New process helps remove toxins, pick rare earth metals from wastewater

Researchers from the Indian Institute of Technology (IITGN) at Gandhinagar, Cambridge University, and the University of Birmingham have developed a method to remove toxic metals and recover valuable rare earth elements (REEs) from wastewater. The process utilizes highly porous materials called metal-organic frameworks (MOFs), which serve as molecular fishing nets with countless pores acting as catching surfaces and specially designed chemical sites that act like hooks to latch onto specific metals.

MOFs have internal surface areas up to 7,000 square metres per gram, making them highly effective at adsorbing pollutants. The technology was tested with industrial wastewater, alkaline, turbid, high in dissolved solids, and artificial seawater, demonstrating substantial adsorption capacities. For instance, one gram of copper-based MOF can capture nearly half a gram of lead and about a quarter of a gram each of cadmium and manganese, while recovering around one-third of a gram of REEs per gram of material.

While batch experiments offer insights, further research is needed to assess large-scale fabrication, costs, life-cycle assessment, and regulatory testing for sustainable implementation.