Understanding the role of Fe(III)/Fe(II) couple in mediating reductive transformation of 2-nitrophenol in microbial fuel cells

• DOI: 10.1016/j.biortech.2010.09.005
• Publication Date: 2010-09-08T09:09:19Z
• Authors: Chunhua Feng; Fangbai Li; Kewen Sun; Yongye Liu; Liang Liu; Xianjun Yue; Hui Tong
• Keywords: Time Factors; Bioelectric Energy Sources; Iron; Electrons; Ligands; 01 natural sciences; 7. Clean energy; Nitrophenols; Kinetics; Electricity; Electrodes; Oxidation-Reduction; 0105 earth and related environmental sciences

The Fe(III)/Fe(II) couple can play a significant role in the abiotic reduction of 2-nitrophenol (2-NP) at the cathode chamber of a microbial fuel cell (MFC). Experimental results demonstrate that Fe(II) addition to the cathode chamber contributes to a significant increase in the reaction rate of 2-NP removal and the power performance of MFC. Observed pseudo first-order rate constants and power densities are heavily dependent on the identity of the Fe(II)-complexing ligands. The Fe(II) complex coordinated with citrate results in the highest rate constant up to 0.12 h(-1) as compared to other organically complexed iron species including Fe(II)-EDTA, Fe(II)-acetate and Fe(II)-oxalate, and iron species uncomplexed with any organic ligands. In addition, the presence of Fe(II)-citrate species leads to a maximum volumetric power density of 1.0 W m(-3), which is the highest value among those obtained with other iron species for the similar MFC system.