尼日利亚电子废弃物的流向和管理实践

ReviewElectronic waste (e-waste):Material flows and management practicesin NigeriaInnocent Chidi Nnoroma,*,Oladele OsibanjobaDepartment of Industrial Chemistry,Abia State University,Uturu,Abia State,NigeriabBasel Convention Regional Coordinating Center for Africa for Training &Technology Transfer,Department of Chemistry,University of Ibadan,NigeriaAccepted 29June 2007Available online 20September 2007AbstractThe growth in electrical and electronic equipment (EEE)production and consumption has been exponential in the last two decades.This has been as a result of the rapid changes in equipment features and capabilities,decrease in prices,and the growth in internet use.This creates a large volume of waste stream of obsolete electrical and electronic devices (e-waste)in developed countries.There is high level of trans-boundary movement of these devices as secondhand electronic equipment into developing countries in an attempt to bridge the ‘digital divide’.The past decade has witnessed a phenomenal advancement in information and communication technology (ICT)in Nigeria,most of which rely on imported secondhand devices.This paper attempts to review the material flow of secondhand/scrap elec-tronic devices into Nigeria,the current management practices for e-waste and the environmental and health implications of such low-end management practices.Establishment of formal recycling facilities,introduction of legislation dealing specifically with e-waste and the confirmation of the functionality of secondhand EEE prior to importation are some of the options available to the government in dealing with this difficult issue.Ó2007Published by Elsevier Ltd.Contents 1.Introduction ..............................................................................14732.E-waste:Composition and generation ............................................................14732.1.Material composition of WEEE ...........................................................14732.2.Trends in e-waste generation .............................................................14742.3.E-waste trade:Nigeria a case study.........................................................14753.E-waste management practices .................................................................14753.1.E-waste management in developing countries..................................................14753.2.Environmental and health implications ......................................................14764.Material recovery from ponent reuse and recycling ...........................................................14764.2.Issues in e-waste management ............................................................14774.2.1.Product take-back (Extended producer responsibility)......................................14774.2.2.Product self-management ..........................................................14775.Recommendations ..........................................................................14785.1.Recommendations to developing countries ...................................................14785.2.Recommendations to developed countries ....................................................14780956-053X/$-see front matter Ó2007Published by Elsevier Ltd.doi:10.1016/j.wasman.2007.06.012*Corresponding author.E-mail addresses:chidiabsu@ (I.C.Nnorom),osibanjo@ (O.Osibanjo)./locate/wasmanAvailable online at Waste Management 28(2008)1472–14795.3.Recommendations to the OEMs (1478)6.Conclusion (1478)References (1478)1.IntroductionFrom past records,it seems certain that new problems of physical,biological and social change,not now widely anticipated,will arise sooner than later.This is because our scientific knowledge of each of these systems is incomplete,the mass of human population and its demands are increasing relentlessly and the possible human adjustments and adaptations,including technol-ogy,are multiplying(White,1996).Only a few years ago,some of the environmental issues of concern included the trio:acid rain,stratospheric ozone layer depletion and global warming.Today,waste electrical and electronic equipment(WEEE)or electronic waste(e-waste)genera-tion,trans-boundary movement and disposal are becom-ing issues of concern to solid waste management professionals,environmentalists,international agencies and governments around the world(Musson et al., 2000;Cui and Forssberg,2003).The useful life of consumer electronic products is rela-tively short,and decreasing as a result of rapid changes in equipment features and capabilities(Kang and Scho-enung,2004).This creates a large waste stream of obsolete electronic equipment.Due to their hazardous material con-tents,WEEE may cause environmental problems during the waste management phase if it is not properly pre-trea-ted.As a result,many countries have drafted legislation to improve the reuse,recycling and other forms of recovery of such wastes in order to reduce disposal.Nigeria is currently undergoing a rapid advancement in information and communication technology(ICT).A very significant proportion of ICT users in Nigeria rely on sec-ondhand equipment from developed countries,primarily from Europe and North America.In the present communi-cation,we review the materialflow of secondhand and scrap EEE into Nigeria,the current management practices for such wastes in the country and the environmental and health implications of such low-end management practices. Material recovery(component reuse and bulk recycling)as an option in the sound end-of-life(EoL)management of e-waste is also reviewed.2.E-waste:Composition and generation2.1.Material composition of WEEEPersonal computers(PCs)constitute the second largest component next to CRTs in the e-waste stream and are growing most rapidly.PCs also contain the largest amount of printed wiring board(PWB)among electronic products. The cathode ray tubes(CRTs)in computer monitors and televisions contain about8%lead by weight(Li et al., 2006);amounting to about2–4kg of lead each(Powel, 2002).Computer CRTs present a disposal problem because of their growing magnitude in the waste stream and their role as a major source of Pb in MSW(Musson et al., 2000;Lee et al.,2000).Consumer electronics account for 27%of Pb discards in MSW in1986in the US and are pro-jected to comprise30%of lead discards by2007.By2000, CRTs were projected to contribute29.8%of all Pb in MSW or approximately98.7%of all Pb from electronics(Musson et al.,2000).The composition of different kinds of CRT glass is given in Table1.Lead is used for various reasons in the CRT manufac-ture,among which is providing shield necessary for x-rays (Lee et al.,2000).The basic functions of Pb in CRTs are shown in Table1.Apart from Pb used in CRTs,another main source of Pb in WEEE is the lead solder.The elec-tronics industry is currently facing significant international legislation and market pressure to phase out the use of tin–lead solder and switch to lead-free alternatives.Concerns over lead in electronics derivable from lead solder are now limited to older electronics.This is because most elec-Table1Composition of different kinds of CRT glassItem Composition Basic functionPanel0–4%lead oxide Optical quality glass;Alkaline/alkaline earth X-ray attenuation;Aluminosilicate Color and tint controlFunnel22–28%lead oxide high X-ray resistance;Alkaline/alkaline earth Viscosity controlAluminosilicateNeck30%lead oxide Thermal expansion matchAlkaline/alkaline earth to funnel composition;Aluminosilicate X-ray absorptionStem29%lead oxide Expansion match to metalAlkalinealuminosilicateWire feed through;X-rayabsorptionGunmountPotassiumaluminosilicateCrystallizationSinteringFrit70–80%lead oxide Low temperatureZinc borateSource:Lee et al.(2000).I.C.Nnorom,O.Osibanjo/Waste Management28(2008)1472–14791473tronic manufacturers are now using lead-free solder.How-ever there are concerns that the lead-free solder(s)may also be of environmental and health concern sooner than later. For example,the96.35Sn/3.2Ag/0.7Cu alloy has been shown to potentially leach silver in concentrations greater than those deemed acceptable(Masanet,2002).2.2.Trends in e-waste generationThe growth of the PC industry started in the early1980sand by1989,an estimated21million PCs were sold world-wide;in1998thisfigure reached93million.This exponen-tial increase in the sale of PCs can be partly attributed to three factors:(1)the decrease in the PC price,(2)the emer-gence of the internet in the early1990s,and(3)the rapid increase in the raw processing power of desktop computers (Campbell and Hasan,2003).In2001,there were over300 million internet users worldwide and this,was estimated to increase to more than500million users by2003(Fichter, 2003).E-waste is growing at a rapid and uncontrollable rate and is the fastest growing portion of the municipal solid waste stream.Currently WEEE constitutes1%of munici-pal waste in the US(Li et al.,2006)and4%in the EU (Yla-Mella et al.,2004).As these PCs become obsolete, they are replaced and the old PCs are disposed.WEEE generation in some countries is shown in Table2.In 1996,there were over300million existing CRTs(TVs and monitors)in North America.Meanwhile,in the same year,42million new CRTs were sold in the US,and79mil-lion computers were retired(Musson et al.,2000).It is esti-mated that for every three new computers purchased,two currently used units will become obsolete.This ratio was expected to increase to2:1by2005(Musson et al.,2000).The level of obsolete PC generation in some countries is shown in Table3.The production of PCs in Taiwan in 1998accounted for13%of global personal computer (PC)production.By2000,it was estimated that about 300,000scrap PCs are generated each year in Taiwan (Lee et al.,2000).In China,the total sales of computer are more than10million sets every year.Meanwhile,a total of5million sets of computers and40million sets of CRT monitors have had to be discarded so far in China (Ecoflash,2003).The questions of how much e-waste is generated,from where and to where it is moving are difficult to answer.This is worsened by the current system of gathering information in which secondary and waste products are by large invis-ible to national statistics in production,sale and trade-in goods.Williams(2005)observed that few if any statistical categories are designed to distinguish new goods from used or waste ones.Hong Kong and Australia were thefirst to develop guidelines for distinguishing between used goods and e-waste(Kojima,2005).In2003,160,000metric tons of secondary and waste electronic equipment were exported from the UK; 133,000tons of this was IT/telecom equipment.In this cat-egory110,000tons were declared exports and properly documented while23,000tons were undeclared or grey-market exports going to non-OECD countries(Williams, 2005).According to estimates,between50%and80%of e-waste collected for recycling in the US each year is being exported,amounting to about10.2million PCs(Roman and Puckett,2002;BAN/SVTC,2002;BAN,2005).Esti-mates show that South Korea exports about1.8million used computers to China each year,to avoid paying the steep recycling and disposal costs within its own borders (Toxic Dispatch,2004).It can be assumed that the disposal of obsolete elec-tronic products is fundamentally driven by the production of new ones.This implies that the growth in global elec-tronic production of4.4%in2002,and6.8%in2003will result in similar growth in e-waste generation(Williams, 2005).Currently the main route of disposal of e-waste in most developed countries is through export to developing countries in the name of‘bridging the digital divide’.Too often,justifications of‘building bridges over the digital divide’are used as excuses to obscure and ignore the fact that these bridges double as toxic waste pipelines to some of the poorest communities and countries in the world. While supposedly closing the‘digital divide’,the developedTable2E-waste generation in selected countriesCountry Year E-waste generated(Metric tons/year)ReferenceGermany20051,100,000Kumar et al.(2005),Williams(2005)aUK1998915,000USA20002,158,490Kumar et al.(2005),Williams(2005)a Taiwan200314,036Kumar et al.(2005),Williams(2005)a Thailand200360,000Kumar et al.(2005),Williams(2005)a Denmark1997118,000Kumar et al.(2005),Williams(2005)a Canada200567,000Kumar et al.(2005),Williams(2005)a Norway1995144,000Lamvik et al.(2002) Switzerland–110,000Brandl et al.(2001) Finland2003120,000Yla-Mella et al.(2004) France–1,500,000Li et al.(2004) Sweden–100,000Yla-Mella et al.(2004) a Source:http://www.ewaste.ch/facts_and_figures/statistical/quantities/.Table3Waste personal computer generation in selected countriesCountry Year Volume(units)ReferenceChina–4million/year Greenpeace(2005) Korea2003 1.2million Oh et al.(2003) North America199679million Musson et al.(2000) Taiwan1998300,000Lee et al.(2000) USA199820million Powel(2002)1474I.C.Nnorom,O.Osibanjo/Waste Management28(2008)1472–1479countries are rather opening a‘digital dump’(BAN,2005). The export of e-waste to Africa and Asia appears to be a preferred option to the developed countries rather than to use the opportunity to enable their own national recy-cling infrastructure,switch to cleaner technologies and develop innovative design to prevent further toxics use (Roman and Puckett,2002).Developing countries are increasingly victimized by a disproportionate burden of the world’s toxic cyber waste.The export of cyber waste to developing countries like Nigeria may be fueling the export of cyber crime to the developed countries,as per-sons involved in cyber crime may obtain information about their victims from the hard drives exported with the e-waste.2.3.E-waste trade:Nigeria a case studyIn Nigeria,secondhand computersfind application in business centers,printing houses;computer institutes/train-ing schools,cyber cafes and home use.Growth in internet use in Nigeria is shown in Table4.The recent Basel Action Network(BAN)coordinated study in Nigeria-Exporting Reuse and Abuse to Africa-revealed the level of trans-boundary movement of secondhand and scrap EEE into Nigeria.The study observed that an average of500 containers enter Nigeria through the Lagos ports monthly with each containing about800monitors or CPUs.This indicates that an average of400,000secondhand or scrap PCs(CPUs)or monitors enter the country monthly through the Lagos ports.This amounts to an annual importation of an estimated5million PC units,with a weight estimated at60,000metric tons(considering an average weight of8–14kg for a PC(Li et al.,2006)and 12kg for a monitor(Lee et al.,2000)).Secondhand com-puter wares are also imported through other sea and air ports,and also through donations by charities to organiza-tions and educational institutions.Data is however scarce on the local generation of e-waste and on the in-flow of new computers and other EEE from the original equipment manufacturers(OEMs).The BAN study observed that about25–75%of the imported secondhand computer wares are unusable junk that are non-functional or unrepairable(BAN,2005).This amounts to an importation of15,000–45,000tons of scrap recyclable electronic components,which may contain as much as1000–3,600tons of lead.In Nigeria,there is virtu-ally no capacity for material recovery operations for elec-tronic waste,as a result of which these items become discarded in local dumps.Assuming this trade continues unabated,with an annual increase of10%,then an esti-mated40million units of PCs or monitors(or468,000met-ric tons of e-scrap)would have been imported over the period2005–2010.This will amount to an importation of about40,000metric tons of Pb for the period under consid-eration or77,000tons of e-scrap/year.From tags on the imported appliances and the information on the computer hard drives,the BAN study estimated that about45%of the imports are from the EU,45%from the US,and the remaining10%from other locations such as Japan,Bel-gium,Finland,Israel,Germany,Italy,Korea,Netherlands, Norway,and Singapore(BAN,2005).Trading of secondhand electronics is currently booming at the famous‘computer village’in Lagos,Nigeria owing to this large-scale importation of secondhand electronics. Brokers and traders from countries in the West African sub-region come to Lagos to buy secondhand computer and accessories and other electronic devices.As a result, a substantial quantity of these imports may be diverted to other African countries,especially countries in the ECO-WAS sub-region.3.E-waste management practices3.1.E-waste management in developing countriesMost developing countries including Nigeria have nei-ther a well-established system for separation,storage,col-lection,transportation,and disposal of waste nor the effective enforcement of regulations relating to hazardous waste management(Mundada et al.,2004).They do not have legislation dealing specifically with e-waste and there is lax enforcement of existing laws dealing with general waste management.Formal recycling of e-waste using effi-cient technologies and state-of-the-art recycling facilities are rare.As a result electronic wastes are managed through various low-end management alternatives such as disposal in open dumps,backyard recycling and disposal into surface water bodies(Furter,2004).Similarly,there is no integrated framework regarding the monitoring and management of toxic and hazardous materials and wastes in these countries.Limited funding has also caused signif-icant impediments to the effective management of toxic wastes.Apart from scarcity offinancial resources,the development of appropriate home-grown technology fol-lowing the principles of waste minimization and sustain-able development has been slow.Crude recycling for e-waste is currently taking place in China,India,and in some other countries in the Asia-Paci-fic axis.These crude‘backyard’recycling processes include open burning of plastics(to reduce waste volume)and cop-per wires(to salvage valuable metals,e.g.copper),and strong acid leaching of PWB(to recover precious metals) etc.These operations are usually carried out with no orTable4Growth in internet use in NigeriaYear internet InternetusersInternet penetration(%)Growth in users(%)2000107,1940.1–2001152,3500.143.062002420,0000.3173.8820031,613,258 1.3284.1120041,769,661 1.59.69Data adapted from BAN(2005).I.C.Nnorom,O.Osibanjo/Waste Management28(2008)1472–14791475very little personal protection equipment or pollution con-trol measures.In open burning of materials,fly ash partic-ulates laden with heavy metals and other toxic materials are usually emitted.This results in inhalation of these toxic materials and also in the contamination of food,soil and surface water after deposition.These crude material recov-ery processes have resulted in environmental pollution while exposing millions of people to toxins.These crude recycling processes are yet to catch up in Nigeria.New management options are needed to divert EoL electronics from disposal with municipal waste in Nigeria and other developing countries.There are several factors to consider in the development of a successful diversion strategy.This strategy must be based on its economics,sus-tainability,eco-efficiency,technical feasibility,and a realis-tic level of social support for the program.This strategy includes reuse,recycling and material recovery of EoL elec-tronic products.Collection methodology,sorting,recovery technologies,material recycling processes and disposal methods are key factors in the comprehensive recycling of e-waste(Kang and Schoenung,2004).3.2.Environmental and health implicationsAdverse health effects on people from contact with haz-ardous wastes may involve any organ system,depending on the specific chemical(s)contacted,the extent of exposure, the characteristics of the exposed individual(age,sex,body weight,genetic makeup,immunological status),the metab-olism of the chemical(s)involved,weather conditions,and the presence or absence of confounding variables such as other diseases(Asente-Duah et al.,1992).A typical example of the hazards of crude recycling of e-waste is the Guiyu town in China.This town attracted international attention after a documentary report on e-waste trading and processing in Asia by Basel Action Net-work and Greenpeace in2002.The majority of e-waste recycling in this town is processed in backyards or small workshops using crude methods such as manual disassem-bly and open burning.Environmental contamination resulting from these crude recycling activities in the Guiyu town have been extensively studied and documented (BAN/SVTC,2002;Greenpeace,2005;Roman and Puck-ett,2002;Leung et al.,2004;Wong et al.,2007).The highly acidic pH of as low as3.4observed in some water bodies of the industrialized areas of Lagos(Sridhar and Bammeke,1986)may accelerate the dissolution and mobility of heavy metals from disposed waste items and from ash and cinder resulting from the open burning pro-cess,toward water bodies used for domestic purposes. Basel Action Network noted that exporting e-waste to developing countries exposes these countries to hazardous waste and toxics,forcing them to choose between‘‘poverty and poison’’(BAN,2005).This is more so because these countries are not using the appropriate technology for waste management(Yanez et al.,2002).The lack of any kind of e-waste recycling in Nigeria and other developing countries means that these recyclables end up as the worst global examples of waste mismanagement.The BAN study in Nigeria observed that‘‘even if Africa possessed state-of-the-art waste management systems,such disproportionate burdening of these peoples and environments in Africa with toxic wastes would be an environmental injustice’’.4.Material recovery from e-wasteThe consequences of the current disposal practices of e-waste in Nigeria include:(1)toxic materials enter the waste stream with no special precaution to avoid the known and documented adverse effects on the human health and the environment;(2)resources are wasted when economically valuable materials are dumped instead of recycled,and additional new resources are required to continue the man-ufacturing process;and(3)scarce land resources are being used in landfills to accommodate discarded waste.How-ever,by reclaiming some of these materials and disposing of the recycling waste appropriately,the ultimate effect on the environment may be mitigated.ponent reuse and recyclingWEEE can be recovered through disassembly,compo-nent reuse,bulk recycling,and energy recovery(especially from waste plastics).The recovery of WEEE for reuse or recycling conserves resources and feedstocks that supply steel,glass,plastics and precious metals.Such recycling also avoids air and water pollution,as well as greenhouse gas emissions associated with material production and manufacturing.Hula et al.(2003)observed that product structure,materials,location of recycling facilities,applica-ble regulations,geography,and cultural context have a major impact on the economics and environmental benefits of material recovery.Resource conservation over the life cycle of products is a key component of sustainability. Recycling of WEEE is an important subject not only from the recovery aspect of valuable materials;there are also sig-nificant energy savings(Table5)when recycled materials are used in place of virgin materials.The application of mechanical processes,such as screening,shape separation, magnetic separation,and jigging to e-waste processing have been reviewed(Cui and Forssberg,2003).Table5Recycled material energy savings over virgin materialsMaterial Energy savings(%) Aluminum95Copper85Iron and steel74Lead65Zinc60Paper64Plastic>80Source:Cui and Forssberg(2003).1476I.C.Nnorom,O.Osibanjo/Waste Management28(2008)1472–1479Data is scarce on the recycling of e-scrap in Africa, except in South Africa where there is an increase in mate-rial recovery activity for electronic scrap.Presently there is mechanical processing of obsolete computers,photocopi-ers,telephones,printers,faxes,telex machines,calculators, cell phones and other post-consumer goods in the country (Furter,2004).Recyclers in South Africa process more than4000tons of electronic waste each year(Finlay,2005).The gold content of a desktop computer is about 0.0016%and yet1metric ton of electronic scrap of PC con-tains more gold than that of17tons of gold ore(Li et al., 2004).This implies that e-waste can be regarded as a high-grade‘ore’.In1998,the amount of gold recovered from e-waste in the United States was equivalent to that from more than2million metric tons of gold ore(Li et al., 2004).There has been much research to date on the possi-bility and practicability of recovering valuable metals in electronic scrap and in particular,from printed wiring board(PWBs)of electronic scrap(Table6).The volume of PWBs is growing worldwide,from90,000tons in2003 up to156,000tons in2009(Tange and Drohmann,2005). In general,PWB scraps contain approximately40%metals, 30%plastics and30%ceramics(Cui and Forssberg,2003). One possible advantage of recycling the e-scrap is the pos-sibility of using the plastic as fuel in energy recovery.The energy recovery not only contributes to reduced fossil fuel consumption by the society,but provides an ecologically sound way to manage a significant portion of the plastics from EoL EEE(Fisher et al.,2005).4.2.Issues in e-waste management4.2.1.Product take-back(Extended producer responsibility)Most developed countries have adopted a series of mea-sures in the management of e-scrap in order to protect the environment and human health and to achieve sustainable development.There are many approaches to dealing with e-waste;one concept has been extended producer responsi-bility,EPR.This model provides incentives for redesigning products that minimize environmental impacts,including by using environmentally safer materials and by designing products that can be more efficiently recycled or reused. The EU,Japan,South Korea,Taiwan and several states in the United States have introduced legislation making producers responsible for their EoL products.EPR was developed with support for the polluter pay principle and the recognition of the need to improve the management and recycling of waste as agreed at the Rio Earth Summit in1992.EPR requires that the people who use the most electronic equipment pay for their share of recycling in the form of higher prices,assuming that producers and manufacturers add the cost of transporting and recycling and disposing of their products into the cost of the product at sale.Based on the concept of EPR,the European Union issued the Waste Electrical and Electronics(WEEE)and the Restriction on the Use of Certain Hazardous Sub-stances(RoHS)Directives.The WEEE Directive aims to implement a take-back system of WEEE for the improve-ment of the environmental performance of all operators in the life cycle of EEE.RoHS aims to restrict the use of some hazardous substances(Pb,Hg,and Cd,hexavalent chromium,polybrominated biphenyls(PBB)and polybro-minated diphenyl ethers(PBDEs))in electrical and elec-tronic equipment beginning in August2006(Walls,2003).4.2.2.Product self-managementThe concept of product self-management has been con-ceived(Thomas,2003).This concept shifts responsibility for product management to the product itself and is a com-bination of information technology and product design that would allow products to more or less automatically manage their EoL.This is expected to make product EoL management more efficient and less expensive and would require that manufacturers include basic product informa-tion on the product,both as a written label and as a bar code(Saar and Thomas,2003).This information will be relevant to the recyclers and dismantlers of products,andTable6Material composition of computer printed wiring board(PWB)Component group Composition by weight(%)Metals(30%)Cu Fe Ni Sn Pb Al Zn10.97.7 2.5 3.9 1.5 1.7 1.1 Precious metals b Au Ag Pd0.004980.008180.002 Metal oxide(40%)Silica Oxides a Alumina Other oxides156613Plastics(30%)CHO Polymers c Halogenated polymers d Nitrogen containing polymers e <25<5<1Source:Oh et al.(2003).a Alkaline and alkaline earth oxides.b Metals+precious metals=30%.c Polymers including polyesters,phenol–formaldehyde etc.d Polymers mainly PVC,traces of PTFE,and polybromo compounds etc.e Polymers including nylon and polyurethane.I.C.Nnorom,O.Osibanjo/Waste Management28(2008)1472–14791477。