Composteo bioaumentado con bacterias de la larva Tenebrio molitor para el tratamiento de un suelo contaminado con hidrocarburos

Abstract

Soil contamination by hydrocarbons is a problem that has been presenting since the different fuels derived from petroleum have been energy sources. Currently, hydrocarbons represent a global problem, as their release into the soil causing some adverse effects on the environment and human health. For this reason, it is necessary to develop effective and robust soil remediation treatments that accelerate the degradation of hydrocarbons. Biological processes are more widely accepted because they are eco-friendly, their costs are low, they do not generate environmental disruption, and there is no demand for energy or heavy machinery. Besides, combined processes tend to be even more efficient. This project, to treat hydrocarbon-contaminated soil, was used soil composting and bioaugmentation. Co-substrates, such as corn flour, wheat bran, and sawdust, were used for composting, and bacteria from Tenebrio Molitor larvae were isolated and selected for bioaugmentation. There is evidence that these bacteria can use hydrocarbons as a carbon source. In this work, the bio-augmented composting process with hydrocarbonoclastic bacteria isolated from the Tenebrio Molitor larva gut to treat diesel-contaminated soils by adding different co-substrates, such as expired corn flour, wheat bran, and sawdust, was assessed. The results showed that the isolated consortium potentiated the treatment and, combined with cornflour, reached greater efficiency (87%) and removal rate (9.10% diesel removed/week). In soils with a concentration of 11796 mg/kg of diesel, this combined treatment reduced hydrocarbons to values below those established by the Official Mexican Standard NOM-138-SEMARNAT/SSA1-2012 in ten weeks.