Environmental Engineering Reference
In-Depth Information
In.China,.10,000.metric.tons.of.brominated.lame.retardants.is.used.in.elec-
trical.and.electronic.products.annually.(Guan.et.al..2007)..For.example,.one.
third.of.the.gross.industrial.output.in.the.Pearl.River.Delta.is.associated.with.
electronic. and. telecommunication. equipment. (Liu. et. al.. 2005b),. leading. to.
large.usage.of.PBDEs.(1300.t).in.the.region.(Decision.Etudes.&.Conseil.2004,.
Guan.et.al..2007)..In.addition,.the.Chinese.government.had.recently.encour-
aged.the.transfer.of.industrial.products.to.the.countryside,.in.order.to.satisfy.
domestic.needs,.which.subsequently.resulted.in.widespread.contamination.
of.PBDEs.in.more.remote.areas.of.China.
The. second. source. of. PBDEs. emitted. into. the. environment. is. from.
uncontrolled. recycling. of. electrical. and. electronic. waste. (e-waste),. which.
has.become.a.global.problem.in.the.twenty-irst.century,.with.about.20-25.
million. ton. of. e-waste. generated. annually. in. the. world. in. recent. years.
(Robinson. 2009).. In. developed. countries,. it. has. become. one. of. the. fastest.
growing.waste.streams.comprising.more.than.5%.of.municipal.solid.waste..
From.1997.to.2004,.there.were.between.315.and.680.million.sets.of.comput-
ers.that.became.obsolete.in.the.world,.amounting.to.around.2-4.million.ton.
of. e-waste. and. accounting. for. approximately. 150,000-900,000.t. of. PBDEs.
separated.and.emitted.into.the.surrounding.environment.of.e-waste.recy-
cling.sites.(Liu.et.al..2007,.2008).
Moreover,.e-waste.is.being.transported.in.massive.quantities.around.the.
world. with. about. 80%. exported. to. Asia,. and. 90%. of. the. e-waste. is. sent.
illegally. to. China. for. recycling. (UNEP. DEWA/GRID-Europe. 2005).. The.
recycling. of. e-waste. in. Guiyu,. a. small. town. in. the. southeastern. part. of.
Guangdong.Province,.China.(Figure.7.1),.has.been.undertaken.by.migrant.
workers. using. primitive. and. environmentally. unacceptable. techniques.
to. separate. recoverable. electronic. components,. mainly. from. computers,.
since.the.late.1980s.and.early.1990s.(Leung.et.al..2007)..This.entailed.the.
burning. of. cables. and. wires. for. copper. recovery,. heating. of. printed. cir-
cuit.boards.for.recovery.of.solder.and.computer.chips,.and.acid.stripping.
of. printed. circuit. boards. for. removal. of. remaining. precious. metals. such.
as. gold. and. platinum.. During. the. crude. recycling. stage,. persistent. toxic.
substances,. including. PBDEs,. are. emitted. into. the. environment. when.
e-wastes. are. heated. and. burnt.. The. total. PBDE. concentrations. found. in.
Guiyu.are.the.highest.in.terms.of.combusted.residue.of.plastic.chips.and.
cables.collected.from.a.riverbank.close.to.village.houses.in.Guiyu,.China.
(63,300.and.48,600.ng/g.dry.wt..for.total.PBDEs.and.BDE-209,.respectively)..
BDE-209. was. the. most. dominant. congener. (35%-82%). among. the. sites.
indicating. the. prevalence. of. commercial. Deca-BDE;. however,. congeners.
from.commercial.Penta-.and.Octa-BDE.mixtures.were.also.present.(Leung.
et.al..2007).
In.addition.to.Guiyu,.there.are.more.than.12.e-waste.recycling.locations,.
distributed.over.7.provinces.in.China,.including.Qingyuan,.Longtang.(north-
western. part. of. Guangzhou),. Zhao. Guang,. Dali. in. Guangdong. Province,.
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