Effects of influent organic loading rates and electrode locations on the electrogenesis capacity of constructed wetland‐microbial fuel cell systems

Abstract

Three novel constructed wetland‐microbial fuel cells (CW‐MFCs), based on electrode location, were developed for wastewater treatment and sustainable electricity production by embedding a MFC into a CW system. In the three CW‐MFCs, electrodes were placed in different locations, including bottom anode‐rhizosphere cathode CW‐MFC (BA‐RC‐CW‐MFC), rhizosphere anode‐air cathode CW‐MFC (RA‐AC‐CW‐MFC), and bottom anode‐air cathode CW‐MFC (BA‐AC‐CW‐MFC), to investigate the combined effects of organic loading rates (OLRs) and reactor configurations on the electrogenesis capacity of the hybrid system. All the systems operated continuously to treat five types of synthetic wastewater with increasing OLRs: 9.2, 18.4, 27.6, 55.2, and 92.0 g chemical oxygen demand (COD) m−2 d−1. The BA‐RC‐CW‐MFC failed to produce electricity at any OLR, whereas the maximum power densities of 0.79 ± 0.01 and 10.77 ± 0.52 mW m−2 were achieved in the RA‐AC‐CW‐MFC with 18.4 g COD m−2 d−1 influent OLR and in the BA‐AC‐CW‐MFC with 27.6 g COD m−2 d−1 influent OLR, respectively. The coulombic efficiencies of the RA‐AC‐CW‐MFC and BA‐AC‐CW‐MFC decreased gradually with the increase in influent OLRs. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 435–441, 2017

A review of the operating parameters on the microbial fuel cell for wastewater treatment and electricity generation

“…A gentle substrate increase in the anolyte (the portion of an electrolyte near an anode, especially in a cell in which the cathode and anode are in separate compartments), through fed-batch or flow, can increase or decrease the power produced by the system (Rabaey et al 2003;Borole et al 2011;Xu et al 2017).…”

Recent advances in constructed wetland‐microbial fuel cells for simultaneous bioelectricity production and wastewater treatment: A review

“…F, Carbon felt anode with presence of roots after being removed . G, Powdered activated carbon anode . H, Granular graphite cathode .…”

“…G, Powdered activated carbon anode . H, Granular graphite cathode . I, Petroleum coke [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…The gravel support is used in horizontal subsurface flow . Xu et al constructed three CW‐MFCs with different types of supporting materials: carbon felt as cathode and granular activated carbon as anode. In the three CW‐MFCs were used the Canna indica plant.…”

“…Constructed wetland‐microbial fuel cell configurations: A, sequencing batch reactor, B, upflow, C, upflow, D, simultaneous upflow‐downflow, E, downflow, F, horizontal subsurface flow, G, upflow, H, upflow, I, horizontal subsurface flow, J, operated in batch, and K, horizontal subsurface flow . Cathode (1), anode (2), material separator (3), resistance (4), support (5), plant (6), influent (7), and effluent (8) [Colour figure can be viewed at wileyonlinelibrary.com]…”