Environmental Engineering Reference
In-Depth Information
are.used.in.industrial.applications.and.in.the.production.of.a.wide.range.of.
products..In.the.past.few.years,.pharmaceutically.active.compounds.(PhACs).
and.personal.care.products.(PCPs).have.been.discovered.in.various.environ-
ments. and. water. sources.. Some. of. those. compounds. have. been. linked. to.
ecological. impacts. at. concentrations. of. less. than. 1.ng/L.. These. PhACs. and.
PCPs.were.eventually.grouped.with. other.emerging. contaminants,.such.as.
nitrosamines. from. disinfection. by-products. (DBPs),. metals,. and. other. new.
additions.of.compounds,.such.as.endocrine-disrupting.compounds.(EDCs),.
and. are. collectively. referred. to. as. compounds. of. emerging. concern. (CECs).
(Drewes.et.al..2006,.WERF.2007)..It.has.been.reported.that.certain.synthetic.
compounds,. such. as. detergents. and. pesticides,. and. natural. compounds,.
such. as. sex. hormones,. can. affect. the. balance. of. normal. hormonal. function.
in.animals..These.substances.are.classiied.as.EDCs.and.have.been.linked.to.
a.variety.of.adverse.effects.in.humans.and.wildlife.(Snyder.et.al..2007)..The.
U.S..Environmental.Protection.Agency.(U.S..EPA).refer.to.EDCs.as.exogenous.
agents.that.interfere.with.the.“synthesis,.secretion,.transport,.binding,.action,.
or.elimination.of.natural.hormones.in.the.body.which.are.responsible.for.the.
maintenance. of. homeostasis,. reproduction,. development,. and/or. behavior”.
(U.S..EPA.1996)..In.humans,.studies.have.linked.the.exposure.of.mothers.to.
phthalates.such.as.diethylhexyl.phthalate.to.adverse.impacts.in.their.children,.
including.lowered.testosterone.levels.in.boys.(U.S..Department.of.Health.and.
Human.Services.2008)..EDCs.are.further.classiied.as.thyroidal.(compounds.
with. direct. or. indirect. impacts. to. the. thyroid. glands),. androgenic. (com-
pounds.that.mimic.or.block.natural.testosterone),.and.estrogenic.(compounds.
that.mimic.or.block.natural.estrogen).(Snyder.et.al..2007)..Recently,.the.illegal.
replacement.of.palm.oil.with.diethylhexyl.phthalate.and.diisononyl.phthal-
ate. (plasticizers). by. some. food-grade. manufacturers. in. Taiwan. has. caused.
huge.product.recalls.in.numerous.food,.drink,.and.medicinal.formulations.in.
Taiwan.and.surrounding.trading.markets.in.June.of.2011.
POPs. and. CECs. cover. very. diverse. structures. and. physical/chemical.
characteristics. such. as. molecular. weight,. water. solubility,. Kow,. pKa,. and.
charge.density..A.single.treatment.process.cannot,.therefore,.be.designed.to.
remove.all.POPs.and.CECs.due.to.the.diverse.nature.of.their.characteristics..
It.is.not.possible.to.use.efluent.quality.contamination.surrogates,.such.as.
biochemical. oxygen. demand. (BOD). and. chemical. oxygen. demand. (COD),.
to.predict.the.removal.eficiencies.of.such.POPs.and.CECs..Currently,.most.
wastewater.treatment.facilities.are.not.designed.to.remove.individual.POPs.
and. CECs. but. are. designed. to. meet. efluent. quality. parameters. such. as.
total.suspended.solids.(TSS),.BOD,.and.COD..Only.limited.information.was.
found. in. other. literature. relating. to. the. waste. sewage. treatment. eficien-
cies.of.POPs.and.CECs.through.the.treatment.processes,.where.the.majority.
of. the. research. and. information. was. based. on. drinking-water. treatment.
processes.. In. the. USDI. (2009). study,. researchers. have. focused. on. under-
standing.the.fate.of.approximately.80.CECs.primarily.during.potable-water.
treatment.. They. selected. those. compounds. because. there. are. analytical.
Search WWH ::
Custom Search