Bioremediation of groundwater contaminated with petroleum hydrocarbons applied at a site in Belgrade (Serbia)

Abstract

Due to their extensive use, petroleum hydrocarbons are among the most common groundwater contaminants. Compared to the traditional methods of physical pumping of contamination from the aquifer and subsequent treatment (i.e., pump and treat), bioremediation is an economically cost-effective technology. The aim of this remediation approach is to transform biologically contaminants, most often by microbiological activity, into non-toxic compounds. More precisely, it is an active remediation process that involves biostimulation (increase of aquifer oxygenation, addition of nutrients) and/or bioaugmentation (injection of a concentrated and specialized population of microorganisms). Using both biostimulation and bioaugmentation, enhanced in situ groundwater bioremediation was applied at a hydrocarbon-contaminated site in Belgrade. The bioremediation treatment, applied over twelve months, was highly efficient in reducing the concentrations of total petroleum hydrocarbon (TPH) to acceptable levels. The concentration of TPH in the piezometer P-5 was reduced by 98.55 %, in the piezometer P-6 by 98.30 % and in the piezometer P-7 by 98.09 %. These results provided strong evidence on the potential of this remediation approach to overcome site-limiting factors and enhance microbiological activity in order to reduce groundwater contamination.