Ball milling was used to prepare two ultrafine magnetic biochar/Fe3O4 and activated carbon (AC)/Fe3O4
hybrid materials targeted for use in pharmaceutical removal by adsorption and mechanochemical degradation of pharmaceutical compounds. Both hybrid adsorbents prepared after 2 h milling exhibited high
removal of carbamazepine (CBZ), and were easily separated magnetically. These adsorbents exhibited fast
adsorption of CBZ and tetracycline (TC) in the initial 1 h. The biochar/Fe3O4 had a maximum adsorption
capacity of 62.7 mg/g for CBZ and 94.2 mg/g for TC, while values obtained for AC/Fe3O4 were 135.1 mg/g
for CBZ and 45.3 mg/g for TC respectively when data were fitted using the Langmuir expression. Solution pH values slightly affected the sorption of TC on the adsorbents, while CBZ sorption was almost
pH-independent. The spent adsorbents with adsorbed CBZ and TC were milled to degrade the adsorbed
pollutants. The adsorbed TC itself was over 97% degraded after 3 h of milling, while about half of adsorbed
CBZ were remained. The addition of quartz sand was found to improve the mechanochemical degradation of CBZ on biochar/Fe3O4, and its degradation percent was up to 98.4% at the dose of 0.3 g quarts