Biomedical Engineering Reference
In-Depth Information
A
- Anode
+Cathode
Euent
Euent
e
-
e
-
Na
+
Cl
-
Influent
Influent
Biofilm
AEM
CEM
B
FIGURE 19.9
(A). Basic. schematic. representing. a. three-chamber. cell. design. for. coupling. a. microbial. fuel. cell. with. a. water.
desalination. system.. (B). Microbial. desalination. cell. prototype.. (From. Cao,. X.,. et. al.,.
Environmental Science
Technology
,.43(18),.7148-7152,.2009..With.permission.)
through. the. anion. exchange. membrane,. so. negatively. charged. ions. from. the. salinated.
water.low.through.the.AEM.to.balance.the.positive.charges.produced..A.similar.process.
takes.place.on.the.cathode.side,.except.protons.are.consumed,.requiring.positively.charged.
ions.from.the.salinated.water.to.cross.the.CEM.to.correct.the.charge.imbalance..Current.
testing.of.these.systems.has.been.conducted.with.NaCl.solutions.at.concentrations.of.5,.20,.
and.35 g/L,.which.is.consistent.with.concentrations.seen.from.brackish.to.seawater..The.
amount.of.salt.removed.from.each.concentration.was.at.least.88%.±.2% for.the.5.g/L.case,.
and.up.to.94%.±.3%.for.the.20.g/L.case.
54
.Comparison.of.the.electrons.harvested.and.NaCl.
removed.revealed.a.charge.transfer.eficiency.of.almost.100%.due.to.negligible.effects.of.
electrolysis.(because.of.the.low.current.generated).and.insigniicant.back.diffusion.of.ions.
from.the.electrode.chambers.to.the.desalination.chamber.
54
