E-Wastes: Bridging the Knowledge Gaps in Global Production Budgets, Composition, Recycling and Sustainability Implications

Abstract

Rapid urbanization, advancements in science and technology, and the increase in tech-savviness of consumers have led to an exponential production of a variety of electronic equipment. The global annual growth rate of e-waste volume exceeds the growth rate of the human population. Electronic waste has now become a point of concern globally (53.6 million metric tons, 2019). However, merely 17.4% of all global e-waste is properly collected and recycled. China is the largest contributor to the global production of e-waste (~19%), the second being the United States. Indeed, only 14 countries generated over 65% of global e-waste production in 2019. E-wastes contain a wide range of organic, and inorganic compounds including various metals. Emerging contaminants like plastics are amongst the fastest growing constituents of electronic waste. The current challenges include the lack of reliable data, inadequate identification and quantification of new emerging materials, limited effectiveness of current recycling technologies, need for cutting-edge detection and recycling technologies, and the lack of e-waste management policies and international collaboration. In this review, we strive to integrate the existing data on production rates at different spatial scales, composition, as well as health, economical, and environmental challenges, existing recycling technologies; explore tangible solutions; and encourage further sustainable technology and regulatory policies.

Waste Electronics in the United States: Future Trends and Economical Potential

“…23,24 In terms of the treatment process, after the waste PCBs are dismantled, shredded, and physically separated into metal scraps (upstream recycling), the metallurgical processes (downstream recycling) are fairly similar whether refining metal from these waste or virgin mines. 25,26 In fact, a majority of the metal recovery from waste electronics are still based on pyrometallurgical pathways, which is also the primary virgin mining process with minor difference between feedstocks (i.e., precious metal vs. base metal refining). 27- Virgin gold mines and refining plants mostly exist in the western states (i.e., Nevada and Arizona) of the U.S., as shown in Figure 1f.…”

Status of Recovery of Strategic Metals from Spent Secondary Products

“…This type of recycling has a huge economic impact on developing countries such as Ghana but, on the other hand, produces a detrimental effect upon exposure to these metals without proper handling gear. The motivation behind the interest in metals contained in e-waste is due to the high metal content in the spent product when compared with their natural ores [71]. For example, printed circuit boards (PCBs) have 20 wt.% copper in most e-waste, but only ~0.62 wt.% is found in natural ores [31].…”

Technospheric Mining of Mine Wastes: A Review of Applications and Challenges

“…Data sharing relevant to stock collection, evaluation, and data management for anthropogenic resources can be expanded to an international level for a holistic approach. Creating an international group of experts for a specific commodity is also suggested, which can be learnt and adopted from the traditional mining industry [99,101]. The authors [99] presented an example where there was an attempt to gather experts in solid wastes in Europe and share brilliant ideas for future processing.…”

“…Another example is the use of benign reagents and processes for metal or mineral extraction and recovery. Bioleaching is an emerging technology and has been actively researched with various sources [51,101,[111][112][113][114]. Since technospheric stocks tend to contain low-grade profitable elements, utilising bio-heap leaching can be one of the beneficial options with minimal investment.…”