Biodegradation of diesel oil in a baffled roller bioreactor

Abstract

BACKGROUND: Ex situ bioremediation is a feasible and economical way to remove petroleum pollutants from contaminated soil or water. A baffled roller bioreactor was shown to be effective for biodegradation of diesel oil as a model petroleum pollutant. Microorganisms enriched from an industrially contaminated soil with heavy hydrocarbons were shown to be the best inoculum source for diesel biodegradation.

Kinetics of biodegradation of diesel fuel by enriched microbial consortia from polluted soils

“…In general, the diesel biodegradation by the consortia was faster than that of other microbes reported in the literature (Vieira et al 2007;Young et al 2005). These results prove the good feasibility of using polluted sites as source of mixed consortia for hydrocarbon degradation, as also has been found in similar previous works (Nikakhtari et al 2009;Vieira et al 2007). However, in the present work no important differences were observed between the three consortia, suggesting that the acclimation process produced mixed consortia with very similar characteristics and efficiencies, and the origin of the soil sample was not a decisive factor.…”

“…The isolation of these species is not surprising due to their frequency in contaminated soils (Barathi and Vasudevan 2001;Ueno et al 2007). All of the other species found in the consortia have been shown to degrade hydrocarbons (Chaineau et al 1999;Lafortune et al 2009;Medina-Moreno et al 2005;Nikakhtari et al 2009;Owsianiak et al 2009;Rahman et al 2002).…”

“…Vieira et al (2007) selected different undefined mixed microbial consortia from petroleum pollutes sites, and evaluated their diesel biodegradation efficiencies. Nikakhtari et al (2009) also used indigenous mixed microbial consortia from polluted sites, whose degradation ability was compared with commercial and donated consortia. However, the real ability, efficiency and rate of these consortia to degrade hydrocarbons should be tested directly in hydrocarbon-water suspensions to avoid the mass transfer limitations that would appear if a soil matrix is present.…”

Biological removal of nitrate by an oil reservoir culture capable of autotrophic and heterotrophic activities: Kinetic evaluation and modeling of heterotrophic process

“…Based on the stoichiometry, concentration of acetate was in excess of the level required for complete reduction of nitrate to N 2 . Effect of temperature (15,20,30,35 • C) was investigated in an incubator with the desired temperature, using CSB medium containing 24.3 ± 1.9 mM acetate and 17.5 ± 0.4 nitrate (COD to nitrate ratio: 2.8 mM O 2 (mM NO 3 ) −1 ). All other conditions and procedures were similar to those described earlier.…”

“…(5)-(8) were solved simultaneously using a 4th order Runge-Kutta method in Excel software. Value of various kinetic coefficients was determined by fitting the data generated in the experiments with 5, 10, 20, 30 and 50 mM nitrate at 25 • C, and those obtained with 24.3 ± 1.9 mM nitrate at 15, 20, 30, 35 • C into the model, and performing non-linear regression using least-squares minimization and Solver routine within Excel TM software [35]. Eq.…”