No abstract

BACKGROUND The limitation on output power is a great challenge for the practical application of sediment microbial fuel cells (SMFC). One of the effective strategies to overcome this problem is to develop better‐performing cathodes. RESULTS Polyaniline (PANI)‐graphene nanosheets (GNS) modified cathodes were fabricated and applied as the cathodes of SMFCs to improve their electricity generation capacity. PANI‐GNS cathodes were fabricated through situ‐polymerization of aniline in a solution containing homogeneously dispersed GNS. The mass ratio between aniline and GNS in the polymerized solution was the key factor controlling the properties of the modified cathode and the optimum ratio was 9:1. Because of the outstanding electrical conductivity of GNS, PANI‐GNS cathodes outperform the control (blank) and PANI cathodes. The PANI‐GNS0.1‐SMFC exhibited the highest output voltage of 640 mV, 5 times that of the blank SMFC; the maximum power density was improved from 0.85 mW m‐2 with the blank SMFC to 99 mW m‐2 of the optimal PANI‐GNS0.1‐SMFC. CONCLUSIONS This study provides a simple electrode modifying method to enable an as‐synthesized PANI‐GNS cathode to dramatically promote the performance of an SMFC. © 2013 Society of Chemical Industry

The electricity production and substrate removal rate of microbial fuel cells (MFCs) could be improved by the application of a static magnetic field (SMF).

The increasing and wide application of silver nanoparticles (Ag NPs) has resulted in their appearance in wastewater. In consideration of their potential toxicity and environmental impacts, it is necessary to find effective technology for their removal from wastewater. Here, forward osmosis (FO) membrane was applied for Ag NPs removal from wastewater, and single and combined fouling of nanoparticles and organic macromolecules were further investigated during the FO process. The findings demonstrated that FO membrane can effectively remove Ag NPs from wastewater due to its high rejection performance. Fouling tests indicated that water flux declined appreciably even at the beginning of the single Ag NPs fouling test, and more remarkable flux decline and larger amounts of deposited Ag NPs were observed with an increase of Ag NPs concentration. However, the addition of bovine serum albumin (BSA) could effectively alleviate the FO membrane fouling induced by Ag NPs. The interaction between Ag NPs and BSA was responsible for this phenomenon. BSA can easily form a nanoparticle-protein corona surrounded nanoparticles, which prevented nanoparticles from aggregation due to the steric stabilization mechanism. Furthermore, the interaction between BSA and Ag NPs occurred not only in wastewater but also on FO membrane surface.