Challenges and opportunities of e-waste management

In this review, the global production of e-wastes is described based on recent surveys and statistics. The variety and projections in e-waste composition is also identified due to the technological improvement in the electronic industry, which introduces difficulty for the development of a universal, sustainable recovery process. The effects of various organic and metal components of e-wastes on human health and the environment are summarized based on the literature findings. This review includes the challenges related to the rapidly increasing e-waste generation and describes the dilema that the developing countries are facing and the opportunities brought along with e-wastes to these countries. The chapter also includes a proposed process for the treatment and recocery of Printed Circuit Boards (PCBs). With advancements in the electronic world almost occurring on a day-to-day basis and increased availability of products to the public, it is not surprising to see a staggering increase in the generation of electronic wastes over the past several decades. According to a United Nations Environment Program (UNEP) alert bulletin in 2006, in the manufacturing industry of industrialized countries, the production of electrical and electronic devices is the fastest-growing sector of industrial development. Thus the handling and treatment of electronic waste, or so-called E-waste, is a topic of concern in the future. Globally, there is no doubt that the amount of E-waste being produced and in turn disposed is sharply increasing. Although it is hard to give an accurate estimate of the global E-waste production due to faulty and sometimes non-existent data, the UN estimate of the global E-Waste production in the same alert was 20-50 million tons per year. In 1998, the E-waste production in the United States was estimated at 6 million tons per year. A more recent report released by the UNEP in July 2009 has shown stunning global facts indicating rapidly growing generation of e-waste. The adverse environmental and health risks caused by E-Waste are of growing importance. E-wastes are made of a variety of organic substances and metals in a polymer matrix. The organic substances, mainly fire retardants and other additives are potential carcinogens. They accumulate in the food chain and the environment due to their non-biodegradable nature. Toxic heavy metals such as cadmium, chromium, mercury and lead are released to the environment mainly through leaching and incineration of the e-wastes. These metals are highly toxic and pose high risk to human health and are a major environment impact. In addition to the toxicity of the e-waste materials, the production process of electronics is often a very energy intensive endeavor. For example, the production of a single personal computer and monitor takes at least 240 kg of fossil fuels, 22 kg of chemicals, and 1.5 tons of water. This amount of water alone, is more than the weight of a modern automobile. This situation further increases the burden to the environment. Having realized the hazards of E-waste, many developed countries are taking actions. In January 2003, The European Union Council addressed the serious issue of electronic waste streams by the Waste Electrical and Electronic Equipment (WEEE) Directive to motivate the reuse, recycling and reduction of WEEE by efficient material recovery methods. It also seeks to minimize the environmental impacts of WEEE by conducting life cycle assessments. Another regulation, the Restriction of Hazardous Substances (RoHS) Directive, has also become EU law in February 2003. It has been established to restrict the use of hazardous substances in WEEE aiming to reduce its impacts on human health as well as the environment. Followed by these EU's pioneer actions, other countries such as Canada, the United States, and the UK, have developed (or partially developed) e-waste related laws and directives in recent years. Although the developed countries attempted to reduce the amount of WEEE by regulation, huge quantities of their WEEE are still exported to developing countries including China, Pakistan, India and Indonesia through different channels. The low concentrations of precious metals in e-wastes provide enough economic incentive for less affluent countries to attempt resource recovery methods. However, most of their e-waste treatment facilities and metal recovery processes are primitive which create significant pollution to the air, water and land resources. The local people in turn suffer from a variety of syndromes due to over-exposure to the toxic substances. Thus, the technological advances in the separation and purification of metals and even organic substances from e-wastes are crucial for minimizing the effects on the environment in the recovery processes. To tackle these challenges from the increasing production and disposal of e-waste, more actions should be taken by the governments including arousing the public awareness, developing environmentally friendly separation and purification processes for recovering valuable materials from e-wastes, establishing new environmental policy and laws, providing safety measures for workers in the recovery facilities, etc. In all probability, e-waste will sooner or later become a commodity due to the abundance of limiting resources such as gold, silver, indium and other precious metals in these solid wastes. What we suggest is the concept of ?mining from the e-wastes{norm of matrix}. With advanced separation technologies, the processes can be developed to take full advantage of e-wastes in an environmentally friendly manner. Here, a sustainable and feasible treatment process for printed circuit boards is proposed and described. Its applicability for metal recovery from e-waste is discussed.

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