Title : Urban biomining of precious and hazardous metals a green circular economy model
Abstract:
Urbanization, economic growth, a desire for novelty, and rapid innovation have resulted in shorter-lasting products in general and electrical and electronic equipment (EEE) in particular. This resulted in an exponential rise in the production of EEE waste (EEEW) around the world. Presently, more than 660 varieties of EEE are used and sold in the global market. Televisions, computers, printers, refrigerators, temperature exchangers, driers, washing machines, cell phones, smart mobile phones, as well as other electrical and electronic devices fall into this category. Globally, about 57.4 million tonnes of EEEW were produced in 2021, and it will reach 74 million tonnes by 2030 and 120 million tonnes by 2050. EEEW is the fastest-growing fraction of municipal solid waste. EEEW has as many as 60 elements from the periodic table along with glass, plastic, flame retardant and several organic pollutants. Despite this, EEEW is poorly collected and not properly recycled, resulting in serious aquatic, terrestrial, and atmospheric pollution as well as even threats to public health. But if the EEEW is considered in terms of the source of base metals, precious metals, platinum group metals (PGM), and rare-earth elements (REE), it is economically valuable. The estimated value of the EEEW produced in 2019 (53.6 million tons) is about the US $57 billion. But currently, only 20% of total EEEW is recycled or processed scientifically, and the rest of the waste is either incinerated or disposed of as a landfill. That has created several environmental and health problems. Pyrometallurgy and hydrometallurgical processes are commonly used for the recovery of metals and REE, but they are energy and cost-intensive, as well as generate secondary pollutants. Bio-hydro-metallurgical methods have recently replaced traditional processes because they are more environmentally friendly, economically viable, and operate at lower temperatures and pressures than pyro- and hydro-metallurgical processes. A consortium of iron oxidizers, sulphur oxidizers, and cyanogenic microorganisms is playing a critical role in the enhanced and rapid extraction of the base, critical, and precious metals as well as REE from a variety of EEEW pre-treatments and applications. Applications of cost-effective technology are among the top priorities in bio-hydrometallurgy for the recovery and recycling of critical, valuable, and toxic elements from the EEEW due to the rapid depletion of their natural resources and serious harmful effects on health and the environment. Given the complexity and diversity of EEEW, effective treatment requires integrated technology with a clear focus on recovering or recycling valuable metals, critical metals, REE, and even hazardous materials to contribute to resource recovery, pollution reduction, environmental conservation, and long-term economic development. Based on the available data on bioprocesses, the replacement of conventional steps used in EEEW recycling with bio-based technological processes can be possible. The current talk will provide insights into the integrated approach to biobased economy and EEEW treatment in this context.
What will audience learn from your presentation:
- The audience will learn about the generation of e-waste along with its harmful and economic values.
- Conventional methods used for e-waste treatment, and their limitations
- Will know the concept of biomining or biohydrometallurgy and their beneficial role in e-waste treatment.
- Will also learn that if e-waste is properly handled it is a rich source of the base, critical, and valuable metals as well as rare earth elements.
- Learn new reactor design and bio-regeneration of ferric for the circular economy.
- Will learn the critical evaluation of pre-treatments and their benefits.
- Also, know the importance of an application of a developed consortium and its significance
