Determinación de la capacidad de degradación de Ralstonia pickettii de Cromo VI en agua proveniente de curtiembre.

Abstract

The present investigation objetive is to avaluate the capacity of the bacteria Ralstonia pickettii for the degradation of Hexavalent Chromium (Cr VI) in waste water of tannery. The Hexavalent Chromium is a toxic element, tested as carcinogenic in humans according to IAR (International Agency for Research on Cancer), it can be found in the waste wáter of tanning. We started evaluating the resistance of R.pickettii to Cr VI using nutritive agar supplemented with dichromate of potassium as a culture médium. The máximum resistance was established to 200 mg/L of Cr VI. Later, we determined the percentage of degradation of Cr VI in nutritive broth supplemented with dichromate of potassium. The following values were gotten: 95.2 %, 92.3 % and 90.87 % of degradation of Cr VI for the initial concentrations of 5, 10 and 15 mg/L of Cr VI respectively. The degradation percentage in waste water of the tanning process was also determinated establishing three units of analysis with different bacteria concentration and controls to 24, 48 and 72 hours. The results were 57.14 % of degradation to 24 hours and 58.73 % to degradation to 48 and 72 hours. It is concluded that the variation on the factors of biomass and time of incubation do not intervene meaningfully in the degradation capacity of Cr VI of R.pickettii.