Title : Development of CSM recovery methods based on their adsorption on biochar from lignocellulosic residues
Abstract:
The technological revolution of green energy and green agriculture relies on critical and strategic minerals (CSM). According to Canada's Critical Minerals Strategy 2022, Canada produces 31 CSM, which are essential for the energy transition and communication sector. The CSM present potential risks all along their life cycle and they must be responsibly handled to avoid affecting the environment. For example, during their extraction great volumes of water are consumed and similar volumes of wastewater with metals are generated. The presence of CSM in wastewater from mining becomes a subject matter for the enterprises who are intending to the development of sustainable exploitation. Environmentally friendly methods have been reported to recover critical and strategic metals (CSMs), such as rare earth elements, cobalt, and lithium, from aqueous solutions. Among these methods, adsorption using biochar has gained attention due to its low cost, sustainability, and high surface reactivity. To optimize this process, adsorption modeling plays a crucial role in understanding the interaction mechanisms between metallic ions and biochar surface functional groups, enabling the prediction of adsorption capacities under various conditions. However experimental assays consume a lot of time and material resources. Molecular modelling can be used to analyze the recovery of CSM particles suspended in wastewater by simulating the electrostatic interactions between functional groups on the biochar surface and CSM ions during the adsorption process. The modeling of CSM ions adsorption on CSM surfaces allows to decrease the number of experimental assays serving as a tool for selecting the highest promising systems and planning well oriented experimental assays. In the present study, copper and nickel ions were used to model its adsorption onto biochar surface. This virtual model will be used to analyze the effect of CSM ions concentration on the adsorption capacity. The kinetics of CSM ions adsorption to determine the contact time to reach the equilibrium and the thermodynamics of adsorption will be studied. Results will allow us to determine the potential to use this process in biometallurgical applications.
