5.5. E-waste stream management
There are reasons to separate the electronics waste stream:
- rapid growth of the electronic manufacturing volume, market, and rapid change in technology resulting in new products
- complexity of electronic products, which requires special approach in recycling
- use of rare and precious metals and compounds, many of which should be recovered
- presence of toxic chemicals and other substances of environmental concern
- opportunities of efficient material and component reuse
Electronics recycling, computers for instance, is essentially a process of breaking down the final product back to components (some of which can be reused) and initial raw materials (such as copper, gold, silver, other metals, plastics). Because of significant load of technological product with heavy metals and toxic compounds (e.g., mercury, cadmium, lead, flame retardants), discarded electronics are classified as hazardous waste. Hence, recycling also requires strict measures of environmental safety.
The following article provides a concise overview of current practices to handle electronic waste in the United States and specifically investigates the health implications and policies required to mitigate the negative impacts. The article contains statistic data on specific parts and components in electronics that are subject to recycling and shows their linkage to chemical resource lifecycles:
Seeberger, J., et al., Special Report: E-Waste Management in the United States and Public Health Implications, Journal of Environmental Health, vol. 79, pp. 8-16 (2016).
This paper is available online through the Penn State Library system. Students regitsred for the course can also access it in Canvas.
Try to find the answers to the following questions, while reading:
- What chemical elements used in electronic products present the highest risk to the public health?
- Can we assume from the EPA data in Figure 2 that e-recyclng industry grew in the US and technologies became more efficient?
- What kind of policies need to be adopted to streamline safe disposal of the electronic waste?
There are companies and government programs that take on the challenge of responsible recycling of electronic products; for example, this one (Liquid Technology):
However, currently existing programs of sorting / disassembly are hardly sufficient. The problem is that current computer and other electronic products are not designed to be recycled. End-of-life disassembly and recovery of pure materials is a tedious and expensive process. Few companies manage to build an effective infrastructure for electronic recycling. Even if responsible recycling practices exist, they hardly keep up with growing market for electronics and accelerating e-waste accumulation pace.
Unfortunately, there are businesses that find it more profitable to export the electronic waste overseas to developing countries. This practice, highly non-sustainable on the global scale and harmful to local population and environment, is an ugly illustration of shifting the environmental burden from one part of the global system to another:
For example, this video contains graphic illustrations of such irresponsible “recycling”.
So, what are possible sustainable solutions to address the root of the e-waste problem?
- Design devices with environmentally benign components and chemicals.
- Design computers and other fast-rotating systems easily recyclable (to cut cost and increase process efficiency).
- Design “product-of-service” programs. This is exemplified in the book Cradle-to-Cradle as follows:
"Instead of assuming that all products are to be bought, owned, and disposed of by “consumers”, products containing valuable technical nutrients – cars, televisions, carpeting, computers, and refrigerators, for example – would be preconceived as services people want to enjoy. In this scenario, customers would effectively purchase a service of such a product for a defined user period – say, then thousand hours of television viewing, rather than the television itself. They would not be paying for complex materials that they won’t be able to use after a product’s current life. When they finish with the product, or are simply ready to upgrade to a newer version, the manufacturer replaces it, taking the old model back, breaking it down, and using its complex materials as food for new products." [McDonough and Braungart, 2002]
Currently in the US, many states have active policies to regulate the e-waste. Different models suggest imposing fees to finance e-waste recycling onto various entities – consumers, manufacturers, municipalities. There are also different mechanisms to facilitate collection and processing of the e-waste. Some examples are given in the following reading:
Want to learn more? This following article provides a detailed overview of materials to be recovered from the consumer electronics and methods involved in management of this growing waste stream:
Solid Waste Technology & Management, Christensen, T., Ed., Wiley and Sons., 2011. Chapter 11.2. “Waste Electrical and Electronic Equipment”, Bigum, M. and Christensen, T.H., pp. 960-968.
This book is available online through PSU Library system.
Check Your Understanding
Apparently, present-day computers are not perfectly designed for end-of-life recycling. Can we estimate the efficiency of recycling of an average desktop computer?
According to the approach outlined in Section 5.3 of this lesson, can you calculate the efficiency of recycling of an average desktop computer based on the following data?
|Input / Output||Component||mass|
|input||mass of the computer placed in the recycling bin||6000 g|
|useful output||mass of salvaged old components for reuse||fan||100 g|
|power supply||1000 g|
|memory chips||100 g|
|optical drive||500 g|
|mass of salvaged raw materials for making new components||Cu||200 g|
|Precious metals (Au, Ag)||1 g|
|recyclable plastics||900 g|
Click for answer.
Efficiency can be estimated as
h = total mass of all useful output materials / total mass of material submitted for recycling = =(100+300+1000+100+200+500+200+300+600+1+900) g / 6000 g x 100% = 70% ]