Bioremediation of soil heavily contaminated with crude oil and its products: Composition of the microbial consortium

Abstract

Bioremediation, a process that utilizes the capability of microorganism to degrade toxic waste, is emerging as a promising technology for the treatment of soil and groundwater contamination. The technology is very effective in dealing with petroleum hydrocarbon contamination. The aim of this study was to examine the composition of the microbial consortium during the ex situ experiment of bioremediation of soil heavily contaminated with crude oil and its products from the Oil Refinery Pančevo, Serbia. After a 5.5-month experiment with biostimulation and bioventilation, the concentration of the total petroleum hydrocarbons (TPH) had been reduced from 29.80 to 3.29 g/kg (89 %). In soil, the dominant microorganism population comprised Gram-positive bacteria from actinomycete-Nocardia group. The microorganisms which decompose hydrocarbons were the dominant microbial population at the end of the process, with a share of more than 80 % (range 107 CFU/g). On the basis of the results, it was concluded that a stable microbial community had been formed after initial fluctuations.

Bioremedijacija, proces koji koristi sposobnost mikroorganizama da razlažu toksični otpad, predstavlja savremeni trend u prečišćavanju zagađenog zemljišta i podzemnih voda. Ova tehnologija je veoma efikasna u uklanjanju kontaminacija naftnog zagađivača. Cilj ovog rada je bio karakterizacija konzorcijuma mikroorganizama pri ex citu bioremedijaciji zemljišta teško kontaminiranog naftom i njenim derivatima iz Rafinerije nafte, Pančevo. Posle 5,5 meseci eksperimenta uz biostimulaciju i bioventilaciju koncentracija ukupnih ugljovodonika nafte je smanjena sa 29,80 na 3,29 g/kg (89 %). Dominantna populacija u zemljištu uključuje Gram-pozitivne bakterije iz grupe aktinomiceta-Nocardia. Mikroorganizmi koji razgrađuju ugljovodonike na kraju procesa su bili dominantna mikrobna populacija sa udelom preko 80 % (red veličine 107 CFU/g). Na osnovu ovih rezultata se može zaključiti da je, nakon početnih promena, došlo do formiranja stabilne mikrobne zajednice.