## 4 Application of Cyclodextrin-Based Adsorbents
### Removal of Organic Compounds
#### 4.3.1 Endocrine Disruptors  
Bisphenol A (BPA) is a commercial substance from a group of phenols that have been commonly used since the 1960s. For years, BPA has been used in the chemical industry, particularly in producing polycarbonate plastics and resins [126; 127]. Exposure to bisphenol A may affect the occurrence of, among other things, diabetes, obesity, metabolic syndrome, cancer, and fertility disorders [128]. To remove chemicals that disrupt the functioning of the endocrine system, CD-MG, mesoporous magnetic clusters connected with \(\beta\)-cyclodextrinrin, were synthesized and studied. Adsorption isotherms showed that BPA adsorption was 52.7 mg/g. In addition, the adsorbent showed an admirable quality of 84.5% in reusability test experiments after four cycles. Their quick process kinetics, delightful adsorption capacity, and CD-MG adsorption mechanism result in high potential for removing active endocrine compounds from the environment [120]. Another work presented an ecological and straightforward method of producing porous poly (chloromethyl styrene) resin modified with \(\beta\)-cyclodextrinrin with a spongy cross-linked material, namely PS@CM-CDP, for the ultrafast and effective removal of organic contamination from aquatic solutions. The obtained PS@CM-CDP, which stood out as having maximum adsorption capacity for BPA, could reach beyond 8.25 mg/g. In addition, the circular identity of the resin rendered native \(\beta\)-CD polymers reusable, even after six usages, without significant performance degradation. The paper also presented the practical application of the obtained material, which illustrated multiple perspectives on the water treatment column [129]. In work from 2021, a cyclodextrin material was designed, produced, and used to eliminate Pb (II) and BPA, which may coexist in the aquatic environment. The characterization outcomes corroborated successful \(\beta\)-CD grafting and Fe\({}_{3}\)O\({}_{4}\) loading. Moreover, the resulting material \(\beta\)-CD@MRHC had commendable magnetic properties for efficient regeneration from water, unaffected by pollutant adsorption. The synthesized material showed excellent adsorption efficiency with a maximum bisphenol A uptake of 412.8 mg/g, and it only took 7.5 min to achieve adsorption equilibrium. In addition, the material accomplished synergistic elimination of Pb(II) and BPA by reversing their competing behaviors, thanks to different holding mechanisms. The adsorbent was found to be promising and suitable for practical use in the simultaneous elimination of heavy metals and organic matter from water resources, employing high-efficiency magnetic recovery [130]. Moreover, [PERSON] et al. synthesized silica particles with \(\beta\)-cyclodextrinrin that showed the ability to remove bisphenol A (BPA) from sewage water. It turned out that this was related to the presence of \(\beta\)-CD groups on the silica surface. The experiments showed that the qe values were 107 mg/g for SiO\({}_{2}\)-\(\beta\)-CD-OH and 112 mg/g for SiO\({}_{2}\)-\(\beta\)-CD-NH\({}_{2}\), respectively, while adsorption equilibrium was reached after 180 min [116]. The bagasse-\(\beta\)-cyclodextrinrin polymer, namely SB-\(\beta\)-CD, accounted for 121 mg/g [131], and showed similar values of the maximum BPA adsorption capacity. Synthetic zeolite with NaX structure was modified with \(\beta\)-cyclodextrintrim (CDG) and used for adsorption of, for example, BPA and ibuprofen from model solutions. The best fit to the Langmuir model shown in adsorption experiments indicated monolayer adsorption and the formation of inclusion complexes with hydrogen bonding. The researchers mentioned that the qmax parameter was 32.7 mg/g for BPA. The adsorptive behavior of NaX-CD designated that it could be a skillful adsorbent for the eradication of EDC pollutants from contaminated water [132]. A new \(\beta\)-CD modified graphene oxide membrane (CDGO) was synthesized in 2019 to effectively remove bisphenol-A.