E-waste (electronic waste) is the most rapidly growing waste stream in the world, with over 50 million tonnes generated globally each year. Millions of people across the world are thought to work informally recycling these materials through open burning, exposing themselves and the environment to toxic fumes which then find their way into the water supply and food chain, poisoning animals and humans.

Formal recycling of printed circuit boards has traditionally come with a large carbon footprint, printed circuit boards can travel thousands of miles to refineries where they are incinerated and a lot of the valuable material lost and not recovered.

N2S has partnered with Coventry University through the Knowledge Transfer Partnership (KTP) programme. This partnership has allowed N2S to access the expertise of Professor Sebastien Farnaud and Professor Derek Renshaw from the University’s Centre for Sport, Exercise and Life Sciences, to develop an innovative solution to recover the precious metals within printed circuit boards through bioleaching techniques.

Project objectives

The aim of the project is to develop a sustainable and environmentally friendly method to recover precious metals from electronic waste that will create a closed-loop system to recycle metals back into the supply chain as required in a sustainable circular economy.

The first objectives, which were pursued in the research group, were to validate bioleaching as a bio-recovery method of the metals from PCB into solution and then, following successful validation, to apply electro-chemical methods to fully recover the metals selectively from the solution.

The next objectives were to transfer and embed the knowledge to N2S, so a microbiology laboratory was developed at their premises. While the initial methodology was transferred into the new laboratory at N2S, further methods were developed in our laboratory at CU to be later transferred to their laboratory where the main work is now taking place. The project has been particularly successful, with pending patents and commercial applications already in place.

Impact statement

From the 50 million tonnes of electronic waste generated globally each year, only 20% are formally recycled, and e-waste is routinely shipped overseas for disposal. Unfortunately, most of it is then burned through inefficient extraction processes, while being detrimental to the environment and the population. This is not just a waste issue, but also an economic concern as worldwide, rare metals including gold, silver, copper and platinum worth an estimated €55bn are lost annually.

To tackle this environmental threat and recycle precious metals in the supply chain, the Bioleaching Research Group in the Health and Wellbeing Institute have developed an innovative and efficient green solution, to recover precious metals from e-waste. This has transformed the commercial capacities of their industrial partner N2S, a company specialised in recycling electronic, whilst tackling environmental issues, and tightening security surrounding e-waste disposal.

Bioleaching has been used in the mining industry for decades, but its application in waste management has never been developed. A few research groups have demonstrated bioleaching applications to e-waste, but none of them has developed a full close-loop system, where metals can be fully recycled into the supply chain. As such, this is the first industrial application of bioleaching to the bio-recovery of metals from e-waste.

As stated by N2S Director, Coventry University’s research has ‘shaped the direction of the company’ and enabled it to develop ‘into a business known for sustainability’. With uptake of bioleaching as a core service, N2S identify that the business now has ‘negative carbon emissions’, and is working towards UN SDGs 6 (Clean Water and Sanitation), 12 (Responsible Consumption and Production) and 13 (Climate Action).

The development of this industrial bioleaching application has led N2S to be recognised as ‘thought-leaders’ within WEE recycling, and as a direct result in 2019 N2S were invited to become founder members of Defra’s Defra e-Sustainability Alliance (DeSA) alongside 13 other organisations including IBM, Vodaphone and Microsoft. The Sustainability and Smart Cities lead for Microsoft Public Sector UK has remarked how N2S’ membership of the group, ‘drawing on their work with Coventry… has helped educate and raise awareness’ of the ‘potential of bioleaching’ as an applied solution.
Outputs

Publications

Vakilchap F, Mousavi S.M., Baniasadi M., Farnaud S. (2020). "Development and evolution of biocyanidation in metal recovery from solid waste: a review"

Baniasadi M., Graves J.E., Ray D.A, De Silva A.L., Renshaw D., Farnaud S.(2020) Closed-Loop Recycling of Copper from Waste Printed Circuit Boards Using Bioleaching and Electrowinning Processes. Waste and Biomass Valorization. Springer

Baniasadi M., Vakilchap F., Bahaloo-Horeh N., Mousavi S.M., Farnaud S.(2019) Advances in bioleaching as a sustainable method for metal recovery from e-waste: A review; Journal of Industrial and Engineering Chemistry. Elsevier. "Volume 76, 2019, Pages 75-90,"

Conference presentations

Baniasadi M., Ray D. Graves J. E., Renshaw D., Morris S., Farnaud S. (2019) Bioleaching for metal recovery from WEEE. “ADVANCES IN (BIO-) HYDROMETALLURGY AND APPLICATION” 14-16th May, 2019, Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) Stilleweg 2, 30655 Hannover (Germany)

Baniasadi M., Graves J.E., Renshaw D., Morris S., Farnaud S. (2019) Oral presentation and short paper: "Bioleaching for metal recovery from IT networking and communication equipment" 16th International Conference on Environmental Science and Technology CEST2019, 4-7 September 2019, Rhodes, Greece.

Baniasadi M.(2019) Bioleaching of metals from PCB. Institute of Circuit Technology Evening Seminar

Ray D.A., Baniasai M. (2020) Opportunities in Urban Biomining from IT and Telecoms Equipment. Institute of Circuit Technology Evening Seminar.

Baniasadi M., Ray D., Graves J., Morris S., Renshaw D., Farnaud S." (2021). Abstract Approved: Effect of mechanical separation on improving metal recovery from ceramic rich electronic waste using bioleaching "17th International Conference on Environmental Science and Technology". CEST2021, 1-4 September 2021, Athens, Greece .