Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Preparation of a novel cross-linked Al(OH)3/PVA/PVP composite for F− removal.

ABSTRACT
With the development of fluorinated waste treatment and the extraction of metals such as rare earths, high-density F− wastewater becomes a potential threat. Compared to inorganic adsorbents for F− removal with high cost due to agglomeration, this paper firstly utilizes maleic anhydride to control pH and achieves cross-linked PVA/PVP as polymer matrix and in situ synthesized Al(OH)3 (ATH) as inorganic particles simultaneously, and obtains cross-linked ATH/PVA/PVP composite films with good mechanical property and excellent F− removal capability. With the increasing ATH contents of ATH/PVA/PVP composites, the initial decomposition temperature improves from 253°C to 262°C. The SEM shows that the in situ synthesized ATH can be relatively evenly distributed on the surface and inside the ATH/PVA/PVP composite with a diameter of 8–30 μm. For the ATH/PVA/PVP composite, the most suitable pH for F− adsorption is 5, and the adsorption capacity can reach 34.9 mg/g, and the F− removal efficiency can reach 98.07%. The F− removal of ATH/PVA/PVP composite can still remain 79.8% after five times regeneration, and interfering ions such as Cl−, NO3
− have little effect on the F− removal. The Young's modulus and tensile strength of the ATH/PVA/PVP composite can remain 6.2 GPa and 10.1 MPa even at 25 wt% ATH contents.