Efficient sustainable bioremediation of long‐chain crude oil in soils using instant Fenton pre‐oxidation

Abstract

AbstractBACKGROUNDMany studies have reported that most Fenton pre‐oxidation steps either do more damage to the indigenous hydrocarbon degraders (IHD) or produce lower concentrations of ammonium‐nitrogen (NH4+‐N) during Fenton oxidation combined with bioremediation for oil‐contaminated soils, which causes the subsequent bioremediation to be unsustainable and poor. The aim of the present study was to find an instant Fenton pre‐oxidation for the efficient sustainable biodegradation of long‐chain alkanes, and to determine the ratio (K) of residual concentration of NH4+‐N to residual population of IHD that can reach a balance after this instant Fenton pre‐oxidation.RESULTSFive Fenton oxidation experiments were carried out with iron bound to soil organic matter (SOM). On this basis, a 75‐day field experiment of instant Fenton pre‐oxidation with K = 46 combined with bioremediation was performed. Experimental results showed that a similar efficient biodegradation (≈261 mg kg−1) of long‐chain alkanes C30–C25 at each stage was obtained after instant Fenton pre‐oxidation with K = 46. So up to 75% of the biodegradation of long‐chain alkanes occurred after instant Fenton pre‐oxidation with K = 46, which was 2.3‐ and 2.0‐fold greater than the corresponding biodegradation of long‐chain alkanes after noninstant Fenton pre‐oxidation with K ≠ 46.CONCLUSIONThe study indicated that efficient sustainable bioremediation of long‐chain alkanes can be achieved after instant Fenton pre‐oxidation with K = 46. Analyses of microbial diversity revealed that a possible explanation for the efficient sustainable bioremediation of long‐chain alkanes in soils was that sensitive, slow growth of the IHDs Nocardiode and Noviherbaspirillum was not damaged after instant Fenton pre‐oxidation with K = 46. © 2019 Society of Chemical Industry