Environmental Engineering Reference
In-Depth Information
From.those.tables.the.notable.exceptions.of.oxidation-resistant.compounds.
are. TCEP,. atrazine,. iopromide,. and. meprobamate.. Generally,. ozone. treat-
ment. decomposes. POPs. and. EDCs. to. smaller. molecules. and. increases. the.
opportunity. for. further. biodegradation.. TSS,. reduced. forms. of. iron. and.
manganese,.and.other.reducing.agents.decrease.the.effectiveness.of.ozone..
Data. from. the.literature.on.ozone. treatment.with.regard.to.the. removal.of.
POPs.and.CECs.are.summarized.in.Tables.8.13.through.8.15.
Reverse Osmosis
Reverse. osmosis. (RO). is.a. iltration. method. wherein. a.selective. membrane.
is. used. and. pressure. is. applied. to. the. solution. from. one. side,. forcing. the.
removal. of. many. types. of. large. molecules. and. ions. from. solutions.. Pure.
solvent. (such. as. water). is. allowed. to. pass. through. the. membrane. into. the.
other.side,.and.the.large.molecules.and.ions.are.retained.on.the.pressurized.
side.of.the.membrane..The.membrane.is.created.to.be.“selective,”.preventing.
large.molecules.and.ions.from.passing.through.the.pores.but.allowing.the.
smaller.molecules.in.the.solution.(such.as.water).to.pass.through.the.mem-
brane. freely.. RO. is. most. commonly. known.for. its. use.with. removing.salts.
and.minerals.as.part.of.the.drinking.water.puriication.process.using.seawa-
ter..In.normal.osmosis,.the.water.(solvent).molecules.pass.through.a.selective.
permeable.membrane.into.a.region.of.higher.salt.(solute).concentration..This.
is.a.normal.physical.process.in.which.any.solvent.moves.without.the.input.
of.energy.or.pressure..In.reverse.osmosis,.the.input.of.energy.or.pressure.is.
to.reverse.the.normal.osmosis.process..RO.involves.a.diffusive.mechanism.
where.the.separation.eficiency.is.dependent.on.pressure,.solute.concentra-
tion,. and. rate. of. water. lux. (Crittenden. et. al.. 2005).. RO. is. one. of. the. most.
effective.process.technologies.(but.not.eficient).that.is.able.to.remove.soluble.
inorganic. and. organic. compounds. from. water,. including. POPs. and. CECs..
There.are.very.few.compounds.that.are.not.fully.removed.by.RO..However,.it.
is.an.incredibly.ineficient.process;.typically.3.gal.of.water.is.wasted.for.every.
gallon.of.puriied.water.it.produces..Although.RO.is.an.ineficient.process,.
for.areas.with.limited.resource.of.surface.water.or.groundwater,.it.is.the.most.
preferred.and.commonly.used.method.for.desalination..The.data.from.the.
literature. on. RO. treatment. in. the. removal. of. POPs. and. CECs. are. summa-
rized.in.Tables.8.13.through.8.15.
Biological Aerated Filters with Active Carbon
Coupled with Ozone Treatment (BAC)
Biological.aerated.ilters.(BAF).are.submerged.ilters.with.attached.biological.
growth. with. bioilm. layer. where. biodegradation. can. take. place.. In. an. aer-
ated. BAF. system,.an. air. header. is.provided. to. ensure. that. oxygen. is.going.
throughout.the.entire.media.bed.layer..It.was.reported.that.the.inner.part.of.
the. BAF. is. usually. oxygen. deicient. and. allows. for. nitrate. formed. through.
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