Baseline assessment of polycyclic aromatic hydrocarbons in surface waters of the huasteca potosina: implications for potential fracking activities and bioremediation using airlift bioreactors

Abstract

This study presents a baseline assessment of polycyclic aromatic hydrocarbon (PAH) contamination in surface water bodies of the Huasteca Potosina and evaluates the potential of airlift bioreactors as a biotechnological remediation strategy for hydrocarbon-contaminated waters (potential fracking activities). While environmental measurements focus on PAH occurrence and source characterization, biodegradation experiments were conducted using diesel as a model petroleum substrate to assess microbial performance and reactor behavior under controlled conditions. The combined environmental diagnosis and process-oriented experimentation provide complementary insights into contamination vulnerability and remediation potential. This study assessed the concentration, distribution, and molecular signatures of 16 priority polycyclic aromatic hydrocarbons (PAHs) in four surface water bodies and municipal tap water. Total PAH concentrations ranged from non-detectable to 21.51 mg L ⁻¹ , with the highest levels observed in Chajir Lagoon and Puente de Dios. Molecular profiles revealed mixed petrogenic and pyrogenic origins, suggesting contributions from petroleum residues, combustion processes, and regional anthropogenic activities. These findings highlight environmental vulnerability and the need for strengthened monitoring in areas susceptible to future hydrocarbon development. To address this issue, a hydrocarbon-degrading bacterial consortium was evaluated in an airlift bioreactor (ALB) using diesel as a model contaminant. Under mineral medium supplementation, the consortium exhibited significant biomass growth and enhanced degradation rates, as confirmed by Gompertz kinetics. Surface tension and emulsification assays indicated biosurfactant production, improving diesel dispersion and biodegradability. In contrast, nutrient-limited tap water conditions resulted in slow microbial growth and lower degradation efficiency. Overall, the study provides the first regional baseline for PAH pollution in key water bodies of the Huasteca Potosina and demonstrates that airlift bioreactors constitute an effective and scalable bioremediation alternative for hydrocarbon-contaminated waters.