Domain, Specialties: CHIMIE
Keywords: biolixiviation, microbiologie
Research Unit: NIMBE / LICSEN
Summary
The increase in the worldwide production of electronic equipment in recent years has led to an increase in the production of electronic waste, the recycling of which is still only partial. New recycling methods based on hydrometallurgy are being developed to recycle the critical metals found in electronic boards. Among these, biohydrometallurgy, based on the use of microbiological cultures, is the subject of much research, as it does not require the use of concentrated acids in large quantities like conventional hydrometallurgy methods. The aim of this internship is to develop methods for monitoring the bacterial cultures used to recycle these electronic boards, in order to characterize the bioleaching process involved.
Full description
In recent years, many industrial sectors, such as electronics, have seen their production increase. This ever-increasing demand for raw materials, particularly critical metals (nickel, cobalt, titanium, rare earths), is accompanied by a complicated supply situation: limited resources and the Chinese monopoly are driving up prices, especially in Europe.
To compensate for this limited access to resources, companies have been turning to a new type of mining for some years now: “urban mining”, focused on recycling used electronic components. At industrial level, most of this recycling is carried out by pyrometallurgy, an energy-intensive and polluting method that recovers only a small proportion of the metals present in electronic scrap. In parallel with these recycling methods, hydrometallurgy is also being researched. Electronic compounds are dissolved using concentrated acids or oxidizing species, then separated using membranes or liquid-liquid extractions, before being reused as raw materials. In order to achieve efficient and rapid leaching, the acids used must be concentrated and in large quantities, and their production is also costly and polluting.
To minimize the use of acids, a new branch of hydrometallurgy is being developed: bio-hydrometallurgy. The principle is based on the use of acidophilic bacteria, which grow optimally at pH < 2, and ferrooxidants, capable of oxidizing Fe(II) to Fe(III). The Fe(III) thus generated will oxidize the metallic species of the electronic components to be recycled, allowing these species to be dissolved and finally recovered by various extraction methods.
The aim of this internship is to study the bioleaching process used at CEA Saclay in order to better characterize the activity of the bacteria used. In particular, it will involve monitoring the bacteria’s ferrooxidant activity, iron oxidation and electronic board leaching kinetics, as well as assessing the toxicity of these electronic boards on the bacterial cultures.
BRGM Orléans is a partner in this project, providing microbiological expertise, and also benefits from collaboration with a research team based in Singapore.
This internship represents an excellent opportunity, not only because of the research involved, but also because of the various collaborations that will enable us to gain an overall understanding of this large-scale project.
Location
CEA – Saclay, 91 Essonne, France
Internship conditions
- Internship duration: 6 months
- Level of study required : Bac+5
- Training : Master 2
- Thesis possible: Yes
- Application deadline: early January, 2025
Experimental skills
Langue : English
Methods, technics:
The trainee will have the opportunity to learn about a wide range of characterization techniques, including X-ray fluorescence, spectrophotometry, infrared spectroscopy and atomic emission spectrometry.
Computer languages and software: Python
Supervisor
Jean-Christophe Gabriel
Tél. : 06 76 04 35 59
Email :