In the past few years there have been a number of reports on microbial fuel cells (MFCs) on the scale of several liters to 1000 liters. Many of these studies used aqueous cathodes, which means that water had to be aerated before being used as a catholyte. While this can reduce the utility of the process to avoid aeration, as done in activated sludge, in some cases the energy costs were still lower than that conventional treatment process.
One study performed at Penn State was using a multi-cathode and anode MFC, where an air cathode was used so that no aeration was needed. The overall power production was 6.3 W/m3, which is the highest power density so far for a domestic wastewater (see the table below).
Penn State, in cooperation with the US Army Engineer Research and Development Center, with engineering services by CDM Smith, is conducting a field test of a 300-L MFC, with funding provided by the Environmental Security Technology Certification Program via cooperative (research agreement W9132T-16-2-0014). Tests are currently scheduled to begin in the late summer of 2020.
|Examples of recently developed pilot-scale microbial fuel cells|
|Reactor||Volume (L)||Power (W/m2)||Power (W/m3)||Reference|
|Air cathode||6.2||0.25||6.3||(He et. al. 2016)|
|Aerated catholye*||10.8 (x 6)= 64.8||
|(Vilajeliu-Pons et al. 2017)|
|Multi-anode, aqueous cathode||20||0.5||—||(Jiang et al. 2011)|
|Aerated aqueous cathode**||20 (x 50)= 1000||0.021||3.1||(Liang et al. 2018; 2019)|
|Air cathode||100||—||0.8||(Goto et al. 2019)|
|Air cathode||120 (x 6) = 720||0.044||0.085||(Das et al. 2020)|
|Aqueous cathode||1500||0.029||0.41||(He et al. 2019)|
|Aqueous biocathode||1500||0.034||0.45||(Dong et al. 2019)|
*Swine manure. Two different materials used with the first one listed using granular graphite and the second one with stainless steel mesh. **Values shown are those in the correction for the original publication.
Das, I., Ghangrekar, M.M., Satyakam, R., Srivastava, P., Khan, S. and Pandey, H.N. (2020) On-site sanitary wastewater treatment system using 720-L stacked microbial fuel cell: Case study. J. Hazard. Toxic Radioact. Waste 24(3), 04020045.
Dong, Y., He, W., Liang, D., Li, C., Liu, G., Liu, J., Ren, N. and Feng, Y. (2019) Operation strategy of cubic-meter scale microbial electrochemistry system in a municipal wastewater treatment plant. J. Power Sources 441, 227124.
Goto, Y. and Yoshida, N. (2019) Scaling up microbial fuel cells for treating swine wastewater. Water 11, 1803.
He, W., Dong, Y., Li, C., Han, X., Liu, G., Liu, J. and Feng, Y. (2019). Field tests of cubic-meter scale microbial electrochemical system in a municipal wastewater treatment plant. Water Res. 155, 372-380.
He, W., Wallack, M.J., Kim, K.-Y., Zhang, X., Yang, W., Zhu, X., Feng, Y. and Logan, B.E. (2016). The effect of flow modes and electrode combinations on the performance of a multiple module microbial fuel cell installed at wastewater treatment plant. Water Res. 105, 351-360.
Jiang, D., Curtis, M., Troop, E., Scheible, K., McGrath, J., Hu, B., Suib, S., Raymond, D. and Li, B. (2011) A pilot-scale study on utilizing multi-anode/cathode microbial fuel cells (MAC MFCs) to enhance the power production in wastewater treatment. Int. J. Hydrogen Energy 36(1), 876-884.
Liang, P., Duan, R., Jiang, Y., Zhang, X., Qiu, Y. and Huang, X. (2018) One-year operation of 1000-L modularized microbial fuel cell for municipal wastewater treatment. Water Res. 141, 1-8.
Liang, P., Duan, R., Jiang, Y., Zhang, X., Qiu, Y. and Huang, X. (2019) Corrigendum to “One-year operation of 1000-L modularized microbial fuel cell for municipal wastewater treatment” [Water Res. 141(2018) 1–8]. Water Res. 166, 114878.
Vilajeliu-Pons, A., Puig, S., Salcedo-Davila, I., Balaguer, M.D. and Colprim, J. (2017) Long-term assessment of six-stacked scaled-up MFCs treating swine manure with different electrode materials. Environ. Sci. Water Res. Technol. 3(5), 947-959.