Biodegradation of oil pollution: laboratory verification of the effectiveness of biostimulation and bioaugmentation

The aim of the experiments was the biodegradation of RL realized in laboratory conditions in order to monitor the decrease of contamination and main nutrients; with the aim of optimizing the process of bioremediation potentially implemented in situ. Several experiences confirm that the biological degradation of contaminants in closed systems and controlled conditions takes place faster and more efficiently compared to in situ processes. However, preliminary results indicate a good condition of the bacterial inoculum composed of autochthonous specialized strains (RL removal rate 1.363 mg · g^-1 dry matter h^-1), even the production of biosurfactants was confirmed. From the point of view of RL degradation, 2 approaches were followed, combined BA+BS and separate BS. Taking into account the NEL-IR parameter, it can be concluded that both approaches were equally effective - 97% degradation of RL was observed and the reduction of the NEL-IR concentration from the original approximately 4-5 mg · l^-1 to 0.1 mg · l^-1 , i.e. under both ID and IT criteria defined in MoE directive no. 1/2015-7 (0.5 and 1 mg · l^-1). (authors)