Effects of salinity, growing media, and photoperiod on bioelectricity production in plant microbial fuel cells with weeping alkaligrass

• Published in: Biomass & bioenergy Vol. 109; pp. 1 - 9
• Main Authors: Md Khudzari, J., Kurian, J., Gariépy, Y., Tartakovsky, B., Raghavan, G.S.V.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2018
• Subjects: Bioelectricity; Fults weeping alkaligrass; Photoperiod; Plant microbial fuel cells; Salinity; Plant microbial fuel cells; Photoperiod; Fults weeping alkaligrass; Bioelectricity; Salinity
• ISSN: 0961-9534; 1873-2909
• DOI: 10.1016/j.biombioe.2017.12.013

This study investigated the potential for bioelectricity production of a salt-tolerant plant, the weeping alkaligrass (Puccinellia distans), in a plant microbial fuel cell (MFC). Air-cathode MFCs with a carbon felt anode were assembled in a cylindrical vessel. The MFCs were operated using growing media of different dry organic matter (OM) mass fractions: potting mix (OM: 89%) and sandy loam (OM: 8%), and treated with different NaCl concentrations of 0, 6, and 12 kg m−3. MFC performance was best at a salinity of 6 kg m−3. Over 114 days, the highest power output was obtained from plant MFC (PMFC) in potting mix at 83.7 mW m−2 cathode area with an average power of 12.78 mW m−2, followed by PMFC in sandy loam (maximum: 8.59 mW m−2, average: 8.35 mW m−2). The total biomass production of alkaligrass was 5–25% higher in the potting mix, when compared to the sandy loam. The presence of alkaligrass in PMFC increased the bioelectricity production by 14-fold compared to that of soil MFC (SMFC). In addition to the standard photoperiod of 16/8 h (light/dark), the MFCs were also operated under 24/0 h, 9/15 h, and 0/24 h photoperiods. Power outputs of 9/15 and 0/24 h were clearly decreased due to the effect of photoperiod, while the power outputs of 24/0 and 16/8 h were similar with some evidence of light-related inhibition. Frequent changes in the photoperiod test affected bioelectricity production and thus, a longer recovery time is recommended to reduce the adverse impact of the changes. [Display omitted] •MFC power performance was best with potting mix at a salinity level of 6 kg m−3.•High concentration of NaCl can be detrimental to MFCs power production.•Total biomass production of alkaligrass increased in saline conditions.•Short intervals between photoperiods resulted in decreased power production.