Water is an essential element for life; thus, its quality is a key marker of both an individual's and society's overall well-being. In the last century, this environmental factor has become a vulnerable resource; therefore, its management and protection have become top priorities worldwide. Global population increase and agricultural and industrial activities have made a substantial contribution to water contamination. Mining activities in Romania, particularly during the socialist era, have left a significant “legacy” of environmental pollution, especially regarding substantial mining wastewater contamination. Tailings ponds and abandoned mines continue to be major environmental hazards even today. In this context, there is a need to support eco-initiatives that promote a clean environment and mining wastewater decontamination challenges through the use of “green solutions”.

This study aimed to prepare and characterize new magnetic core–shell nanoparticles coated with functionalized eco-friendly polymers. The new nanostructures were investigated by Fourier-transform infrared spectroscopy, transmission and scanning electron microscopy, thermogravimetry and magnetization measurements and afterwards were used for the removal of heavy metals from both batch solutions and mining wastewater samples. The heavy metal concentrations were determined by atomic absorption spectroscopy, and the nanomaterials’ adsorption capacities/mechanisms were also studied. The high heavy metal removal efficiencies (>80%) obtained indicate the need for newly developed magnetic nanostructures for further applications in the field of wastewater treatment.