Environmental Engineering Reference
In-Depth Information
Many.PCPs.and.PhACs.have.been.discovered.in.surface.water.and.ground.
water;.some.of.these.compounds.could.cause.environmental.and.ecological.
impacts. at. trace. levels.. These. PhACs. and. PCPs. were. eventually. grouped.
with.other.emerging.contaminants.and.are.collectively.referred.to.as.CECs.
(Drewes.et.al..2006,.WERF.2007)..CECs.can.be.classiied.into.different.catego-
ries. based. on. their. impacts. to. humans. or. the. environment,. which. include.
the.following.groups:
•. Agricultural.and.Industrial.compounds
•. Hormones.and.antibiotics
•. Other.pharmaceutical.compounds
Agricultural and Industrial Compounds
CECs. in. agriculture.applications. include. pesticides,.herbicides,. and. insec-
ticides. such. as. Atrazine,. Lindane,. DDT,. and. DEET.. They. are. used. for.
preventing,. destroying,. repelling,. or. mitigating. pests.. The. residues. from.
agricultural. applications. and. runoff. at. environmentally. relevant. concen-
trations.can.affect.the.reproductive.systems.of.animals.(van.Vuuren.2008)..
CECs.used.as.industrial.and.household.products.such.as.coolants,.plasticiz-
ers,.wood.preservatives,.ire.retardants,.and.detergents.cover.a.broad.range.
of. compounds.. PCBs. are. one. of. the. most. well-known. pollutants. within.
the. group. of.industrial.and. household. products.. They.were. commercially.
produced.as.complex.mixtures,.containing.multiple.isomers.with.different.
degrees.of.chlorination.and.used.as.coolants.and.insulating.luids.for.trans-
formers.and.capacitors..The.toxicity.associated.with.PCBs.and.other.chlori-
nated.hydrocarbons,.including.polychlorinated.naphthalenes,.were.noticed.
very.early.on.due.to.a.number.of.industrial.incidents.(Drinker.et.al..1937)..
Once. PCBs. enter. into. the. inluent. of. the. sewage. system,. adsorption. and.
subsequent. sedimentation. may. immobilize. them. into. the. aquatic. system.
for.a.long.duration..PCBs.that.are.redistributed.into.the.water.column.can.
vaporize.from.the.water.surface.into.the.air.and.into.the.environment..PCBs.
contained.in.aquatic.sediments.can.act.as.environmental.reservoirs.and.will.
release.slowly.over.a.long.period.of.time.
Hormones and Antibiotics
Hormones. include. the. naturally. occurring. hormones. estrone. (E1),.
17β-estradiol. (E2),. and. estriol. (E3),. and. synthetic. hormone. such. as.
17α-ethinylestradiol.(EE2)..They.are.in.birth.control.pills.and.are.discharged.
into.the.environment.mainly.through.wastewater.efluent..The.agricultural.
runoff.introduces.hormones.from.animal.source..Antibiotics.are.commonly.
overprescribed.in.the.industrial.world..The.practice.of.adding.antibiotics.to.
the.feed.of.livestock.and.in.the.ish.farms.leads.to.the.creation.of.antibiotic-
resistant.strains.of.bacteria,.a.harmful.side.effect.(WHO.2002).
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