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1 Introduction

With the beginning of this millennium, the world has been struggling to deal with increasing quantities of solid waste. Rapid advancement in technology, especially the production of electrical and electronic goods has resulted in a new stream of waste known as electrical and electronic waste making it the fastest growing waste stream in the world. Equipment at the end-of-life (EOL) leads to e-waste generation in huge amounts. Increasing obsolescence rates of electrical and electronic equipment result in higher e-waste generation rates leading to disposal problems. E-waste, if managed improperly or inadequately, can cause enormous impact on the global environment as well as on human health.

Discarded electronic devices like televisions, PCs, floppies, CDs, batteries, switches, telephones, air conditioners, cell phones, electronic toys, refrigerators, washing machines, kitchen ware and even parts of aircraft are included in the list of electrical and electronic wastes and the substances present in them are listed in Table 12.1. Typical weights and life-spans of some of the most common electronic waste items are summarised in Table 12.2. E-waste covers more than 1000 materials which can be categorized as ‘hazardous’ or ‘non-hazardous’. Mostly, it consists of ferrous and non-ferrous metals, plastics, glass, plywood, printed circuit boards, rubber, concrete and ceramics, etc. Iron and steel constitute a major part of Waste Electrical and Electronic Equipment (WEEE). Non-ferrous metals include copper, aluminium, precious metals like gold, silver, platinum, palladium, etc. Heavy metals like lead, mercury, arsenic, cadmium, etc. are also present in large quantities.

Table 12.1 Substances present in e-waste
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Table 12.2 Typical weights and life spans of e-wastes
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1.1 Problems Associated with E-Waste

Proper care, management and handling procedures should be taken into account when dealing with e-waste. Improper handling may cause serious damage to human health as well as to the environment. Table 12.3 shows some of the constituents present in e-waste and their effects on human health and on the environment.

Table 12.3 Effects of e-waste on human health and environment
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2 E-Waste Generation

2.1 Global Perspective of E-Waste Generation

In a United Nations University-Institute for the Advanced Study of Sustainability (UNU-IAS) report published in 2015, global generation of e-waste was estimated to be 41.8 million tons per year (Baldé et al. 2015). Asia was found to be the largest producer of e-waste with a generation rate of 16 million tons per year which amounts to a per capita generation rate of 3.7 kg/person-year. In comparison, Europe had the highest per capita generation rate of 15.6 kg/person-year. A list of the top ten e-waste generating countries in order of the annual e-waste generated is provided in Table 12.4 based on the UNU-IAS report. India is the fifth largest generator of e-waste at the global level and third in Asia behind China and Japan. However, per capita e-waste generation rates in India are amongst the lowest (1.3 kg/capita-y) in comparison to the highest per capita e-waste generation rates of 28.3 kg/capita-y in Norway (a complete list of all countries ranked in order of per capita e-waste generation rates is provided in Appendix C, based on the UNU-IAS report, 2015).

Table 12.4 Top ten e-waste generating countries in terms of kilotons/year
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Major generators of e-waste are developed countries such as the USA, several European nations and Brazil. They produce large amounts of e-waste each year and in the name of international trade, many developed countries are dumping their e-waste in developing countries like India and China. Developed countries mainly adopt the “reuse” procedure to save their environment and money flow.

In the global scenario, the demand for certain metals like rare earth metals, platinum group elements, certain base metals and precious metals, etc. has increased day-by-day but the supply has become negative. So to maintain the demand and supply ratio of the requisite metals, various technologies are used. This process is also known as ‘Urban mining’. Urban mining is the process of recovering different compounds and elements from various products and wastes which would otherwise be left open in the environment to cause different levels of pollution (Fig. 12.1). By changing our way of thinking, we can reuse and recycle valuable components from the wastes, paving the way towards a zero-landfill future and can also save our environment.

Fig. 12.1
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Management of e-waste through urban mining (http://ecyclingusa.com)

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2.2 Indian Scenario of E-Waste Generation and Management

The most recent estimate (2013) of e-waste generation in India is 1.6 million tons/y (Baldé et al. 2015). The top ten states in India generating e-waste are shown in Table 12.5. These 10 states generate 70% of the total e-waste and 65 cities are responsible for generating 60% of the total e-waste in the country (Vats and Singh 2014). E-waste generation in India is estimated to be increasing by 10% annually. Issues regarding collection of information from industry and compliance with regulations are major deterrents in e-waste management in India.

Table 12.5 E-waste/WEEE generation in ten states of India
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In response to the E-waste (Management and Handling) Rules, 2015, CPCB now has 138 registered e-waste recyclers as of Nov 2014 with a total handling capacity of 0.35 million tons/annum.

3 Management Practices for E-Waste

For the proper management of e-waste, effective and practical solutions are required. First of all, generation of waste from source has to be reduced. Second, collection centres should be located where transportation is available. After collection, wastes should be safely transferred to different recycling centres for further processing. Various rules, regulations and methods are adopted for the management of e-waste (Fig. 12.2). A comprehensive review of e-waste management issues is available in Terazono et al. (2006).

Fig. 12.2
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Steps involved in E-waste management

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3.1 E-Waste (Management and Handling) Rules

The E-waste (Management and Handling) Rules, 2011 have been modified in the year 2015 and apply to every manufacturer, producer, consumer, bulk consumer, collection centres, dealers, refurbishers, dismantlers and recyclers involved in the manufacture, sale, transfer, purchase, collection, storage and processing of e-waste or electrical and electronic equipment (EEE). It also explains the role of the producer clearly. Producer Responsibility Organizations (PROs) are also included in the new rules of 2015 in addition to the Extended Producer Responsibility (EPR).

Penalty and punishment for non-compliance are defined in Sections 15 and 16 of the Environment (Protection) Act, 1986 which says that whoever fails to comply with the rules will be punishable with imprisonment for a certain period which may be extended to 5 years or with penalty which may extend to Rs 1 lakh. More details regarding these rules can be found in Appendix B of this book and the full text of the rules is available at the Ministry of Environment and Forests (MoEF) website (http://www.moef.gov.in/).

3.2 Extended Producer Responsibility (EPR)

EPR is an environment protection strategy which makes the producer responsible for the entire life-cycle of the product and principally for take-back, recycling and final disposal. EPR uses financial incentives to encourage manufacturers to design environmentally-friendly products and hold them responsible for the costs of managing their products to the end-of-life (EOL). A summary of EPR legislation in different countries is provided in Table 12.6.

Table 12.6 The role of EPR and e-waste legislation in different countries
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3.3 Take-Back Policy

Several countries have policies related to return of appliances to their manufacturers, also called ‘take-back’ policies. Europe has a WEEE directive which requires manufacturers to take-back their products. Asian countries like China, Japan, and Korea have policies that require recycling of discarded appliances. Special national funding is available in China for doing so while manufacturers in Japan are allowed to charge consumer fees for return of appliances. Manufacturers are required to pay recyclers a fee in Korea (Terazono et al. 2006).

Considering the take-back policy in India, most manufacturers of electrical and electronic appliances like Apple, Microsoft, Panasonic, PCS, Philips, Sharp, Sony, Sony Ericsson and Toshiba provide a take-back option. Samsung has a take-back service but only one collection centre for all of India; HCL and WIPRO have the best take-back policies in India. Other brands like Nokia, Acer, Motorola and LGE perform comparatively well. There is also a discount process where old products can be exchanged for new ones at a discounted price. However, these policies apply only to some electrical and electronic companies and needs to be adopted by developed and under-developed countries for managing e-waste.

3.4 Collection Centres and Deposit Boxes

Some electronic companies like HP, Nokia and Microsoft operating in India in various towns and cities have deposit boxes in their stores for the collection of end-of-life products for recycling purposes. There are certain collection centres in different parts of the states which collect e-waste and transport them to different recycling units for further processing.

3.5 Basel Convention

The Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal, generally shortened to “Basel Convention” is an international treaty that was designed to reduce the movement of hazardous waste between nations, and particularly to prevent transport of hazardous waste from developed to developing countries. The twelfth meeting of the Conference of Parties (COPs) to the Basel Convention was held from 4 to 15 May 2015 in Geneva and included the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal, the Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade and the Stockholm Convention on Persistent Organic Pollutants, respectively. One of the major outcomes of this meeting was the formulation of technical guidelines regarding the transboundary movement of e-waste which is a matter of growing concern for less developed countries. This meeting also deliberated over the definition of ‘waste’ and ‘non-waste’ since waste in one country is a usable second-hand appliance in another country. The need for inventorizing the amount of e-waste generated in different countries was also highlighted (UNEP 2015).

Major issues that were pointed out in this meeting were:

  1. (a)

    Residual lifespan and age of used equipment;

  2. (b)

    Management of hazardous wastes from repairing and refurbishment operations in developing countries;

  3. (c)

    Obsolete technologies like cathode ray tubes; and

  4. (d)

    Existence of hazardous components in used equipments.

4 Techniques for Recycling and Recovery

The most useful techniques for management of electronic wastes are recycling and recovery.

Recycle

The first level of environmentally sound e-waste treatment includes decontamination, dismantling and segregation. After dismantling, the parts which can be recycled are transported to the respective industries for further use and the remaining parts are used for recovery of metals. Each of the electronic products consists of glass, plastics, ferrous and non-ferrous metals. Plastics constitute about 20.6% of the product (ETC/RWM 2003). Iron and steel comprise the largest fraction in WEEE materials, 47.9%. The non-ferrous component contributed 12.7% of which Cu weighed 7% (Bandyopadhyay 2008). After dismantling electronic products, segregation of the different parts is done and these are recycled and processed accordingly. The idea of developing economic and environmental benefits through inter-firm waste exchange is known as ‘Industrial Symbiosis’ in which one firm’s waste becomes the raw material of another firm.

Currently in India, there are two segments managing the recycling and disposal of the electronic wastes namely: formal recyclers and informal recyclers. Formal recyclers deal with a very small percentage which is close to 5% of the total e-waste recycled in India (19,000 MT) whereas the rest is recycled by informal recyclers. Formal recyclers are less in number and follow environmental, health and safety rules as they are frequently audited and certified by renowned regulatory agencies. Informal recyclers are more in number, better networked and more skilled in collection and recycling of e-waste.

4.1 Glass

Glass in electronic products can be recycled and used for different applications. Cathode Ray Tube (CRT) glass in old computer monitors and televisions are used as raw materials for ceramic glazes (Andreola et al. 2005). CRTs contain hazardous materials like lead, so they should be handled properly and recycled before reuse or disposal. LCD screens in television sets contain several thin mercury lamps and liquid crystals which makes them a challenge for recycling.

4.2 Plastic

All plastics are transferred to recyclers who use them as raw material to manufacture new products without altering their properties. However, there is a big challenge in separating the high value plastic streams from the mixed plastics present in electronic waste. CreaSolv process has been developed for the recovery of polymer fraction from the plastics present in mobile phones (Maurer et al. 2004). Plastic recovery techniques are difficult due to the variety of polymers used in e-goods and the labour-intensive nature of separation of plastic from e-waste.

4.3 Ferrous Metals and Non-ferrous Metals

Magnetic separation of ferrous metals and non-ferrous metals can be done to separate the two fractions. Recovery of various non-ferrous metals can be done by using any of the following processes:

  1. 1.

    Pyrometallurgy

  2. 2.

    Hydrometallurgy

  3. 3.

    Biometallurgy or Bioleaching

  4. 4.

    Electrometallurgy

4.3.1 Pyrometallurgy

Pyrometallurgy is the thermal treatment of minerals and metallurgical ores resulting in the physical and chemical transformation of valuable metals. In this process, electronic waste is heated above 1500 °C in a closed reactor, i.e. in the absence of oxygen, especially designed to ensure zero emissions. This process includes a number of procedures like calcining, roasting, smelting and refining. Elements that can be recovered by pyrometallurgical process include oxides of less reactive elements like iron, zinc, copper, manganese, chromium, tin, etc. Some pyrometallurgical studies for metal recovery are summarized in Table 12.7.

Table 12.7 Pyrometallurgical methods for recovery of metals from electronic waste
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4.3.2 Hydrometallurgy

Appropriate chemical reagents are used in hydrometallurgy to dissolve metals from e-waste. The various chemical reagents used are aqueous and organic solvents, mineral acids, some bases, and mixed acids. The various types of solvents used are cyanides, thiourea, and thiosulfate, for the recovery of precious metals from e-waste. The different processes involved in hydro-metallurgy are:

  1. (a)

    Leaching: The most efficient leaching agents are acids as they have the capacity to solubilise both, base and precious metals.

  2. (b)

    Solution concentration and purification: The main purpose is to remove undesired impurities so that metal concentration in solution increases. Purification of the solution is done by ion exchange, adsorption and solvent extraction processes.

  3. (c)

    Recovery of metal: After solution purification, metal is to be recovered chemically or electrochemically.

Applications of hydrometallurgical methods for metals recovery from e-waste are summarized in Table 12.8.

Table 12.8 Hydrometallurgical methods for recovery of metals from electronic waste
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4.3.3 Biometallurgy

Biometallurgy involves the use of microbes in an aqueous environment to produce metals and has been used for decades for the recovery of metals like copper, gold and uranium. Almost a quarter of the global production of copper is done by bioleaching (Madigan et al. 2015). Bioleaching is defined as the mobilization of metal cations from mineral ores by biological oxidation. Biometallurgical methods used for metal recovery are summarized in Table 12.9.

Table 12.9 Biometallurgical methods for metal recovery from electronic waste
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4.3.4 Electrometallurgy

Electrometallurgy involves the use of electro-plating or electro-deposition methods. In these methods, electrolytic cells with different types of electrolytes and electrodes are used for deposition of expensive metals on the surface of the appropriate electrode. Methods and efficiency of metal recovery from e-waste are summarized in Table 12.10. The most common processes used in electrometallurgy are:

  1. (a)

    Electro-winning: A leach solution containing the metal of interest is added to an electrolytic cell. When current is passed through the cell, the metal is deposited on the cathode while the anode remains inert.

  2. (b)

    Electro-refining: An acidic electrolyte is added to an electrolytic cell with anode made of impure metal. When current is passed through the cell, the anode dissolves into the electrolyte from where pure metal is deposited on the cathode resulting in greater metal purity.

  3. (c)

    Electro-forming: Thin metal parts are moulded on pre-formed cathodes and manufactured through electroplating.

Table 12.10 Electrometallurgical methods for recovery of metals from electronic waste
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5 Conclusions

E-waste management has become a serious concern for the world after municipal solid waste and hazardous waste. Best methods from different countries can be incorporated to develop and design safe and hazard-free e-waste management systems. Proper e-waste management will help in efficient resource recovery and in e-waste management from cradle-to-grave. In India, E-waste (Management and Handling) Rules, 2011 have been modified to E-waste (Management) Rules, 2015, in which producers, distributors, and importers are held responsible for the proper recycling and disposal of e-waste. Efficient collection of e-waste and its treatment can lead to a better environment and huge piles of e-waste can be turned into lucrative products and business opportunities.