Preparation of novel magnetic porous biochar and its adsorption mechanism on cerium in rare earth wastewater.

A novel and efficient process for the removal of Ce(IV) from aqueous solutions was sought, and a new magnetic porous biochar (PBC/ZF) was synthesized by loading ZnFe 2 O 4 (ZF) onto porous biochar (PBC) using a one-step hydrothermal method. The SEM observation of the external features showed that the cubic spinel structured ZnFe 2 O 4 (ZF) particles were loaded onto the porous biochar (PBC) surface. This resulted in a composite with superb paramagnetic properties as well as higher adsorption properties. In addition, the microstructure was characterized by FTIR, which demonstrated that the target material was supplied with a large amount of carboxyl groups (-COOH) by citric acid during the synthesis process. The BET showed that the target material had a higher specific surface area than ZnFe 2 O 4 with PBC, confirming the successful preparation of the target material after activation of the biomass using ZnCl 2 immersion as well. The effect of different factors on the adsorption effect was investigated experimentally. The results showed that PBC/ZF had a good adsorption effect on Ce(IV) with a short adsorption equilibrium time and a maximum adsorption capacity of 228.9 mg/g at room temperature with lower acidity (pH = 2.5). The adsorption kinetics and isotherm analysis showed that the Ce(IV) adsorption process fitted well with the quasi-secondary kinetic model and Langmuir model. It indicates that the process is a single molecular layer adsorption process. It was demonstrated that PBC/ZF also has high removal rate for high concentration Ce(IV) solution, and it is easy for solid-liquid separation under the action of applied magnetic field after adsorption. It provides a new treatment method and theoretical support for the adsorption treatment technology of Ce (IV) wastewater. [ABSTRACT FROM AUTHOR]