title: Bioelectrochemical stimulation of petroleum hydrocarbon degradation in saline soil using U-tube microbial fuel cells.
abstract: Bioremediation is a cost-effective and eco-friendly approach to decontaminate soils polluted by petroleum hydrocarbons. However, this technique usually requires a long time due to the slow degradation rate by bacteria. By applying U-tube microbial fuel cells (MFCs) designed here, the degradation rate of petroleum hydrocarbons close to the anode (<1 cm) was enhanced by 120% from 6.9 ± 2.5% to 15.2 ± 0.6% with simultaneous 125 ± 7 C of charge output (0.85 ± 0.05 mW/m(2) , 1 kΩ) in the tested period (25 days). Hydrocarbon fingerprint analysis showed that the degradation rate of both alkanes and polycyclic aromatic hydrocarbons (PAHs) was accelerated. The decrease of initial water content from 33% to 28% and 23% resulted in a decrease on charge output and hydrocarbon degradation rate, which could be attributed to the increase of internal resistance. A salt accumulation was observed in each reactor due to the evaporation of water from the air-cathode, possibly inhibited the activity of exoelectrogenic bacteria (EB) and resulted in the elimination of the current at the end of the tested period. The number of hydrocarbon degradation bacteria (HDB) in soil close to the anode increased by nearly two orders of magnitude in the MFC assisted system (373 ± 56 × 10(3)  CFU/g-soil) than that in the disconnected control (8 ± 2 × 10(3)  CFU/g-soil), providing a solid evidence for in situ biostimulation of HDB growth by colonization of EB in the same system.
authors: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300071, China.
authors: Xin
authors: X
authors: Wang
authors: Zhang
authors: Z
authors: Cai
authors: Qixing
authors: Q
authors: Zhou
authors: Zhineng
authors: Z
authors: Zhang
authors: Cuihong
authors: C
authors: Chen
mesh_terms: D001673:Biodegradation, Environmental; D001674:Bioelectric Energy Sources; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004867:Equipment Design; D006838:Hydrocarbons / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010578:Petroleum / Q000032:analysis* / Q000378:metabolism; D054712:Salinity; D012989:Soil Pollutants / Q000737:chemistry* / Q000378:metabolism
chemical_list: D006838:Hydrocarbons; D010578:Petroleum; D012989:Soil Pollutants