Bioelectricity Generation from Marine Algae Chaetoceros Using Microbial Fuel Cell

Marine algae Chaetoceros can be effectively used both as an electron donor and methanogen inhibitor in MFCs due to its high organic matter content and methanogen inhibition properties. Hexadecatrienoic acid present in Chaetoceros inhibits the growth of gram-positive methanogenic archaea via adsorption and disruption of cell membrane. Performance evaluation of two dual-chambered MFCs without any pretreatment of anaerobic sludge used as anodic inoculum was compared using Chaetoceros and acetate as substrate. MFC fed with Chaetoceros having a COD concentration of 2000 mg l(-1), could produce a maximum operating voltage of 495 mV and sustainable power density (PD) of 12.25 W m(-3) after a period of 12 days from start-up. A maximum PD of 15.13 W m(-3) and Coulombic efficiency (CE) of 47.25 % could be obtained in MFC fed with Chaetoceros; whereas MFC fed with acetate (2000 mg COD l(-1)) produced a maximum PD of 3.64 W m(-3) and a CE of 19.65 %. An average total chemical oxygen demand, carbohydrate and protein removal efficiencies of 73.57 +/- 2.1 %, 75.77 +/- 1.1 %, and 43.11 +/- 1.4 % were obtained in MFC using Chaetoceros as substrate. Cyclic voltammetry study reveals a higher electron discharge on the anode surface of the MFC fed with Chaetoceros.