Because
of their hazardous content, electrical and electronic equipment cause major environmental
problems during the waste management phase if not properly pre-treated. As more than 90%
of Waste Electrical and Electronical Equipment (WEEE) is land filled, incinerated or
recovered without any pre-treatment, a large proportion of various pollutants found in the
municipal waste stream.
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The proposed Directive on Waste Electrical and Electronic Equipment will contribute to the
protection of human health and the environment. The principal objectives of this proposal
are to protect soil, water and air from pollution caused by current management of WEEE, to
avoid the generation of waste, which has to be disposed of and to reduce the harmfulness
of WEEE.
1. Incineration of WEEE
The emission from waste incineration
account for 36 tonnes per year of mercury and 16 tonnes per year of cadmium in the
Community.
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Furthermore, the incineration of non-hazardous waste has been identified as the largest
source of emission of dioxins and furans to air in Europe
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The WEEE stream contributes significantly
to the heavy metals and halogenated substances contained in the municipal waste stream. In
addition, specific adverse effects could occur during incineration due to the variety of
different substances found together in WEEE. Copper works like a catalyst, thereby
increasing the risk of formation of dioxins when flame retardants are incinerated. This is
of a particular concern as the incineration of brominated flame retardants at a low
temperature (600-800°C) may lead to the generation of extremely toxic polybrominated
dibenzo dioxins (PBDDs) and polybrominated dibenzo furans (PBDFs).
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The proposal for a Council Directive on the incineration of waste from 7 October 1998
provides for stringent emission limit values, which should lead to a significant reduction
of emissions of various pollutants into atmosphere
Separate collection and treatment of
waste streams (such as WEEE) contributes to a cleaner municipal waste stream and thereby a
reduction in the emission caused by the incineration or the smelting of WEEE containing
heavy metals and halogenated substances.
There is substantial evidence supporting the view that PVC is not suitable for
incineration, particularly in view of the quantity and the hazardous nature of the flue
gas residues resulting from incineration
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The introduction of several WEEE into incinerators results in high concentrations of
metals, including heavy metals, in the slag, in the flue gas or in the filter cake, with
further consequences for post processing or use.
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Landfilling of WEEE
The risk relating to the landfilling of
WEEE is due to the variety of substances contained in WEEE. The main problems in this
context are the leaching and evaporation of hazardous substances. Leaching of mercury
takes place when certain electronic devices, such as circuit breakers, are destroyed. The
same is true for PCBs from condensers. When brominated flame retarded plastic or cadmium
may leach into the soil and groundwater. The vaporisation of metallic mercury and
dimethylene mercury, both part of WEEE, is also of concern. In addition, uncontrolled
fires may arise at the landfills. In such fires, both metals and other chemical, such as
the extremely toxic dioxins and furans including tetrachlorodibenzodioxin (TCDD) and
polychlorinated and polybrominated dioxins and furans (PCDDs, PBDDs and PCDFs) from
halogenated flame retardant products and PCB containing condensers may be emitted.
Losses of plasticizers, especially
phthalates, from the landfilling of PVC are widely recognised and can have potential
effect on the human health and the environment.
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Extrusion
Halogenated substances contained in WEEE,
in particular brominated flame retardants, are also of concern during the extrusion of
plastics, which is part of plastic recycling .
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Due to the risk of generating dioxins and furans, recyclers usually abstain from recycling
flame retarded plastic from WEEE.
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In view of the lack of proper identification of plastic containing flame retardants and
the inherent difficulty in distinguishing flame retardant plastic from ordinary plastic,
most recyclers do not process any plastic from WEEE.
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Shredding
Hazardous emission to the air also
results from the recycling of WEEE containing heavy metals, such as lead and cadmium. As
WEEE is in most cases shredded without proper disassembly, hazardous substances, such as
PCB’s contained in capacitors, may be dispersed into the recovered metals and the
shredder waste. Shredder waste has a high concentration of lead, ranging from 940 to 9,400
mg/kg. Around 95% of the PCB contained in capacitors (617,5 mg/kg) end up in the shredder
dust. Therefore, the contaminated shredder has to be dealt with as dangerous waste.
Compared to the incineration of ordinary wastes the incineration of dangerous waste is an
expensive process. As a consequent the PCB contamination of shredder waste entails an
enormous increase in costs.
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