Fig. 3From: Magnetic Carbon Microspheres as a Reusable Adsorbent for Sulfonamide Removal from WaterNitrogen adsorption–desorption isotherms and the pore size distributions of MCMs. a MCMs without ZnCl2 impregnation. b MCMs calcined at 550 °C for 1 h without ZnCl2 impregnation. c MCMs with ZnCl2 impregnation for 1 h were calcined at 550 °C for 1 h. d MCMs with ZnCl2 impregnation for 1 h were calcined at 600 °C for 1 hBack to article page