Electronic waste (e-waste) disposal, reuse and re-cycle technologies
Prof. Dr. Muammer Kaya
Osmangazi University, Technological Research Centre (TEKAM),
26480, Eskişehir, Turkey_________________________________________________________
The purpose of this study is to raise awareness of the large and growing scope of the e-waste prob-lem in the World. Specifically, this study attempts to inform the public, researchers and policy mak-ers regarding the volume and hazards pose by e-waste, the growing financial impact on local gov-ernments and taxpayers for its cleanup. Even though there are conventional disposal methods (such as landfill and incineration) for e-waste, these methods have both economic and environmental dis-advantages; recycling is a new waste management option which diverts end-of-life (EOL) electronics from landfill and incineration [1, 2]. Successful diversion strategy must be based on economic sustai-nability, technical feasibility and social support . Recycling infrastructure, which is not yet estab-lished well in the World, includes transportation, collection, recovery and resale establishments. The first part of this paper describes the e-waste facts, how big is the e-waste problem and existing recycling programmes and collecting methods in the USA and Europe; second part, describes vari-ous methods available to recover valuable materials (glass, plastic and metals ( Cu, Al, Steel, Ni, Au, Pd, Cu etc)) in e-waste for a safe and environmental friendly disposal.
1 What is e-Waste?
Since the 1980s, with the development of consumer-oriented electrical and electronic technologies, countless units of electronic equipment have been sold to consumers. E-waste, is the inevitable prod-uct of a technological revolution. When electronic products become obsolete and are ready for dis-posal, they are known as e-waste. Whether generated at our home or at office, e-waste is most rapid-ly growing waste problem in the world. Information technology and electronic industry are the world’s largest and fastest growing manufacturing industries and as a consequences of this alarm-
ing growth, combined with rapid product obsolescence, discarded electronics is now the fastest growing solid waste stream in the industrialized world. Most of the governments have been forced to respond/solve this serious problem. But to date, industry, government and consumers have only tak-Proceedings of EMC 2007 1
en small steps to deal with this looming problem. Developed countries that use most of the world’s
electronic products and generate most of the e-waste, tried to solve the problem by exporting ha-
zardous e-waste to the developing poor countries of Asia and Africa. 2 Classification of e-Waste
According to the Waste Electrical and Electronic Equipment (WEEE) directive, e-waste definition,
classification, recovery, reuse and recycling ratio aims are given in Table 1: Table 1: E-Waste Classification and Recovery, Reuse and Recycling Ratio in WEEE Directives.
WEEE Category Rate of Recovery Rate of Reuse
1. Large household appliances (ovens, refrigerators, 80% 75%
driers, washing machines, air conditioners etc.)
2. Small household appliances (toasters, vacuum 70% 50%
cleaners, mixers, ovens etc.)
3. IT& telecommunication appliances (PCs, desk 75% 65%
tops, lap tops, printers, phones, scanners, mouses, fax-
es, photocopy machines, computer peripherals, wireless
4. Consumer equipments electronics (TVs, flat pa-75% 65%
nels, plasmas, LCDs, HiFis, portable CD players,
DVDs, VCDs, iPods, MP3s, PDAs etc.)
5. Lighting equipments (mainly fluorescent tubes/ 70% 50%
bulbs) (gas discharge lamp 80%)
6. Electrical and electronic tools (E-tools) (drilling 70% 50%
machines, electric lawnmowers etc.)
7. Toys, leisure & sports equipments (electronic toys 70% 50%
training machines etc.)
8. Medical devices (X-Ray, MRI, EKG, SEM, Micro-To be established by end of 2008
70% 50% 9. Monitoring and control instruments (Lasers,
80% 75% 10. Automatic dispensers (ticket issuing, vending
machines automats etc.)
3 e-Waste Problem
E-waste has become a serious problem not only of quantity but also a crisis born from toxic ingre-
dients (such as Pb, Be, Hg, Cd, Cr and brominated flame retardants (BFRs) which create both occu-
pational and environmental health threats and hazards. E-waste contains over 1000 different sub-
2 Proceedings of EMC 2007
stances, many of which are toxic, and creates serious pollution problems upon land filling/burning. Due to the extreme rates of obsolescence, e-waste produces much higher volumes of waste in com-parison to other consumer goods. The life span of a computer has shrunk from five to two years due to rapidly evolving technology. Consumers nowadays rarely take broken equipment to repair shop because replacement is now easier and cheaper than repair. Cathode Ray Tubes (CRTs) in computer monitors, TV sets and video display devices contain significant concentrations of Pb and heavy metals. For these type of hazardous waste disposal to the municipal solid waste (MSW) land-fills is prohibited. Each computer or TV set display contains 2-4 kg of Pb. Monitor glass contains about 20 wt % Pb that protects consumers from X-ray radiation. Consumer electronics already constitute 40% of Pb and about 70% of the heavy metals (Hg and Cd) found in landfills. These heavy metals and other hazardous substances found in electronics can contaminate ground water and pose other environmental and public health risks. Historically, e-waste has been dumped in landfills or burned in incinerators, just like other MSW. It is better to get rid of old electronic devices as soon as it seems to be obsolete. Because stored old e-waste is more difficult to recycle and more toxic and generally does not contain any residual value.
3.1 Some Facts about e-Waste in the World
* According to the US Environmental Protection Agency (EPA), in 1997 more than 3.2 million tons of e-waste ended up in US landfills. Yearly electronic waste produced in the USA, is esti-mated 5 to 7 million tons. Only 10% of this e-waste is recycled. 30% or more stored typically for 3-5 years for future disposal and the rest is land filled . Electronic waste already constitutes from 2% to 5% of the US MSW stream (more than beverage containers, disposable diapers and about the same level as plastic packaging) and is growing rapidly . In Europe, the volume of e-waste is rising 3% to 5% per year- almost three times faster than the MWS.
* Today’s computer industry innovates very rapidly, bringing new technologies and “upgrades” to market on average of every 18 months. Conventional TV sets will be replaced by high-definition TVs soon, which will put millions of kilos of Pb/CRT into the environment. According to Stan-ford Research Inc. (SRI) US sales of CRTs used for computer monitors, terminals and worksta-tions equaled 28.4 million units in 2000. Between 1980 and 2005, an estimated 410 to 460 million computer CRTs have been sold in the US. Each year, some 50 million computers and 20 million TVs become obsolete. Approximately 25 million TV sets are sold in the USA annually. Yearly sales have equaled or exceeded 20 million units for the last decade. The use of TVs in US may be double that of computer monitors. But the rate of sales growth (and obsolescence) is slower in TVs than in computers. Annually less than 20000 TV units are being recycled in the USA.
* In the USA, Americans own about 2 billion electronic devices or 25 per household. Consumers have on average 2 to 3 obsolete computers in their garages, closets, basements, storerooms, attics or storage spaces for later disposal. Americans have buying more computers, than any other na-tions. Currently over 50% of US households own computers. Half of the turned-in computers are in good working conditions but they are replaced with the latest technology.
Proceedings of EMC 2007 3
* The lifespan of PCs is getting shorter, in 2006 the lifespan of PCs will be 2 years . In the USA, there are 315 to 680 million unused computers. SRI projects that total of nearly 500 million obso-lete computers between 1997 and 2007. Between 1997 and 1999, only 50 million US comput-ers dumped, burned, shipped abroad or stored for disposal. In 1999, NSC reported 11-15% dis-carded computer is recycled compared with 28% of overall MSW and 70% of the major appliances (like refrigerators, washing machines, dryers) recycling in the USA.
* In EU, 6.5 million tones of e-waste are generated yearly . In USA, between 50% and 80% of the collected e-waste for recycling are not recycled domestically at all, but very quickly placed on container ships bound for destinations like China, India, and Nigeria etc. . India exports 4.5 million PC every year from developed countries.
* In California alone, over $1.2 billion will be spent for e-waste disposal over the next 5 years. Recycling price of a computer is about $10 to $30 per unit. The cost of properly disposal of TVs or PCs could easily be $25 to $50. . According to the International Association of Electronics Recyclers (IAER), 7000 employees were working and $ 700 million annual revenue were obtained from electronic recycling in the USA in 2003. One hundred thirty million cell phones are retired each year in the USA.
* According to EPA, approximately 78 to 80 million automotive batteries are consumed and re-placed in the USA, not including those used for large tracks or nonautomotive uses, such as lawn and garden machinery and emergency power and the nationwide recycling rate is about 90%. 80% of the consumed Pb is manufactured by the recycling of old Pb-acid batteries in the secondary smelters. Average battery contains about 9 kilos of lead. Primary Pb industry is declining and na-tional demands are filled by secondary smelters using recycled materials .
* Household battery industry in the USA is estimated to be a $ 2.5 billion industry with annual sales of nearly 3 billion batteries. These batteries are used in over 900 million battery operated devices  In 2000, over 75 million NiCd batteries, which are considered one of the most hazardous with respect to disposal, were sold. The battery consumption per person is about 10 in Europe . In Europe 5 billion units of batteries were produced in year 2000 . Zn-C cells represent 39%, alkaline cells 51% and rechargeable batteries represent 8% of European portable household bat-tery market. Among the rechargeable batteries NiCd represents 38%, NiMH 35% and Li-ion 18% of the European market . E-waste market will be expected to generate $ 7.2 billion in 2007 and $11 billion in 2009.
4 Current e-Waste Disposal Methods
The volume of obsolete electronics thrown out or temporarily stored for later disposal is already a serious problem. Land filling, exporting, re-using and recycling are the currently used processes. The overwhelming majority of the world’s hazardous waste is generated by industrialized market econo-
mies. Exporting this waste to less developed countries has been one way in which the industrialized world has avoided having to deal with the problem of expensive disposal and close public scrutiny at home. Exporting of e-waste is profitable and cheaper because of labor costs and regulations offshore are lax compared to developed countries law. Shipping monitors (at a price of working $24 and non-4 Proceedings of EMC 2007
working $6 each) to poor countries for reclamation is 10 times cheaper than recycling the same units at home. Due to horrific working conditions and weak labor standards in many developing countries where e-waste is sent, women, children and prisoners are often occupied and directly ex-posed to Pb and other toxic materials when they manually dismantle the EEE to recover valuable parts for resell. The open burning, acid baths and toxic dumping into the land, air and water expose the men, women and children of poor peoples to poison. These operations are likely to be seriously harming human health. Free trade in hazardous wastes leaves the poorer people of the world with an untenable choose between poverty and poison. This e-waste practice should not be encouraged. Basel Convention banned the export of toxic components/hazardous waste (e-waste) from rich coun-tries to poor countries for final disposal in 1997. However the USA has refused to participate in this ban. The US has lobbied Asian governments to establish bilateral trade agreement to continue dump-ing hazardous waste after the Basel Ban came into effect on Jan. 1, 1998.
5 Hazardous Materials in the e-Waste and Their Effects on Hu-mans and the Environment
Over 1000 materials, including chlorinated solvents, BFR, PVC, heavy metals, plastics and gases are used to make electronic products and their components. The presence of toxic chemicals also makes e-waste recycling particularly hazardous to workers, as well as the environment. The list of toxic components in the computers include: Computer circuit boards contain heavy metals such as Pb and Cd; Computer batteries containing Cd, Ni; BFRs used in printed circuit boards, cables and plastic casings; PVC coated Cu cables and plastic computer casings that release highly toxic dioxins&furans when burned; Hg switches; Hg in flat panel screens; Poly Chlorinated Biphenyls (PCBs) present in older capacitors&transformers; CTR glass panels contain 2.3-2.8% Pb in frit, glass funnels contain 22-25% Pb and electron guns contain Cu yoke/wires. CRTs sometimes contain Ba. When these items are dumped into landfills or improperly recycled, they pose a significant hazard to the environ-ment and human health. E-waste is classified as hazardous waste in some countries. Some of the toxic metals and their effects are summarized below:
Lead (Pb): The effects of Pb are established and well recognized. Toxic heavy metal Pb can cause damage to the nervous and blood systems and kidney in humans. Pb accumulates in the environ-ment, and has acute and chronic toxic effects on plants, animals and microorganisms. Children suffer developmental effects and loss of mental/brain ability, even at low levels of exposure. Consumer electronics constitute 40% Pb found in landfills. The main concern in regard to the presence of Pb in landfills is the potential for the Pb to leach and contaminate drinking water supplies. The main appli-cations of Pb in electronics are soldering of printed circuit boards and other electronic components and glass panels in monitors (CRTs).
Cadmium (Cd): Cd compounds are classified as toxic with a possible risk of irreversible effects on human health. Cd and its compounds accumulate in the human body, in particular, in kidneys. Cd is absorbed through respiration but is also taken up with food. Due to the long half-life (30 years), Cd Proceedings of EMC 2007 5
can easily be accumulated in amounts that cause symptoms of poisoning. Cd shows a danger of cumulative effects in the environment due to its acute and chronic toxicity. In EEE, Cd occurs in certain components such as chip resistors, infrared detectors and semiconductors. Older models of CRTs contain Cd which is also used as a plastic stabilizer.
Mercury (Hg): Hg is very toxic at low dosages. When inorganic Hg is introduced into natural water systems, it is transformed into methylated Hg in bottom sediments that can easily accumulate in liv-ing organisms and concentrates through the food chain, particularly in fish. Methylated Hg causes chronic damage to the brain. It is estimated that 22% of the yearly world consumption of Hg is used in EEE. It is primarily used in thermostats, position sensors, relays and switches and discharge lamps. It is also used in medical equipment, data transmission, telecommunications, mobile phones, batte-ries, switches/housing and printed wiring boards.
+6Hexavalent Chromium (Cr): Some manufacturers still use this substance as corrosion protection
+6of untreated and galvanized steel plates, and as a decorative or hardener for steel housings. Cr easi-
ly passes through cell membranes and is then absorbed – producing various toxic effects within con-
taminated cells. It causes strong allergic reactions in even small concentrations. Asthmatic bronchitis
+6+6is a typical allergic reaction linked to Cr which may also cause DNA damage. In addition, Cr
compounds are toxic in the environment. Incineration results in the generation of fly ash from which Ch is leachable.
Plastics: There are more than 2 billion kilos of plastic present in computer waste. It is estimated that total electronic plastic scrap amounts to more than 580000 t/y in the USA . This same study estimates that the largest volume of plastics used in electronics manufacturing (at 26%) is PVC, which creates more environmental and health hazards than most other types of plastic. While many computer companies have recently reduced or phased out the use of PVC, there is still a huge volume of PVC in the computer scrap that continues to grow – potentially up to 125 million k/y.
The use of PVC in computers is mainly found in cabling and computer housings, although many computer moldings are now made from somewhat more benign ABS plastics. PVC cabling is used for its fire-retardant properties, fumes from PVC cabling can be a major contributor to fatalities and hence there are pressures to switch to alternatives for safety reasons. Alternatives include low-density polyethylene and thermoplastic olefins. PVC is a difficult plastic to recycle. It contaminates other plastics in the recycling process . More importantly, the production and burning of PVC products generate dioxins and furans.
Brominated Flame Retardants (BFR): BFRs are a class of brominated chemicals commonly used
in electronic products as a means of reducing flammability. In electronics, they are mainly used in four applications: printed circuit boards, components such as connectors, plastic covers and cables. They are also used in furniture foam, plastic covers of TV sets and in domestic kitchen appliances. Various scientific observations indicate that Polybrominated Diphenylethers (PBDE) might act as endocrine disrupters. Cu is a catalyst for dioxin formation when flame retardants are incinerated. 6 Proceedings of EMC 2007
oThis is particular concern as the incineration of BFRs at a low temperature (600-800C) may lead to
the generation of extremely toxic polybrominated dioxins (PBDDs) and furans (PBDFs).
6 Current Regulations/Legislations for Solving e-Waste Prob-lem
Basel Convention banned the transport/export of hazardous material (e-waste) from rich countries to poor countries in 1989. Today, 149 countries signed this convention. E-wastes contain some valua-ble materials and components that are technically recyclable. The problem is the lack of collection incentives and recycling infrastructure as well as high cost of material collection, handling and processing. Consumers and local governments have neither the technical ability nor financial re-sources to address this problem on their own. Recently, some local governments and at least two computer manufacturers have established “pay-as-you-go” collection program that require consum-
er and small business to pay a fee (7-30 $) in order to drop off or ship their obsolete computers for recycling. Europe has taken the lead in addressing the e-waste problem by proposing an ambitious system of “extended producer responsibility”. In May 2001, the EU Parliament adopted a direc-
tive that requires electronic producers to take responsibility-financial and otherwise- for the recovery and recycling of e-waste. A second directive requires manufacturers to phase out the use of hazard-ous materials. US should follow the EU’s lead. Most of the legislation for solving e-waste problem
falls into three groups: Producer TakeBack, Advanced Recycling Fee (ARF) and Tax Incen-
6.1 Producer TakeBack Program
E-waste takeback campaign aims to create an effective system for environmentally responsible recy-cling and reuse of consumer electronic products. This campaign promotes three points: Take it
Back, Make it Clean and Recycle Responsibly. Manufacturers may be slowly acknowledging the
inevitability of extended producer responsibility (EPR) campaigns. The objective of EPR is to
make brand name manufacturers and distributors financially responsible for their products when they become obsolete. In the USA, Gateway PC offers a rebate of up to $50 when they bring in any old PC for reuse or recycling. IBM will provide customers with a box and mailing label to ship old com- puters via UPS for reuse or recycling at a cost of $30. Currently, the expense of collecting, managing and disposing of discarded electronics are paid by taxpayers at local levels. Manufacturers and dis-tributors of electronic equipment must take financial and/or physical responsibility for their products at the EOL. This responsibility must include: Reduction of hazardous materials in products; Collec-tion, disassembly, reuse and recycling of discarded equipments; Requirements of environment friend-ly recycling; Follow high standards for recycling including worker health and safety; Don’t export the
e-waste to developing countries; Don’t use prison labor, women and children for disassembly.
The European Union (EU) has recognized the scope and urgency of the e-waste problem, recently approving two directives dealing with this important issue; “Waste Electrical and Electronic
Proceedings of EMC 2007 7
Equipment (WEEE Directive)” and “ A directive on the Restriction on the Use of Certain Hazardous
Substances in Electrical and Electronic Equipment (RoHS)”. The WEEE Directive requires that pro-
ducers supply systems for the treatment of WEEE. The directive also requires labeling of e-waste identifying the different components and materials within those components. The RoHS takes pre-vention a step further by phasing out the use of hazardous substances in the production of EEE by 2008. Table 2 shows the limits for hazardous materials in WEEE. Due to its danger to human health and the environment, Pb is particularly targeted by this legislation. Essentially, the EU is demand-ing that the industry find better, less toxic ways to produce their products in hopes of diminishing the risks of the equipment in the future. The directives also place full financial responsibility on produc-ers to set up collection, recycling and disposal systems, and contain effective and feasible goals for recycling. The cost for this legislation is only an additional 1% to 3% of retail prices.
Table 2: Hazardous Materials Limits at WEEE according to RoHS Directive.
HAZARDOUS MATERIAL LIMIT HAZARDOUS MATERIAL LIMIT
Cadmium (Cd) 100 mg/kg %0,01 Hexavalent Chromium 1.000 mg/kg %0,1 +6(Cr)
Lead (Pb 1.000 mg/kg %0,1 PBB 1.000 mg/kg %0,1
Mercury (Hg) 1.000 mg/kg %0,1 PBDE 1.000 mg/kg %0,1
The US government and American manufacturers are claiming that the EU’s environmental and health protections constitute “unnecessary barriers” to trade, particularly the ban on certain mate-
rials, burdensome takeback requirements for EOL equipment, and mandated design standards. Addi-tionally, US companies, through their trade association, have threatened to challenge the European initiative through the World Trade Organization (WTO) when the directive goes into effect. Howev-er, even in the face of these threats the Parliament not only approved the WEEE and RoHS direc-tives, but also went so far as to strengthen the directives initially proposed by the Commission. A recent study out of the International Institution for Industrial Environmental Economics concluded that as a result of mandated extended producer responsibility, manufacturers in Japan are building computers with EOL consequences in mind. Because the companies will bear the burden of dispos-al/recycling, they are finding ways to produce equipment that will last longer, can be disassembled more easily, is less toxic, and contains more standard components.
In ARF model, only consumer pay in advance the recycling fee, and producer does not have any re-sponsibility for their products (Figure 1). In September 2003, SWICO (Swiss Association for Infor-
mation, Communication and Organization Technology) ARF fund was established in Switzerland. Swico fund is distributed among logistics, collection points, recyclers and control board. Recyclers receive 1/3 of funding from secondary material selling and 2/3 from Swico fund. In tax credit ap-proach, tax credits are offered to recycling businesses and to consumers who recycle. It is expected that the tax credit method is unlikely to meet the fundamental goal of creating more recycling . 8 Proceedings of EMC 2007
Figure 1: Swico advanced recycling fee (ARF) funding system .
7 e-Waste Disposal/Recycling Processes and Technologies There are different alternatives to the final disposal of e-waste: landfill (contaminate groundwater), stabilization (requires pretreatment and expensive), incineration (release metal to air and to the ashes) and recycling (by hydro/pyro-metallurgical processes). Simplified flow diagram for the recy-cling of an e-waste is given in Figure 2. E-waste recyclers first identify products which can be resold for reuse. Then the remaining products are manually/mechanically disassembled for recycling.
Figure 2: Simplified flow diagram for the recycling of an electronic product.
7.1 Collection and Transportation of e-Waste for Recycling Permanent collection, special drop-off and curbside collection are the most extensively used pro-grams. A permanent collection option is essentially a year-round collection event. The MSW collec-tion site can be used for collection of e-waste. This method is cost effective and collected material are transported to the recyclers, when certain quantities are collected, by municipality/recyclers  Proceedings of EMC 2007 9
7.2 Materials Recovery Facility (MRF)
E-waste firstly tested and sorted for reuse/resale (sold/donated to secondary users as a whole or parts/components) or recycle for valuable materials. Plug-and-play test is used to determine the de-vices are working or not for reuse. If equipment fails, parts are manually/mechanically dismantled starting from valuable to cheap ones, respectively (Figure 3). After working valuable components and hazardous materials are removed from the e-waste, the materials recovery process begins. Table 3 shows the valuable materials in residential e-waste, TVs and computers in weight %. Ferrous metals are recovered by magnetic separation, non-ferrous metals by eddy current separation and plastics by density separation at the MFR.
Figure 3: Manual/mechanical dismantling flow sheets of e-waste.
Table 3: Valuable Materials in Residential e-Waste, TV and Computers in Weight %.
Materials Residential e-Waste TV Computer
Glass 47.6 24.8
Plastic 33 14.7 23.0
Precious Metal 27.1 0.02
Iron - 20.47
Lead - 6.3
Aluminum - 14.17
Copper 4.8 6.93 eOthers 6 - 4.3 CRT 12 R
Total 100 100 e
d7.3 Cathode Ray Tube (CRT) Recycling u
cCRTs are one of the major toxic items in electronic recycling due to their volume, costs and disposal t
restrictions in many countries. A CRT consists of two parts. one is glass components (funnel glass, i
opanel glass, solder glass and neck) and the non-glass components (plastics, steel, Cu, electron gun nand phosphor coating). CRT glass consists of SiO, NaO, CaO and other components for coloring, 22/
10 Proceedings of EMC 2007 e