Compost can salvage rare earth elements

Neodymium was captured from electronic waste using tomato peel, sweetcorn, wood pulp and cotton paper.

Micro- and nanoparticles of organic materials enabled researchers at Pennsylvania State University, USA, to capture rare earth elements from aqueous solutions.

The Sheikhi Research Group ground tomato peel and sweetcorn, and also cut wood pulp and cotton paper into small, thin pieces and soaked them in water. These materials were chemically treated to disintegrate them into three fractions of functional materials: microproducts, nanoparticles and solubilised biopolymers.

Adding the microprducts or nanoparticles to neodymium solutions triggered separation, resulting in the capture of neodymium samples.

Now, the team has extracted larger samples from less concentrated solutions.

Next steps are to partner with interested industries to test the process in real-world scenarios.

'We also hope to tune the selectivity of the materials toward other rare earth elements and precious metals, like gold and silver, to be able to separate those from waste products as well,' says principal investigator Amir Sheikhi.