Biorremediação de solos contaminados por lixiviado de aterro sanitário: uma revisão sistemática

Abstract

The increase in the generation of urban solid waste has aggravated soil contamination, especially by landfill leachate, a highly polluting effluent that contains toxic substances and, if poorly managed, poses significant risks to ecosystems and public health. In this context, bioremediation has emerged as a sustainable approach, using microorganisms and plants to degrade or immobilize pollutants, promoting environmental recovery in an economically and ecologically viable way. Thus, the present study aims to review the bioremediation processes applicable to soils contaminated by landfill leachate in Brazil, through a systematic analysis of the literature. To this end, searches were carried out in databases such as Google Scholar, Scopus, SciELO, Web of Science and Capes Periódicos, with keywords in Portuguese and English. Articles published between 2010 and 2024 were included, prioritizing those peer-reviewed and that experimentally evaluated the efficiency of bioremediation techniques. The main approaches include biostimulation, which stimulates the native microbiota; bioaugmentation, which introduces exogenous microorganisms; phytoremediation, which uses plants to stabilize pollutants; mycoremediation, which uses fungi to degrade toxic compounds; and natural attenuation, based on the spontaneous degradation of contaminants. The results indicate that biostimulation and bioaugmentation achieve up to 90% removal of organic compounds, while phytoremediation demonstrated great efficiency in the absorption of heavy metals, reaching removals of over 75% for lead, chromium, and zinc. Mycoremediation showed promise in reducing leachate toxicity by promoting adjustments in pH and electrical conductivity, while natural attenuation proved viable for the spontaneous degradation of pollutants in the long term, depending on environmental conditions. The combination of bioremediation with physical-chemical methods emerges as a promising alternative to increase the removal of contaminants in severely impacted soils. Furthermore, the choice of the most appropriate technique depends on factors such as temperature, humidity, pH and leachate composition, which directly influence the efficiency of the processes. It is concluded that bioremediation is a highly efficient and sustainable approach for the recovery of contaminated soils, especially when combined with other strategies. Future research should explore synergies between different methods and adapt the processes to the specific conditions of each region. Therefore, the advancement of technologies and the development of new studies will contribute to the optimization of these practices, ensuring greater safety and sustainability in the management of contaminated areas.