BIORREMEDIAÇÃO COMO ALTERNATIVA DE TRATAMENTO DE SOLOS CONTAMINADOS COM METAIS TÓXICOS.

This study aimed to conduct a literature review and a discussion of the main aspects related to the bioremediation techniques used in the treatment of soils contaminated with toxic metals, especially to the main microorganisms used and the factors that influence the results, highlighting some studies focused the bioremediation of lead metal. Lead is one of the metals most commonly found in soil and their presence in living organisms is harmful in any concentration, therefore, the application of technologies for their remediation is necessary to avoid harmful effects to the environment and human health, because of its high toxicity. In the context of the approaches of the technologies used in the treatment of contaminated soils with toxic metals, the bioremediation is acquiring significant importance, mainly due to its low cost of application, aesthetics and acceptability, being that, some processes associated with bioremediation, such as bioleaching, biomineralization, biotransformation, bioaccumulation and biosorption, show quite efficiency for the treatment of toxic metals. In the case of metals, due to their non-biodegradability, the bioremediation may be reached primarily with the solubilization, stabilization, detention or modification of speciation with reduced toxicity of the metals present in the soil. It is therefore concluded that although a wide variety of genera, species and microorganisms associations, fungi and bacteria especially, can be used in the bioremediation of toxic metals, secure the fundamental microbial conditions, the optimum concentration of the metal and the exposure time are essential factors in getting effective results. [ABSTRACT FROM AUTHOR]