title: The effect of salinity, redox mediators and temperature on anaerobic biodegradation of petroleum hydrocarbons in microbial fuel cells.
abstract: Microbial fuel cells (MFCs) need to be robust if they are to be applied in the field for bioremediation. This study investigated the effect of temperature (20-50°C), salinity (0.5-2.5% (w/v) as sodium chloride), the use of redox mediators (riboflavin and anthraquinone-2-sulphonate, AQS) and prolonged fed-batch operation (60 days) on biodegradation of a petroleum hydrocarbon mix (i.e. phenanthrene and benzene) in MFCs. The performance criteria were degradation efficiency, % COD removal and electrochemical performance. Good electrochemical and degradation performance were maintained up to a salinity of 1.5% (w/v) but deteriorated by 35-fold and 4-fold respectively as salinity was raised to 2.5%w/v. Degradation rates and maximum power density were both improved by approximately 2-fold at 40°C compared to MFC performance at 30°C but decreased sharply by 4-fold when operating temperature was raised to 50°C. The optimum reactor performance obtained at 40°C was 1.15 mW/m(2) maximum power density, 89.1% COD removal and a degradation efficiency of 97.10%; at moderately saline (1% w/v) conditions the maximum power density was 1.06 mW/m(2), 79.1% COD removal and 91.6% degradation efficiency. This work suggests the possible application of MFC technology in the effective treatment of petroleum hydrocarbons contaminated site and refinery effluents.
authors.affiliation: Department of Molecular and Applied Biosciences, Applied Biotechnology Research Group, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK. Electronic address: o.adelaja@my.westminster.ac.uk.
authors.forename: Oluwaseun
authors.initials: O
authors.lastname: Adelaja
authors.affiliation: Department of Molecular and Applied Biosciences, Applied Biotechnology Research Group, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK. Electronic address: t.keshavarz@westminster.ac.uk.
authors.forename: Tajalli
authors.initials: T
authors.lastname: Keshavarz
authors.affiliation: Department of Molecular and Applied Biosciences, Applied Biotechnology Research Group, University of Westminster, 115 New Cavendish Street, London W1W 6UW, UK. Electronic address: g.kyazze@westminster.ac.uk.
authors.forename: Godfrey
authors.initials: G
authors.lastname: Kyazze
mesh_terms: D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D001674:Bioelectric Energy Sources; D010084:Oxidation-Reduction; D010578:Petroleum / Q000378:metabolism*; D054712:Salinity; D012989:Soil Pollutants / Q000378:metabolism*; D013696:Temperature
chemical_list: D010578:Petroleum; D012989:Soil Pollutants
keywords: Degradation rate; Microbial fuel cells; Petroleum hydrocarbons; Salinity; Temperature