Magnetic porous biochar with nanostructure surface derived from penicillin fermentation dregs pyrolysis with K₂FeO₄...

Magnetic porous biochars (MC_HCl, MC_HAc) with nanostructure on surfaces were prepared from penicillin fermentation dregs by pyrolysis with K₂FeO₄ activation and used in penicillin adsorption. MC_HCl and MC_HAc had high BET surface areas of 672 and 735 m²/g, respectively; mainly be attributed to the activation of K₂FeO₄ as well as acid pickling. Saturation magnetizations of MC_HCl and MC_HAc were 75.29 and 42.45 emu/g, respectively; the magnetism was mainly derived from the Fe₃O₄ and Fe₃C in magnetic biochars. MC_HCl had nano sticks of ~ 80 nm and MC_HAc had petal-like slice of ~ 30 nm on surfaces. The maximum adsorption capacities of penicillin on MC_HCl and MC_HAc were 196 and 322 mg/g at 308 K, respectively. The adsorptions of penicillin on MC_HCl and MC_HAc were consistent with pseudo primary kinetics and the Langmuir adsorption isotherm model, and thermodynamic analysis indicated that the adsorption mechanism included physical and chemical adsorption.