Eficacia de los consorcios bacterianos y fúngicos nativos en la remoción de metales pesados por biolixiviación de los sedimentos de la laguna de San Antonio de Padua de la Ciudad de Riobamba

Abstract

The bioleaching of heavy metals from sediments was carried out in San Antonio de Padua Lake from Riobamba city, Province of Chimborazo, the physical and chemical sediment characterization was made determining the contamination by Ba, Cu and V. The bacterial strains reactivation was made from master cell banks stored at the Technical Solutions Center and Environmental Technology Transfer identifying the fungal genus strains through morphological analysis and was purified with the successive sowing technique. The heap bioleaching was carried out, the process was executed with liquid inoculation both bacterial and fungal native consortium to remove metals found in the sediments to the leaching. Using equipment such as: horizontal laminar flow bench, autoclave, incubator, inductively coupled plasma (ICP), stove. Two microbial consortium were formed by Xenorhabdus nematophilys and E.coli inactiva and the fungal consortium composed by the genus géneros Xylohypha, Aspergillus, Trichoderma, Penicillum, Cladosporium y Humicola, type in fungi filamentous. Based on the bioleaching test, through the use of bacterial consortium obtaining concentrations of Ba= 3,96 mg/L, V= 0,0448 mg/L and Cu= 0,0585 mg/L and the case of fungal consortium Ba= 1,68 mg/L, V= 0,1119 mg/L y Cu= 0,0579 mg/L; concentrations are relatively low in leaching liquor. It is concluded that the bioleaching is not effective removing Ba, Cu and V because the native consortium are not capable to produce organic acid with bioleaching capacity, on the other hand while the microbial consortium have optimal growing conditions, in the heap leaching method are not highly selective in the extraction of heavy metals. It is recommended the research be expanded in the use of bacterial and fungal consortium in basic and acidic media, moreover to carry out studies with the Aspergillus Niger fungal strain which has a great potential of bioleaching producing citric acid in its metabolic activity, reducing environmental impact in lacustrine system.