Conversion of organics and minerals into electricity and microalgae using a dual-membrane cylinder photo-microbial fuel cell

摘要

Wastewater remediation using microbial fuel cells (MFC) is an advanced method to produce energy and reduce environmental pollution, yet actual energy yields are low and mineral matter is hardly removed. Here we constructed a dual-membrane cylinder photo-microbial fuel cell (DCP-MFC), equipped with cation and anion exchange membranes, to produce electricity and microalgae, and to remove both organics and minerals. Results show that this cell displayed higher electric generation capacity, of 671.6 mV and 0.39 W/m(2), during 1000 h of stable running, than the control cell, of 601.2 mV and 0.31 W/m(2). Microalgal biomass increased from 2.90 to 3.80 g/L owing to dissolved oxygen scavenging. Nitrogen recovery increased from 0 to 92.6%. Energy yield increased from 2.33 kJ for the control MFC to 118.28 kJ for microalgal cultivation, and to 155.21 kJ for the DCP-MFC. Microbial community analysis revealed that nitrate was mostly converted into nitrite by denitrifying bacteria in the anode chamber, then used by microalgae in the cathode chamber of the DCP-MFC.