Environmental Homework

Environment International 98 (2017) 35–45

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Review article

From electronic consumer products to e-wastes: Global outlook, waste quantities, recycling challenges

Berrin Tansel Florida International University, Civil and Environmental Engineering Department, 10555 West Flagler Street, Engineering Center, Miami, FL 33174, USA

E-mail address: [email protected].

http://dx.doi.org/10.1016/j.envint.2016.10.002 0160-4120/© 2016 Elsevier Ltd. All rights reserved.

a b s t r a c t

a r t i c l e i n f o

Article history: Received 8 May 2016 Received in revised form 4 October 2016 Accepted 4 October 2016 Available online 8 October 2016

Advancements in technology, materials development, andmanufacturing processes have changed the consumer products and composition of municipal solid waste (MSW) since 1960s. Increasing quantities of discarded con- sumer products remain a major challenge for recycling efforts, especially for discarded electronic products (also referred as e-waste). The growing demand for high tech products has increased the e-waste quantities and its cross boundary transport globally. This paper reviews the challenges associated with increasing e- waste quantities. The increasingneed for rawmaterials (especially for rare earth andminor elements) and unreg- ulated e-waste recycling operations in developing and underdeveloped counties contribute to the growing con- cerns for e-waste management. Although the markets for recycled materials are increasing; there are major challenges for development of the necessary infrastructure for e-waste management and accountability as well as development of effective materials recovery technologies and product design.

© 2016 Elsevier Ltd. All rights reserved.

Keywords: Sustainability e-Waste Rare earth elements Recycling Materials recovery Cross boundary e-waste transport

Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2. Global outlook and increasing e-waste quantities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3. Materials demand for high tech products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4. Recovery of materials from e-waste and recycling challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 5. Global cross boundary e-waste transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 6. Proactive vs reactive strategies for e-waste management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 7. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

1. Introduction

Rapid advancements in material science, manufacturing processes, and electronic products have created global markets with rapid diffu- sion of technology to consumers. In recent years, the advancements in telecommunication and information technologies have increased glob- alization, making it possible to develop markets for the new products at scales larger than before in terms of data acquisition, product dissem- ination, technology application, consumer behavior, and market pene- tration. Increase in production of consumer products and their distribution to global markets combined with their affordability have created challenges for managing municipal solid waste (MSW), espe- cially for the increasing quantities of discarded electronic consumer

products. At the global scale, there are some inconsistencies in the un- derstanding and application of the term electronic waste (e-waste) from both legislation and everyday use perspectives (UN Step, 2014). The applicable US regulations implemented by different states; Swiss Ordinance on the Return, Taking Back and Disposal of Electrical and Electronic Equipment (Swiss ORDEE); and European Union Waste of Electrical and Electronic Equipment (EU WEEE) Directive have some differences in their definition of waste electrical and electronic equip- ment (WEEE). For example, in the US, large and small household appli- ances (e.g., refrigerators, microwave ovens, coffee makers, toasters) are not considered as e-waste in most states while they are included under the EUWEEEDirective and the Swiss ORDEE regulations. The EU ORDEE Directive considers medical, surveillance, and automatic issuing ma- chines as e-waste while these are not included under the Swiss ORDEE regulations but considered under separate regulations. Lighting

36 B. Tansel / Environment International 98 (2017) 35–45

equipment, electric/electronic tools, recreational equipment (e.g., treadmills, slot machines) and toys (e.g., electric train sets) are not in- cluded under the Swiss ORDEE regulations (since 2005); however, they included under the EU WEEE Directive. In general, e-waste in- cludes old, end-of-life or discarded appliances using electricity. These include computers, consumer electronics (i.e., computers, LCD/CRT screens, mobile phones), large appliances (e.g., refrigerators, washer/ dryers) and similar consumer products which have been disposed of by their original users.

Although both the development and diffusion of new technologies to consumers are occurring at faster rates; development of appropriate technologies and policies that address the management of e-waste are only at the beginning stages. There are limited controls on manufactur- ing of new products that include considerations for systematic and sus- tainable utilization of resources while continuing the development of new products, as these factors increase the production costs (Amankwah-Amoah, 2016; Singh et al., 2016). Some of the highly in- fused technologies have resulted in production of large quantities of e- wastewith significant environmental challenges (e.g., lack of infrastruc- ture formaterials collection and recovery and associated environmental risks during e-waste handling/recycling) (Garlapati, 2016; Julander et al., 2014; Song and Li, 2014a; Song and Li, 2014b; Feldt et al., 2014).

Both formalized and unregulated regional small scale operations have been established for recovery operations of somemetals with rel- atively high market values (Garlapati, 2016; Ruan and Xu, 2016; Davis and Garb, 2015). However, these operations; especially the uncon- trolled entrepreneurial efforts; present challenges for safe handling of materials and work environments (Pinto, 2008; Robinson, 2009; Sepúlveda et al., 2010; Chen et al., 2011; Grant et al., 2013; Song and Li, 2014a, 2014b; Feldt et al., 2014). Tissue samples from residents living near the e-waste handling/processing areas and workers at the e-waste recycling facilities show high levels of pollutants associated with e- waste (i.e., PBBs, PBDEs, PCBs, PCDD/Fs, and heavy metals) (Song and Li, 2014a, 2014b;Wang et al., 2016; Lu et al., 2016).Wastemanagement and chemical use practices at unregulated e-waste recycling operations can contaminate soils, plants and groundwater samples with significant increases in heavy metal concentrations (Zhang et al., 2012; Pradhan and Kumar, 2014).

This study reviews the challenges ofmanaging e-waste; the need for developing controlledmechanisms and infrastructure for collection and recycling in view of thematerials sustainability and global environmen- tal quality. The quantities of e-waste have exponentially increased in the last several decades. The issues addressed include increasing e- waste quantities; increasing materials demand for manufacturing high tech products; recycling challenges for e-waste components; and global cross boundary transport of e-waste. The increasing needs for rawma- terials (especially for rare earth and minor elements) as well as

Table 1 Increasing trends in world population, water consumption, plastics production, oil production,

Year World population (billions)

Life expectancy (yrs)

Water consumptione

(billion m3/yr)

World plastics productiona

(million tons/yr)

World crude o productionb

(million barre

1960 3.03 52.48 2000 15 21 1970 3.69 59.60 2550 35 45 1980 4.44 63.19 3200 69 60 1990 5.28 65.70 3500 104 59 2000 6.10 67.69 3900 185 65 2010 6.88 70.32 4300 270 70 2015 7.21 71.00 4550 300 75

a Association of Plastics Manufacturers (2016). b Sieminski (2015). c Yu et al. (2010). d Stromberg (2013). e MIT (2016). f Baldé et al. (2014). g NA: Not available.

increasing numbers of uncontrolled e-waste recycling operations con- tribute to the growing concerns for e-waste management. The cross boundary transport of e-waste at the global scale to areas with low labor costs creates environmental problems and health risk concerns at these locations. There is an increasing need for developing effective e-waste accounting mechanisms, waste management programs, and material recovery technologies.

2. Global outlook and increasing e-waste quantities

During the last 50 years, theworld population has doubled,with bal- ance tipping towards urbanization. Over half of the world population now lives in the urban areas. As a result of increasing population, in- creasing urbanization, and increasing life expectancy; the demands for water and crude oil have more than doubled in the last 50 years (Table 1).

Waste quantities have been increasing globally, however, at differ- ent rates in different counties. As presented in Table 2, per capita MSW generation rates in the developed and developing countries are almost three times the average per capita waste generation globally (the estimated amount in 2000 in the US was 760 kg/ca-year vs 234 kg/ca-year worldwide). There is also a significant disparity in per capita e-waste generated between developed and developing countries (the estimated amount of e-waste in 2014 in the US was 22.1 kg/ca-year vs 5.4 kg/ca-year worldwide) (Table 2).

The quantities of discarded consumer products, especially e-waste, have increased exponentially as a result of advancements in materials technology, manufacturing processes, rapid market penetration and planned obsolescence (Table 3). A significant fraction of the globally generated e-waste is not documented or handled in controlled manner for materials recovery. In 2014, only about 6.5 millionmetric tons of the 41.8 million metric tons of e-waste was documented and recycled with the highest standards (Baldé et al., 2014). The quantity of e-waste pro- duced globally is expected to increase up to 50 million metric tons in 2018 (Baldé et al., 2014).

3. Materials demand for high tech products

Electronic devices have high demand for materials, especially for rare earth elements (REE) and minor minerals (MM) (Table 4, Fig. 1). Currently, there are no specific technical criteria andmetrics for system- atic evaluation and comparison of the relative demand of consumer products for materials; at the same time, allow an objective determina- tion of the utilization of natural resources during their production. This creates opportunities for mass production of electronic products while creating gradually increasing stress on the environment as the virgin

and estimated e-waste quantities generated during 1960–2015.

il

ls/d)

Obsolete computers in developing regionsc

(million units)

MSW generationd

(million tons/d)

e-Wastef

(kg/ca-yr) e-Waste generatedf

(million tons/yr)

0 1.5 0.02 NA 0 2.0 NAg NA 0 2.5 NA NA 3 3.0 NA NA 50 3.2 NA NA 120 3.6 5.0 33.8 200 4.0 6.1 43.8

Table 2 Comparison of municipal solid waste and e-waste quantities in some countries in recent years.

County MSW generated per capitaa,b

(kg/ca) in 2000

e-Waste generated per capitaf,g (kg/ca) in 2014

e-Waste generatedf

(million tons) in 2012

e-Waste generatede,g

(million tons) in 2014

United States

760 22.1 7.1 7.07

China 444 (urban) 4.4 6.0 6.03 Japan 410 17.3 2.2 2.20 Germany 618 21.6 1.8 1.95 Russia 330c 8.7 1.2 1.23 Brazil 365d 7.0 1.4 1.41 United Kingdom

560 23.5 1.5 1.51

France 510 22.1 1.4 1.42 Australia 690 20.0 0.6 0.47 South Africa

730d 6.6 0.3 0.35

Worldwide 234 5.4 37.3 41.8

a Eurostat (2015). b NationMaster (2015). c International Finance Corp. (2015). d Kawai and Tasaki (2016). e The World Bank (2016). f Baldé et al. (2014). g StEP (2016).

37B. Tansel / Environment International 98 (2017) 35–45

materials are extracted and utilized at larger quantities than before (Gordon et al., 2005; Graedel et al., 2015; Peck et al., 2015).

In view of the available quantities of the elements in the Earth's crust (Fig. 1a), and their productions rates (Fig. 1b); high tech products have high demand for REE and precious metals (Fig. 1c). The increasing de- mand for REE created economic stresses and price fluctuations due to their limited availability at global markets. Manufacture of one mobile phone utilizes between 60 and 64 elements (Nuwer, 2014).Most tablets and smart phones use aluminum or plastic enclosures with glass dis- plays (39–46% by weight), batteries (22–26% by weight) and printed circuit boards (8–9%byweight) (Marwede, 2013).Metals constitute be- tween 50 and 60% of the product weight of cell phones and laptop com- puters (US DOE, 2013). One computer contains over 30 elements (Fig. 1d). Hence, manufacturing of high tech products creates a substantial materials demand in view of the quantities manufactured and increas- ing global demand.

Availability of mineral deposits for elements that are used in high tech products at specific regions have resulted in shifts in market con- trols accompanied with increases in production in the recent years.

Table 3 Average use time of some electronic products reported by consumers.

E-product or service

Expected use time by consumersa,c (yrs)

Year marketed

Time to reach 60% of US populationb (yrs)

Flat panel television

7.4 1990 –

Digital camera 6.5 1998 9 DVD player or recorder

6.0 1997 –

Desk top computer

5.9 1980 35

Note book, laptop computer

5.5 1980 –

Tablet computer 5.1 2008 – Cell phone (not smart phone)

4.7 1985 15

Smart phone 4.6 2000 10 Internet NA 1990 24 Electricity NA 1911 32

a Consumer Technology Association (2014). b McGrath (2013). c NA: Not applicable.

For example,magnetmaterials based on REE experiencedmajor cost in- creases over the last 6 years due to the increasing demand and limited supply. Currently, 97% of the world's rare earth ores used for commer- cial production are located in China (Integrated Magnetics, 2015). Due to the rapid growth in its own demand, China has imposed strict quotas in 2011 on the export of these ores. The reduction in the exported amounts of rare earth ores and REE have resulted in major increases in their price within less than 6 months (e.g., the price of neodymium increased from about $40 per kg to $460,000 per kg; the price for dys- prosium increased from about $500 per kg to $3400; the price for terbi- um from about $600 per kg to $5300 per kg in less than one year) (Integrated Magnetics, 2015).

4. Recovery of materials from e-waste and recycling challenges

The design improvements that increase marketability and durability of high tech products (i.e., embedded systems and printed circuit boards) also create recycling challenges for separation of the compo- nents and materials recovery (Table 5). For example printed circuit boards (PCB), lamination of components and embedded systems in- crease durability of components while reducing their size. However, structurally integrated materials make it difficult for disassembly and recovery of materials. In addition, coatings and sealants applied (e.g., polymers, siloxane based materials) to improve moisture resistance and durability of products need to be removed by acid dissolution or heat application (Surita and Tansel, 2015).

The materials present in e-waste are valuable secondary resources (Baldé et al., 2014). Sustainable e-wastemanagement requires a holistic approach rather than improving recycling rates of selected materials. Both the product design and collection methods affect the characteris- tics of the waste streams. In some communities, different e-waste com- ponents are collected separately based on category (e.g., computers, telephones, monitors) while in others they are collected without presorting. It is important to develop management strategies for recycling the entire products at the end of their useful lives insteadof re- covering specific materials contained in them (UNEP, 2013). The main challenges for managing e-waste include generation of high volumes, large variety of products, lack of effective collection mechanisms and networks, presence of toxic materials, difficulty of separation (i.e., com- ponents being bolted, screwed, snapped, glued or soldered together), lack of financial incentives, and lack of adequate regulations (Lundgren, 2012). For some elements used in small quantities (e.g., Au, Ag, Pd, Pt, Rh, Ir, Ru), the economies of scale can only be attained through processing at central facilities which may require facilitation of cross-border transportation of e-waste in a transparent and sustain- able manner (UNEP, 2013; Khaliq et al., 2014). Organized e-waste col- lection efforts are necessary for maintaining sustainable quantities of discarded products to implement profitable e-waste management busi- nesses and recycling centers (Ponce-Queta et al., 2011).

The e-waste requires hand sorting to produce adequate quality of recycled products (van Schaik and Reuter, 2010). The separation chal- lenges due to presence of elements with similar characteristics (i.e., physical, chemical, thermodynamic properties) can be reduced by presorting the input entering the process to liberate the materials from each other by physical force (Froelich et al., 2007). Liberation pro- cesses include shredding steps (by crushing, grinding or shearing) which typically provide partial liberation (van Schaik and Reuter, 2010, 2012). The main components of e-waste which offer economic advantages include the following:

1. Metals: The metal scraps containing ferrous and major non-fer- rous alloys can be recovered partially, but not all metals can be recov- ered effectively from e-waste. Depending on the quantities present and value of the metals, iron and aluminum have been economically feasible for recovery and recycling. The e-waste also contains relatively high amounts of copper, silver, gold and palladium which can be eco- nomically feasible to recover (Namias, 2013).Metals recovery processes

Table 4 Elements used in computers and high tech devices (compiled based on information provided by Namias, 2013; Jorgensen, 2004; Haque et al., 2014; Fornalczyk et al., 2013; Szałatkiewicz, 2014; Uddin, 2012).

Metal Atomic no Rare earth element Precious metal Very rare on Earth's crust Use in high tech industries and computersa

Aluminum 13 x PWB, computer chips, hard drives, CPU, connectors Silicon 14 CRT, PWB Scandium 21 x Lasers, lighting, aerospace Titanium 22 Housing Vanadium 23 CRT Chromium 24 Housing Manganese 25 Housing, CRT, PWB Iron 26 Housing, CRT, PWB Cobalt 27 x Housing, CRT, PWB, hard drive Nickel 28 x Housing, CRT, PWB Copper 29 x CPU heat sinks, wiring/cables, PWB, computer chips, CRT Zinc 30 x PWB Gallium 31 PWB Germanium 32 PWB Arsenic 33 PWB Selenium 34 Rectifiers, PWB Yttrium 39 x Lasers, superconductors Niobium 41 Housing Ruthenium 44 x PWB Rhodium 45 x PWB Palladium 46 x x Hard drives, circuit board components (capacitors), PWB Silver 47 x PWB, computer chips, keyboard membranes, capacitors Cadmium 48 Housing, CRT, PWB Indium 49 PWB Tin 50 x PWB, CRT, computer chips Antimony 51 Housing, CRT, PWB Barium 56 CRT Lanthanum 57 x Batteries, catalyst, lenses, CRT Cerium 58 x Catalyst, fuel additive, optical polish Praseodymium 59 x Lasers, magnets, lighting, alloys Neodymium 60 x x Lasers, magnets, computers (hard drive) Promethium 61 x Nuclear batteries Samarium 62 x Lasers, magnets, neutron absorption Europium 63 x Lasers, phosphors, lighting Gadolinium 64 x Lasers, magnets, computers, X-rays Terbium 65 x Lasers, phosphors, lighting, CRT, PWB Dysprosium 66 x Lasers, magnets, car Holmium 67 x Lasers, magnets, optics Erbium 68 x Lasers, alloys, photography Thulium 69 x Lasers, X-rays Ytterbium 70 x Lasers, alloys, gamma rays Lutetium 71 x Catalyst, medicine Tantalum 73 x PWB, capacitors, power supply Osmium 76 x Biomedical applications, electron microscopy Platinum 78 x x Hard drives, circuit board components Gold 79 x x PWB, computer chips (CPU), connectors/fingers Mercury 80 Housing, PWB Lead 82 Glass in CRTs, PWB Bismuth 83 PWB

a PWB: Printed wiring board, CRT: Cathode ray tube, CPU: Central processing unit.

38 B. Tansel / Environment International 98 (2017) 35–45

generally involve either pyrometallurgical processes with high energy demand or hydrometallurgical processes with chemical demand. Pyro- metallurgical processes involve melting of the metals, hence; have high energy demand and difficult working environments. Hydrometallurgi- cal processes require solvents for dissolving or leaching metals with subsequent recovery from the solutions. The most common chemicals used for metals leaching include nitric acid and hydrochloric acid, cya- nide, halide, thiourea and thiosulfate are the most commonly used leaching (Namias, 2013). Hence, the materials recovery and separation processes create waste streams that require further management (EEA, 2003). Novel technologies such as biohydrometallurgy and hybrid processes (i.e., physical-chemical-biological, or chemical-biological) show promise for effective recovery of selected metals from e-waste (Pradhan and Kumar, 2012). Mild extracting reagents (i.e., chlorideme- dium, ammonia–ammonium and non-cyanide lixiviants) have shown promising results with recovery rates as much as 98% for copper and 70% for gold. Technologies with high recovery rates utilizing electro- chemical, supercritical, vacuum extraction steps can be feasible for e- waste processing (Zhang and Xu, 2016). The recovery rates over 84%

for copper and over 89% for lead have been achieved by supercritical water oxidation combined with electrokinetic separation. Other novel technologies include ultrasonic, mechanochemical, and molten salt ox- idation processes (Zhang and Xu, 2016).

2. Plastics: Due to their relatively inexpensive production, light- weight, durability, and suitability for molding; use of plastics have in- creased in e-waste both in types and quantities. Although plastics have a high recycling potential from the materials separation perspec- tive; most of the plastic components used in electronic products have toxic additives, brominated flame retardants (BFRs) or polyvinyl chlo- ride (PVC), which make them unsuitable for recycling into new elec- tronic products. In recent years, there has been some reduction in the use of BFR and PVC as some companies are moving away from their use. A Swiss study reported that about 80% w/w of e-waste includes plastics that are acrylonitrile butadiene styrene (ABS), acrylonitrile bu- tadiene styrene/polycarbonate (ABC/PC), high impact polystyrene (HIPS), polyphenylene (PP) and polyurethane (PUR) (Wäger et al., 2009). The most common plastics used in computers, PC monitors and office equipment are ABS, ABS/PC-blend and HIPS. Although the

H

Li

Be

B

C

N

O

F

Na Mg

Al

Si

P

S Cl

K Ca

Sc

Ti

VCr

Mn

Fe

Co

Ni

Cu

Zn

Ga

Ge

As

Se

Br

Rb

Sr

Y

Zr

Nb

Mo

Ru

Rh

Pd

Ag

Cd In

Sn

Sb

Te

I

Cs

Ba

La Ce

Pr

Nd

Sm

Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

Lu

Hf Ta

W

Re

Os Ir

Pt

Au

Hg

Tl

Pb

Bi

Th

U

1E-4

1E-3

1E-2

1E-1

1E+0

1E+1

1E+2

1E+3

1E+4

1E+5

1E+6

A b o n d a n c e i n c

r u s t

( p p m

) Rock forming (major)

Rare earth element

Precious metal

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

Atomic number

1E+0

1E+2

1E+4

1E+6

1E+8

1E+10

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

P r o d u c ti o n (

to n s /y

r )

Rare earth

elements

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

R e la

ti v e h

ig h t

e c h d

e m

a n d

c

1E-4

1E-3

1E-2

1E-1

1E+0

1E+1

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95

A m

o u

n t in

o n

e c

o m

p u

te r (

k g

)

Atomic number

d

H L i

B e B C N O F

N a

M g

A l

S i

P S C l

K

C a

S c

T i

V

C r

M n

F e

C o

N i

C u

Z n

G a

G e

A s

S e

B r

R b

S r

Y Z r

N b

M o

R u

R h

P d

A g

C d In

S n

S b

T e I

C s

B a

L a

C e

P r

N d

P m

S m

E u

G d

T b

D y

H o

E r

T m

Y b

L u

H f

T a

W R e

O s Ir P t

A u

H g T l

P b

B i

T h U

a

b

Fig. 1.Availability and demand for elements available onEarth's crust: a. abundance onEarth's crust (USGS, 2002), b. annual global production (formines) (USGS, 2010), c. relative demand for manufacturing high tech products as scored from 1 (low) to 3 (high), d. estimated amounts of some elements in one computer (after MCC, 1996).

39B. Tansel / Environment International 98 (2017) 35–45

presence of ABS/PC-blend and HIPS have been reported in the older studies and/or the mixed e-waste fractions containing older monitors and television sets; the ABS/PC-blend and HIPS were not present in the newer CRT- and LCD-monitors (Wäger et al., 2009; Schlummer et al., 2007). The plastics used in large and small household appliances contain decabromodiphenyl ether (deca-BDE), octabromodiphenyl ether (octa-BDE) and/or cadmium at levels that are above the European UnionWaste Electrical and Electronic Equipment Directive (WEEE) and Restriction of Hazardous Substances Directive (RoHS) limits (Wäger et

al., 2009). Due to these challenges, the recovered materials are often recycled into lower grade products (i.e., deck furniture or aggregate in road resurfacing).

3. Glass: Glass can be 100% recyclable without loss in quality or pu- rity. However, the varieties of impurities used in different products cre- ate challenges for recycling glass from e-waste. Impurities, metals and coatings (which are difficult to separate) can affect the quality of glass and its subsequent use potential. Before 2009, glass recovered from cathode ray tubes (CRT) displays was widely used for manufacturing

Table 5 The design improvements that increase the marketability of e-products and create challenges for recycling and materials recovery.

Product design, manufacturing and delivery Recovery and recycling

Products Marketability goals Design improvements Challenges for recycling Processes used for recycling, recovery, disposal

-Television -Keyboards -CPU monitor -CPU -Flat panel -Laptop -Solar cells -Smart phones -VCR -Display units -Printed wiring boards

-Functionality -Durability -Size -Price -Market locations

-Complex design -Multifunctional -Compact design -Variety of materials -Embedded components -Imprinted circuitry -Coatings -Sealants

-Complexity -Compact design -Labor needs -Energy needs -Removing coatings -Removing sealants -Variety of components -Variety of materials -Integrated components -Embedded components -Toxic/hazardous components -Use of toxic/hazardous materials during recovery -Toxic releases during processing

-Hand separation -Manual disassembly -Crushing/shredding -Magnetic separation -Solvent cleaning -Acid dissolution -Dissolution/ionic recovery -Ion exchange -Leaching -Smelting -Melting -Shredding -Pelletization -Incineration -Land disposal

40 B. Tansel / Environment International 98 (2017) 35–45

new CRTs (glass-to-glass) and lead smelting as a fluxing agent in the smelting process. However, after 2013, the liquid crystal displays (LCDs) and plasma display panels (PDPs) have been consistently

Fig. 2. Examples of processes used for recovery of metals from e-waste. Only main process un second stream which requires additional handling.

replacing CRT displays. CRTs still comprise a significant amount (as much as 60%) of discarded electronics in recycling programs. Some re- cyclers have been storing CRT glass which needs to be recycled in cost

its are shown for simplification of the flow diagram. Each processing step also produces a

41B. Tansel / Environment International 98 (2017) 35–45

effective manner (Kyle, 2012). Due to decline of themarket demand for recycled CRT glass, disposal and treatment of leaded glass have become one of themajor challenges in e-wastemanagement (Singh et al., 2016; Meng et al., 2016).

4. Rare earth elements (REEs) and minor metals (MMs): REEs in- clude the 14 naturally occurring lanthanides (Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in addition to scandium (Sc) and yttrium (Y). Both the REE and MM are used for their electronic (Ta, Ga, Co, In), strength (Mo, Zr), alloying (Cr, V) and performance (Ti, Re) properties in high tech products. Their unique electronic, magnetic, optical, strength and other key properties find new applications in medicine, electronics and photonics, including consumer products of the modern age (e.g., telephones, computers, electric cars, solar panels, LED televi- sions). While many REEs andMMs are recognized as trace elements es- sential for life, their fate and persistence profiles in the environment and ecosystem responses to exposure are largely unknown. Because of their intrinsic high cost, opportunities exist for recycling products containing REEs and MMs (e.g., solar panels, electronic component). Neodymium, dysprosium, terbium, yttrium and europium are the top five REEs with the highest importance for high tech industries, especially for clean energy production (Bakas et al., 2012). The neodymium-magnets used in electronic components with hard disks constitute about 20% of the total demand for REEs (Bakas et al., 2012). However, new technolo- gies (i.e., solid-state disks) can lower the demand for REEs used in hard drives.

Regardless of the material, recovery from e-waste involves labor in- tensive steps. The materials recovery entails preliminary steps such as manual separation, disassembly and shredding followed by material specific recovery processes (Fig. 2). The processing steps for recovery of metals involve separation with energy and chemical requirements for dissolution, leaching, and recovery. Each processing separation step also produces a second stream which requires further management.

After 2000, there has been an increase in patent filings related with materials recovery from e-waste. Recent patent filings related with e- waste relate to application for recovery of non-ferrousmetals (e.g., cop- per, nickel), plastics, ferrous metals and hazardous materials (e.g., arse- nic, antimony, primarily, lead) as well as recovery of rare earth metals and precious metals (i.e., gold, silver or platinum) (WIPO, 2013). In

Fig. 3. Cross boundary transport of e-waste to major disposal and recycling locations transpos 2012; Chen et al., 2011; Lewis, 2011; UNEP, 2013; World population density map: Worldomet

2011, the European Union Waste Electrical and Electronic Equipment Directive (WEEE) and Restriction of Hazardous Substances Directive (RoHS) have implemented restrictions in use of silver in soldering. These restrictions may be the reason for reducing the demand for silver formanufacturing in electronic products after 2011 (WIPO, 2013). RoHS also restricts the use of lead, cadmium, hexavalent chromium, mercury and two brominated flame retardants in electrical and electronic equip- ment (Calder, 2010). The new requirements by RoHS have force the manufacturers and distributors to redesign the products and/or use al- ternative materials, implement supplier/customer management, and education efforts (Calder, 2010). Effective recycling efforts require im- provements in product design for recycling (DfR), design for sustain- ability (DfS) or design for resource efficiency (DfRE) (UNEP, 2013). Design for disassembly (DfD) concepts that have been identified as pos- sible options for electronic consumer products includeuse of biodegrad- able materials where possible, using accessible parts and fasteners for ease of disassembly, reducing weight of individual components, using standardized joints to reduce the tools necessary for disassembly, mod- ular components for parts replacement, using connectors rather than hard wiring, using thermoplastics instead of thermoset adhesives, using quick snap fasteners, and designing the product with weak spots to aid disassembly (Hester and Harrison, 2009; Gordon, 2013).

5. Global cross boundary e-waste transport

Management and fate of e-waste in different countries show signif- icant differences between developed and underdeveloped countries. One of the most commonly used waste management options for e- waste is deposition in landfills. The potential incompatibility of mate- rials deposited in landfills creates environments for formation of de- composition products which may be more hazardous and can enhance the mobility of metals and other organic compounds in landfills. Even after closure, landfill sites pose increasing liability from environmental, social, and economic perspectives. Variety of materials deposited, pres- ence of slow degrading materials, possibility of toxic materials leaching into the ground water, and potential long term hazards (i.e., earth quakes, flooding) create concerns for integrity of the landfills over long periods of time after they are closed. The increasing regulatory re- quirements in developed nations create bottle necks for economically

ed on population density map (sources: e-waste flows and recycling locations: Lundgren, ers, 2015).

Table 6 Technical and economical considerations for developing e-waste recycling infrastructure.

a. Technical considerations

Criteria Factors

Quantity assessment -Demand and supply analysis -Past trends -Present trends -Future trends

Inventory assessment -Material identification -Chemical analysis -Categorization of similar components

Methods -Waste collection -Collection locations -Transfer stations -Drop off centers

-Waste separation -On site or off site -Quality control

-Processing and handling -Size reduction -Processing equipment -Processing for specific standards -Delivery to markets

-Handling post processing wastes Machinery -Collection and processing

-Separation and processing -Materials recovery -Downstream processing (materials and waste) -Quality control -Packaging/labeling for specific users

Health risks and safety -Exposure during handling -Post processing wastes -Worker safety training

Markets -Existing markets -Potential markets

Quality assurance and quality control

-Existing markets -Potential markets

b. Economic considerations Criteria Factors Machinery -Capital cost: Collection, separation, processing,

packaging and labeling for specific users -Operating cost: Collection, separation, processing, packaging and labeling for specific users

Storage Capital cost (temporary, short term, long term) Health risks and safety training and liability

-Worker safety training -Managing post processing wastes

Processing and marketing -Contractor training and public information -Existing and potential markets -Networking of suppliers and users

Return on investment -Contractors savings -Savings on waste management fees -Income from sale of recycled materials -Control of illegal damping

Cost/benefits assessment -Short term (monetary and nonmonetary) -Long term (monetary and nonmonetary)

42 B. Tansel / Environment International 98 (2017) 35–45

feasible and environmentally sound management options for e-waste (as well as hazardous waste). This has created cross boundary move- ment of wastes globally.

In 1989, the United Nations international community held Basel Convention on the control of transboundary movements of hazardous wastes and their disposal in response to emerging concerns associated with hazardous waste trafficking. The Basel Convention treaty, which was entered into force in 1992, requires all countries to obtain informed consent from a receiving country before exporting hazardous waste (UNEP, 2014). In 1995, delegates from developing countries created the Ban Amendment, which aims to completely prohibit the export of hazardous waste from more developed countries to less developed countries. The Basel Convention has increased awareness of the cross boundary movement hazardous waste (which also includes compo- nents of e-waste) and has initiated formalized actions for developing regulatory control mechanisms in some countries. However, in most of the developing and under developed countries adequate oversight mechanisms either do not exist or have not been established adequate- ly. In addition, there are a number of counties where the Basel Conven- tion has not entered into force.

The e-waste from nations with strict environmental regulations still continue to be shipped to countries where the environmental regula- tions are not strict and/or labor is cheaper (e.g., China, India, Pakistan, Nigeria, and other developing countries) (Sthiannopkao and Wong, 2013; Lundgren, 2012). Evaluation of e-waste based on definition, clas- sification, operating procedures, and enforcement levels show that reg- ulations may be contributing to raising barriers for reusing the recycled materials (Milovantseva and Fitzpatrick, 2015). The cross-border ship- ping of e-waste often takes place through middlemen, and under tariff classifications, resulting in poor tracking of the quantities being transported globally.

Employment potential associated with the international trade in used electronics, and access to technology show that perceived value and geographical location determine the rate of disposal of computers and the opportunities to recover materials (Estrada-Ayub and Kahhat, 2014; Sthiannopkao and Wong, 2013). Analysis of the cross-border e- waste shipping trends indicate that large quantities of the e-waste are transported globally to areas that are highly populated where cheap labor is available (Fig. 3) (Chen et al., 2011; Lewis, 2011; UNEP, 2013; Lundgren, 2012). The global e-waste trade value chain has created emergence of local enterprises as well as uncontrolled processing and materials recovery operations which contribute to the deterioration of the soil and water quality due to disposal and handling of secondary waste streams from such operations (Pradhan and Kumar, 2014). The proposals for e-waste bills necessary for implementation of formalized regulatorymechanisms often do not receive support because of the con- tribution unregulated e-waste handling operations to local economies and job creation (Devia, 2014).

6. Proactive vs reactive strategies for e-waste management

Technological advancements have resulted in rapid improvements in range of consumer products and manufacturing processes which in turn resulted in production and distribution of affordable systems at global scale. The availability and affordability of the new products have created a culture of rapidly changing high tech products, hence, re- ducing their use times by the consumers. However, from the environ- mental perspective, the necessary infrastructure and formalized mechanisms are not developed for effectively collecting, recycling, and disposing the increasing quantities of e-waste.

Development of effective and proactive e-waste management pro- grams require active involvement of stake holders and businesses that are involved in manufacturing and distribution of products and collec- tion and processing of discarded items in view of the appropriate tech- nical and economic criteria not only for products but also for the discarded items. Technical considerations for e-waste management

include assessment of quantity, development of a detailed inventory of specific waste components, establishment of methods for waste col- lection, separation, and processing and handling; acquisition ofmachin- ery, identification of potential markets, and establishment of quality assurance and quality control (QA/QC) mechanisms specific to each market (Table 6a). Product quality criteria are needed for recycled ma- terials (e.g., content of foreign materials, radioactivity, hazardous prop- erties, coatings, paints, plastics) (Muchova et al., 2011). Main economic considerations include capital and operating costs and uncertainty with the return on investment for the e-wastemanagement program forma- terials recovery and recycling (Table 6b). Efficient designs for ease of disassembly can promote economics of value for recovery from discarded products.

Changes in product designs for ease of disassembly andmaterials re- covery process are necessary for recovery of materials from the increas- ing quantities of e-wastes. The variety of products present in the e- waste stream requires labor intensive separation and handling. The

Table 7 Focus areas and driving forces for product development vs e-waste management.

Focus area Product development & marketing (1980–present)

Waste management & materials recovery (1960–present)

Effort/investments Driving forces Effort/investments Driving forces

Research and development Proactive Financial Technological

Reactive Operational Financial

Cost reduction Proactive Financial Reactive Financial Political

Service and delivery network Proactive Financial Political Technological

Reactive Proactive

Financial Political

Demographics and culture Proactive Financial Political Cultural

Reactive Financial Political Cultural

Laws and policies Proactive Reactive

Financial Political Cultural

Reactive Political Cultural

Global interactions Proactive Financial Political Technological Cultural

Reactive Financial Political Cultural

Education and skills development Proactive Reactive

Financial Political Cultural Technological

Reactive Financial Political Cultural Technological

43B. Tansel / Environment International 98 (2017) 35–45

existing recovery methods are limited to materials with market value (i.e., metals). The recovery processes have limited recovery efficiencies while requiring chemicals (e.g., solvents, acids) and generate additional waste streams which require further downstream management and disposal.

Proactive entrepreneurial efforts and shifts in business strategies by high tech industries have resulted inmajor advancements in technology and development of efficient and useful consumer products for a wide range of applications but limited use times due to rapidly changing soft- ware, needs, life styles and applications (Table 7). Although the high tech products are being distributed in large quantities at the global scale; the necessary infrastructure for environmental awareness, educa- tion and regulatory development for e-waste management have been limited to primarily reactive actions in response to potential health and safety issues.

At locations where e-waste management programs have been established, management of the discarded products occurs by placing the responsibility either to manufactures or consumers. Extended pro- ducer responsibility (EPR) approach makes the e-waste recycling and collection the responsibility of themanufacturers. However, theproduct designers andmanufacturers need to be providedwith clear regulations and requirements to improve the product design towards facilitating product disassembly (Fishbein et al., 2011). The Advanced Recycling Fee (ARF) laws in California, USA require consumers to pay a recycling fee (referred as Green Tax) when they purchase electronic products for their end-of-life management once discarded (Nixon and Saphores, 2007).

As technology advances, the probability of discarding an old system over any given time interval increases (Carlaw, 2005). Thus, the larger is the improvement in technology, the greater is the probability of discarding the old systems before the end of their physical service lives. Therefore, rapid technological change investment in new capital systems can be increasing while at the same time old capital systems are discarded at a faster rate (Carlaw, 2005). Determinants of consumer intentions and behavior towards e-waste recycling in the major metro- politan areas of Brazil showed that consumers have a positive intention towards recycling electronic appliances (particularly female, middle- aged individuals from lower income groups). In contrast, only a minor- ity of respondents had reported adequate recycling practices for their discarded items (Echegaray and Hansstein, 2016).

7. Conclusions

During the last 50 years, waste characteristics have changed signifi- cantly as a result of technological advancements and changes in con- sumer goods, especially high tech products. Embedded systems, coatings, and amendments used to improve product quality and dura- bilitymake it difficult to recovermaterials from the discarded electronic products. Increasing quantities of e-waste and the need formaterials for manufacturing new products have increased the need for materials re- covery and recycling efforts fromdiscarded items. Although themarkets for recycled materials are gradually increasing; major challenges for managing e-waste still remain. The main challenges include lack of in- frastructure for collection and separation of e-waste; lack of accounting mechanisms for cross boundary transport e-waste; and lack of aware- ness and training for safe handling and processing during materials re- covery at uncontrolled recycling operations. The patent applications for materials recovery from e-waste have increased in the recent years as a result of regulatory restrictions and increasing market value of mate- rials. There is a need for establishment of accounting mechanisms for e-waste transport and handling at the global scale as well as oversight for safe handling and recovery of materials at recycling operations. It is also necessary to align the design of high tech products for ease of dis- assembly so that materials recovery processes can be feasible.

The increasing quantities and current challenges associated with e- waste require proactive strategic programs for establishment of infra- structure for e-waste management for controlling the magnitude of the potential impacts at the global scale. There is a growing need for e-waste tracking and materials recovery technologies from discarded products.

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