Removal of Estradiol from Water with a Hybrid MIP-TiO2 Catalytic Adsorbent

• Published in: Water, air, and soil pollution Vol. 231; no. 5
• Main Authors: Tonucci, Marina Caldeira, dos Santos Xavier, Leandro Pablo, da Silva, Adilson Candido, Aquino, Sergio F., Baeta, Bruno Eduardo Lobo
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.05.2020; Springer Nature B.V
• Subjects: 17β-Estradiol; Adsorbents; Adsorption; Analytical methods; Atmospheric Protection/Air Quality Control/Air Pollution; Climate Change/Climate Change Impacts; Earth and Environmental Science; Electron microscopy; Endothermic reactions; Environment; Environmental monitoring; Hydrogeology; Imprinted polymers; Infrared spectroscopy; Natural waters; Photocatalysis; Polymers; Regeneration; Regeneration (biological); Removal; Scanning electron microscopy; Sewage; Sex hormones; Soil Science & Conservation; Titanium dioxide; Ultraviolet radiation; Water Quality/Water Pollution; Water treatment; X-ray diffraction; Xenoestrogens; 17β-Estradiol; ); Molecularly imprinted polymer (MIP); Adsorption; Titanium dioxide (TiO; Photocatalysis
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-020-04586-y

17β-Estradiol (E2) is one of the main compounds responsible for estrogenic activities in sewage and natural waters and has been found in these matrices all around the world, thereby justifying the development of technologies for its removal. In this work, pure or TiO 2 -containing molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs) were prepared using E2 as template. The materials were characterized by infrared spectroscopy, X-ray diffraction, adsorption/desorption of N 2 , and scanning electron microscopy (SEM). The characterization analyses showed that TiO 2 was incorporated in the polymers and that all materials could be characterized as mesoporous and had surface areas ranging from 238 to 279 m 2 g −1 . Adsorption studies showed MIP-TiO 2 had a high capacity to adsorb E2 from the water phase leading to q max values of 15.16 to 26.49 mg g −1 at temperatures from 25 to 45 °C, respectively. In addition, the thermodynamic study showed that the adsorption process is endothermic, spontaneous, and entropically driven. The results also showed that the presence of TiO 2 decreases the adsorption performance of MIP-TiO 2 when compared with MIP (without the photocatalyst) during the adsorption. However, the application of MIP-TiO 2 in a process of adsorption followed by photocatalysis resulted in 100% of E2 removal allowing the reuse of adsorbent. In addition, MIP-TiO 2 maintained its E2 removal capacity even after five cycles of regeneration–reuse, which shows the ability of UV light to regenerate the specific adsorption sites. The results presented in this paper show MIP-TiO 2 has potential to be applied in water treatment systems to remove E2.