Adsorption of pharmaceuticals and heavy metals from water on the microwave-assisted activated carbon based on Pinus nigra cones

Water pollution caused by inorganic and organic compounds is one of the most important challenges worldwide. In recent years, the use of alternative precursors for AC preparation has gained attention. The study highlights Pinus nigra cone–derived microwave-activated carbons as promising and sustainable adsorbents for the treatment of complex wastewater matrices containing co-occurring pharmaceuticals and heavy metals. In this work, five samples of carbon based on Pinus nigra (PN) cones (PN-P, PN-NaOH, PN-Na2CO3, PN-KOH, and PN-K2CO3) were prepared and tested for the removal of pharmaceuticals (metformin, caffeine, telmisartan) and heavy metals (copper (II), cadmium (II), lead (II)) from water. Potassium-based activators lead to the creation of predominantly microporous adsorbents with open pores and more disrupted structures than their sodium-based analogues. Caffeine and telmisartan were most efficiently removed by the adsorbents activated with sodium-based activators, while those activated with potassium-based activators were best suited for the adsorption of metformin. For heavy metals, PN-Na2CO3 and PN-KOH exhibited the highest combined uptake, with >90% removal of Pb2+ and 80-90% of Cu2+ within the first hour.