The present study was carried out in order to investigate the ability of isolated subsurface bacteria, from a non-history clay soil, to biodegrade the non-aqueous phase-liquids (NAPLs), monoaromatic hydrocarbons: benzene, toluene and ethylbenzene. First stage of the study was focussed on stand-alone biodegradation of each contaminant under described conditions. Benzene (100, 260 and 500 mg/l) exposed to isolated soil bacteria for 14 days, was biodegraded 100, 70 and 50%, respectively, ethylbenzene (100, 260 and 500 mg/l) at 85, 87 and 90%, respectively and toluene (100, 260 and 500 mg/l) revealed the lowest rate of 45, 50 and 52%. Toluene and ethylbenzene showed a direct increase in biodegradation associated with increase in their concentration. The second stage was the biodegradation of benzene, toluene and ethylbenzene admixture (all three compounds at the very same concentrations, w/v) in glucose absence and supplemented with Tween 80 (10 and 15 mg/l). The overall biodegradation improved when contaminants were mixed together.
Effect of hydraulic retention time on a continuous biohydrogen production in a packed bed biofilm reactor with recirculation flow of the liquid phase