Growth of Microbial Cells on Modified Montmorillonites with Crude Oil Hydrocarbons as Carbon Source

摘要

The effect of modified montmorillonites on microbial growth with crude oil as carbon source was investigated in aqueous clay/oil microcosm experiments with microorganism community that is predominantly Alcanivorax spp as the hydrocarbon degraders. The unmodified montmorillonite was treated with didecyldimethylammonium bromide, hydrochloric acid and the relevant metallic chloride to produce organomontmorillonite, acid activated montmorillonite and homoionic montmorillonites respectively which were used in this study. The parameters used for the assessment of the effect of the clay samples on microbial growth were maximum cell yield, specific growth rate and percentage utilization of hydrocarbons. The study estimated percentage utilization of the hydrocarbons based entirely on growth in the exponential phase. The study indicated that organomontmorillonite, acid activated montmorillonite and potassium-montmorillonite did not stimulate microbial growth whereas unmodified montmorillonite, calcium-and ferric(IIl)-montmorillonite were able to stimulate the growth of the microbial cells. The estimated hydrocarbon utilization indicated that appreciable percentage of hydrocarbons was utilized in Ca-and Fe(III)-montmorillonite-oil-microbe systems (63 and 57 % respectively) unlike in organo-. potassium-and acid activated montmorillonite-oil-microbe systems with low hydrocarbon utilization (25, 21 and 15 % respectively).