In Field Applications of Single Chamber Membraneless Microbial Fuel Cells (SCMFCs) for Wastewater Treatment, Metal Reduction and Nutrients Removal

Abstract

In this study, prototypes of SCMFCs were applied or are in process to be applied for real world applications. Particularly, several large surface electrodes MFCs are currently operating in the 32 parallel lines wastewater treatment plant of Nosedo (Milan,Italy). Different chemical and biological conditions led to favorable environment for the development of effective bioanodes and biocathodes in MFCs immersed in the anoxic and aerobic tanks, despite low organic load in the wastewater inlet. The influence of carbon electrode surface extent was preliminary evaluated, showing the possibility of scale-up processes. Another preliminary study is currently in progress in the water of a prealpine meromictic lake (Idro Lake, Italy). The possibility of using bio-electrochemical/electrolyses system for remediating a local pollution will be deployed. The typical presence of the net separation between an aerobic and anaerobic area in the water body makes a meromictic lake affine to a massive MFC. A optimized procedure for the electro-sorption of specific oxide/hydroxide transitional metals (e.g. manganese and other metals and nutrients) on cathodes of MFC systems will be developed for the application in field, as a new innovative strategy for metal pollution remediation. Future applications will be also directed in deploying sediment MFC with anode immersed in the sediments and cathode covered by plants. Based on the preliminary results, a “garden island” will be designed for covering a wetland in order to reduce significantly also the organic load in the pool. Prototype of multi–array MFCs, with an impressive design and style of “little floating garden” will be studied and presented at the International Exposition in Milan 2015. Preliminary experimentations are now devoted to develop and validate electrochemically/chemically activated materials and hierarchically catalyzed surfaces, in collaboration with several different specialists, in order to enhance the performance of cathodes and anodes of the SCMFC tested and decrease operating costs.