Abstract
This study addresses the environmental and health risks arising from soil contamination with polychlorinated biphenyls (PCBs) from dielectric oils associated with abandoned electrical transformers. An ex-situ bioremediation strategy was implemented based on the immobilization of microorganisms on coconut fiber, conceived as an environmentally sustainable alternative. To this end, indigenous microorganisms capable of metabolizing dielectric oil as their sole carbon source were isolated, and two biological pathways were compared: Pseudomonas spp. and a native microbial consortium. The coconut fiber was previously characterized and used as an organic support to promote cell stability and enhance metabolic activity. The experiments were carried out under controlled conditions, evaluating the process using respirometry, enzyme activity determination, and gas chromatography with electron capture detection (GC-ECD) for PCBs quantification. The results showed a decrease in the contaminant, with removal efficiencies of 32.20% and 27.96% for Pseudomonas spp. and the microbial consortium, respectively, with no statistically significant differences between the two routes. Likewise, partial improvements were recorded in some soil properties, suggesting functional recovery and confirming the technical and environmental viability of microbial immobilization on coconut fiber.
