Novel anionic functionalized magnetic β-cyclodextrin composites with excellent adsorption capacity for moxifloxacin and wide pH adaptive adsorption capability for copper ion.

Antibiotics and heavy metals pose severe risks to human health and ecological environment. Therefore, developing a multifunctional adsorbent to remove these contaminants from wastewater is an urgent need. Herein, novel anionic sulfonic acid groups functionalized magnetic β-cyclodextrin (β-CD) composites (FCD@AA) were synthesized by coating poly(2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS)) on the surface of magnetic β-CD particles (FCD). Several characterization techniques were utilized to comprehensively analyze the surface physicochemical properties of FCD@AA. The adsorption properties of FCD@AA toward antibiotics (moxifloxacin (MOX) as model) and heavy metals (copper ion (Cu) as model) were systematically studied under different conditions on adsorption time, temperature, initial concentration, solution pH and coexisting ionic strength. In single systems, the adsorption isotherm data for MOX and Cu were well fitted to Langmuir and Freundlich models, respectively. The maximum adsorption capacities of FCD@AA toward MOX and Cu were 118.98 and 19.29 mg·g, respectively. The pseudo-second-order model could better describe the kinetic processes. In binary systems, the presence of Cu exhibited a pronounced antagonism on the adsorption of MOX. The influence of co-existing MOX on the capture of Cu changed from inhibition to promotion as the initial Cu concentration increased. And after five adsorption cycles, FCD@AA still had satisfactory reusability. The results indicate that FCD@AA is a promising adsorbent for treating water contaminated by MOX and Cu, which broadens the application of magnetic β-CD adsorbents in environmental protection.