Preparation, characterization, and application of modified carbonized lignin as an anode for sustainable microbial fuel cell

Microbial fuel cell (MFC) is the most prominent bioelectrochemical approach in electricity generation while metal removal is its secondary application. However, ongoing challenges including low electron transfer rates and unstable biofilm formation on the anode surface need to be addressed. As an attempt to overcome such drawbacks, in the present study, the anode was prepared from graphene oxide (Lg-GO) obtained from lignin and subsequently modified with a metal oxide (i.e., TiO2). Thus, the plain Lg-GO and Lg-GO/TiO2 delivered 57.01 mA/m2 and 70.17 mA/m2 of current density along with 85 % and 90 % of Pb (II) ions removal from synthetic wastewater, respectively within the 90-day operation of MFC. The recorded maximum power density at the Lg-GO anode was 0.44 mW/m2, while the maximum PD at the Lg-GO/TiO2 anode was 0.78 mW/m2. The prepared anodes were characterized, and the operational conditions were optimized to validate their performances. The results showed that the optimum performance of the anode was in normal environmental conditions (e.g., pH 7, room temperature). In conclusion, the obtained results indicated that the prepared electrodes (i.e., Lg-GO and Lg-GO/TiO2) are suitable for energy generation and metal removal via MFC.