Bioremediation of a diesel contaminated soil and the relationship between the addition of poultry manure and microbial activity

The increase in environmental pollution caused by inadequate anthropogenic practices is emerging as a global threat to human health and ecosystems. Bioremediation plays a crucial role in responding to contemporary environmental challenges, standing out as an important tool in the search for sustainable solutions for the remediation of contaminated soils. This study addresses the feasibility of bioremediation to mitigate the adverse impacts of soil contamination by petroleum hydrocarbons through the use of laying hen manure as a biostimulating agent, in the form of manure stabilized by simple drying and compost from fresh manure subjected to a composting process. The specific objectives of the work included analyzing the interaction between manure and contaminants, evaluating the influence of physicochemical and microbiological variables, comparing the efficiency of adding manure in different proportions and evaluating contaminant reduction rates. Physico-chemical and biological monitoring and statistical analysis of the results were carried out. The results show that the treatment with stabilized manure differed significantly from the control sample, while the treatment with compost did not. The statistical analysis confirmed the effectiveness of the treatments with stabilized manure in reducing total petroleum hydrocarbons compared to the control treatments, with reductions of up to 98 % in total petroleum hydrocarbons (TPH) concentrations in 60 days and microorganism populations of around 107 CFU/mL. In this way, stabilized poultry manure proved to be an effective organic additive for promoting the degradation of TPH in the experiments, and its combined application with sawdust is recommended for improving soil structure in remediation processes.