Performance of trickling bed microbial fuel cell treating isopropyl alcohol vapor: Effects of shock-load and shut-down episodes.

This work investigates the enhancement in the removal efficiency of isopropyl alcohol (IPA) vapor by a hollow trickling-bed microbial fuel cell (TB-MFC) that can be achieved by certain modifications. The effects of shock load and shutdown on the performance of TB-MFC were evaluated. When organic loading (OL) of IPA was approximately 22.1-88.5 g m-3 h-1, the removal efficiency of 85.1-93.8% of the TB-MFC was achieved. With an empty bed residence time (EBRT) of 60 s and an inlet IPA concentration of 4.42 g m-3, the TB-MFC achieved its maximum EC of 150 g m-3 h-1, which was 1.7-4 times higher than reported for conventional biofiltration technology. A maximum closed-circuit voltage (CCV) of 173 mV and maximum power density (PDmax) of 53.2 mW m-3 were obtained under optimal conditions (IPA concentration = 0.73 g m-3; EBRT = 60 s). Short-term shutdown (seven days) did not cause significant changes in EC, CCV, and PDmax of the TB-MFC. This investigation establishes the feasibility of using a trickling-bed MFC to substantially increase the removal of IPA and handle shock-load and shut-down events. To increase EC and power output, this laboratory-scale TB-MFC could easily be scaled up by stacking anodes, and has great potential for future application in the field in various industries.