Adsorption Behavior of Two Types of Magnetic Functional Microspheres for Congo Red.

In this paper, two types of microspheres encapsulating magnetic carboxyl-modified Fe₃O₄ have been synthesized to compare their adsorption to Congo Red, one has been prepared by taking 3-aminopropyltriethoxysilane (APTES) as the functional monomer; the other has utilized chitosan and gelatin as the wall materials. The former is named as ASM and the latter is called as CGM. SEM, FTIR, XRD and TGA have been used to characterize the morphology and structure of microspheres. The adsorption experiments have shown that they both could absorb the dye rapidly and continuously and adsorption kinetics conform to pseudo-second-order model. The adsorption test data of ASMs have been fitted better with the Freundlich isotherms. The CGMs follow Langmuir isotherms. The maximum adsorption capacity of the dye onto the former at room temperature is 585 mg/g and the latter is 364 mg/g, indicating highly efficient adsorption capacity. The high reusability means that the products have promising potentials in advanced treatment of industrial wastewater. [ABSTRACT FROM AUTHOR]