Application of a microbial consortium immobilized onto a biochar for the remediation of a polluted soil with hydrocarbons

Abstract

The contamination of soils by hydrocarbons is a serious environmental problem both due to the persistence of this pollution and by its effects on even the most pristine areas of the planet. Hydrocarbon decontamination techniques entail a high cost, imply in many cases their off-site treatment, and entail environmental risks. In contrast, the use of microbiological techniques through the addition of microbial consortia with the capacity to degrade these contaminants, are alternatives for soil biorecovery that are gathering growing interest in the construction of biopiles or ecopiles. However, for an effective application of these biotechnological techniques, it is necessary to guarantee an effectiveness in the action of these microbial consortia, whose persistence in soil is generally low. In this work, the stabilization of a microbial consortium specialized in the degradation of hydrocarbons and isolated from the own soil, has been studied through its immobilization on two classes biochars obtained form apricot stones at pyrolysis temperatures of 450° and 650°C, respectively, as well as the increase of its efficiency rate through the addition of rhamnolipids. The introduced microbial consortium achieved a degradation of 17% of the highest molecular weight hydrocarbons, an efficiency that was increased with the application of biochar and rhamnolipids up to 25% of their initial content.