Magnetic porous biochar with nanostructure surface derived from penicillin fermentation dregs pyrolysis with K2FeO4 activation: Characterization and application in penicillin adsorption

Magnetic porous biochars (MC HCl , MC HAc ) with nanostructure on surfaces were prepared from penicillin fermentation dregs by pyrolysis with K 2 FeO 4 activation and used in penicillin adsorption. MC HCl and MC HAc had high BET surface areas of 672 and 735 m 2 /g, respectively; mainly be attributed to the activation of K 2 FeO 4 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 Fe 3 O 4 and Fe 3 C 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.