Sustainable long-alkanes biodegradation with moderate pre-oxidation in soil

Abstract

ABSTRACT This study aimed to investigate the mechanism of sustainable biodegradation of long-alkanes with moderate pre-oxidation in soil. Moderate pre-oxidation was performed with two consecutive doses of 1.35 mL 30% of H2O2 (225 mM) in two soil. After moderate pre-oxidation, the experiment of sustainable biodegradation of long-alkanes during 80 d was conducted. Then, long-alkanes relative activity coefficient (K), NH4 +-N allocation (G) and the performance of hydrocarbon degraders (E) was calculated. Long-alkanes were sustainably biodegraded with moderate pre-oxidation (1765 mg/kg, 2438 mg/kg and 2672 mg/kg). Long-alkanes biodegradation (8723 mg/kg) with moderate pre-oxidation was 2.5 folds of excessive pre-oxidation. The average increment in long-alkanes biodegradation with moderate pre-oxidation was 30–38% as K values improved (0.28–0.48). The bacterial destruction D decreased to 14–17% and hydrocarbon degraders activity increased to 0.065 mol CO2/kg with moderate pre-oxidation. Basidiomycota and Acinetobacter sp. showed high tolerance with moderate pre-oxidation and remained dominant strains throughout the bioremediation. NH4 +-N consumption played an essential role as nutrients in growth of hydrocarbon degraders (Basidiomycota and Acinetobacter sp.). Then, high and sustained E was achieved with decreased D and elevated hydrocarbon degraders activity, resulting in high K. So, long-alkanes sustainably increasing biodegraded under high E assisted with elevated G with moderate pre-oxidation.