title: Efficient salt removal in a continuously operated upflow microbial desalination cell with an air cathode.
abstract: Microbial desalination cells (MDCs) hold great promise for drinking water production because of potential energy savings during the desalination process. In this study, we developed a continuously operated MDC--upflow microbial desalination cell (UMDC) for the purpose of salt removal. During the 4-month operation, the UMDC constantly removed salts and generated bio-electricity. At a hydraulic retention time (HRT) of 4 days (salt solution) and current production of ∼62 mA, the UMDC was able to remove more than 99% of NaCl from the salt solution that had an initial salt concentration of 30 g total dissolved solids (TDS)/L. In addition, the TDS removal rate was 7.50 g TDSL(-1)d(-1) (salt solution volume) or 5.25 g TDSL(-1)d(-1) (wastewater volume), and the desalinated water met the drinking water standard, in terms of TDS concentration. A high charge transfer efficiency of 98.6% or 81% was achieved at HRT 1 or 4d. The UMDC produced a maximum power density of 30.8 W/m(3). The phenomena of bipolar electrodialysis and proton transport in the UMDC were discussed. These results demonstrated the potential of the UMDC as either a sole desalination process or a pre-desalination reactor for downstream desalination processes.
authors.affiliation: Department of Civil Engineering and Mechanics, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA.
authors.forename: Kyle S
authors.initials: KS
authors.lastname: Jacobson
authors.forename: David M
authors.initials: DM
authors.lastname: Drew
authors.forename: Zhen
authors.initials: Z
authors.lastname: He
mesh_terms: D000388:Air; D001673:Biodegradation, Environmental; D001674:Bioelectric Energy Sources; D019149:Bioreactors; D004560:Electricity; D004566:Electrodes; D012965:Sodium Chloride / Q000191:economics*; D012996:Solutions; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014867:Water; D012965:Sodium Chloride