Bioremediation of groundwater contaminated by petroleum hydrocarbons

Abstract

Groundwater is an very important natural resource. Clean groundwater is essential for the pres- ervation of the entire ecosystem. Bioremediation is a process which is based on the natural capacity of microorganisms to remove or transform hazardous substances from the environment into less toxic or harmless products. This paper presents the bioremediation of groundwater contaminated by petroleum hydrocarbons. The contaminated area was located at the thermal energy facility, near the city of Belgrade, on the terrace sediments of the Sava River. In the process, which lasted for 18 months, groundwater was treated by in situ bioremediation. Bioremediation treatment was conducted by a combination of biostimulation and bioaugmentation. Biostimulation was conducted by injection of nutrients. Bioaugmentation was achieved by injection of a zymogenous consortium of microorganisms, previously isolated from the contaminated groundwater, which were capable of using the contaminating substances as nutrients. The treatment was carried out in a closed bipolar system„with groundwater recirculation, by combination of extraction and injection wells. During the bioremediation, the content of petroleum hydrocarbon in groundwater decreased by 93% of the initial level. This indicates that the process of bioremediation was performed successfully.