites sp; the average removals of COD were of 97,31 % and 95,94 % for Canna limbata; 94,49 % and 93,50 % for Heliconia psittacorum; 97,39 % and 97,13 % for Phragmites sp. In BOD they were of 100 % and 99,36 % for Canna limbata; 99,09 % and 97,49 % for Heliconia psittacorum; 100 % and 99,45 % for Phragmites sp. We conclude that there are significant differences in DQO removal between different plants (P < 0,05); in BOD5 removal significant differences between the different plants do not exist statistically (P < 0,05). This study demonstrates the option to reduce the polution from organic matter using constructed wetlands.
  • Miniatura
    PublicaciónAcceso abierto
    Remoción de níquel y DQO presentes en las aguas residuales de la industria automotriz mediante electrocoagulación
    (2013-10-22) Gonzalez-Silva, G. (German); Valencia, S. H. (Sergio Humberto)
    By means of this study was determined if the electrocoagulation technique helps to minimize the nickel and organic matter, chemical oxygen demand (COD) concentration, present in wastewaters from automotive industry. A randomized multilevel factorial experimental design was used; being the current density and reaction time evaluated in three levels, while the separation between electrodes was analyzed at two levels. Electrocoagulation was carried out in a batch reactor using iron electrodes with monopolar arrangement. The acid digestion, atomic absorption air-acetylene flame and the closed reflux-colorimetric (micro COD) analytical techniques were used to determine the content of the contaminants. The conditions where it got the most decontamination of the water analyzed were found; being the Applied current density: 1,04 A/dm2, operative time: 17 minutes y; did not the electrode separation influence. The results show that electrocoagulation could be effective to reduce nickel and organic matter (COD) present in wastewaters from automotive industry.