In vitro evaluation of the bacterial capacity to remove lead in synthetic wastewater

Abstract

With the purpose of mitigating the environmental impacts caused by different industrial activities related to the mining, petrochemical, metallurgical sector, among others, an in vitro characterization of 152 microorganisms has been carried out between strains and bacterial consortia. In the isolation and biostimulation phase the bacteria were subjected to selection in a modified culture medium, in which concentrations of 20 and 100 ppm of Pb were added, finally obtaining five strains that showed to be resistant and / or tolerant to Pb. The determination of the bacterial capacity of removal of Pb was experienced under two conditions: incubation at a controlled temperature of 25 ° C and incubation at room temperature (between 5 °C and 23 °C for the southern zone of Quito in the months of study). The biochemical characterization was carried out through the Kit Microgen GN-ID A + B, identifying the following genera: Acinetobacter, Pseudomona, Aeromona and the species: Aeromona hydrophila and Photobacterium damselae, the same one that obtained 99.8% certainty. In the development of the curves of kinetics of bacterial growth and removal of Pb, turbidimetry and atomic absorption techniques were used, where Aeromona hydrophila showed greater ease of growth at 20 ppm in incubation at room temperature, while that Pseudomona sp recorded a percentage of total Pb removal of 96.30% at 100 ppm and incubation at temperature ambient. The research aims to serve as a guide for future studies so that it can be used as a more efficient and economical remediation alternative in relation to conventional remediation technologies.