**Abstract**

Electronic waste, or e-waste, is said to be the fastest growing stream of hazardous waste in the world. E-waste is comprised of a variety of inputs including hazardous materials, potentially valuable and recyclable materials, and other inputs. E-waste follows a range of pathways after disposal, including formal and informal recycling, storage, and dumping, in both developed and less-developed country contexts. Globally, the handling and regulation of e-waste as both a hazardous waste stream and as a source of secondary raw materials has undergone significant changes in the past decade. A growing number of countries have adopted extended producer responsibility laws, which mandate electronics manufacturers to pay for proper recycling and disposal of electronics. The e-waste recycling industry is becoming more formalized as the potential to recover valuable materials has increased, but a range of recent studies have shown that e-waste recycling continues to carry a range of occupational health and environmental risks.

**Keywords:** e-waste, waste electrical and electronic equipment, extended producer responsibility, Basel Convention

### **1. Introduction**

Electronic waste, sometimes referred to as e-waste or waste electrical and electronic equipment (WEEE), is a highly varied stream of hazardous waste. This waste stream is comprised of any electronic items that a consumer or business intends to dispose of, or is no longer useful for its original purpose. E-waste has generated a considerable amount of public and political interest due to a confluence of factors, including: the exponential rise in the generation of e-waste, the potential value of recycling the waste in order to recover precious metals and other elements, and the environmental and human health risks associated with improperly storing, disposing of, and recycling e-waste. Some of the major responses to the rising generation of e-waste (and growing demand for secondary raw materials that it contains) have included the development of producer "take-back" legislation, technological innovations in recycling processes, and the formation of partnerships to facilitate the transfer of e-waste between the informal and formal recycling sectors [1].

E-waste is an incredibly complex waste stream, as it encompasses a wide range of items and the exact composition of many electronic components are considered to be trade secrets, meaning they are the confidential information of the manufacturer. Generally speaking, "modern electronics can contain up to 60 different elements; many are valuable, some are hazardous and some are both. The most complex mix of substances is usually present in the printed wiring boards (PWBs)" [2].

To use a specific example, the material content of a mobile phone includes "over 40 elements in the periodic table including base metals like copper (Cu) and tin (Sn), special metals such as cobalt (Co), indium (In) and antimony (Sb), and precious metals including silver (Ag), gold (Au), and palladium (Pd)" [2].

Electronics that had been used in industrial or business applications, such as medical equipment, have been recycled in the formal recycling industry for more than 40 years. These large items have frequently been exported within industrialized countries in the OECD to specialized facilities where they are processed for the purpose of extracting secondary raw materials. Consumer electronic waste from smaller items such as cell phones and televisions have not historically been profitable to recycle in countries with higher labor costs, since the quantity of recoverable valuable materials is relatively low. Hence, these items have typically either been disposed of, stored in consumers' homes, or exported (often illegally) to less developed countries such as China, India, Ghana and Nigeria, where they are recycled by informal recyclers using low-tech methods such as manual dismantling, open burning and acid leaching in order to recover gold, copper and other valuable metals. These methods generate subsistence livelihoods for workers but also result in significant hazards to human health and the environment as a result of the toxic materials that are also embedded in consumer electronics. This chapter will explore these conventional recycling efforts and the ways in which they are evolving alongside global economic developments and the introduction of new recycling processes and technologies.

Generally speaking, the e-waste recycling process consists of five basic stages: collection, toxics removal, preprocessing, end processing and disposal [3]. There are wide degrees of variation in how these stages are managed worldwide. For much of the global waste stream, e-waste may be collected informally via "waste pickers" or more formally through voluntary or mandatory producer "take-back" programs. In terms of consumer electronics, regions where e-waste is picked up by informal collectors have historically achieved significantly higher recycling rates than those where waste is dropped off through formal channels [4]. After reaching the recycling site, dangerous components that require special treatment (e.g., batteries, Freon) are removed. The units are then separated into more homogenous groups based on material. This can be done manually, mechanically or a combination of both. Manual dismantling involves tools such as screwdrivers, hammers and labeled containers, while mechanical dismantling may involve conveyor belts, giant shredders and magnets [5].

Following the separation and dismantling phases, more homogenous groups of material (e.g., gold, copper, plastic, circuit boards) are then treated through a refining process: this can be accomplished chemically, with heat, or with metallurgical processes. This stage can be as high-tech as a giant smelter in Antwerp, Belgium or as low-tech as acid stripping in a backyard in Guiyu, China. Research has uncovered how sites will often compete for the waste by offering low-cost strategies, sometimes described as a "race to the bottom" process of increasingly lower standards and environmental protection [6]. Finally, all of the components that cannot be sold or used as secondary raw materials are disposed of through means such as incineration or landfill.

The level of efficiency achieved through e-waste recycling depends upon the process that is followed, especially in the separation and dismantling phases. In dismantling electronics, manualized options are often much more effective than mechanized processes in gaining access to the best quality secondary raw materials. Mechanized take-back programs such as those in the E.U. do not even come close to the efficacy of the labor-intensive e-waste collection rates found in many African countries [4, 7]. Manual dismantling is also preferable to machine shredding, which

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*Source: [2].*

*A sample of valuable elements in electronic wastes.*

**Table 1.**

*Electronic Waste Recycling and Disposal: An Overview DOI: http://dx.doi.org/10.5772/intechopen.85983*

within electronic devices are represented in **Table 1**.

low [3].

(Y) [12, 14].

damages and does not completely separate individual materials. For example, while 90% of the gold in discarded mobile phones can be recovered when manually dismantled, only 26% is recovered through mechanical shredding [8]. However, these more labor-intensive options are not cost effective unless labor costs are extremely

**2. Secondary raw materials recovered in electronic waste recycling**

quantities, when the dismantling costs have been low enough [9]. Some of the applications and quantities extracted for different "important" or valuable elements

E-waste contains components that have historically been valuable in significant

In addition to these metals, there is also another subset of elements—known as rare earth elements—which are crucial to the functioning of the newest electronics, particularly those with LED lighting and touch screen technologies. Rare earth elements are available in abundant quantities globally, but the process of their extraction can create widespread environmental problems, including radioactive contamination [10]. **Table 2** provides a list of the rare elements that are used in various electronics. It is worth noting that the actual quantity of these elements used is relatively small, but that their properties are closely linked to the performance level of these technologies [11]. Rare earths play a particularly decisive role in the high performance functioning of magnets. The information provided in **Table 2** has been adapted from information derived from the U.S. Department of Energy, a report commissioned for the U.S. Interior Department and the U.S. Geological Survey, as well as industry trade publications [12–14]. Those rare earths considered to be of the highest potential resale value (and the highest risk for supply shortages) are neodymium (Nd), europium (Eu), dysprosium (Dy), terbium (Tb) and yttrium

Recent technological developments, including improvements to the mechanization process as well as pilot projects that combine low-tech and mechanized

**Element Main applications Total tons/year [2006]**

Silver Contacts, switches, solders 6000 Gold Bonding wire, contacts, integrated circuits 300 Palladium Multilayer capacitors, connectors 33 Platinum Hard disk thermocouple, fuel cell 13 Ruthenium Hard disk, plasma displays 27 Copper Cable, wire connector 4,500,000 Tin Solders 90,000 Antimony Flame retardant; CRT glass 65,000 Cobalt Rechargeable batteries 11,000 Bismuth Solders, capacitor 900 Selenium Electro-optic copier, solar cell 240 Indium LCD glass, solder, semiconductor 380

*Assessment and Management of Radioactive and Electronic Wastes*

metals including silver (Ag), gold (Au), and palladium (Pd)" [2].

To use a specific example, the material content of a mobile phone includes "over 40 elements in the periodic table including base metals like copper (Cu) and tin (Sn), special metals such as cobalt (Co), indium (In) and antimony (Sb), and precious

Electronics that had been used in industrial or business applications, such as medical equipment, have been recycled in the formal recycling industry for more than 40 years. These large items have frequently been exported within industrialized countries in the OECD to specialized facilities where they are processed for the purpose of extracting secondary raw materials. Consumer electronic waste from smaller items such as cell phones and televisions have not historically been profitable to recycle in countries with higher labor costs, since the quantity of recoverable valuable materials is relatively low. Hence, these items have typically either been disposed of, stored in consumers' homes, or exported (often illegally) to less developed countries such as China, India, Ghana and Nigeria, where they are recycled by informal recyclers using low-tech methods such as manual dismantling, open burning and acid leaching in order to recover gold, copper and other valuable metals. These methods generate subsistence livelihoods for workers but also result in significant hazards to human health and the environment as a result of the toxic materials that are also embedded in consumer electronics. This chapter will explore these conventional recycling efforts and the ways in which they are evolving alongside global economic developments and the introduction of new recycling processes

Generally speaking, the e-waste recycling process consists of five basic stages: collection, toxics removal, preprocessing, end processing and disposal [3]. There are wide degrees of variation in how these stages are managed worldwide. For much of the global waste stream, e-waste may be collected informally via "waste pickers" or more formally through voluntary or mandatory producer "take-back" programs. In terms of consumer electronics, regions where e-waste is picked up by informal collectors have historically achieved significantly higher recycling rates than those where waste is dropped off through formal channels [4]. After reaching the recycling site, dangerous components that require special treatment (e.g., batteries, Freon) are removed. The units are then separated into more homogenous groups based on material. This can be done manually, mechanically or a combination of both. Manual dismantling involves tools such as screwdrivers, hammers and labeled containers, while mechanical dismantling may involve conveyor belts, giant shred-

Following the separation and dismantling phases, more homogenous groups of material (e.g., gold, copper, plastic, circuit boards) are then treated through a refining process: this can be accomplished chemically, with heat, or with metallurgical processes. This stage can be as high-tech as a giant smelter in Antwerp, Belgium or as low-tech as acid stripping in a backyard in Guiyu, China. Research has uncovered how sites will often compete for the waste by offering low-cost strategies, sometimes described as a "race to the bottom" process of increasingly lower standards and environmental protection [6]. Finally, all of the components that cannot be sold or used as secondary raw materials are disposed of through means such as incinera-

The level of efficiency achieved through e-waste recycling depends upon the process that is followed, especially in the separation and dismantling phases. In dismantling electronics, manualized options are often much more effective than mechanized processes in gaining access to the best quality secondary raw materials. Mechanized take-back programs such as those in the E.U. do not even come close to the efficacy of the labor-intensive e-waste collection rates found in many African countries [4, 7]. Manual dismantling is also preferable to machine shredding, which

**48**

and technologies.

ders and magnets [5].

tion or landfill.

damages and does not completely separate individual materials. For example, while 90% of the gold in discarded mobile phones can be recovered when manually dismantled, only 26% is recovered through mechanical shredding [8]. However, these more labor-intensive options are not cost effective unless labor costs are extremely low [3].
