title: Microbial Fuel Cell-driven caustic potash production from wastewater for carbon sequestration.
abstract: This work reports on the novel formation of caustic potash (KOH) directly on the MFC cathode locking carbon dioxide into potassium bicarbonate salt (kalicinite) while producing, instead of consuming electrical power. Using potassium-rich wastewater as a fuel for microorganisms to generate electricity in the anode chamber, has resulted in the formation of caustic catholyte directly on the surface of the cathode electrode. Analysis of this liquid has shown to be highly alkaline (pH>13) and act as a CO2 sorbent. It has been later mineralised to kalicinite thus locking carbon dioxide into potassium bicarbonate salt. This work demonstrates an electricity generation method as a simple, cost-effective and environmentally friendly route towards CO2 sequestration that perhaps leads to a carbon negative economy. Moreover, it shows a potential application for both electricity production and nutrient recovery in the form of minerals from nutrient-rich wastewater streams such as urine for use as fertiliser in the future.
authors.affiliation: Bristol BioEnergy Centre, Bristol Robotics Laboratory, University of the West of England, BS16 1QY, UK. Electronic address: iwona.gajda@uwe.ac.uk.
authors.forename: Iwona
authors.initials: I
authors.lastname: Gajda
authors.affiliation: Bristol BioEnergy Centre, Bristol Robotics Laboratory, University of the West of England, BS16 1QY, UK; Biological, Biomedical and Analytical Sciences, University of the West of England, BS16 1QY, UK.
authors.forename: John
authors.initials: J
authors.lastname: Greenman
authors.affiliation: Bristol BioEnergy Centre, Bristol Robotics Laboratory, University of the West of England, BS16 1QY, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Melhuish
authors.affiliation: Department of Chemical and Biological Engineering, Center for Micro-Engineered Materials (CMEM), The University of New Mexico, MSC01 1120, Albuquerque, NM 87131-0001, United States.
authors.forename: Carlo
authors.initials: C
authors.lastname: Santoro
authors.affiliation: Bristol BioEnergy Centre, Bristol Robotics Laboratory, University of the West of England, BS16 1QY, UK; Biological, Biomedical and Analytical Sciences, University of the West of England, BS16 1QY, UK.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Ieropoulos
mesh_terms: D001639:Bicarbonates / Q000302:isolation & purification; D001674:Bioelectric Energy Sources; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002245:Carbon Dioxide / Q000302:isolation & purification; D057965:Carbon Sequestration; D045424:Complex Mixtures / Q000302:isolation & purification*; D004553:Electric Conductivity; D004566:Electrodes; D059013:Microbial Consortia / Q000502:physiology; D017680:Potassium Compounds / Q000302:isolation & purification; D062065:Wastewater / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification
chemical_list: D001639:Bicarbonates; D002245:Carbon Dioxide; D045424:Complex Mixtures; D017680:Potassium Compounds; D062065:Wastewater; C518454:potash; C026329:potassium bicarbonate
keywords: Carbon capture; Caustic potash; Kalicinite; Microbial Fuel Cell; Wet scrubbing