Enhanced biodegradation of phenanthrene using different inoculum types in a microbial fuel cell

Abstract

Environmental pollution by petroleum hydrocarbons from contaminated groundwater and soils is a serious threat to human health. Microbial fuel cells ( MFC s) could be employed in the treatment of these recalcitrant pollutants with concomitant bioelectricity generation. In this study, the use of MFC s in biodegradation of phenanthrene, a model hydrocarbon, was investigated with respect to its biodegradation rate, biodegradation efficiency, and power production using a range of inocula ( Shewanella oneidensis MR 1 14063, P seudomonas aeruginosa NCTC 10662, mixed cultures, and combinations thereof). All the inocula showed high potentials for phenanthrene degradation with a minimum degradation efficiency of 97%. The best overall performing inoculum was anaerobically digested sludge supplemented with P . aeruginosa NCTC 10662, having a degradation rate, maximum power density and chemical oxygen demand removal efficiency of 27.30 μM/d, 1.25 mW/m 2 and 65.6%, respectively. Adsorption of phenanthrene on the carbon anode was also investigated; it conformed to a Type II adsorption isotherm and could be modelled using a modified Brunauer, Emmett and Teller model with a maximum monolayer capacity of 0.088 mg/cm 2 . This work highlights the possibility of using MFC s to achieve high degradation rates of phenanthrene through co‐metabolism and could potentially be used as a replacement of permeable reactive barriers for remediation of hydrocarbon‐contaminated groundwater.

Key findings

• ▸Different inocula showed high potentials for phenanthrene degradation.
• ▸Anaerobically digested sludge supplemented with Pseudomonas aeruginosa NCTC 10662 was the best performing inoculum.
• ▸Power production was concomitant with biodegradation in MFCs.

Keywords

Identifiers

DOI

10.1002/elsc.201300089

Journal

Engineering in Life Sciences

Year

2014