BTX biodegradation using selected microorganisms of soil and industrial wastewater

Abstract

Problems associated with the exploration and trade of oil and its derivatives, such as undue and accidental leaks, have been provoked serious environmental damages, demanding the development of treatments in order to reduce this negative impact. Among the strategies to eliminate the BTX (benzene, toluene e xilene isomers), the bioremediation is an option which the process consist of the capacity of microorganism to metabolize these compounds in inert substances. The main of this study was to select microorganisms which degrade BTX, as well as to verify the microbial degradation of the compounds. The qualitative methodology was used to investigate the potent microorganisms to degrade BTX, which use the dye 2, 6-diclofenol-indofenol (DCPIP). Of the 33 microorganisms, four were able to degrade BTX. These microorganisms (Biopetros 01 a 04) were submitted to fermentations and parameters as pH tests, DQO, protein concentration, dry cell mass and BTX concentration reduction were assessed. The obtained percentages of DQO reduction were satisfactory using the Biopetros 01, 02 and 03. In the tests that quantify the BTX degradation, realized by chromatography analysis (GC/MS), it was detected reduction of this solvents despite the loss by volatilization; spite of the their loss, the Biopetro 03 showed the best results to benzene (19.37%) and toluene (86.38%) and the Biopetro 04 to xilenes (96.33%). According to the obtained results, the used methodology revealed a considerable degradation potential to apply in bioremediation treatments.